Time to learn from the past: Indigenous Peoples are leading land management in Southwest Australia, and the rest of the world should take note

By Adam Cross. Western Australia faces a biodiversity crisis driven by climate change and inadequate conservation and land management. Rates of extinction here are already among the highest in the world, and government projects have struggled to improve the situation for most species. But as land management is increasingly being turned over to Indigenous Australians, successes have begun emerging from the ashes.

Western Australia is known internationally for its remarkable biodiversity and high levels of floristic endemism. It is a landscape of rugged natural beauty that supports among the most ecologically unique and highly specialised organisms on the planet, and in which occur some of the world’s oldest rocks, oldest living life forms, and oldest continuous human cultures. And, it is a landscape of extremes—not only environmental extremes, such as the contrast between the cool, wet forests of the southwest and the hot, dry deserts of the interior, but also extremes in human impact.

Curtin University PhD student Thilo Krueger undertaking a biodiversity survey in the seasonal wetlands near Esperance with Tjaltjraak Aboriginal Rangers. Such projects are examples of the highly successful cross-cultural learning between Indigenous and Western scientists that are increasingly underpinning land management in Western Australia. Photo: Zoe Bullen.

In the southwestern corner of the 2.6 million km² state, the result of wholescale clearing of millions of acres of native forest and woodlands for broadacre agriculture, mainly in the 1940s–1970s but continuing today, can be easily seen from space. Flying over Western Australia’s Wheatbelt region can yield horizon to horizon views containing little more than scattered handfuls of trees in a vast ocean of yellow-brown. In large areas of the Wheatbelt, for example, less than 3% of the landscape remains covered by native vegetation. It is among the most extreme examples anywhere in the world of habitat destruction on an industrial scale in an astonishingly short time frame.

In contrast, in the remote north of Western Australia in a region known as the Kimberley, there remain vast wilderness areas of remote savannah woodland, among the most ecologically intact and least human-impacted ecosystems still in existence. Although globally some 70% of tropical savannah ecosystems have been lost, a vast 1.5 million km² of them remain in northern Australia, mostly in good condition, of which nearly 350,000 km² is in the state of Western Australia. Nestled within this seasonally-dry savannah are rivers and deep rocky gorges, extensive sandstone plateaus and uplands, rugged ranges, and a myriad of seasonal and wetland habitats, providing a complex suite of more mesic habitats supporting high levels of botanical endemism. Over half of the 3,000 plant species currently known from the region have been described scientifically in just the last four decades, highlighting how remote and inaccessible the Kimberley remains even today.

A huge pall of smoke rises from an intense prescribed burn in seasonally wet peatland ecosystems near Albany, September 2017, turning a bright spring midday into an apocalyptic scene. Photo: Adam Cross.

These extremes in human impact come with considerable challenges in how we manage, conserve, and restore biodiversity and ecological resilience. Not even the Kimberley region is immune from external anthropogenic threats: weed invasion and rangeland stocking levels are ongoing concerns, and mining activities impact some areas. Indeed, a copper mine proposed within 20 km of the iconic Horizontal Falls in the Kimberley archipelago is cause for concern. Apparently illegal track and exploration clearing at the site has already prompted outcry from tourism operators, environmentalists, and the general public. Conflict between development, industry, and environmental interests in this manner is common in Australia, and current approaches and legislation are far from doing a sufficient job of managing and maintaining the country’s unique natural environment.

After reportedly being buried for several months by the previous federal government, the recently published 2022 Australian State of the Environment Report paints a bleak picture of a continent’s ecosystems in ecological freefall. Vegetation loss due to land clearing continues at remarkably high rates around the country. Nearly 2,000 species are now threatened with extinction and some 19 ecosystems remain on the brink of complete collapse. Conservation and land management strategies are poorly coordinated and often fail. In addition, anthropogenic climate change is now recognised as a threat to every Australian ecosystem and is expected to compound the significant and growing impacts of numerous other threats and stressors.

The enormous smoke cloud from a prescribed burn darkens the sky over agricultural land near Margaret River, September 2017. Photo: Adam Cross.

Indigenous land management leaders

One of the very few positives presented by the 2022 State of the Environment Report, however, is recognition that Indigenous land management and the incorporation of Traditional Ecological Knowledge in environmental programs is having real, genuine benefits for biodiversity and the integrity of Australia’s ecosystems. Native Title, recognition by Australian Common Law that Indigenous Australians have cultural and historic land rights and interests, has resulted in over half of the Australian landmass being recognised as Indigenous estate. This means that now 54% of the National Reserve System of protected natural ecosystems consists of Indigenous Protected Areas and conservation reserves that are jointly managed by Indigenous Australians in partnership with other groups. In many cases, traditional approaches are returning to the management of Australia’s land and seas for the first time since European colonisation.

Cool fire-stick burns such as this one in open savannah woodland in the North Kimberley, April 2019, promote pyrodiversity by creating complex matrices of burnt and unburnt habitat in the landscape. Photo: Adam Cross.

Many around the world will have heard of the recent catastrophic bushfires spread across eastern Australia, caused by climate change coupled with changes in the way that we manage our native forests. These fires, impacting some 28 million acres, are estimated to have killed or injured over 3 billion native animals, and damaged many ecosystems to the point where their recovery remains uncertain. And, amid highlighting the growing urgency for improved management and increased efforts to undertake ecological restoration across the Australian landscape, they rekindled the vigorous debate over a controversial topic in Australia—prescribed burning. Many of the areas that burned intensely in the summer 2019/2020 fires had recently undergone prescribed burning regimes in an effort to reduce fuel loads, a practice undertaken throughout many Australian ecosystems despite mounting evidence of its inadequacy at achieving safety outcomes and significantly deleterious impact on native biodiversity.

Contemporary prescribed burning is often undertaken by dropping incendiaries from aircraft, complemented by drip burning around the edges of the target area to be burnt to ensure fire boundaries are maintained. It is also typically undertaken in winter and spring, when weather conditions are most conducive to ensuring that fires do not become uncontrollable, at fire return intervals of seven years (studies suggest natural fire return intervals in most Western Australian ecosystems are in the decades or centuries). Unfortunately, the reality of this strategy means that large areas of remnant bushland are repeatedly incinerated from the outside inwards, often during peak flowering and breeding season for most species of native flora and fauna. For example, a catastrophic prescribed burn in one of southwest Western Australia’s most biodiverse regions in March 2019 transformed over 2200 acres of biodiverse woodland into a desolate, blackened ‘morgue’. However, in some regions, land managers are increasingly turning to the Traditional Owners of the land, Indigenous Australians, to understand how fire might be better managed.

Cool fire-stick burns such as this one in open savannah woodland in the North Kimberley, April 2019, promote pyrodiversity by creating complex matrices of burnt and unburnt habitat in the landscape. Photo: Adam Cross

Indigenous Australians have employed traditional approaches to fire use and management for tens of thousands of years, particularly in fire-prone ecosystems such as the monsoon tropical grassy savannah of the Kimberley. Every year, around 40% of the vast 420,000 km² region can burn. In recent decades, driven both by recognition of the inadequacy of Western fire management strategies and by Native Title returning the management of Traditional Lands into the hands of Indigenous Australians, Indigenous fire management has returned to the Kimberley. While many prescribed burns in the region are still undertaken by dropping incendiaries from a helicopter, much greater focus is being placed upon the timing and spatial arrangement of burning. This ensures the landscape comprises a complex mosaic of different burn ages, providing suitable habitat for native species that often possess very different fire resilience strategies. Indigenous fire management centres around lighting fires in the late wet season (March–July) rather than in the late dry season (October–December), resulting in cooler fires that burn slowly and remove fuel for more intense fires later in the dry season. Often these fires are lit on foot, a traditional practice referred to as ‘firestick farming’.

Even when fire from cool, early wet-season fire-stick burns does intrude into sensitive habitats such as this outcropping of sandstone pavement, the impacts are typically patchy rather than resulting in entire outcrops burning. Photo: Adam Cross.

As an indication of how cool the fires started by traditional burning practices can be, one can often step over the fire front as it passes slowly through the Savannah grasses; fire intensity several orders of magnitude lower than dry season fires that can individually burn millions of hectares and may burn for weeks at a time in rugged, remote country not at all conducive to firefighting. And, crucially, cool burns lit on foot typically result in remarkable ‘pyrodiversity’: crosshatch patterns of fire scarring representing complex mosaics of different fire ages, fire sizes, and fire intensities. Individual fire areas from this approach are often tens of square kilometres or less, and don’t homogenise the landscape in the same manner as huge dry season fires.

Example of a sandstone outcrop habitat following the passage of a cool late wet season burn, showing the patchiness of fire impacts and illustrating how these habitats often act as areas of fire refugia. Photo: Adam Cross.

For Indigenous Australians, ‘Country’ is inseparable from the people who live within and upon it. Indigenous land management aims to maintain healthy Country through the practice of cultural lore and activities, and traditional approaches to healing Country are increasingly recognised as a profound form of ecological restoration. Such activities are holistic, also achieving cultural and community healing, and are not limited only to terrestrial ecosystems: Indigenous approaches to restoration have also markedly improved the outcomes of restoration in seagrass and other marine and near-coastal ecosystems.

Indigenous land management initiatives, including the highly successful Aboriginal Ranger Program, appear to be taking strides forward in appropriately managing Australia’s threatened ecosystems and biota where many other initiatives continue to flounder or fail. For example, in 2017 the Auditor General’s Conservation of Threatened Species Follow-up Audit examined whether progress had been made on a suite of recommendations made during an environmental audit in 2009. It found that progress by the State Government department tasked with managing Western Australia’s biodiversity had been “disappointing”, noting that the department has “considerable work to do” and will “continue to struggle to show… that scarce resources are being effectively targeted to conserve our world-renowned biodiversity”.

Blackened stumps and bare soil, all that remain of biodiverse forest in Southwest Australia following a prescribed burn near Albany, 2019. Though a different ecosystem in another region from the North Kimberley savannah, the significant ecological impacts of intense, aseasonal prescribed burning are clearly evident. Photo: Amanda Keesing.

In 2009, 601 Western Australian species were threatened with extinction and 37% of these had recovery plans (strategies for improving their conservation status) in place. By 2017, another 71 species had been placed in the threatened list and 55% of all threatened species had recovery plans. But, as the threats to our environment have increased, staffing and expenditure on conservation and threatened species management by the State Government has fallen. Fortunately, this contrasts with an increase in funding for Indigenous land management programs, with nearly $AUD 37 million ($USD 25.8 million) committed to develop new Indigenous Protected Areas between 2018 and 2023 and over $AUD 746 million ($USD 521.5 million) allocated to support Indigenous Ranger Programs until 2028. There are lessons to be learned by Australian land managers around the country from the success of returning traditional Indigenous land management approaches to areas like the Kimberley, as the 2022 State of the Environment Report implies. We need to find a mixture of modern ways with the old ways. We need to adjust, or completely change, the way we approach land management in Australia across the board: not only in fire management but in appropriate stocking levels, weed control, regenerative farming practices, sustainable mining, conservation, and the restoration of areas that have already been degraded or destroyed. Unlike the Kimberley, where we are lucky that so much remains so intact, so many other ecosystems around Australia are in increasingly dire need. Hopefully, with Indigenous Australians leading the way, there is still enough time to conserve or restore them before it is too late. 

The low flames from a cool fire-stick burn lick through the still-green savannah grasses in the North Kimberley, April 2019. Photo: Adam Cross

The ‘botanical melting pot’ of Madeira: Notes on natural history and ecological restoration at species, ecosystem, and landscape scales

By Thibaud Aronson and James Aronson. All photos by Thibaud Aronson.

The main island of Madeira is just 740.7 km² (286 mi²), while the handful of others are rather barren, and mostly uninhabited. That means the entire Madeiran archipelago is about the size of a medium-sized National Park in the US, such as Crater Lake, in Oregon, for a total population of just over 250,000.

For garden and natural history/cultural history-oriented travellers, Madeira and its neighbors – the cooler Azores to the north, and the drier Canary Islands – are spectacular: these are three of the most appealing areas of the Atlantic for human habitation, gardening, farming, and hiking, with floras and faunas related to European, Mediterranean, and African biota, as well as some unifying Macaronesian elements shared among the three archipelagos. Agricultural crops are also quite spectacularly varied, with a strong presence of vineyards of very stunning appearance, and also subtropical bananas (about which, for some history, including the tale of the EU’s “bendy banana law”, see here).

Traditional vineyards with heritage grape varieties on the slopes of Câmara de Lobos, west of the capital. Numerous banana fields share this valley and many others like it in the periurban area around the capital city of Funchal.

Of particular interest on the island – of combined natural and cultural heritage value, are the laurel forests (laurisilva to botanists). Mostly dominated by evergreen trees and tall shrubs of medium stature – no more than 15-20 m high – these kinds of forests typically occur at subtropical latitudes, in areas with mild climate and high humidity. They can be seen – in unconnected fragments for the most part, and with varying botanical composition of course – in places such as the Himalayan foothills, central Chile, or the highlands of Ethiopia. In Europe, true laurel forests used to cover much of the Mediterranean basin during the Tertiary era, from which they receded and disappeared as the region’s climate got progressively drier. Apart from a few fragments left in the remote Anti-Atlas Mountains of Morocco, and one small patch in southern Spain, the only surviving Atlantic laurel forests are found in Macaronesia. The highlands of Madeira hold the largest and best-preserved stands, somewhat protected over the past six centuries by the island’s dramatic topography and, since 2009, thanks to recognition as a UNESCO World Heritage site covering 15,000 hectares.

Madeira’s laurisilva is draped in mist more often than not, and exuberant lichens and ferns cling to every tree branch, giving these forests a very primeval feeling, unlike anything else in Europe. The forest type is dominated by under a dozen evergreen tree species, most notably laurels (5 species in 4 different genera of Lauraceae) and tree heaths (Erica spp.), some of which get to be exceptionally tall for Ericas. But there are several dozen endemic shrubs and herbs in the undergrowth, such as various Geraniums and several giant daisy relatives. It has three endemic bird species as well.

The whistles of the Madeiran Firecrest (Regulus madeirensis) are one of the most common sounds of the laurisilva, as this tiny sprite of a bird flits from branch to branch.

The shy Trocaz Pigeon (Columba trocaz) is endemic to the forests of Madeira. Its two closest relatives are also laurisilva specialists, found in the western Canary Islands.

The Madeiran Chaffinch (Fringilla coelebs maderensis) is most abundant along the levada canals of the Madeiran highlands, where these fearless birds have become accustomed to being fed crumbs by hikers.

The archipelago was uninhabited until Portuguese sailors claimed it for the Portuguese crown in 1417. The island’s appealing climate was not lost on them and they set about settling it. Much of what they did shaped the island that we know today and no doubt led to a massive amount of irreversible clearing, deforestation, and soil erosion, as we will discuss further on.

Madeira’s climate is very unbalanced. The northern slopes can receive nearly 3000 mm of rain in a year, while the southern part of the island is much, much drier. However, the south has gentler slopes, making it much more suitable for building and agriculture. Therefore, the Portuguese set about building levadas, irrigation canals to bring water from the north to the south. This enormous network, spanning thousands of kilometers, much of it dug from sheer cliff faces, with numerous long tunnels as well, was built over four centuries (with slave labor, many of whom lost their lives in the process); without it, large-scale settlement of Madeira would have been near impossible.

A narrow path along the levada of the Caldeirão Verde (Green Cauldron), in the island’s central highlands.

Waterfalls are plentiful along the sheer slopes of the highlands.

The island also achieved tremendous prosperity especially in the 17^th, 18^th and 19^th centuries, thanks to its privileged position for maritime trade in the north Atlantic and, for a while, its role as one of the world’s largest sugar cane exporters. The richer inhabitants, taking advantage of the favorable weather, began a tradition of having extravagant gardens, with plants from all over the world. Indeed, a walk in the streets of any town on the island today will reveal gardens bursting with an incredible melting-pot of plants, with Hydrangeas (from east Asia), growing side by side with Agaves and Yuccas (from Mexico), Agapanthus (from South Africa), Brugmansias and Passionflowers (from the Andes), Bougainvillea from the South Pacific, and more marvels, all under the shade of massive Agathis and Eucalpyts (Australia) and Araucaria trees (Norfolk Island, and Chile)! There is perhaps no better illustration of this potpourri quality of the cultivated plants than the fact that Madeira’s official flower is the Bird of paradise, Strelitzia reginae, a native of… South Africa!

However, to anyone with naturalist’s eyes, a lot of what is seen outside of gardens is quite worrisome when one considers the island’s native flora, fauna, and varied ecosystems outside of the protected areas where the laurisilva occurs. There are massive areas of soil erosion, and as elsewhere throughout the Mediterranean region, abandoned lands and pastures that appear to have been cleared and then repeatedly burned over several centuries to maintain grazing lands for sheep and goats. Most of the extant revegetation has been done with Eucalyptus globulus, Mediterranean pines, and various other non-native conifers and  Australian Acacias. Of these latter fast-growing, colonizing, bird-dispersed trees, at least 6 are invasive on Madeira and the Azores, the worst of the lot being Australian blackwood.

Most slopes on the southern face of the island are completely overtaken by Australian blackwood (Acacia melanoxylon) invasion, as seen here just above Funchal, the capital.

So what now, from a restoration ecology perspective? Madeira is subject to strict Portuguese laws regarding sale or import of known invasive plant species; this makes a lot of sense given that already 15% or more of the flora of Portugal, and probably more than that in the Azores and Madeira consists of non-native invasives. But a lot of work beyond protection against new invasions could be envisioned, starting with control or eradication efforts on such an island whose natural beauty and biodiversity are its greatest asset. Reintroduction and reinforcement of populations of endangered native species are also needed and initial experiments in ecosystem restoration could be undertaken on the main island and perhaps some of the smaller islands as well. Education and job training and greater funding for restoration work are all needed and would probably be of great, and lasting value to local communities and the Autonomous Region as a whole. Coordination with similar efforts in the Azores, and on the mainland territory of Portugal should all be encouraged.

One invader to be carefully monitored on Madeira is Kahili Wild Ginger (Hedychium gardnerianum) a garden-escape that is known to do great ecological damage to native woodlands in Hawai’i, and elsewhere. The IUCN considers it to be one of the world’s 100 worst invasive species. Indeed, its 1.5 to 2 m tall stalks can form extensive stands, with dense mats of rhizomes, that can choke out native understory if left unchecked. Reportedly, control efforts are underway inside the Madeira Natural Park.

But what about all the areas infested with woody weeds outside the parks and UNESCO Heritage sites in the mountains? From our point of view, the extensive and multiplying stands of Acacia melanoxylon and other invasive wattles (Australian acacias), of Gorse (Ulex europaeus) and a few other noxious woody weeds we saw plenty of,  it seems clear that manual and mechanical controls, and perhaps some biocontrol would be worth testing.

And, what about everything that ecological restoration, sensu lato, could bring to Madeira? On one road, in the center of the country, we saw a rather large plantation of tree saplings that looked like Ocotea foetens, one of the five native laurels of the laurisilva. That was encouraging to see, but the trees were planted grid-fashion and in monoculture, so that it was unclear what the intention was. As readers of this blog well know, reintroduction (or reinforcement of populations) of a single species of native plant or animal is not the same thing as ecological restoration: ‘restoration of Ocotea foetens’ is a non sequitur whereas reintroduction of this native tree, or its use in reforestation does make sense.

We also learned that studies are underway regarding the native olive tree, long considered a feral ecotype or, for some systematists, a subspecies of the widespread European olive, Olea europaea, but now generally accepted as an island endemic Olea madeirensis. Pride in such native species should be definitely encouraged, serving as a driver for more attention to what should be planted in the context of future ecological restoration programs in coastal areas and hills, and in environmental education programs, parks, and botanical gardens as well.

Next, let’s consider the spectacular Dracaena draco, or Dragon tree, that prospered on Madeira and also in the Canary Islands, Morocco, and Cape Verde, until Europeans in the 15^th and 16^th century began aggressive tapping of the sap from this stem succulent tree – the so-called Dragon’s blood – which was widely prized as a durable natural dye. By the end of the 16^th century, Dragon tree was rendered nearly extinct in its natural distribution area thanks to a typical boom and bust pattern of exploitation, and today, the only wild populations of any importance occur on Tenerife, in the Canary Islands, with a few individuals in Morocco and Cape Verde.

This iconic tree is seen planted all over Madeira, and indeed in frost-free dryland gardens all over the world. But there probably isn’t a single wild dragon tree left on the island! So, what should attempts to restore an ecosystem with populations of Dragon tree look like, over and beyond reintroductions? What reference should be used and which provenances of what trees should be planted and what else is needed for the project to survive and be meaningful to Madeirans?

Rather spotty plantation of Dracaena draco along with the showy but non-native and potentially invasive Aloe arborescens near the village of Caniçal, on the easternmost peninsula of Madeira.

A centuries-old specimen Dragon tree in one of the surviving stands of native Dracaeno draco on Tenerife, (near El Draguillo), Canary Islands.

And now, for our last snapshot, let’s consider the Foxtail Agave, that is widely planted and clearly spreading on coastal cliffs and hills in Madeira. It is an absolutely stunning plant, and of great natural history interest but it starting to naturalize, following in the pattern of Agave americana and Opuntia stricta, that could already be considered serious weeds. Local people probably don’t consider that a problem, and we can certainly understand that, given the newcomer’s graceful beauty. But like the Kahili ginger, and the widely planted Aloe arborescens, the Foxtail Agave is a serious pest on O’ahu and other Hawai’ian islands, and this should give cause for concern to Madeirans.

Fox-tail Agave, Agave attenuata naturalized near Câmara de Lobos.

But, then, who are we to say what attitude Madeirans and their authorities should adopt towards non-native invasives? Given the fact that tourism is now far and away the leading economic sector on the island, perhaps – like the Galapagos Islands, or Iceland, or Malta – greater sensitivity to the need for and the value of ecological restoration efforts will develop in the future.

One thing we could offer is a reminder that ecological restoration clearly includes restoration (or ecological and economic rehabilitation) of cultural or semi-cultural ecosystems, not to mention social-ecological systems and cultural landscapes. In the case of Madeira, this line of thinking would allow for reflection, and encourage investment in the restoration and rehabilitation of the working landscapes that thrived in lower latitudes on the southern half of the island with irrigation water being provided from the levada networks in the mountains. We can imagine remarkably interesting and inspiring landscape-scale restoration with ample opportunities for agritourism, and an expanded form of nature-based or ecotourism that would include cultural landscapes and heritage crops and traditional livelihoods, developed along corridors and valleys connecting levada canals all the way down to restored ‘working landscapes’ that certainly could have multiple benefits for local communities, for biodiversity, and for an emerging restoration economy linked to tourism. Worth considering, no?

 

Translocating a threatened totem: The impacts of mining on a culturally-significant species

Holly Bradley, Bill Bateman, and Adam Cross (Curtin University) describe the natural history and conservation of the Western Spiny-tailed Skink, an Australian lizard with a mixed history of translocation success. For more information, read their 2020 review on migration translocations in Conservation Biology.

Australia harbors approximately 10% of the Earth’s reptile species, and over 96% of all lizards and snakes occurring there are found nowhere else in the world. However, this incredible and irreplaceable biodiversity is under threat. Australia is one of the highest contributors to species losses globally, with over 1700 species and ecological communities threatened with extinction. In the last 20 years alone the number of threatened reptiles has nearly doubled, with 61 species now federally listed.

The Western Spiny-tailed Skink (Egernia stokesii badia) is just one example of a unique, endemic reptile threatened with extinction in Australia. Continued habitat degradation from practices such as grazing and mineral extraction (largely iron ore) are some of the major contributors to population decline.

The Western Spiny-tailed Skink (Egernia stokesii badia), an endangered Australian reptile threatened by habitat loss and disturbance from mining and farming activities. Photo: Holly Bradley

Western Spiny-tailed Skinks are one of the most social of all snake and lizard species – an uncommon trait among reptiles. Colonies of the skinks reside together in log ‘castles’, consisting of hollow logs and fallen branches. These natural structures provide a year-round residence for the skinks, who create latrine piles in select areas outside of the logs in order to keep the hollows clean.

Cultural significance

As well as being an ecologically unique threatened subspecies, with distinct spined scales particularly on their tails, and occurring only in a small region of Western Australia, spiny-tailed skinks are also culturally significant. PhD researcher Holly Bradley met with Badimia elder Darryl Fogarty to discuss the cultural significance of the skinks in her study area, the southern region of the Mid West. Elder Darryl Fogarty informed the local name of the skinks to be meelyu, and for some members of the regional community they represent a sacred totem. Totemic animals are common for many Indigenous groups across Australia and are linked with the worldview that people are an integral part of nature, belonging to a network of spiritual and physical entities.

Often, a totem will represent one’s connection with one’s nation, clan or family group. With a preordained totem comes a spiritual responsibility, where a person is accountable for the stewardship of their totem, meaning it is protected and passed down to the next generation. For many groups, this means that a person cannot eat the animal totem. Before Europeans colonized Australia, this traditional practice contributed to maintaining biodiversity and ensuring an abundance of food supplies; part of ‘caring for country,’ or maintaining ecosystem health.

The reverence with which totemic species were regarded helped to prevent significant declines in certain animal population numbers in the past. However, after the imposition of European land management into Western Australia, changes have occurred to the ecosystem balance. For example, large areas of native vegetation have been cleared, largely for urban development and agriculture, and the introduction of hoofed livestock has degraded and compacted soils. Introduction of domestic animals has also led to feral cat invasion across over 99.8% of the Australian land mass, which has led to wildlife devastation. For the skink, these changes have meant significant population declines throughout its Mid West range.

Example of in-tact open Eucalypt woodland (skink habitat) at risk of continued degradation from grazing and mining practices in the Mid West region of Western Australia. Photo: Holly Bradley.

Translocation requirements

In the face of continued transformation, habitat loss, and landscape-scale degradation, one of the ways in which Australia is trying to combat biodiversity loss is by relocating wildlife away from areas where they are likely to be (or definitely will be) impacted by these threats. Under Commonwealth regulation, if a proposed action by a mining company, such clearing of native vegetation, causes significant impact to a threatened species, approval may be conditional upon mitigation or offset measures, such as the translocation of individuals away from the threat. However, translocation is rarely a condition included as part of a decision notice without a high degree of certainty of success.

For non-threatened species, there are no Commonwealth laws which require a standard for translocations, and decisions are made on an ad hoc basis, generally with assisted relocation of larger charismatic mammals such as kangaroos and quenda, allowing local cities or councils a social license to continue urban development, without providing ongoing funding to monitor the long-term success of these translocations. After analyzing the outcomes of hundreds of translocation efforts around the world, we (Bradley et al. 2020) urge all land managers to shift their thinking away from what appears to be a poorly effective strategy. Although removing animals from areas destined for clearing might appear a simple resolution to the threats posed by activities such as urban sprawl or mining, it does not actually guarantee the survival of the individuals that are ‘saved’.  In fact, our review of this practice indicates that there is little follow-up on the success of translocation and many translocations may result in the eventual death of the translocated individuals.

To be successful, translocations need to ensure not only that relocated individuals survive but also that they contribute to the long-term persistence of a self-sustaining, reproducing population. Many mitigation-motivated translocations, i.e., relocations that respond to an immediate threat to individuals, have only the single goal of moving an individual or population away from the immediate danger. However, for these animals to actually survive and persist, it is critical that the design of translocation efforts be informed by sound science and an understanding of the complex ecology of the different species targeted for “saving”. Crucially, it is essential to monitor the translocated animals to understand their behaviour in the new location, estimate likely population viability in that location, and better understand and communicate how translocation efforts might be improved in the future.

We have just entered the United Nations Decade on Ecosystem Restoration, which represents a growing global commitment towards preventing, halting and reversing the degradation of ecosystems. However, for there to be the restoration and protection of fully functioning, healthy ecosystems, it is important for translocations to target a suite of ecologically significant species, rather than just the larger, charismatic mammals. Current biases generally exclude consideration of reptiles within assessments of mine site restoration success, despite their particularly high diversity and abundance within the arid mining regions of Australia, and their occupation of important ecological niches. The well-known ‘Field of Dreams’ idea, presented as one of the abiding myths of restoration ecology, assumes native animals will return on their own after revegetation of a site but, in practice, it doesn’t always work out that way.

Example of a naturally occurring log pile surrounded by everlastings (Rhodanthe collina) and red soil typical of the Mid West region of Western Australia. Log piles typically consist of a single fallen Eucalyptus tree log, overlapped by a number of branches. Photo: Holly Bradley.

Translocation case study: spiny-tailed skinks

As iron ore extraction continues in Western Spiny-tailed Skink’s habitat throughout the Mid West region, future translocations of colonies of this endangered reptile are likely. Understanding the basic requirements for establishment and persistence is crucial, and gathering this knowledge requires significant investment in research and monitoring. For example, detailed studies are required of the diet and habitat log pile characteristics needed for colonies to thrive. As these skinks are shy and observational records are difficult to obtain, this means other research methods are required, such as collecting scats for visual and genetic analysis of the invertebrate and plant contents of their diet. A more informed understanding of diet can help improve translocation site selection, as it is important to know what plant and animal species are important food sources that must be present or else be planted or reintroduced in restoration sites for successful recolonization.

An adult and juvenile spiny-tailed skink (Egernia stokesii badia) sharing a log pile as their permanent residence. Photo: Holly Bradley.

Another example of critical information to promote successful translocations is understanding the key predation threats to the Western Spiny-tailed Skink. Despite the protection of their unique spined tails which allow them to lodge tightly into crevices and act as a defensive mechanism against attack, they are still at risk of decline from predation. One method to understand the key predators of skinks within the Mid West has been to place camera traps at active colony sites. Below is an example of an image captured of a feral cat with an adult skink in its mouth, indicating that control of feral predators, particularly cats, is likely to be critical in ensuring the initial survival of relocated skink individuals.

Feral cat with an adult spiny-tailed skink within its mouth, at a log pile site within the Mid West. Footage captured using a motion-activated camera. Photo: Holly Bradley.

It is also important to understand how translocated individuals integrate within the recipient ecosystem, and that they do not introduce any non-native parasites, or outcompete any native species for food resources. Research by Bradley et al. (2020) shows that those who undertake mitigation translocations rarely consider the long-term impacts of how translocated animals affect the recipient ecosystem, and if the carrying capacity of the translocation site has space for the introduction of new individuals.

Translocation can be expensive (for example, the relocation of cheetahs (Acinonyx jubatus) in Namibia cost about $2800 USD per individual), and the continued funding and implementation of ad hoc species relocations to justify continued habitat loss may be both wrong-headed and a waste of limited conservation dollars. Translocation is also a highly stressful practice for the animals, and it is counter-productive to go through such efforts if there are no territories or food resources available for their survival.

To improve the outcome of future translocations of the Western Spiny-tailed Skink, it is also important to understand the complexity of the recipient ecosystem and how best to help translocated individuals assimilate there. Detailed habitat assessment and locating appropriate log pile structures can determine if the recipient site is appropriate for the skinks, and targeted surveys can determine if skinks are already present within the area. Selection of translocation sites as close as possible to the source location will prevent the co-introduction of non-native parasites or diseases.

An adult Western Spiny-tailed Skink sunbathing on a log pile. Photo: Holly Bradley

The way forward

Less than half of all published studies undertaking translocations compared or tested different techniques (Bradley et al. 2020). Without a comparison of different techniques, such as whether supplementary feeding during an ‘acclimation’ phase at the translocation site or if the establishment of temporary fencing might help population establishment compared with simply releasing animals into new habitat, it will be very difficult to improve translocation practices for the future. Given current success rates are less than 25% for mitigation translocations around the world (i.e., the number resulting in self-sustaining populations), there is huge room for improvement. A holistic approach to land management considering both ecological and cultural significance can both protect and restore community wellbeing, as well as promote the return of functional, self-sustaining ecosystems in restoration practice.

For more information, read our 2020 review of migration translocation success in Conservation Biology: Bradley H, Tomlinson S, Craig M, Cross AT, Bateman B. 2020. Mitigation translocation as a management tool. Conservation Biology https://doi.org/10.1111/cobi.13667.

A foray in the Mojave Desert

Thibaud Aronson describes the botany, ecology, and degradation of southern California’s unique desert woodlands.

There are four deserts in North America – the Great Basin, Chihuahuan, Sonoran, and the Mojave. Both the Great Basin and the Chihuahuan deserts can have bitterly cold winters, and as a result their vegetation is quite stunted compared to the other two, with precious few trees. A few years ago, my father and I spent a fair amount of time in the Sonoran desert, both in Arizona and in Baja California, documenting its remarkable trees.

To fill an important gap in our survey of desert trees of the world, I recently visited the Mojave desert, home to one of the most iconic desert trees on the continent. Indeed, just about every time one mentions desert trees, at least in the US, the most common response is: “Oh, like Joshua trees?” Like Joshua trees, indeed.

The iconic Joshua tree (Yucca brevifolia) in the national park that bears its name in southern California’s Mojave desert.

As is typical in California, very different landscapes succeed each other in a relatively small area. So, over a week and surprisingly small distances, I traveled the region to get a sense of its rich tapestry of habitats  (see my itinerary).

Heading east from LAX Airport, I drove up a winding road into the San Gabriel Mountains. By the time I reached 2000 meters (6500 feet), I was completely surrounded by tall, dense forests comprising six or seven intermingled conifer species, and a number of ski resorts, deserted in the summer season. At my campsite that night, the temperature dropped to just a hair above freezing, quite a contrast from the stifling August heat I’d experienced that very morning!

The next day, I followed the spine of the mountains through the San Gabriels and on to the San Bernardinos. Driving along the glittering blue waters of Big Bear Lake, I went past “Starvation Flats Road”, a warning of what lay ahead. And indeed, I soon reached the eastern slopes, which gave me a striking view of the Mojave desert below – stark yellow plains that disappeared in the haze. Making my way down, the conifers began to thin out, and soon the first Joshua trees began to appear, some of them nearly as tall as the oaks they grew with.

On the eastern foothills of the San Bernardino mountains, Joshua trees grow together with Valley oaks (Quercus lobata) and California Black oaks (Q. kelloggii).

Turning back to look at where I had come from, I could see Old Greyback, the tallest summit in southern California. Then I headed southeast, hugging the base of the mountains, to the famous town of Palm Springs. Originally the town was named for the freshwater springs that flow down from the mountains and the California Palms (Washingtonia filifera) that grow along the canyons. Today the palms line every street in town, towering above the low buildings.

The skinny, carefully trimmed palms that define the look of Palm Springs are in fact unnatural, as wild fan palms develop thick skirts from their dead leaves that can extend almost all the way down to the ground. See below.

The landscape to the east of town is desolate, highlighting how precious and unusual the springs are. Creosote shrubs, their leaves a characteristic greyish yellowish, grow on the dusty flats as the incessant wind spins the thousands of turbines of the San Gorgonio Pass wind farm (the third largest in the state). Suddenly, a green ribbon appeared in the distance, and as I got closer, it resolved itself into a copse of large cottonwood trees, towering over an incredibly thick mesquite thicket. This is Big Morongo Canyon, the largest freshwater spring in the region.

The thick canopy of cottonwoods (Populus fremontii) at Big Morongo canyon.

As soon as I stepped under the trees, it was clear that I had entered an oasis of life: orioles, goldfinches and hummingbirds flitted in the undergrowth, while jays pestered a great horned owl that they had found perched in a cottonwood. Cottontail rabbits hopped on the path ahead of me, and a coachwhip (Masticophis flagellum) rattled its tail at me, this tiny, harmless snake attempting (as many other local snakes do) to look like a rattlesnake to scare off potential predators.

A female Anna’s hummingbird (Calypte anna) and some bees drinking at Big Morongo.

Before it got too hot, I continued on my way farther east, until I reached Yucca Valley, and from there Joshua Tree National Park. It is a surreal experience, as they appear almost out of nowhere, the phantasmagorical silhouettes of these giant tree Yuccas stretching to the horizon, the unique bluish grey tinge of their leaves giving a peculiar appearance to the air itself. It is a landscape quite unlike any I had ever seen. Though it is hard to understand how the first pilgrims decided that one of these trees was the prophet Joshua, pointing them in the direction of the promised land, as each tree seems to point a different way!

Right on the edge of the national park, a Greater Roadrunner (Geococcyx californianus) looks for its next prey perched in a Joshua Tree.

While the northern parts of the Mojave are low-lying, making up the famously inhospitable Death Valley, Joshua Tree National Park sits at the southern edge of the desert, on a plateau about 1200 meters (4000 ft) above sea level. The cooler temperatures at that altitude are what allow the Yuccas to thrive, in truly remarkable numbers.

A typical scene from the northern section of the park. I couldn’t find any data on this, but there must be tens, if not hundreds of thousands of Joshua Trees in the park.

While Joshua trees are the most distinctive – and seemingly the hardiest, growing even in the most exposed flats – they are not the only trees of the park. Many sandy desert washes cross the plateau, and along each of them grow various dicot trees. Most noticeable among these is Chilopsis linearis, in the Bignonia family. In the vernacular, it is known as ‘Desert willow’ because of its unusually long, narrow leaves and the fact that it grows in riparian habitats. Another tree found in the Mojave is the Papilionoid legume Psorothamnus spinosus, known as ‘Smoke tree’, as its pale grey leaves look like a cloudy puff of ashes, brightened in  summer when the trees are covered with gorgeous indigo-tinted, pea-like, flowers.

Smoke trees in the aptly-named Smoke Tree Wash, inside the Joshua Tree National Park.

Finally, there are two species of the legume tree Palo Verde (Parkinsonia), one of which I found providing shelter for a desert bighorn one evening near my campsite.

A young desert bighorn sheep (Ovis canadensis nelsoni). Bighorn populations have recovered quite well in recent decades, though they are still facing various threats in the California deserts. There are fewer than 300 found in Joshua Tree National Park (ca. 800,000 acres, or 3,200 km² in size).

Furthermore, the park is known for its elaborate formations of basaltic rock, which add to the surreal beauty of the landscape, and attract rock-climbers from all over the world. These rock piles, with the shelter and extra moisture that they provide, also allow oaks, pinyon pines, and junipers (all trees that typically grow on the higher mountain slopes) to survive down on the plateau as well.

At Hidden Valley, in the central section of the park, large pinyon pines (Pinus monophylla) grow among the basalt rock piles.

There are also several fan palm oases in the park, from Fortynine Palms, standing on its own amid the bare rocky slopes, reminding me of the mountains of northern Oman, to the glorious Cottonwood Springs, where massive cottonwoods barely top over the enormous palm trees, who formed a dense cluster sheltering a family of barn owls.

The saddest fan palm oasis is undoubtedly Mara, also known as Twentynine Palms. It is said that the Serrano Indians who used to live in the area planted one palm tree for each son that was born to the tribe after they first settled there. Last year, a criminal fire swept through the area, killing several of the palm trees. Some blackened trunks still stand, while several others had to be completely cut down. All in all, it is a sadly apt metaphor for what has befallen these first nations of indigenous people who called the area home for centuries prior to the arrival of Europeans.

Compare the glorious Cottonwood spring, protected as it is in a remote part of the national park, with the sad oasis of Mara, still showing the scars from last year’s fire that was set by an arsonist.

From there, I drove south through the park, and the landscape began to change markedly, as this is the where the Mojave gives way to the Sonoran desert. It got warmer and drier as the elevation decreased. The Joshua trees disappeared, replaced by ocotillos and in some areas, fields of teddybear cholla cacti (Cylindropuntia bigelovii). Passing through spectacular layers of exposed rock, I reached the Bajada, a grassy savanna with large ironwood trees (Olneya tesota, also a tree legume) a scene more akin to an African savanna than the landscapes I had left behind that same morning! This was quite striking as we had found ironwood trees to be much scarcer in Baja California!

From there, it was only a short way to the final stop on my trip: the Salton Sea. Lying about 70 meters below sea level, this is actually a depression, which was periodically filled by exceptional flooding on the Colorado River. The last time this happened was in 1905. Since it has no outlet, the lake progressively becomes more saline and eventually evaporates, until the Colorado floods its banks and fills it again.

Furthermore, because of repeated Colorado River floods, the surrounding soils are very fertile, despite the extremely dry climate. As a result, in the early 20th century, at the height of the hubris that characterized the development of the American Southwest, massive irrigation projects were put in place in the Coachella and Imperial valleys, at the northern and southern ends of the Salton Sea, respectively. The latter – formerly called Valley of Death, was rebranded as Imperial Valley – in a remarkable feat of marketing well described by Fred Pierce in When the Rivers Run Dry (2006). Today, the landscape as seen from the sky is surreal: the deep blue waters contrasting with the yellow of the surrounding desert, while the valleys at both ends are an incongruous green. The perfectly rectangular fields stretch all the way to the Mexican border, for a combined irrigated area equal to nearly three times that of the Salton Sea itself! These fields produce a large portion of the state’s lettuce, broccoli, carrots, and especially alfalfa, to feed California’s behemoth dairy industry. The sight of the hundreds of sprinklers going full tilt in the midday heat, to water alfalfa that could be grown in the East for a fraction of the cost, was rather off-putting, to say the least. (For a comprehensive and depressing history of water usage in the American West, read Cadillac Desert (1986), by Mark Reisner).

Irrigated vineyards in the southern end of the Coachella Valley. Note the extremely arid ranges in the distance, which stretch between Joshua Tree National Park and the Salton Sea.

As is by now well known, the Colorado has been well and truly “tamed”, its once wild run dammed in fifteen places, and every ounce of its water used to irrigate the thirsty cities and fields of the West, so that hardly a drop reaches its once mighty delta. In other words, the Salton Sea may soon be gone for good. And what else can we look forward to?

In a nutshell, the whole area is a mess. For a century, agricultural runoff has ended up in the Salton Sea itself and now, as the Sea is shrinking, more and more of its bed is being exposed and sediments heavily contaminated with salt and pesticides are being picked up by the winds. This is a massive public health issue. Not to mention the ecological disaster as the waters become too saline to support the fish that dwell in it, depriving the millions of birds that pass through the area of some of the only food available on that portion of the migration flyway. Furthermore, the well-publicized water shortages and catastrophic wildfires of California get worse with every passing year.

Obviously, agriculture in southern California will continue, but in what fashion? According to the California Department of Agriculture, more than half of the irrigated cropland in the state is badly affected by salinization. Surely this should be a wake-up call to explore alternative futures. For one thing, as Richard Felger, doyen of US-based Sonoran desert botanists and explorers, puts it, we need to learn to “Fit the crop to the land, not the land to the crop.”

Even though desert organisms are tremendously well-adapted to the harsh conditions they face on a daily basis, even they can only take so much. According to a recent study, rising temperatures are rapidly making the national park unsuitable for Joshua Trees themselves. In the best-case scenario, major efforts to reduce greenhouse gas emissions could save around 20% of suitable habitat for Joshua trees within the park after the year 2070. In the worst case, with no reduction in carbon emissions, 50 years from now,  the Joshua Tree National park will retain a mere 0.02 percent of its Joshua tree habitat.

The first white explorers who saw the Western deserts of North America thought them so hostile that they could never support settlement, disregarding the Native Americans and the wealth of fauna and flora who had long been living in the desert, in a very delicate balance. But in the frenzy of the twentieth century, through truly prodigious amounts of effort, descendants of the European colonists radically reshaped these landscapes to suit their needs with very little understanding of the long-term consequences of their actions. The entire enterprise is clearly and dangerously unsustainable, as water reserves that accumulated over hundreds of thousands of years were drained in just a few decades.

We often hear about the fight against desertification, which is conflated with some sort of fight against advancing deserts. But it is important to remember that deserts, while harsh, can still be beautiful and full of vibrant and unique life. Joshua Tree National Park, the Mojave National Preserve, and a few other protected areas give us a glimpse into what once was. But they are mere handkerchiefs. If the region is to have a chance at a sustainable future, we need new paradigms, new laws based on a much better understanding of how life can balance itself in arid lands. Based on that understanding, it is imperative that we move away from the pattern of careless exploitation and transformation, stretching farther and farther away from what these deserts once were. Instead, it is past time to commit to ecological restoration and allied activities for the Mojave and indeed all degraded and mis-used deserts and semi-deserts, especially as climate chaos unfolds.

Desert Trees of the World – A new database for ecological restoration

For the past five years, James and Thibaud Aronson have been traveling to the driest parts of the world to collect data about the distribution, ecology, uses by humans, and up-to-date systematic botany of  the soul-satisfying and mind-boggling trees that grow in Earth’s beleaguered, beloved, and mega-diverse drylands. Here they describe the content and purpose of their new Tropicos database. This work builds on more 3 decades of collaboration between James and Edouard Le Floc’h, who is also a co-author of the database and a book-in-progress on desert trees and their role in ecological restoration and allied activities.

Desert Trees of the World represents a multi-purpose, participatory database in which we have gathered a vast array of information about dryland trees, where and how they live, the communities they are part of, the many ways in which they are used by people, and some elements about their successful cultivation.

Our database brings together the most up-to-date botanical, biogeographical, ecological, and ethnobotanical information on 1576 species of trees from the arid and semi-arid regions of five continents and many islands. And because it is hosted on Tropicos, the Missouri Botanical Garden’s vast botanical database, a user can seamlessly access any supplementary information that may be available for a given species thanks to research carried out in other MoBot projects. Further, maps of collection sites, as well as full nomenclatural, bibliographic, and voucher specimen data accumulated digitally at MBG these past 30 years are available.

The data base is intended for students of natural history, practitioners, policy-makers, and scientists working in ecological and biocultural restoration, conservation, and sustainable and restorative environmental management.

Trees in the desert?

Most people think that deserts are – by definition – devoid of trees. Not true! Indeed, some of the strangest, oldest, and most remarkable tree species on the planet are found in drylands, a term often used to refer to deserts and semi-deserts, also known as arid and semi-arid lands.

For our purposes, drylands are all the lands of the globe that receive less than 400 mm (ca. 16 inches) of rain in an average year. In total, this concerns over 42% of all lands on Earth, so listing all the tree species that occur in them was no small task! But, we were drawing on decades of travel, research and residence in quite a spectrum of the world’s deserts and semi-deserts. We also pored over specimens housed in three dozen major herbaria, and read thousands of technical scientific articles and floras in several languages. And, as this is the 21^st century, we used information already online in another Tropicos project, the Catalogue of the Flora of Madagascar as well as many other online sources.

A cardón (Pachycereus pringlei) and a boojum (Fouquieria columnaris) in the Central Desert of Baja California, Mexico. In the harsh conditions of deserts, evolution has favored some of the strangest-looking trees on the planet.

In southern Oman, we explored the remote Wadi Aful, where wild frankincense trees (Boswellia sacra) grow between sheer rock walls.

The irontree (Astrotricha hamptonii) is not among the most impressive-looking desert trees in our database. And yet, because it only grows on ironstone formations, clever prospectors used its distribution to discover some of the largest iron ore deposits in Western Australia.

Since there had been no previous attempts at documenting the trees of all the deserts in the world, we weren’t sure how many species we would end up with. And the end result was truly remarkable: a sum of 1576 species of trees native to deserts around the world, occurring in  422 genera and 100 families of flowering plants. Of course, new tree species are still occasionally being discovered, mainly coming out of Namibia, Somalia, and southern Arabia, but we are confident that we have captured the great majority of all extant dryland trees in this database.

Then again, some desert trees are not so unfamiliar to visitors from Europe or North America, such as these junipers (Juniperus phoenicea) and oaks (Quercus calliprinos), growing in the central mountains of Jordan.

What does a desert tree look like?

If asked about what a desert tree looks like, you might think of spiny or resinous, sticky trees. And you would be right. Fabaceae, the legume family, make up just over a quarter (403) of all species, and of those, 217 are Acacia sensu lato. The next ‘big’ family is the Myrtaceae (the Eucalyptus family), with 133 species, all but one found in Australia, the exception, Myrcianthes ferreyrae, being restricted to the fog oases of Peru’s hyper-arid coast. And in third place are the Burseraceae, with 111 species. This is the family of myrrh and frankincense, two desert trees whose importance for humans dates back millennia, tied as they are to the great cultures of the Old World. For reference, people’s most common images of desert trees are palms (think – oasis) and tree cacti. But there are only 28 desert palm species, and 49 tree cactus species.

We also have some remarkable oddities, such as one arborescent member of the cucumber family (Dendrosicyos socotrana), and several rose relatives (Polylepis spp.) that grow above 4000 meters in the most parched areas of the Andean cordillera!

Where do desert trees grow?

Interestingly, the different desert areas of the world are not equal in terms of their contributions to our database (see the table below, the full version of which is posted on the homepage for our database).

Region	Number of Species	Endemic species*	Number of Genera	Number of Families
Australia	389	373	62	34
Madagascar	355	311	160	55
North America	272	222	126	55
Northeast Africa	233	80	87	42
West Asia	224	86	97	46

*Endemic to the country or region indicated.

Five regions alone account for two thirds of all the species in our database, with the deserts of Australia and Madagascar being almost preposterously rich in tree species. But of course the area of arid Australia is vastly greater than that of Madagascar, so that in fact the numbers of families, genera and species in the latter country are really the most impressive of all.

 

Highly degraded spiny thicket vegetation at the edge of the Ranobe PK32 Protected Area near the town of Ifaty, in western Madagascar, with few trees other than the emergent baobabs, Adansonia rubrostipa (Malvaceae) remaining. Young plants of the spiny tree, Didierea madagascariensis (Didiereaceae) developing in the bare sandy soil around the baobab in the foreground. 11 September 2006. © Peter Phillipson, Missouri Botanical Garden. http://www.tropicos.org/Image/100624586.

Secondary growth spiny thicket near the Ranobe PK32 Protected Area north of Toliara, in Madagascar, with occasional individuals of the locally endemic spiny tree Pachypodium mikea (Apocynaceae) – center image, but dominated by mature Didierea madagascariensis (Didiereaceae). 03 December 2018. © Peter Phillipson, Missouri Botanical Garden.

A zoom on the astonishing dryland tree species richness and diversity of Madagascar can already be found in an article we published last year, covering the remarkable assemblages of 355 tree species found in the driest part of Madagascar, of which no less than 311 are endemic to the country. This is all the more remarkable considering that they are all crowded into a narrow coastal strip in the Southwest, which is a mere 14,480 square kilometers (5591 square miles), or the same size as Connecticut.

For us, a key feature when discussing desert trees is the fact that even in the harsh areas where they found, trees can grow densely enough to form true woodlands, sometimes even with dense canopies, which has enormous importance for desert ecosystems and people. In previous blog posts we have reported on striking examples – in northeastern Jordan, and coastal Peru, among others, where evidence of former woodlands provide rays of hope and guidance for people attempting ecological restoration in desert lands.

Back in 2013, James and Edouard published a first book in French (Les Arbres des Déserts: Enjeux et Promesses) profiling desert trees and developing the subject of desert woodlands. We now have a more comprehensive book in preparation, called Desert Canopies: Reimagining our Drylands. Three chapters on animal-tree relations, and photos and drawings by Thibaud will help make this of interest for a wider audience, not just specialists. We also develop the theme of ecological restoration and provide profiles and virtual field trips from many restoration programs in drylands around the world.

 Where can one see living Desert Canopies today?

Unfortunately, most drylands are found in poverty-stricken regions of developing countries, where trees are an extremely valuable resource. In recent decades, desert canopies have been hammered by rising populations of people and livestock. As a result, today these canopies are so degraded and fragmented that it’s hard to imagine what they once looked like. Western Australia is one of the few places where reasonably intact desert woodlands still cover large areas.

A typical landscape of the Great Western Woodlands, in the semi-arid southwest of Australia (mean annual rainfall 250 – 400 mm), with gimlet eucalypts (E. salubris) growing over a beautiful understory of blue bush daisy (Cratystylis conocephala).

In our last blogpost, we reported on some notable trees, tree canopies, and indigenous peoples of the Guajira peninsula in northern Colombia.

From looking at the tree cover, it is hard to believe that this area of Colombia is technically a desert!

Young Wayuu and their donkeys, standing in the shade of a tree, on their family farm in the Serranía de Macuira, a mountain oasis in the middle of the Colombian desert. The Guajira, as the region is called, is a microcosm of the problems and drivers of arid lands everywhere, as well as a good example of the diversity and life and beauty that can be found in deserts.

Other striking tree canopies can still be found in diverse places today, including some of the driest places on Earth.

The Rub al Khali, the famous Empty Quarter of Arabia. Even there, trees can thrive amid the sand dunes (in this case, the venerable khejri, Prosopis cineraria), that we were lucky enough to observe in northern Oman.

On the arid coast of northern Peru, Prosopis pallida and other trees can grow in the ever-so-slightly richer soils at the bottom of gullies amid the plains.

As noted earlier, drylands make up more than two-fifths of all lands on Earth, at present. Furthermore, despite their harsh conditions, drylands are presently home to well over 2 billion people, and indeed many of these are among the poorest and most vulnerable populations on Earth. The United Nations, and many other organizations are working hard on the problems of drylands and their peoples, but it is very much an uphill battle… As we passed Earth Overshoot Day on July 29^th this year– the earliest date ever – it is timely to stress once again that the restoration and rehabilitation of degraded ecosystems will be key if we are to hope for a sustainable future. Restoration is undeniably harder in arid lands than in many other places, but that only means that it is more necessary. We are happy to relate that the Society for Ecological Restoration’s scientific journal, Restoration Ecology, is launching a new initiative devoted to dissemination of scientific advances on ecological restoration and rehabilitation in arid lands. Our database is offered in that spirit.

The small, arid Isla Guadalupe, off the coast of northwestern Mexico, is home to several endemic tree species, which were almost extirpated by introduced goats. But now that the goats have been removed from the island, the trees are making a comeback. Pictured here is the endemic cypress Cupressus guadalupensis, and some of the people who’ve made this recovery possible.

A large number of the trees included – 932 out of 1576 to be exact – are endemic to a single country – and most are in urgent need of committed conservation, restoration, and better management. We hope that our database can act as a reminder of the wealth of life forms that can thrive in arid lands, and an exhortation to not give up on their desert homes, scarred and battered as they may be, but rather to try and help them flourish once again.

Virtual field trip to the Guajira desert and the Serranía de Macuira in northern Colombia

James and Thibaud Aronson describe the natural and cultural context of a little-known area of northern Colombia, home to the Wayuu people and a microcosm of arid lands worldwide.

Colombia is one of the world’s seventeen megadiverse countries.  In a few hours of travel, one can go from the sweltering Amazonian lowlands to the snow-capped peaks of the Andes. It even has a true desert, a small peninsula called la Guajira, shared with Venezuela, which constitutes the northernmost point of South America.

For most of the last 50 years, the Guajira was notoriously dangerous, principally because of drug trafficking, but things have improved in recent years. We traveled there last month, shortly after the first big rains the region had received in several years. ​ And we found that it’s a poignant example of the plight of drylands globally and their peoples.

The Guajira peninsula, in northern Colombia, including the authors’ itinerary.

Our trip actually began in Panama, which was part of Colombia until 1903. While much smaller, Panama is also a country of contrasts. Much of the Pacific coast used to be covered in seasonally dry tropical forest, and some fragments persist today in and around Panama City itself, while the forests of the Caribbean slope, a mere 50 km away, are much wetter. A curious switch occurs near the Colombian border, where the wet forests then extend down the Pacific coast of Colombia and Ecuador – the famous Chocó-Darien rainforest, one of the wettest and most diverse tropical forests on Earth.

Meanwhile, the seasonally dry forests continue along the 1,000 km long Caribbean coast of Colombia and give way to semi-desert and then true desert (annual rainfall < 250 mm), lined by a coast with mangrove forests, and a series of lagoons and bays where flamingos and ibises add a shock of color.

Mangroves in Bahia Hundita, Alta Guajira, showing desert woodland with tree cacti (Stenocereus griseus) and various legume trees growing on the sandstone bluffs in the background.

Roseate spoonbills, great egrets, and a white ibis sharing a coastal wetland near Uribia.

As if this wasn’t enough contrast, halfway along the Caribbean coast rises the Sierra Nevada de Santa Marta, Colombia’s tallest mountain range, reaching 5,700 meters (18,700 feet) above sea level at the highest peak. It takes only about two hours to drive from its foothills, where toucans and monkeys chatter in the majestic trees, to Riohacha, the gateway to the desert.

A brown-throated three-toed sloth (Bradypus variegatus) hanging by one arm in a Cecropia tree in Tayrona National Park, at the base of the Santa Marta mountains.

Alta Guajira’s desert trees and woodlands

The Alta Guajira is arid indeed, but it hosts trees, remarkable both in their exuberant diversity and their abundance, considering the high temperatures and meager rainfall. We saw what we consider true desert canopies, such as we have described in other posts. However, no desert flora exists in isolation, and indeed the kinship to the ecosystem type known as Seasonal Dry Tropical Forest (SDTF; see map above) seems to be strong.

The dominant trees of the Guajira are species of Prosopis, Caesalpinia, Vachellia (formerly part of Acacia s.l.), Parkinsonia and other legume genera, accompanied by Bursera, Capparis relatives, Bignoniaceae, and other species common in the dry forests of Central and South America, and 3 kinds of tree cacti (Stenocereus, Pilocereus, and Pereskia), growing close together, often covered in climbing vines. In particular, it was interesting to see bona fide desert woodlands dominated by two well-known legume trees, Prosopis juliflora and Vachellia farnesiana, which are widespread and often strongly invasive in other parts of the world, but not here! Fascinating biogeographical and ecological questions abound in this poorly explored region, many of which are relevant to conservation and restoration.

Regarding  landscape ecology in the region, the vegetation is curiously like a patchwork, alternating between dense desert woodlands, nearly pure tree cacti stands, sometimes with a dense grass cover, and sometimes not, and frequent saline flats where nothing grows. In our opinion, the human element, namely land and resource use history, is paramount to understanding what one sees when travelling here and trying to ‘read’ the landscapes.

Mixed patch of tree cacti and spiny legume trees with a surprising amount of grass understory. Elsewhere under similar stands, for no clear reason, there is no grass cover at all.

A track of the Alta Guajira, near Nazareth, at the base of the Macuira hills where the notorious Prosopis juliflora, known in Colombia as Trupillo, is so exuberant and long-lived it forms a natural tunnel above this track.

Prosopis juliflora colonizes newly exposed beach dunes, in areas where the shoreline is receding. Here, at Camarones, it occurs alongside Calotropis procera, a woody weed of the Apocynaceae known in English as giant milkweed, and familiar throughout the Caribbean islands, the Middle East and drylands of Africa. It survives because of its toxic milky latex where most other plants get eaten out by livestock.

Other standouts are the beautiful Palo de Brasil, Haematoxylum brasiletto, with its unusual fluted trunks and Pereskia guamacho, an enigmatic ‘primitive’ tree cactus with true leaves and one of the most exquisite tasting fruits we know. This is one of the least well-known but most intriguing of all desert trees to our minds.

Typical landscape of the northern Guajira desert woodlands, with an even-aged stand of one of the several neotropical legume trees known as Brazilwood: Haematoxylum brasiletto, or Palo de Brasil in Spanish.

Despite those common names, this species is in fact only found wild along Caribbean coastlines from Colombia and Venezeula, all the way north to both coasts of Mexico. The scientific name is thus a misnomer. The most famous Brazilwood tree is another legume, Paubrasilia echinata (= Caesalpinia echinata) that once grew abundantly along the Atlantic coast of Brazil, as a large tree with a massive trunk, reaching up to 15 meters tall. Today, it’s almost entirely gone in the wild, and mostly planted in gardens and along roadsides. It was prized for the bright red dye obtained from the resin that oozes from cut branches or trunks. The dye was widely used by textile weavers in the Americas and Europe in the 17^th-19^th centuries. The tree also provided the wood of choice for high quality bows for stringed instruments and was widely used for furniture making as well. So important was its economic value that the country was named after it, originally Terra do Brasil (Land of the Brazilwood), later shortened to Brazil. Recently it was designated as sole member of a new genus, as part of a comprehensive revision of the entire genus Caesalpinia, carried out by an international team of experts.

It’s curious that H. brasiletto bears the same common name as P. echinata, since the two trees are nothing alike, apart from their red sap and heartwood. Little literature exists for H. brasiletto, and we are embarking on some detective work to shed some light on this puzzle. We go into detail as these are both relatively fast-growing trees with great economic as well as ecological value. They would both be excellent candidates for inclusion in ecological restoration work and are both in dire need of conservation efforts.

Wayuu: Alta Guajira’s Indigenous People

This desert also hosts a fairly large human population. The Guajira is the home of the Wayuu, Colombia’s largest surviving Indigenous group and, along with the Navajo, one of the last desert-dwelling peoples in the New World. These fiercely independent people, organized in 17 matrilineal clans, were never subjugated by the Spanish, and even today the Guajira region functions mostly in isolation from the rest of the country. As we were heading well off the beaten track, we needed a guide, a 4 x 4 jeep in good condition, and a skilled driver to navigate the meandering and unmarked desert paths.

Despite an ancient history of human presence, and some periods of intensive exploitation and intervention (such as a pearl harvesting boom that took place soon after European explorers arrived), the ecological condition of the region at the landscape scale is remarkably good. Indeed, apart from the salt works in the small town of Manaure, which produce two thirds of Colombia’s salt, and El Cerrejón, South America’s largest open-pit coal mine, in the south of the Guajira, there is no major industry.

Typical traditional salt works at Manaure worked by hand by local men and women just as they have for generations.

And the isolated people who dwell here – fishermen, shepherds, and weavers – are right out of a Gabriel García Márquez story. Indeed the author, most famous for One Hundred Years of Solitude, grew up on Colombia’s northern coast, speaking both Spanish and the Wayuu language, Wayuunaiki. As we traveled deeper into the desert, we traversed small settlements with simple houses made of wood and yards surrounded by tree cacti hedges.

The Wayuu village of Boca de Camarones, in the south of the Guajira peninsula, showing the living hedgerows of columnar cacti produced from tall stanchions. In the background, surrounding the homes, are Trupillos, and good specimens of Dividivi Libidibia coriaria (formerly called Caesalpinia coriaria).

This third caesalpinoid legume tree, closely related to the two Brazilwoods mentioned above, is the source of another lovely red dye, derived in this case from its pods. Until recently, there was an annual festival in Camarones, in honor of this formerly major economic plant product. The tree was also used as an important source of tannins. Like Paubrasilia echinata, it deserves more ethnobotanical and biogeographical studies.

Here, as in many other arid lands, goats and sheep are important for the Wayuu people, as a source of food and social currency. For example bride price during arranged weddings, and gifts for guests attending vigils of important elders and healers, are paid to this day in heads of live goats or sheep. Historically, mules and donkeys were very common as well, but now they are increasingly replaced by motorcycles.

Small children following a flock of desert-hardy sheep in Boca de Camarones. The peaks of the Sierra Nevada de Santa Marta are visible in the background.

Crown jewel of the Alta Guajira

The crown jewel of this desert, its best kept secret, is the Serranía de la Macuira, a small mountain range (serranía meaning “small sierra” in Spanish) in the northeast of the peninsula. This miniature sky island is almost impossibly lush, thanks to moisture-bearing clouds that shroud its upper reaches. They feed streams that flow year-round, and sustain many kinds of trees that grow to well over 10 meters tall.

As one climbs the slopes of the Macuira, the humidity dramatically increases and the parched lowlands, with their desert woodlands, blend perceptibly into a seasonally dry tropical forest reminiscent of those we had seen in Panama. A little-known fact: seasonally dry tropical forests are the most endangered of all tropical forest types, and those in La Guajira are worthy of much greater research, conservation, and restoration.

Climbing higher still, the mid- and upper ranges of the Macuira seem like another world. Most astonishing of all, there is apparently an abrupt transition above 550 meters, and the higher reaches are covered in true cloud forest, with mosses, epiphytic orchids, tree ferns, and dozens of tree species that otherwise occur hundreds of kilometers away! This is probably the only place in the world where cloud forest is found less than 5 km from true desert. Fortunately – from a conservation point of view, but unfortunately for us – the upper peaks of all three peaks of the Macuira are sacred to the Wayuu, and completely off-limits, to native people and visitors alike. Try as we might, we were unable to get permission to hike up there.

Seasonally dry tropical forest on the northeastern facing slope of the Macuira, where precipitation is much higher than in the surrounding lowlands occupied by desert woodlands.

Even though the whole Macuira is officially protected as a national park, the reality is more complicated. While walking inside the park, we encountered recently cut trees, the ubiquitous goats, and even a Wayuu man hunting birds with a slingshot in broad daylight. The beautiful continuous tree canopy covering most of the slopes stands in stark contrast to the severely eroded, nearly bare hilltops, on which stand small Wayuu homesteads. Still, the presence of clear ecotones speaks to mostly healthy landscapes.

The severe erosion around a small Wayuu farm inside the Macuira National Park.

Alta Guajira’s ecological future

The pressures on the Guajira’s ecosystem health include a large mine (El Cerrejón, mentioned above), overgrazing by domestic livestock, and stark poverty facing the native people and more recent immigrants. But there are positive factors as well. There are progressive laws in Colombia related to ecological restoration. Moreover, since 2012, Colombia has a National Restoration and Rehabilitation Plan (pdf), as well as a Law of Remediation, which imposes large environmental offset payments from large-scale development projects (like hydroelectric dams) to underwrite conservation and restoration work. Moreover, the national park system, within its network of 56 protected areas, harbors populations of almost half of the 102 Indigenous peoples in the country, and in the case of Macuira, this is clearly not just a paper park idea.

Still, the national park (25,000 ha in size; officially designated in 1977), operates with a skeleton staff attempting to carry out an ambitious management plan (pdf) despite an insufficient budget. Staff and volunteers provide short tours to day-visitors, and maintain some fenced-off livestock exclosure plots, where they are studying natural regeneration. Daily interaction with the Wayuu living in the park appear to be harmonious, and indeed there is a clear sense that part of the Park’s mission is to restore and protect the Wayuu people’s natural and cultural heritage. Recently, the Instituto Humboldt, Colombia’s stellar national research institute, has established permanent plots in the Macuira range as part of a series of 17 plots including all the tropical dry forest types in Colombia. In the Macuira, this work is done in collaboration with botanists from the Universidad de Antioquia, in Medellin. Furthermore, researchers at Kew, the Smithsonian Institute, and many conservation NGOs are all developing collaborations with the Colombian government to explore and help the country move forward with green development.  The Missouri Botanical Garden also has long-standing MoUs for joint research with 3 different institutions in Colombia, with bright prospects for deepening cooperation in the future.

Like many Indigenous peoples around the world, the Wayuu are at a crossroads. Their language and some of their traditions are still alive and well, but others have already faded. There are few legal sources of income in the harsh desert, the ancestral Wayuu land. How will they manage in the future? What can they do to adapt?  Some, like our guide, José Luis, are trying to change mentalities, but they clearly need more help.  As throughout Colombia, there is clear and urgent need to build on the alpha-level studies already underway, and move onto applied ecology, agroforestry and land management programs, including community-based restoration programs and ecotourism in conjunction with the national parks.

Our Wayuu guide José Luis Pushaina Epiayu (on the right) and Macuira park ranger Ricardo Brito Baez-Uriana (on the left), talking about birds with a local Wayuu family.

Cactus conservation and restoration of arid environments in Central Mexico

En route to attending the 4th meeting of the Ecological Restoration Alliance of Botanic Gardens Conservation International, in Xalapa, Veracruz, Mexico, James Aronson stopped off to visit Beatriz Maruri Aguilar, a recent Bascom Fellowship recipient who works as Scientific Research Coordinator at the Cadereyta Regional Botanic Garden, and her colleagues, Director Emiliano Sanchez Martinez, and Research assistants Hailen Ugalde de la Cruz and Hugo Altamirano Vázquez in Cadereyta de Montes, Queretaro, north of Mexico City. Beatriz and Hailen describe the Garden’s work conserving an endangered, endemic cactus, and an innovative restoration project.

Main entrance to Cadereyta Regional Botanic Garden

Cadereyta de Montes is close to the southern end of the Chihuahuan Desert, in the semiarid zone of Queretaro and Hidalgo. The place is relevant for biodiversity because of its number of endemic arid plants. However, today some habitats have been definitively altered and several special plants are on the brink of extinction.

One of those emblematic species, popular among succulent plant collectors around the world, is under severe threat to its survival. Worldwide growing successfully in cultivation, Mammillaria herrerae Werderm. is facing tough conditions and could eventually disappear from its original habitat. Scientists from the Cadereyta Regional Botanic Garden have done a survey which indicates that there are only a few hundred individuals remaining in the wild, that the species shows very low recruitment by seed, and that seedlings grow on rocky substrates beneath nurse plants.

Expedition day: James and Beatriz descend the slopes where Mammillaria herrerae lives. Photo by Hailen Ugalde de la Cruz.

Observing the remaining individuals is a shocking experience that moves to reflection.

They look small and fragile, but these geometric, almost spherical, plants are a beautiful example of the precision of nature, which gives each organism the characteristics it requires to survive in its natural habitat.

The beautiful Mammillaria herrerae Werderm., also known as “golf ball cactus” or “bolita de hilo” (small ball of thread). Photo by Beatriz Maruri Aguilar.

Densely covered with white spines and half-buried in the rock, Mammillaria herrerae hides its presence in the limestone soil. Its densely-distributed spines also help harvest fog at this elevation, where atmospheric moisture can condense. In an arid region like central Mexico, such adaptations provide species with strategies to reach the vital element.

A small group of Mammillaria herrerae struggle to persist on the steep slope. Photo by Hailen Ugalde de la Cruz.

Their permanence wouldn’t be menaced, but infrastructure development has reached them.

The pipes of the “Acueducto II” Hydraulic system climb more than 1200 meters to reach an elevated point from which it carries water by gravity to Queretaro City. Photo by Beatriz Maruri Aguilar.

In such a challenging environment, the construction of this infrastructure has severely damaged the landscape where Mammillaria herrerae lives. Photo by Beatriz Maruri Aguilar.

As the aqueduct was constructed over several years, several efforts were conducted to relocate bigger native plants. Photo by Hailen Ugalde de la Cruz.

Efforts will continue. The Cadereyta Regional Botanic Garden team will conduct a 2-year demographic study, study the floral biology of the species, and describe plant community biodiversity at the specific distribution points. Stock propagation at the Garden will continue. The path is being prepared to, one day, return these jewels to their place in their natural environment, and to protect them better in situ.

Hailen Ugalde (left), Hugo Altamirano (center), and Beatriz Maruri (right), the staff of the Cadereyta Regional Botanic Garden, visit a remnant population of Mammillaria herrerae . Photos by James Aronson (left) and Hailen Ugalde de la Cruz (right).

The landscape around M. herrerae’s natural habitat. The mountain in the background is the southern facies of the Sierra del Doctor, part of the Sierra Madre Oriental. Photo by Hailen Ugalde de la Cruz.

Some of the globose companions of Mammillaria herrerae Werderm. Left: Astrophytum ornatum (DC.) Britton & Rose; Right: Mammillaria parkinsonii Ehreb. Photos by Hailen Ugalde de la Cruz.

“An unusual model of assisted ecological restoration”

At first sight, the arid scenery of the surroundings of the small city of Cadereyta, in Queretaro, Central Mexico, could transport us to past times.

Panoramic view from Cadereyta de Montes, and the ancient flavor of the streets. Photos by José Belem Hernández Díaz.

However, this semi-urban and semi-rural zone combines the features of ancient Mexican villages and landscapes with the unmistakable signs of the transformation that progress usually brings.

The peripheral landscape of Cadereyta de Montes (14,000 inhabitants) is showing signs of transformation. The urban area is gradually displacing the agricultural parcels and the native flora, giving rise to an interface formed of irregular patches that combine new houses and small agricultural parcels. A third type of ground, neither agricultural nor urban, is also present. This type of land is isolated from wild and agricultural areas, and can degrade easily.

The polygon of the Cadereyta Regional Botanic Garden, highlighted in yellow, in the vicinity of Cadereyta de Montes. Map prepared by Beatriz Maruri Aguilar.

In additional to its formal collections and buildings, the Cadereyta Regional Botanical Garden maintains an area that exemplifies the conditions found in much of the surrounding semi-arid region. Xerophytic shrub-dominated matorral is the main vegetation type which is generally highly degraded by human activities over the last decades, and surviving remnants in good ecological condition are only found quite isolated from agricultural areas. The vegetation comprises an interesting assemblage of native species in the Asteraceae, Poaceae, Solanaceae, Verbenaceae, Euphorbiaceae, Cactaceae, Fabaceae and other families, many of which are struggling to survive within large patches of invasive grasses.

A view from the top: looking down at degraded land to be managed by the Botanic Garden. Photo by Hailen Ugalde de la Cruz.

Another view from the top: Hugo, Beatriz, and James observe the transformed landscape of Cadereyta de Montes from one of the Garden’s balconies. Photo by Hailen Ugalde de la Cruz.

In this area, the Botanic Garden is working on restoration models that will be of interest – and direct use – to local landowners. It is an unusual model of assisted ecological restoration, with an agroforestry approach. The core idea is that through the implementation and monitoring of native vegetation and economic plant mosaics, it should be possible to combine conservation of biodiversity, sustainable development for small farms, and ecological restoration of degraded lands.

The pilot project will have two different types of parcels for comparative and demonstration purposes. One type will be built following an ecological approach to restoration, using only native plant species; the other will have an agroforestry approach, combining a group of native species with some selected edible/useful species. The area of the plots where the two strategies will be implemented will be prepared by removing an invasive species of grass (Melinis repens Willd. (Zizka), or “pink grass”). The agroforestry model will also generate useful products, such as agave leaves, which are used in the region for several purposes including to make pulque – an ancient beverage made by the fermentation of the agave sap, highly popular in this region. This model will also include aromatic plants – such as the asters Matricaria chamomilla L. and Calendula officinalis L. and the mint Salvia sp., as well as other useful plants as the euphorb Jatropha dioica Sessé, “sangregado”, commonly used as an ingredient in shampoos and formulas against gray hair.  These human uses are valuable in areas like this, where some human populations are suffering from an elevated degree of marginalization. The Cadereyta Regional Botanical Garden has developed propagation protocols of native species, and part of the stock produced will be used in the model described.

Some of the stock of native species produced at the Cadereyta Regional Botanic Garden. Photos by Beatriz Maruri Aguilar (top) and Hugo Guadalupe Altamirano Vázquez (bottom).

At Cadereyta de Montes, some areas need a helping hand to keep the landscape in good shape. Other places hide extremely valuable living treasures that are currently struggling for survival. The Cadereyta Regional Botanic Garden is working every day to contribute to the conservation of the highly remarkable flora of the southern end of the Chihuahuan Desert, as well as to offer sustainable solutions for landscape use in a transforming environment. This way, the Garden intends to become an active participant for the achievement of Mexico’s goals for plant conservation.

South Africa 3 | Town and country: aiming for ecological restoration at the landscape scale

James and Thibaud Aronson offer their third photo essay from South Africa, highlighting FOSTER, a dramatically successful community-based restoration program in the Eastern Cape, aimed at eradicating an invasive Australian acacia, and reducing urban wildfire risk, and a private restoration program at Kaboega Farm, situated in a megadiverse landscape of extraordinary conservation and educational value.

The Republic of South Africa is rightly famous for its 22-year old Working for Water program, WfW, and offshoots such as Working for Wetlands. These government-funded programs aim at restoring both natural and social capital, which are clearly the wave and the way of the future. They are also increasingly working with NGO implementers, private companies, and landowners in the Karoo, as we highlighted in two earlier posts (here and here). Teams, partnerships, and networks are essential here, given the complexity of the landscapes – both biophysical and political.

To close our trip in South Africa, we traveled to Cape Saint Francis, on the coast of the Eastern Cape, where our friends Richard Cowling and Shirley Pierce, who have lived there for more than 20 years, long ago founded a restoration project they dubbed FOSTER (short for Friends of the St Francis Nature Areas).

Richard, a top academic, communicator, and world expert on the ecology, biodiversity, and landscapes of South Africa has also worked closely with the WfW government programs elsewhere in the country, not only in the fynbos (the mega-diverse shrublands of the mediterranean-type climate region of the Cape) but also the karoo and subtropical thicket (on which, more below).

Richard Cowling and Shirley Pierce-Cowling in their adopted habitat, St Francis Bay. 2013.  

In and around Cape St Francis, and St Francis Bay, one of the main issue is Acacia cyclops (known in South Africa as rooikrans), one of many fast-growing acacias intentionally introduced from Australia 150 years ago for sand dune stabilization.

In 1994, Richard and Shirley took up the challenge of developing a conservation plan and implementation strategy for consolidating 230 ha of municipal land and existing protected areas into a network that would sustain – among other things – faunal movement. More than 50% of this was densely invaded with rooikrans; only 38 ha was officially proclaimed a nature reserve. It was a slow process. Rooikrans grows quicker and taller than the native plants. But they had a very strong motivation. Indeed, “as a result of its greater biomass and more flammable foliage, rooikrans increases fire hazard by several fold relative to uninvaded fynbos” says Richard.

Over 20 years, they achieved near total success in removal of seed-bearing alien plants through the generous funding from the World Wide Fund (WWF) and residents’ donations, but only on the 132 hectares of public lands where they could work, often with the enthusiastic help of school groups and volunteers who learned much along the way.

FOSTER restoration workers conducting follow-up removal of the alien invasive rooikrans, Acacia cyclops, in the Cape St Francis nature reserve. Photo. R.M. Cowling.

A learner from a local school enjoying the leaves of Brunsvigia gregaria (Amaryllidaceae) during an excursion organized by FOSTER. Photo. R.M. Cowling.

 

 

Brunsvigia gregaria in bloom; this species is popularly known as candelabra flower.  Cape St Francis, Apr 7, 2016.

But there were hundreds of hectares more to clear, both on public and private lands around the town. Then, in late 2012, a fire swept through, leaving severe damage and a wake-up call.

By that time, WfW was ready to help with restoration on private lands, provided that landowners contributed to the effort. The help from WfW and others much expanded FOSTER’s reach, and in only four years, some 1000 hectares of rooikrans were cleared from private lands in the area.

This of course dramatically reduced the township’s vulnerability to wildfire damage. As proof, when another massive wildfire swept through the area in January 2016, only three houses were destroyed. Notably, all three belonged to owners who had refused access to WfW workers seeking to eradicate rooikrans.

Other communities along the coast have taken notice and hopefully will follow the example of Cape St Francis.

Second landscape example: Kaboega farm

Finally, following Richard’s advice we drove two hours inland from Port Elisabeth, not too far from St Francis Bay, to visit a truly remarkable place where four different ecosystem types meet and intermingle in a property of only 6550 hectares: 1) fynbos, 2) the karoo desert, here at its southernmost limit, 3) the northernmost temperate rain forest fragments of the South East, of which the only important remnants are found in the Knysna region, and 4) subtropical thickets.

Outenieqwa-geelhout, or small-leaved yellowwood, Podocarpus falcatus. Outstanding specimen of the relict population growing near a perennial stream at Kaboega Farm.

What South Africans call subtropical thickets are in fact a remarkable tapestry of vegetation types, with as many as 116 distinct variants (Cowling et al. 2005). Of particular interest here is the so-called spekboom-dominated thicket, characterized by the spekboom (Portulacaria afra).

Fully mature spekboom, one of the largest individuals known

Spekboom-dominated thicket once flourished on approximately 1.4 million hectares (3.46 million acres), but today it occupies barely one-seventh of its former area. “The remainder has been degraded by over-exploitation, mainly through injudicious farming with angora goats……” (see the report Investing in Sustainability). However, spekboom is an extremely hardy succulent tree, remarkably fast-growing and readily propagated from cuttings, or even large stancheons.

This makes it attractive for large-scale restoration work. Indeed, it has been the focus of much attention from Working for Woodlands, another member of the Working-for family of government restoration programs. The manager and co-owners of Kaboega Farm, Ian and Sandra Ritchie, stopped all agricultural activity on their land 20 years ago, to allow the land to recover from an estimated 135 years of over-grazing by small livestock. They live instead by hosting visitors, including succulent plant lovers, drawn to this hotspot of Haworthias, and university groups led by Richard Cowling. Among other recent discoveries, Cowling and co-workers have shown that subtle difference in community-level frost tolerance can determine the boundaries between tightly packed biomes at Kaboega, where diversity is sky-high despite an average rainfall of just 300 mm per annum and frequent, extreme droughts.

Spekboom cuttings struggling to get going

Furthermore, Ian and Sandra Ritchie are attempting to restore swathes of spekboom thicket at strategic spots on their farm, as a part of an ambitious large-scale program with support of Working for Woodlands.

They plant spekboom cuttings, which over time create an enhanced micro-environment in an otherwise harsh and difficult environment for young plants, and thus try to kick-start the regeneration of the habitat, biological community, and ecosystem. Furthermore, spekboom traps large amounts of CO₂, and the general hope is that carbon credits can help finance large-scale restoration in the future. In the meantime, this is a remarkably attractive destination for nature-lovers.  In addition to the flora and landscapes, giraffe, kudu, and other game are added and allowed to roam free for the pleasure of visitors (and the owners). When numbers grow too high, however, there is a risk of exceeding carrying capacity, and some animals are captured for resale to other land-owners. This provides an additional income flow as game ranching linked to tourism and recreational hunting is increasingly popular in the region.

Portion of a thriving population of 28 South African giraffe or Cape giraffe (Giraffa giraffa giraffa) at Kaboega Farm. While some argue that giraffes are not native to the area, nearby millennial cave paintings indicate the contrary.

At this remarkable farm, science-based conservation and restoration are making progress in an attempt to enhance biodiversity conservation, tourism revenues, and ecosystem services of all kinds. Clearly, spekboom planting is not an all-in-one solution; for jumpstarting restoration and assisting regeneration in a complex landscape and land tenure situation like this one, where temperate forests, fynbos, thicket, and karoo shrublands all occur and interact, a landscape perspective on the challenges of ecological restoration is essential. We’ll be posting more on this challenge in the future.

South Africa 2. Toward a Restoration Culture? Good news from the Karoo

In this 4^th post from southern Africa, James and Thibaud Aronson report on a pioneering, science-based restoration project, the associated private restoration company, and also a nature reserve, all founded by one pair of scientists in Prince Albert, Western Cape province, South Africa.

Last October, posting from SW Australia, we reported on Gondwana Link and some of the activities of the Australasia chapter of SER. These are just two of the thousands of independent non-governmental groups of people working for joint environmental and social change around the world, as celebrated in Blessed Unrest, Paul Hawken’s 2007 best-selling book dedicated to the “unnamed movement” to reimagine our relationship to the environment and one another. After a year and a half researching our book on arid and semi-arid land trees, and ecological restoration projects and programs in the world’s drylands, we still like our name for that “unnamed movement” Hawken referred to, namely a restoration culture for the 21^st century.

Opportunities for grassroots or combined bottom-up – top-down efforts and synergies abound in South Africa, with its outstanding research, technology, and capacity-building from academics, think tanks, not-for-profit organizations, and small companies offering restoration services and counsel. In our last post, we described a few Working for Wetlands programs and the participation of SAN Parks (the body that governs South African national parks) developing new ways to restore natural capital and social capital at the same time. Here we move to the vast central drylands of southern Africa, known very broadly as the Karoo.

As compared to other inland arid regions, landscape complexity here is enormous and, remarkably, ecotones, a.k.a. frontier zones are largely visible, if not intact.

A klipspringer (Oreotragus oreotragus) in the Swartberg, near Prince Albert. This small antelope, which occurs throughout much of sub-Saharan Africa, is unusual in that it walks on the tips of its hooves, an adaptation to its rocky habitat.

This huge inland semi-desert has at least four sub-regions, and borders to the southeast an archipelago of more than 100 recognized types of subtropical thicket, a plant formation forming a key transition zone, in ecological and evolutionary terms, intermediate between forest and savanna. According to plant ecologist Prof. Sue Milton and ornithologist Dr. Richard Dean,  the archeological and historical evidence indicate that the Karoo has been largely treeless for millennia. Trees are mostly prevented from growing in the Karoo, not only by the aridity (<200 mm precip./year), but also by shallow soils and cold winter temperatures. The Karoo was prehistorically grazed by nomadic ungulates that were hunted by hunter-gathers (San or Bushmen) and by transhumant pastoralists – the Khoe-khoe. Yet, a huge change came about when European colonization in the 18^th century brought wire fencing, deep drilling and wind pumps for extracting underground water. As Sue and Richard put it, “combined with a large demand for wool in Europe, this led to a boom in sheep farming and the development of rural villages, mostly dependent on ground-water.”

 

Southern African biomes, highlighting the large extent of the Karoo (yellow & brown), and the two sites we visited: Prince Albert and the Plains of Camdeboo. Modified from: http://www.plantzafrica.com/vegetation/vegimages/biomes800.jpg 

We traveled to Prince Albert, a small town in the Karoo, where we met up with our old friends and colleagues Sue Milton and Richard Dean, who are the co-owners of Renu-Karoo Veld Restoration and founders of the Wolwekraal Conservation and Research Organization, a unique research site Sue and Richard acquired in 2007, very near the edge of this isolated town. After nearly 40 years of hard work as international researchers and teachers, Sue and Richard decided to focus their considerable energy for the remainder of their careers to their town, and a community-based restoration and revitalization program for the Karoo. Unlike many NGOs in the “restoration movement” theirs is firmly grounded in science. Prior to launching Renu-Karoo, when they first moved to Price Albert, they continued teaching part-time in Cape Town – a full day’s drive away, and ran the Tierberg Karoo Research Station, a long-term ecological research site nearby, for many years. They have also written or edited the major ecological textbooks on the Karoo, both for basic researchers and managers. And indeed, it is a complex area in need of serious restoration work.

The plant nursery is a key component for all of Renu-Karoo’s activities, producing indigenous Karoo plants and plugs for landscaping and restoration. Availability of indigenous plants in the village has also gradually led to increased popularity of water-wise gardening and to an awareness of local plant diversity.

Sue Milton and Richard Dean surrounded by native and ornamental plants at the Renu-Karoo nursery.

One of the nursery’s 10 employees beginning the day with a round of watering.

As Sue and Richard explain:

“……the vast plains of the Karoo, the wooded drainage lines, the ancient gnarled trees of the dunes and mountains, and the elusive wildlife have been damaged by poor agricultural practices. The area is also currently threatened by development of solar and wind energy generation facilities, and uranium and gas mines that could convert the quiet Karoo into the ‘power factory’ of South Africa. A combination of conservation, education, and continuous active rehabilitation will be needed to enable future generations of people to benefit economically as well as recreationally and scientifically from this rocky and glorious desert landscape.”

When Sue and Richard established Renu-Karoo a decade ago, their goal was to grow and supply Karoo shrub and grass seeds and to provide consulting services on how to re-establish or “repair” Karoo vegetation. Through trial and error, research by students and interns, collaboration with other companies and not-for-profit organizations, and follow-up surveys of restoration and rehabilitation projects, they have produced valuable knowledge, made available both informally and in scientific publications. Additional services, such as contract growing of plugs and plants of never-before propagated veld (the South African name for the sparsely vegetated landscapes typical of the Karoo) plants have added to the interest and capabilities of the business. They also provide free environmental classes and natural history talks and walks to school children and adults. They are truly global citizens working locally to build a Restoration culture in their home, the Karoo.

As part of their work to advance the movement, and raise the bar in restoration and management work, Sue and Richard’s consulting work takes them to businesses and private farms throughout the Karoo. From Prince Albert, we traveled north- east, to visit one such place, the Plains of Camdeboo Nature Reserve, a privately-owned property on the edge of the Karoo.

A male vervet monkey (Chlorocebus pygerythrus) feeding in an Acacia, at Camdeboo National Park.

This nearly 9000-ha property once encompassed three game farms, which were severely overgrazed for a century, if not more. The properties were acquired by Vincent Mai, a South African who lives and works in New York City, and his wife Anne. They wanted to help preserve a piece of the Karoo where Vincent had grown up.

As it was clear that overgrazing in the past had seriously damaged the land, a South African conservation organization, the Wilderness Foundation, was invited to help. For the past six years, this foundation has been carrying out restoration work on the reserve. Their main focus is on eroded and impoverished soils, and they have undertaken a range of approaches, from grazing native Zulu cattle, to using agave stems and hay to block erosion gullies. A number of mammal species were also reintroduced. Angus Tanner, the indefatigable manager, showed us the range of their work on the reserve. Money and manpower is limited, and there are still many obstacles, but they are making great strides. They rely on Renu-Karoo for advice and seeds and technical advice. They are also reaching out to cooperate with the nearby township and their neighbors. Stitch by stitch, and farm by farm, the restoration culture is spreading in the Karoo.

Traditional Zulu cattle in the Plains of Camdeboo Nature Reserve. They both break up compacted soil and fertilize it as the managers move them around the property.

Two adjacent erosion gullies at the Plains of Camdeboo. The one on the right was plugged with a fence gabion and agave stems, in order to slow water flow and trap sediments. The gully on the left was not treated. A year later the difference between the two speaks for itself.

South Africa 1. Restoring natural and social capital in Namaqualand

James and Thibaud Aronson post the third of four photo essays on their recent field trip to Namibia and South Africa.

As soon as we crossed over the border from southern Namibia into northwestern South Africa, it was clear that we were looking at a whole different story. We were now in the driest part of South Africa and one of the most sparsely populated. Also, Namaqualand – a winter-rainfall desert of ca. 50,000 km² – is one of the biodiversity hotspots of the world. The area is well known to tourists for the few weeks in August-September (the southern winter), when hundreds of plant species, benefiting from the winter rains, put on an incredible floral display and tapestry of textures and colors, down below your ankles.

A rich community of toe-high succulents endemic to saline quartz patches . This photo was taken at Douse The Glim, not far south of Garies in southern Namaqualand. Many endemics of the Mesembs (Mesembryanthemaceae) occur here, including the sunken “Silver skin”, Argyroderma delaetii,  Cephalophyllum spissum, and “Redbeads”, Sarcocornia xerophila, a cousin of the cosmopolitan Salicornias. Identification of plants: Sue Milton and Richard Cowling, both of whom we will meet in the next blog post.

 

 

Argyroderma delaetii, a dwarf, sunken ‘silver skin’, of a genus restricted to the Western Cape, South Africa, in the Knersvlakte Nature Reserve . This photo was taken by Sue Milton in 2014, a much wetter year  than 2016.

All in all, apart from natural history buffs, botanists, and conservationists, not much attention is paid to this poor, rural area. In a nutshell, the rapidly exploitable resources that could be had – copper, timber, and the like – are now long gone. What is left is – to speak bluntly – a lot of poverty and a lot of land degradation. And a lot of biodiversity: indeed the Succulent Karoo region of Namaqualand and southern Namibia is one of the biodiversity hotspots of the world.

We met with some of the people making a difference there, working with South Africa’s most iconic environmental program, the Working for-family of government-funded programs, working together to restore natural capital and social capital at the same time.

Sheep grazing on  abandoned crop land in Namaqualand, near Leliefontein.

The Western Cape, South Africa has had a tradition of rather damaging sheep farming for centuries. But the country as a whole has also had a proud tradition of nature conservation for over a century, which is a lot more than most countries can boast.

However, what is  even rarer is that ecological restoration has been part of the national vocabulary for a generation. A game-changing initiative that moved the country to the next level was a government program launched in 1995, called Working for Water, or WfW.

South Africa was faced with two metaphorical birds. On the one hand, approximately half of its population lived (and unfortunately still does) in poverty. On the other, several invasive non-native tree species had taken over many of the country’s waterways, outcompeting native species, choking river beds, and draining the water tables.

Working for Water was the stone. Every year it hires some of the country’s poorest people –  38,000 in 2015 –  in rural areas in all nine provinces and employs them to remove those noxious woody species. Since its inception, the program has spent hundreds of millions of dollars and provided desirable jobs near home each year. The benefits to people are in fact multiple. Workers are provided with both an income and on-the-job training and capacity-building, with some going on to start their own companies, providing ecological restoration services to private landowners. They also acquire an esprit de corps  and pride in their achievements.

With the same ‘stone’, over 2 million hectares, mostly along water courses, have been cleared of invasive trees and water supply has been notably increased for the associated communities. Finally, the large amounts of timber and vegetable biomass harvested from the invasive trees are used to produce eco-furniture, which is then sold to help finance the program. Research is under way to find methods for producing biofuel from the woody weeds as well as to improve the ecological impact of the effort.

The small town of Garies, southern Namaqualand. The riverbed is completely dry, but there is enough moisture in the soil to support what may look like natural riparian vegetation. In fact, not a single tree is native. Instead they are Mesquites (Prosopis hybrids) from South America, Salt cedars (Tamarix hybrids), and Australian Wattles (Acacia karroo,  A. cyclops).

The Australian wattle (Acacia cyclops), one of the worst invasive trees in various habitat types in South Africa.

WfW now oversees over 300 projects across South Africa, and its success has led to the establishment by successive government administrations of several other programs, such as Working on Fire, Working for Wetlands, and Working for Woodlands. The goals are ambitious and together this ‘family’ of Working for- programs exemplifies the emerging understanding that ecological restoration can be a bridge-builder between long-term conservation efforts, and sustainable socio-economic development goals. At a time when protected areas are menaced worldwide by dubious government cop-outs on protected areas, South Africa is a refreshing exception that deserves praise and celebration.

Thanks to introductions set up by our friend Dr. Christo Marais, the number 2 man of WfW, we had a chance to talk to Ronnie Newman, Amanda Bourne, and Halycone Muller from Conservation South Africa (CSA), who work in Namaqualand on restoration projects, in close liaison with SAN Parks (the body that governs South African national parks), and through financing of Working for Wetlands.

From left to right, Amanda Bourne, Ronnie Newman, and Halcyone Muller at CSA offices in Springbok.

SAN Parks and CSA use funding from a new programme under WFW called Land User Incentive Programme, to hire people to restore degraded rangelands.  CSA and SAN Parks are thus implementing agents for Working for Wetlands in this arrangement, something new in the history of the Working for- programs. The focus of this trio here in Namaqualand is to repair erosion gullies, called “dongas” in southern Africa. These are very often a result of over-stocking and overgrazing by domestic livestock and get continually worse if left unattended. Thanks to this government-funded effort,  workers build beautiful gabions and other structures to slow water flowing downhill, catch sediments and eventually fill the gullies. Most of the gabions are made with metal baskets, or simply dry stones carefully assembled by skilled workers to make low but sturdy walls. However, in some cases, larger gabions are made out of concrete. As Amanda Bourne put it,  “this is about supporting the people who live and work on the land to restore and better manage it.  They are paid at a supplementary rate to undertake restoration on their own land, which will directly benefit their other (mostly agricultural but not only) activities.”

Working for Wetlands workers building a series of stone retaining walls, near Kamieskroon. In small rivulets like this one the metal baskets of typical gabions are not easy to use and are not deemed cost-effective.

A week later, in Cape Town, we met up with Christo Marais, and with Sarah Frazee, the head of CSA. She told us that they aim at working at critical spots upstream of water points of importance to local communities whose livelihoods are largely dependent on sheep grazing. CSA also provides veterinary services at no cost to participating farmers, and tries to persuade them to reduce their herds and flocks to avoid over-stocking, especially in drought years like the current one. As Sarah put it, 80% of the biodiversity in Namaqualand is associated with wetlands, which makes focusing on their restoration important from a conservation perspective. But, as more broadly throughout South Africa, public-private efforts like this one can effectively address biodiversity, water supply, land erosion, as well as poverty and related social issues at the same time.

From a classical economics perspective, however, ecological restoration work in arid lands is slow, and often hard to justify, since the value of the land for production purposes is so low. However, not just here in the Western Cape, but throughout South Africa, the multiple goals of the Working for- program are being pushed forward and steadily refined.

There has been frequent criticism of the programs and not without cause. In particular, monitoring has not been implemented as well as could have been hoped, though the program has continually improved since its inception, both scientifically and in terms of its impact on ecosystems and people. It will be a long battle to achieve all of its goals, but despite its flaws, it remains one of the absolute best examples worldwide of programs that combine restoration of social and natural capital.

Six months after the building of the stone walls near Lileifontein, complemented by brushpacking to help build up organic matter, things are looking pretty good.

We close with a mention of the fabled triple bottom line – the holy grail of progressive governments. How to achieve social, ecological, and economic benefits with a single program? Next steps in improving the work of the Working for- programs, according to  Christo Marais, should include: 1) still greater investments in education, capacity-building and outreach to bring all of South Africa’s society on board with the restoration movement, and 2) galvanizing private investment in restoration. The introduction of implementing agencies like SAN Parks and CSA should help with both.

In our next two blogposts, we will report on what some private landowners and three wonderful NGOs, including RENU KARROO and F.O.S.T.E.R. are doing in the Nama Karroo and Thickets biomes.