Special Feature: Ecological Restoration in a Changing Biosphere

The following is an introduction by Leighton Reid and James Aronson to a special feature in Annals of Missouri Botanical Garden about ecological restoration in a changing biosphere. The eight papers described are derived from presentations last October at the 65th Annual Plant Symposium. The full issue can be found here.

Restoration efforts will affect large areas of the planet and hundreds of millions of people over the coming decades, but what will these actions look like, and what will they achieve? Debate continues about what constitutes appropriate restoration targets in our human-dominated and ever more rapidly changing world, and the outcome of this debate will impact the actions taken to conserve biodiversity, sequester carbon, and improve human livelihoods at large spatial scales. This special issue brings together eight scientific, historical, and journalistic perspectives to address these two critical questions about ecological restoration in a rapidly changing biosphere.

In the post-COP22 world, when all three of the UN’s “Rio Conventions” call for scaling up and mainstreaming of ecological restoration (UNCBD 2012; UNCCD 2015; UNFCCC 2015), and dozens of governments have made ambitious restoration commitments (IUCN 2016), it is clear that restoration programs will affect hundreds of millions of hectares – and as many people – over the coming decades. At the same time, we find ourselves in an era of unprecedented change where climate, ecological baselines, and future land-use changes are highly uncertain (Steffen et al., 2015). This raises the crucial question: What will large-scale restoration activities look like in the coming years?

Unsurprisingly, there are differences of opinion about the future of restoration and how to scale it up and integrate it with larger programs in an era of major, anthropogenic changes. Hobbs et al. (2011; pg 442) observe that “…the basic principles and tenets of restoration ecology and conservation biology are being debated and reshaped. Escalating global change is resulting in widespread no-analogue environments and novel ecosystems that render traditional goals unachievable. Policymakers and the general public, however, have embraced restoration without an understanding of its limitations, which has led to perverse policy outcomes.” [Emphasis added]

This perspective has received considerable attention (ESA 2016) and also pointed criticism (Murcia et al., 2014). Aronson et al. (2014; pg 647) retort that “…Restoration includes a wide range of practical possibilities for dealing with transformed ecosystems, including rehabilitation, reclamation, and remediation. Some will bring the ecosystem back to its historical trajectory, some will bring back only some attributes, but the intention is that the end product is better than the degraded ecosystem. Importantly, a label such as novel ecosystem implies no need for further intellectual exertion – and ignores the growing science of the young discipline of ecological restoration.” [Emphasis added]

The debate goes on about what we are trying to restore (Hobbs, 2016; Kattan et al., 2016; Miller & Bestelmeyer, 2016), with implications far beyond academia. Billions of dollars are now being spent to rehabilitate and restore degraded ecosystems, sometimes at large scales, and the science of restoration ecology must adapt to be integrated in larger planning and management schemes, wherein conservation, management, and restoration will all take place.

On 8 Oct 2016, we convened a panel of six scientists, one historian, and a journalist, all with long-standing involvement in the field of restoration ecology. The goal was to discuss ecological restoration in a changing biosphere at the 63rd Annual Fall Symposium at Missouri Botanical Garden. Each speaker has contributed a paper to this special issue.

The first set of papers focus on the question: Has global change outpaced and rendered obsolete the so-called “classical” ecological restoration approach? Aronson et al. (2017) say no, far from it; for example, the historically-based reference system ‒ a pillar of ecological restoration to date ‒ is more valid than ever and can indeed be adapted to landscape and higher levels of complexity. They emphasize that while restoration ecology has produced many useful ecological models, a participatory approach and consensus-building among stakeholders are crucial at these higher levels of integration. Falk (2017), in contrast, says yes: global change calls for radical rethinking of ecological restoration. He focuses on ponderosa pine forests in the southwestern US, which are undergoing a major, climate change-induced biome shift from forest to shrub land, and he concludes that a shift towards resilience-based management is necessary to supplement traditional ecological restoration. Meine (2017) takes the middle ground through an historical analysis; he notes that Aldo Leopold (1887-1948) would likely have concluded that a simple “yes” or “no” was inappropriate and that ecological novelty is neither novel nor absolute.

Whereas the first group of papers asks what we should restore, the second group focuses more on how we will restore at larger spatial and temporal scales. Brancalion & van Melis (2017) suggest that to bridge the gap between science and practice, we need to innovate; rather than refining current approaches, restoration ecologists must look outside of their disciplinary silos for fresh solutions to contemporary dilemmas. One source of new insights will be through joint research between scientists and practitioners. To this end, Holl (2017) presents several new directions for tropical forest restoration research (graduate students – take note!). She emphasizes that for research to best inform practice, it should be conducted at large spatial and temporal scales, research projects should be undertaken jointly with stakeholders, and resulting knowledge should be shared across regions. Chazdon (2017) argues that natural regeneration, more than any other method, is the key for scaling up to efficient forest and landscape restoration, and she emphasizes the need to identify priority areas where natural regeneration is maximally feasible and minimally competitive with alternative land uses. Finally, Reid et al. (2017) argue that however we restore ecosystems, we should plan to make them last; the longevity of restored ecosystems, they suggest, is variable, often finite, and determined to some degree by stakeholder preferences, environmental attributes, and the umbrella of governance. These papers emphasize tropical forest restoration, particularly in Latin America, which is appropriate given this biome’s global importance, yet the topics addressed will be of interest to readers with experience in many ecosystems.

The last word (for this special issue, at least) is left to Paddy Woodworth (2017), an international journalist with broad and optimistic perspectives on ecological restoration (Woodworth, 2013). Looking across the contributions, he observes that the words we choose have meaning and cautions against the use of the word “restoration” for anything less than the process of assisting the recovery of an ecosystem that has been degraded, damaged, or destroyed (SER 2004).

We hope that readers from many backgrounds, including researchers, practitioners, and policymakers, will find this special issue worth pondering as they move forward with our collective task to progress towards a more sustainable, just, and desirable future.

 

References

Aronson, J., J. Blignaut & T. B. Aronson. 2017. Conceptual frameworks and references for landscape-scale restoration: Reflecting back and looking forward. Annals of the Missouri Botanical Garden 102(2): 188–200.

Aronson, J., C. Murcia, G. H. Kattan, D. Moreno-Mateos, K. Dixon & D. Simberloff. 2014. The road to confusion is paved with novel ecosystem labels: a reply to Hobbs et al. Trends in Ecology & Evolution 29: 646-647.

Brancalion, P. H. S. & J. van Melis. 2017. On the need for innovation in ecological restoration. Annals of the Missouri Botanical Garden. 102(2): 227–236.

Chazdon, R. L. 2017. Landscape restoration, natural regeneration, and the forests of the future. Annals of the Missouri Botanical Garden. 102(2): 251–257.

ESA (Ecological Society of America). 2016. Ecological Society of America announces 2016 award recipients. The Bulletin of the Ecological Society of America 97: 337-351.

Falk, D. A. 2017. Restoration ecology and the axes of change. Annals of the Missouri Botanical Garden. 102(2): 201–216.

Hobbs, R. J. 2016. Degraded or just different? Perceptions and value judgements in restoration decisions. Restoration Ecology. doi: 10.1111/rec.12336.

Hobbs, R. J., L. M. Hallett, P. R. Ehrlich & H. A. Mooney. 2011. Intervention ecology: Applying ecological science in the Twenty-first Century. Bioscience 61: 442-450.

Holl, K. D. 2017. Research directions in tropical forest restoration. Annals of the Missouri Botanical Garden. 102(2): 237–250.

IUCN (International Union for Nature Conservation). 2016. Bonn Challenge commitments. http://www.bonnchallenge.org/commitments. Date accessed: September 22, 2016

Kattan, G. H., J. Aronson & C. Murcia. 2016. Does the novel ecosystem concept provide a framework for practical applications and a path forward? A reply to Miller and Bestelmeyer. Restoration Ecology 24:714-716.

Meine, C. 2017. Restoration and “novel ecosystems”: Priority or paradox? Annals of the Missouri Botanical Garden. 102(2): 217–226.

Miller, J. R. & B. T. Bestelmeyer. 2016. What’s wrong with novel ecosystems, really? Restoration Ecology 24: 577-582.

Murcia, C., J. Aronson, G. H. Kattan, D. Moreno-Mateos, K. Dixon & D. Simberloff. 2014. A critique of the ‘novel ecosystem’ concept. Trends in Ecology & Evolution 29: 548-553.

Reid, J. L., S. J. Wilson, G. S. Bloomfield, M. E. Cattau, M. E. Fagan, K. D. Holl & R. A. Zahawi. 2017. How long do restored ecosystems persist? Annals of the Missouri Botanical Garden. 102(2): 258–265.

SER (Society for Ecological Restoration). 2004. The SER primer on ecological restoration. http://www.ser.org/content/ecological_restoration_primer.asp. Date accessed: September 28, 2009

Steffen, W., W. Broadgate, L. Deutsch, O. Gaffney & C. Ludwig. 2015. The trajectory of the Anthropocene: the great acceleration. The Anthropocene Review 2: 81-98.

UNCBD (United Nations Convention on Biological Diversity). 2012. UNEP/CBD/COP/DEC/XI/16. https://www.cbd.int/doc/decisions/cop-11/cop-11-dec-16-en.pdf. Date accessed: 12 December 2016

UNCCD (United Nations Convention to Combat Desertification). 2015. Land matters for climate: reducing the gap and approaching the target. http://www.unccd.int/Lists/SiteDocumentLibrary/Publications/2015Nov_Land_matters_For_Climate_ENG.pdf. Date accessed: 12 December 2016

UNFCCC (United Nations Framework Convention on Climate Change). 2015. Paris agreement. http://unfccc.int/files/essential_background/convention/application/pdf/english_paris_agreement.pdf.  Date accessed: 12 December 2016

Woodworth, P. 2013. Our Once and Future Planet. University of Chicago Press, Chicago.

Woodworth, P. 2017. Meeting  the twin challenges of global change and scaling up, Restoration needs insights from the humanities as well as analysis from science. Annals of the Missouri Botanical Garden. 102(2): 266–281.

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Tree islands for tropical forest restoration: the outlook is rosy after 10 years

Planting tree islands has many of the benefits of larger plantations, but entails significantly less cost. Karen Holl (University of California, Santa Cruz), Leighton Reid (Missouri Botanical Garden), and Zak Zahawi (American University of Beirut) describe recent findings on tree seedling recruitment in a long-term experiment in southern Costa Rica.

Over the past few years there have been a growing number of commitments at the global, national and regional scale to restore forests because of their importance to conserve biodiversity, sequester carbon, reduce erosion, and provide goods and services to people. For example, Initiative 20×20, led by the International Union for the Conservation of Nature, aims to restore 20 million hectares of tropical forest by 2020, an area roughly equivalent to the size of Uruguay or Nebraska.

A common strategy to restore forests is to plant trees. But, the big question is: where will the money come from to plant billions of trees when there are so many pressing needs? As restoration ecologists, we started thinking about how we could most efficiently allocate resources to get the best bang for the buck and restore the largest area of forest.

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Trade-offs in forest restoration strategies. Planting fewer trees leaves more to chance and can require more time, but tree plantations are more expensive and leave a bigger ecological footprint. Our study tests an intermediate option, and after 10 years it appears to provide a good balance. Figure modified from Corbin & Holl (2012).

Starting over 10 years ago, we set up a large-scale tropical forest restoration experiment in southern Costa Rica to test two ideas.

First, we tried planting tree “islands”. The idea is to plant groups of trees that attract birds and bats, which disperse most tropical forest tree seeds. The tree canopy also shades out light-demanding grasses that can outcompete tree seedlings. In one experimental treatment, we planted tree islands that covered about 20% of 50 × 50 m plot of former cattle pasture. We compared that to plots where no trees were planted (natural recovery) and to the more intensive (and more typical) restoration strategy of planting trees in rows throughout the plot (plantation).

Second, we asked: is it only possible to restore forest near remnant forests or can you restore forest anywhere in the landscape? This is important information to help guide forest restoration efforts. To do this we set up our entire experiment at 13 sites, some of which were mostly surrounded by agricultural land and some of which were adjacent to the largest remaining forests in the region.

Then we monitored establishment of new tree seedlings in our research plots over a decade. We compared the number of seedlings, number of species, and types of species in the restoration plots with those found in the nearby forest to evaluate how well the forest is recovering.

The tree island planting method not only saves money on buying, planting, and maintaining seedlings, but it also results in a more heterogeneous distribution of trees, so it looks more like a natural forest.

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Profuse tree seedling and sapling recruitment in the understory between two tree islands in southern Costa Rica.

We counted over 6000 tree seedlings, 88% of which have seeds that are dispersed by animals. On average there were many more tree seedlings in the tree island and plantation treatments than in the natural recovery plots. These results suggests that some tree planting helps the forest to recover faster, but that it is not necessary to plant the whole area with trees. The tree island planting method not only saves money on buying, planting, and maintaining seedlings, but it also results in a more heterogeneous distribution of trees, so it looks more like a natural forest.

Even though there were many tree seedlings in the island and plantation plots, on average there were less seedlings of tree species that have big seeds (>0.5 cm/0.2 inches across) compared to mature, reference forests. It seems that the larger-seeded species that are common in mature forests are much slower to colonize restored sites, likely because they are eaten and dispersed by a small number of larger animals, such trogons and agoutis. Many of those dispersers are less likely to visit early successional forest.

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Small frugivores, small seeds. Most of the birds we see in these experimental plots are small-gaped omnivores (e.g., Yellow-bellied Elaenia, Elaenia flavogaster, left), but it usually takes large-gaped species to disperse larger seeds1. The figure at right shows the maximum fruit size that a bird species with a given gape size was able to consume in a cloud forest in central Costa Rica (modified from Wheelwright (1985)). In our experiment, small seeds were ubiquitous, but large seeds were mostly absent.

We were surprised that the amount of forest cover around the experimental plots had a weak effect on the number of seedlings establishing. In other words, isolated plots had just as many tree seedlings as plots right next to old-growth forests. We think that this is likely due to the fact that there are many trees in the agricultural landscape surrounding our plots; these trees include remnant trees, living fence rows, and riparian corridors. Trees in the landscape can serve an important role in both providing sources of seeds and stepping stones for the movement of seed-dispersing fauna. We anticipate that having forest nearby will be more important in future years as these forests build up greater diversity of rare, large-seeded species. Nonetheless, our results suggest that there are good prospects for restoring forests in many locations in this landscape.

Our key finding is that planting tree islands can be a cost-effective way to restore tropical forests at our study site in Costa Rica, but we hasten to note that the strategy should be tested in other locations, particularly areas with fewer forest elements in the surrounding countryside. Our study also demonstrates that tropical forests can recover some species quickly but it will take many decades, if ever, for forests to fully recover. So, preserving existing rain forests is critical to conserve biodiversity and the services they provide to people.

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Diverse tree cover in an agricultural landscape in southern Costa Rica. Remnant trees in pastures, trees along fence rows, and riparian forests provide important sources of flora and fauna to speed up forest recovery.

1See Melo et al. (2009) for an example to the contrary: small-gaped animals dispersing fairly large fruits and seeds.

This work was supported by a grant from the National Science Foundation.

Ecological Restoration in a Changing Biosphere

If you were at the MBG Fall Symposium, we want to hear from you! How did the symposium change your perception of restoration? Send us an email at leighton.reid@mobot.org.

On October 8th, Missouri Botanical Garden hosted its 63rd annual Fall Symposium. This year’s theme was Ecological Restoration in a Changing Biosphere. Author and journalist Paddy Woodworth moderated the day, and seven speakers presented contemporary perspectives on a core challenge in modern restoration ecology. Namely: in the post-COP21 world, when all three UN conventions call for scaling up and mainstreaming of restoration, it is clear that restoration will affect hundreds of millions of hectares – and as many people – over the coming decade. At the same time, we find ourselves in an era of unprecedented change where climate, ecological baselines, and future land-use changes are highly uncertain. This raises the question: What should large-scale restoration look like in the remainder of the 21st century?

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2016 Fall Symposium speakers. From left to right: Peter Wyse Jackson, Curt Meine, Robin Chazdon, James Aronson, Leighton Reid, Pedro Brancalion, Karen Holl, Don Falk, Paddy Woodworth, and Jim Miller. Photo by Andrea Androuais.

Talks during the morning focused on tropical forests, where much of the international restoration dialogue is focused.

  • Leighton Reid (Missouri Botanical Garden) opened with a presentation on restoration longevity – the idea that some restoration projects create ecosystems that persist for more than a century (e.g., Floresta da Tijuca), while other projects fail quickly. Dr. Reid argued that how long restored ecosystems persist is quantifiable, predictable, and manipulable, opening the possibility for more ambitious restoration planning.
  • Robin Chazdon (University of Connecticut and beyond) then spoke about forest landscape restoration, an approach that aims to regain ecological integrity and enhance human well-being in deforested, human-impacted, or degraded forest landscapes. Drawing on a wealth of large-scale studies, Dr. Chazdon made the case that natural forest regeneration is the most ecologically effective and economically feasible approach to forest restoration globally.
  • Karen Holl (University of California Santa Cruz) presented her take on research priorities for forest restoration in the Neotropics. She highlighted that researchers could make an impact by studying forest restoration at larger spatial scales, at longer temporal scales, and in collaboration with stakeholders. Improving information exchange and standardizing monitoring protocols were also among her top priorities. (Graduate students, take note!)
  • Dr. Pedro Brancalion (University of São Paulo) completed the morning session with a TED talk-style discussion of the linkages between science, technology, policy, and best practice in Brazilian Atlantic Forest restoration. Using Thomas Kuhn’s structure of scientific revolutions, Dr. Brancalion argued that restoration ecology is in a crisis period, in part because disciplinary research has predominantly created solutions at smaller spatial scales than the (growing) problems the discipline seeks to address. Perhaps restoration is ripe for a paradigm shift?
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Dr. Pedro Brancalion (right) asks whether restoration ecology is ready for a new paradigm shift, as Paddy Woodworth (left) moderates. Photo by Robin Chazdon.

After lunch, the conversation turned towards a major academic debate in restoration ecology. Has global change outpaced the restoration approach? And is a new approach needed?

  • Curt Meine (The Aldo Leopold Foundation) drew on his long experience in the upper Midwest, and, in particular, his studies of author and environmentalist Aldo Leopold (1887-1948). He argued that Leopold avoided the simple polarities through which some contemporary restoration debates are framed. He viewed nature in a relative way, neither entirely wild, nor entirely domesticated in any given landscape. Although he practiced ecological restoration in some contexts, he also advocated soil conservation and sustainable agriculture – activities motivated by his core values, as expressed in The Land Ethic (1949).
  • James Aronson (Missouri Botanical Garden) followed with an elucidation of the reference ecosystem concept. Reference ecosystems, he noted, help determine the social and ecological vision for a restoration project or program – a critical issue for restoring historic continuity in degraded landscapes. Dr. Aronson described a family of restorative actions for achieving progress towards the reference system, drawing on examples from Jordan and South Africa. He argued we need to look deeper into the past and ponder our choices from many angles as we decide how to do more effective restoration at the landscape and larger scales.
  • Donald Falk (University of Arizona) delivered the keynote address. He painted a disturbing portrait: rapid climate change is driving a massive forest-to-non-forest transition in the southwestern United States. In particular, many ponderosa pine forests will not be able to persist in the future where they have been in the recent past and present. Perhaps restoration ecologists should transition too. Rather than “chasing the ambulance”, maybe we could get out ahead of disasters and ease transitions between stable ecosystem states. Anticipating ecosystem transitions could mitigate the loss of ecosystem functioning that accompanies major climate-driven forest fires, but it would require a shift in restoration thinking. Importantly, Dr. Falk noted that ecosystems do not care what words we use – ecosystems respond to actions.

With moderator Paddy Woodworth’s help, we finished the day with a panel discussion, inviting questions from the audience. Among the thoughts and questions that we were left with:

  • Is ecological restoration more difficult in places with greater population density?
  • Should restoration focus on policy, economic, or cultural motivations for engaging people?
  • Are values a better guide for land management than ecological history? Are the two complementary?
  • How can the reference ecosystem concept accommodate rapid biome changes, as we are seeing in the Southwestern USA?
  • What is the way forward to mainstream serious, multisectorial monitoring and evaluation with all these new factors to consider? Who will fund it?
  • To what extent can we move from restoring degraded ecosystems to avoiding degradation in the first place?
  • Can forest landscape restoration and natural forest regeneration bridge the gap between small-scale, past restoration experience and present, large-scale restoration needs?
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PhD candidates Ricardo Cesar (University of São Paulo) and Leland Werdan (University of Minnesota) compare notes on seedling functional traits in dry tropical forest restoration. Leland was the recipient of the annual Delzie Demaree award. Photo by Robin Chazdon.

mbg63-registrants

More than 150 people registered for the symposium. They came from three continents, five countries, and seven US states.

Epiphyte restoration in Brazil’s Atlantic Forest

CCSD restoration ecologist and PARTNERS member Leighton Reid spent 10 days collaborating with scientists and students in the Tropical Silviculture Lab (LASTROP) at the University of São Paulo. Epiphytes were a central theme of the visit.

Vascular epiphytes are plants that live non-parasitically on other plants. Readers from the tropics will be quite familiar with some epiphytes, like the ubiquitous Tillandsia of Neotropical powerlines, but temperate zoners will have seen many epiphytes as well, at the florist, the botanical garden, and the mall. These plants are incredibly diverse; by one estimate, epiphytes make up 9% of all vascular plants worldwide. But epiphytes also face serious challenges in today’s world. Habitat loss and overharvesting threaten some epiphyte species with extinction. Many epiphytes also have a hard time recolonizing new habitat in regenerating forests, but new studies on epiphyte restoration could help.

I spent the past 10 days in the State of São Paulo learning about epiphyte ecology, conservation, and restoration from students and scientists at the University of São Paulo’s College of Agriculture (Escola Superior de Agricultura Luiz de Queiroz). This part of Brazil was once covered in semideciduous tropical and subtropical forests, which hosted about 150 vascular epiphyte species. Today, only ~15% of the forest remains, but there is a large effort underway to restore 15 million hectares (nearly 58,000 square miles) of it by 2050.

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ESALQ maintains shade house with more than 3,000 orchids, including (A) Cattleya loddigesii, (B) C. forbesii, and (C) Arpophyllum giganteum.

Frederico Domene is a doctoral student studying epiphyte reintroduction in restored Atlantic Forest. Like his advisor, Pedro Brancalion, Fred’s interest in epiphyte restoration stems from a passion for orchids. He grows a variety of them at his house in Piracicaba, preferring true species over horticultural varieties.

Fred picked me up in his black pickup, “mamangava”, and took me on a tour of several tree plantations where he has been developing methods for reestablishing populations of epiphytic orchids, bromeliads, cacti, and aroids. Fred’s basic procedure involves collecting epiphyte seeds (or purchasing small plants, in the case of orchids), growing them out in a nursery, and then attaching them to trees using twine or plastic. He started his work in 2010 and has been monitoring his plants, and reintroducing new plants, every year since. He uses a ladder to put the orchids up high, out of easy reach for would-be poachers.

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Atlantic Forest restoration plantations. Left: 60-year old plantation along the Rio Piracicaba near Rio Claro. Right: 12-year old plantation at the Anhembi Forest Science Experimental Station. The older restoration site had considerably more naturally recolonizing epiphytes than the younger site.

Late August is mid-winter in São Paulo, and while it doesn’t get particularly cold, it is quite dry. The restoration plantations were crunchy with desiccated leaves and twigs. These are harsh conditions for epiphytes, which do not have the luxury of soil to buffer to their roots from the sunlight and dry air. Some of Fred’s epiphytes have withered and died, especially during a 100-year drought in 2012. But others are thriving, thanks to special adaptations, such as the velamen of orchid roots, which wicks up rainwater when it drips down the tree trunk during storms. Many individuals have started fruiting and flowering, a good sign for the future viability of these reintroduced populations.

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Epiphyte reintroductions in restoration plantations. (A) A reintroduced festoon of bromeliads, orchids, and cacti. (B) A fruit-bearing orchid (Cattleya forbesii), six years after reintroduction. (C) This reintroduced cactus (Epiphyllum phyllanthus) seemed to grow better in tree forks than on vertical stems, as did an aroid, (D) Philodendron bipinnatifidum. (E) Two tiny cacti have germinated in this direct seeding experiment, using seeds enrobed in paper discs. (F) Even where epiphytes have dessicated and died, experimental infrastructure continues to enhance epiphyte development; here a small bromeliad (Tillandsia recurvata) uses a piece of natural twine as a foothold.

To identify the key challenges for epiphyte restoration, it is also important to study epiphyte recolonization in naturally regenerating forests. Alex Mendes, an undergraduate researcher at ESALQ, is doing just that. On an unseasonably rainy morning, Alex, Fred, and I visited three regenerating forests near the sugar town of Rio Claro. We ducked under barbed wire fences and wandered through low, dense vegetation where Alex is systematically searching for vascular epiphytes. Two forests had rather few epiphytes – mostly generalist bromeliads – but one forest had a high density of orchids, which happened to be flowering spectacularly on the day we visited. Based on historical aerial photos, Alex knows that these three forests are at least 20 years old. They are part of a network of 75 sites that he will ultimately search for epiphytes. By the end of his undergraduate program, Alex hopes to be able to predict where epiphyte communities will regenerate on their own, and where they will need more assistance.

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This secondary forest near Rio Claro might have felt like your average overgrown Psidium guajava patch had it not been  decorated with dozens of Ionopsis sp. orchids.

These are early days for learning about epiphyte restoration, and there is still a lot of work to be done. The projects that I visited in Brazil are making headway, complementing our research in Costa Rica. It remains to be seen under what circumstances epiphyte reintroductions will be most successful. Perhaps an even more important issue will be convincing funding agencies and land managers to think beyond trees.

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Fred Domene and Alex Mendes are making strides in the ecology of epiphyte reintroductions and community assembly. Here, they pose with a reintroduced bromeliad (Billbergia zebrina) at Anhembi experimental station.

Fig Stakes: Shoreline Restoration for a Costa más Rica

Andres Santana is the graduate program coordinator at the Organization for Tropical Studies. During a recent fieldtrip in southern Costa Rica, he and CCSD restoration ecologist Leighton Reid compared notes on using fig stakes for ecological restoration.

Tropical beaches are many things to many people. To plants, beaches are hot, sandy, and salty – complicating their restoration.

Costa Rica has 1228 km (763 mi) of coast line – including 1016 km on the Pacific side and 212 km on the Caribbean. Along Costa Rica’s northern Pacific coast, the beach forms the natural edge of the dry forest. Farther south the adjacent forest is more humid. Giant trees, 40 m or more in height, grow right up to the high tide mark, particularly along the Caribbean.

But as with so many tropical ecosystems, Costa Rica’s coastal forests have been subject to human impacts. Many shoreline forests were cleared for cattle ranching, and exotic grasses were introduced as forage. Some of these grasses are fierce competitors and prevent tree seedlings from establishing, even long after the pastures have been abandoned.

Playa Hermosa Antes y Despues

Playa Hermosa, before (left) and after (right) planting 2-m long cuttings of a coastal fig species (Ficus goldmannii).

In 2009, a small non-profit organization, Costas Verdes, was formed to restore coastal forests along degraded shorelines, particularly wildlife refuges. The restoration work was initially challenging; tree seedlings were hard to establish along the coast because of the harsh environment – high temperatures and salinity and lack of freshwater were among the most significant obstacles. Not to mention the invasive cattle forage grasses.

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Coastal restoration at Playa Hermosa

Playa Hermosa, a surfing destination on the Central Pacific coast, was among the most heavily deforested project sites. This area, part of a wetland and river estuary, was declared a national wildlife refuge in 1998. By 2009, very little forest had naturally regenerated. This led Costas Verdes to implement a restoration project at this beach. Planting plots were established where invasive grass was removed. In other areas, grasses left intact, as a comparison. It quickly became evident that tree seedlings were outcompeted by the grass. Those in the cleared plots grew better, but they still faced the other coastal habitat challenges.

Some native trees are resistant to hot substrates and high salinity, but these species were not available in tree nurseries, most of which focused on ornamental species. This meant that seedlings needed to come from locally collected and germinated seeds. We realized that this would take time to get going. Tree seedlings under 50 cm rarely survive, even if they have the proper coastal adaptations.

To accelerate the restoration, we decided to use tree cuttings rather than growing seedlings from seed. A colleague suggested Ficus goldmannii as a candidate species, so in 2011 we conducted a planting trial. We planted 225 2-m long cuttings. Of these, 195 (87%) survived their first year. By the second year all 195 survivors had become established and were quickly providing canopy cover and lowering the temperature of the sand.

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An established fig stake with a dense canopy. Note the weak, patchy grass below it.

Once fig stakes created some canopy cover, we brought in other tree species – mostly from the coastal tree nursery that we created. Shade from the fig canopy also began to inhibit the invasive grasses, which require high sunlight to photosynthesize efficiently. Reduced competition with these grasses allowed other tree seedling species to survive.

In this instance Ficus cuttings turned out to be useful in promoting restoration. We have since used cuttings for other plots with similar success.

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Coastal trees and shrubs growing below established fig cuttings at Playa Hermosa.

Reforesting with Figs

 Benjamin E. Smith is a Ph.D. student at George Washington University. He recently completed a field ecology course with the Organization for Tropical Studies in Costa Rica, where he worked with CCSD scientist Leighton Reid. When he’s not coring fig trees in Costa Rica, Benjamin studies plant-herbivore interactions in American chestnut.

It was my recent privilege to spend a week at Las Cruces Biological Station in Costa Rica where I learned about some amazing properties of fig trees.

The genus Ficus contains over 800 species, which can be found in the tropical to warm temperate regions throughout the world. Where they occur, figs are vital components of their local ecosystems because they provide high quality fruits for many animals. Animals attracted by the delicious figs often carry other plants’ seeds in their digestive tracks and subsequently deposit them below the fruiting fig tree. This can lead to patches of forest with especially high plant diversity.

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Two individuals of Ficus obtusifolia demonstrating the strangler lifestyle (left) and the free-standing lifestyle (right). The individual on the left has overtaken one host tree and is reaching out to claim another. The individual on the right was planted (either by humans or birds) in a fence row.

Some fig species have the ability to resprout roots, branches, and leaves from broken limbs – an adaptation that would be useful in an ecosystem with frequent disturbances, like hurricanes or landslides. Rural people have been utilizing this incredible feat of nature to create living fences for hundreds of years; they simply cut branches from a tree and plant them. Plant a large enough branch, and you’ve got an instant tree.

Instant fruiting trees could be a practical tool for ecological restoration, and there is currently an experiment underway to test this idea. But not all fig species can resprout from cuttings, so in order for this tool to be useful outside of southern Costa Rica, it would be helpful to know which species will resprout and which will not.

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A healthy cutting of Ficus colubrinae. This instant tree was planted in May 2015.

Does wood density predict resprouting in figs?

We sought a way to determine whether a particular fig species would be able to resprout from a limb cutting before actually cutting apart large trees. This would mean only trees whose cuttings will survive would be used and trees that can’t resprout could be left undamaged.

We believed that wood density would be a good measure to figure this out. Wood density can tell you a lot about a tree’s life history strategy. Is it a hard tree that will resist snapping in a stiff breeze? Or is it a softer tree that might break, but then resprout?

To test this, we took core samples from seven fig species and headed to the lab. After a couple days of measurements, we had our data.

Methods

(A) OTS student Orlando Acevedo Charry extracts a core from a Ficus colubrinae. (B) Cores were cut into small pieces. We measured the mass of the water that each segment displaced to determine the wood’s green volume. (C) Next, samples were placed in a drying oven at 106° C for 24 hours. Finally, we measured the mass of the dried samples and divided by the green volume to determine wood density.

The fig species we tested turned out to have pretty similar wood densities. Also, the slight variations in wood density did not correlate with trees’ resprouting abilities. This initially came as a big disappointment, but after taking a second look at our data we started to see a trend that may actually be much cooler.

Results

Wood density was a poor predictor of resprouting capacity (measured by tallying fig cuttings that were planted in April-May 2015; Left), but strangler figs in the subgenus Urostigma performed much better than two free-standing species in subgenus Pharmacosycea.

Fig species come in a variety of forms. Some are rather conventional free-standing trees that grow from the ground up, but others start as seedlings high in the canopy of another tree and send roots down to the ground, gradually strangling their host. Still others are shrubs, climbers, and epiphytes. We found that stakes cut from strangling figs, the ones that initially rely on a host tree, were much more likely to resprout than stakes cut from free-standing fig species. If this holds true, no measurements will be needed in the future. People around the world may be able to tell if a tree will likely sprout from a cutting just by the way it grows.

The Huarango and Algarrobo forests of coastal Peru: rays of hope

James and Thibaud Aronson report from coastal Peru, where they travelled in December, with Oliver Whaley, of RBG Kew.

Yesterday, at our local market here in France, we saw Peruvian avocados. We’d seen them there before, and we don’t buy them. But we’d never really given them more than a passing thought. Now, having come back from coastal Peru, where they are grown, we have a very different outlook.

Passing through much of Peru’s southern coast is perhaps more interesting to geologists than ecologists. The tenuous ecological balance, and its rather checkered history since humans arrived, needs time to reveal its secrets. But the earth’s surface here is simply naked and laid out as for a desert geomorphology text book. An extension of the famous Atacama desert of northern Chile, it is one of the driest places on Earth, with an average annual rainfall of 0.3 mm, or barely more than one tenth of an inch.

Here more than in nearly any other desert, life is almost entirely confined to areas with some amount of moisture. As a result, the few river valleys that come down from the Andes form spectacular green ribbons among the dunes. They carry some water down from the rainstorms high in the mountains but the critical driver here is El Niño. It brings down tremendous amounts of water and sediment once every 6 to 15 years, thereby rejuvenating the whole system, and generating extremely fertile alluvial soils.

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The last remaining stretch of Prosopis limensis riparian forest near Copara, Ica region, southern Peru.

500 years ago, the river valleys were occupied by dense woodlands or veritable forests of Prosopis limensis (local name – Huarango), which is often misidentified as Prosopis pallida, teeming with wildlife in the canopy and understories. Today, most of the Prosopis are gone, the excellent charcoal produced from their wood having been used up to fuel the stream engines of the now defunct coastal railway and, more recently, for fast food chicken restaurants ‘pollo a la brasa’ and millions of barbecue fires in cities and roadside restaurants. Instead, one now sees vast monocultures of asparagus, avocadoes, and table grapes, producing cash crops for the North American and European export markets.

This story of deforestation is in fact almost complete, with nearly 99% of the original vegetation having been removed.

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There once were countless Prosopis trees such as this one, which has probably lived for a thousand years on this sand dune, near Copara.

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Most of them fell to the charcoal burners’ axes, and even though it is now forbidden to harvest firewood from live trees, illegal cutting continues, as seen here, 20 meters from the tree pictured above.

Depressing? Yes, but as engaged ecologists, we were also encouraged that change is happening; there is cause for hope. There are program in community-based restoration led by Ecoan underway in the high Andes, near Cuzco and environs, and science and conservation efforts underway at the Missouri Botanical Garden’s station at Oxapampa.

We were lucky to spend 10 days with Oliver Whaley, from RBG Kew, who has been instrumental in many of the first initiatives attempting to reverse some of the damage done on this arid coast and to find a new path that explicitly includes restoration. Particularly noteworthy is a partnership he’s brokered with the large agroindustry supply chain, including a giant supermarket chain where almost half of the UK buys its vegetables, and which is the destination of a high percentage of the region’s produce.

The agro-industries overcome the lack of reliable rainwater by installing intensive irrigation systems, which although highly efficient, are driving unsustainable expansion even as they produce spectacular crop harvests.

However, the coast also experiences strong winds coming from the coast year-round, which require that rows of trees be planted as windbreaks to shield the valuable crops. Furthermore security hedging today is almost entirely composed of introduced water-guzzling African or Asian exotics. Under Whaley’s in-farm reforestation  program, some producers have begun planting native Prosopis, Parkinsonia, and Acacia trees yielding a mixed forest instead, which provides habitat for wildlife and also improves the neighboring soils through their capacity to fix atmospheric nitrogen in symbiosis with rhizobacteria. They require far less water than introduced trees, and will never become weeds. Agroindustry management has also donated land for restoration corridors, a vitally important undertaking at the landscape scale that has not yet been well-explored in coastal Peru or other drylands.

The Kew Peru team planted 7,000 trees and shrubs of 15 native species derived from the degraded tiny relicts. The results have been nothing short of astounding, with over 70 new native plant species, 45 bird species, various lizards, desert fox and wild guinea pigs recolonizing areas that were nothing but barren soil 9 years ago. (The full results of this work will be published in the spring). Whaley takes a practical and patient view – whereby to nurture back woodland and a cultural re engagement with what nature provides takes time and needs to show results.

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A patch of restored land on the edge of an asparagus field, showing the difference 10 years make. Santiago de Ica, southern Peru.

Whaley and the local NGO, Conservamos por Naturaleza that he helped found and works closely with, is also committed to education and communication, working in Ica, Nasca, and elsewhere, to change people’s perception of the key desert plants such as Prosopis and Capparis, and their ecosystems, and of native biodiversity in general. Cultural reengagement, he argues, is about changing perception from symbols of a rural, backwards environment to be left behind in the wake of progress, to highly useful and valuable trees and woodlands that are part of the local heritage. These ecosystems clearly are worthy of pride, not only for their inherent value, but also because they offer the prospects of  sustainable, profitable agriculture that is also conservation-friendly.

The Huarango Festival in Ica, which focuses on the numerous products that can be extracted from the tree, such as algarrobina, a sweet spread, a sweet drink, high quality honey, ink, and more has been a large success, and is now in its eleventh year. Whaley also works with schools, working to restore small patches of native vegetation inside the school compounds and promoting ecological consciousness through small nurseries and gardening projects.

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Seedlings in a native species nursery funded by the Royal Botanic Gardens, Kew, at the Faculty of Agronomy at the University of Ica.

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Middle school students in their school’s nursery, in a town near Ica, where they grow native species and food crops and have a great time doing it.

The other unique feature of the southern coast is an inland archipelago of sorts, made up of coastal fog oases, or lomas, in Spanish. Fed by the moisture provided by coastal fogs, they rise from the surrounding desert and harbor herbaceous vegetation and in some cases various kinds of trees, all of which show high rates of endemism. Most of the lomas are sadly threatened by mining and other uses today, but Whaley has already succeeded in helping protect the new national reserve of Lomas San Fernando. This and other efforts , such as drone surveys and modelling, are conducted with help from Kew GIS staff, and Whaley’s team in Peru that includes Alfonso Orellana, Consuelo Borda, Ana Juarez and other dedicated workers. They are currently doing the baseline research in two other lomas reserves to help strengthen the case for protected area status.

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The amazing vegetation supported almost entirely by coastal fogs in the Lomas de Atiquipa, home to an endemic very endangered Myrtaceae:  Myrcianthes ferreyrae.

 

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A female Andean condor (Vultur gryphus), in the Lomas de San Fernando reserve, the only place in Peru where this raptor roosts near sea level.

Whaley and his co-workers are also engaged in restoration efforts the tropical northern coast of Peru, where the circumstances are rather different. The north coast receives significantly more rainfall than the south, i.e., about 100 mm per year (!), that is 4 inches. This permits the vegetation to climb out of the river valleys, and in fact, the local Algarrobo (Prosopis pallida and in the extreme North only P. juliflora along with hybrids between the two), and Capparis species, among others, still form true woodlands. Traditionally, the trees were preserved by the local people as their leaves and in particular their pods are remarkably nutritive, and provide prime forage for free-ranging cattle, the peoples’ primary source of income.

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The remarkable woodlands dominated by Prosopis pallida (Algarrobo), in the Pomac Forest Sanctuary, Lambayeque Region, northern Peru.

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The Algarrobo trees have been preserved in large part because they provide excellent forage for the local people’s cattle.

However, a still poorly understood plague, apparently resulting from the combination of a small fly and a fungus, are decimating the woodlands; in some areas over 80% of the Algarrobo have apparently died. Just like in the South, El Niño is paramount in keeping the system healthy and, in particular, no Prosopis seedlings have been seen germinating in the last 50 years, except during El Niño years. What’s more, the next El Niño event is overdue: the last one came in 1997/1998, and now the system appears exhausted. Clearly the system is waiting for the next El Niño, and the long wait appears to have increased the Algarrobo’s vulnerability to the plague.

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Severe Prosopis pallida dieback, near Talara, Piura region.

However, El Niño is coming this year, and according to the climate experts, it’s going to be a big one. As a result, Whaley and his team are scrambling to prepare as many Prosopis seeds as possible, to be sown during or right after the heavy rains. As the trees slowly dying from the plague usually fail to set seed, Whaley and his collaborators fear that much of the soil seed bank is exhausted and this could truly be the last chance for this species in its wild state.

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A seed-ball with 4 native species, including Algarrobo, being prepared at a community nursery, near Salas, Lambayeque region.

Now there is an additional layer to the issue, which asks of would-be restorationists exactly what it is that they are trying to do. There hasn’t been nearly as much deforestation in Peru’s North coast as in the South, so there are still reasonably large tracts of native vegetation left intact. Further, apart from Algarrobo, none of the other five dominant native tree species, including two species of Capparis,  appear to be affected in any way by the plague.  Domestic cattle will also eat the leaves of these other trees and shrubs, though they aren’t quite as good as the Prosopis.

Therefore, some might say that this is just a natural transition occurring within an ecosystem, and it would be foolish, or even a case of trying to play God, to attempt to save the Prosopis at all costs. However, Whaley thinks differently, and we agree with him. The Algarrobo, like the Huarango, is a remarkable tree, fantastically well adapted to its environment, capable of living 1000 years of more, and clearly the keystone species of the riparian and related ecosystems where it occurs.

It forms remarkable canopies, and in areas where it is absent, we did not see the other tree species present produce anything like it, rather forming a much more open low savanna. Further, it has been a pillar of the various civilizations that have existed in the area for the last 4000 years. Therefore, Whaley is not yet ready to just let it go…

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A thousand-year old Prosopis pallida in the Pomac Forest Sanctuary, possibly the oldest of its kind still alive in northern Peru…