Seed additions facilitate herb-layer restoration in a temperate oak woodland

By Andrew Kaul, a Restoration Ecology Post-doc in the Center for Conservation and Sustainable Development at the Missouri Botanical Garden. His new, open-access paper in Ecological Solutions and Evidence is available here.

Throughout most of the eastern United States, oak woodlands were once a widespread and dominant ecosystem. These woodlands experienced periodic fires, which prevented woody trees and shrubs from growing so densely that the overstory canopy became closed. The partly open canopy allowed light to reach the ground, supporting a diverse community of herbaceous plants including wildflowers, grasses, and sedges. However, over the past two centuries, human induced changes including fire suppression, invasion by non-native shrubs, and other factors have caused most woodlands to become overgrown, and lose much of the diversity of plant species in the herbaceous ground layer.

Research on how to manage and restore these woodlands has shown that cutting down some trees to thin out the woodland, as well as removing non-native shrubs, and reintroducing periodic fires, are all strategies that help improve the quality of these habitats. However, even after employing all of these management strategies, many desirable plant species may still not return on their own. Ecosystem restoration often involves re-introducing plant species as a seed mix distributed over a cleared area, and this method can be very effective for grassland and savanna habitats that contain few trees. Restoring wildflowers and grasses in wooded areas with the addition of a seed mix could drastically improve the diversity and quality of the herbaceous community, but this approach has not been experimentally studied, and little is known about how to select the right species for re-introduction this way.

To address these knowledge gaps, scientists and land managers at the Missouri Botanical Garden started an experiment at the Shaw Nature Reserve in 2016, where highly diverse seed mixes of native plants were added to a degraded woodland undergoing active restoration. Throughout late 2016 and much of 2017, crews of managers and volunteer land stewards worked to thin the canopy by removing less desirable tree species, especially the aggressively fast growing native conifer, Eastern Redcedar (Juniperus virginiana). After thinning the canopy, crews used a combination of mechanical removal and herbicides to control the dense non-native shrubs. Fire was reintroduced through controlled burns starting in late 2017.

Large Eastern Redcedars dominate a degraded woodland at Shaw Nature Reserve in Gray Summit MO. The understory is overgrown with non-native woody species including bush honeysuckle (Lonicera maackii), privet (Ligustrum obtusifolium), and wintercreeper (Euonymus fortunei). The lack of recent fire has led to a build up in leaf litter, and native herbaceous species are mostly absent. Photo: CCSD & SNR staff.

After the woodland was thinned, in January of 2018, we added seed mixes to three different management units, along a gradient of lower/wetter to higher/drier parts of this landscape. The seed mixes contained between 79 and 93 species, and all of the seed was collected from plants growing at the nature reserve. In order to track how these seed additions influenced the establishment of the herbaceous community, we collected data on the composition of the plant communities in areas that received seed and areas that did not. We sampled the plant community in 2017 before the seed additions and in the following two years, 2018-2019.

Top: Woodland under management at Shaw Nature Reserve in March of 2017, after selective thinning of trees to open up the canopy and removal of most woody shrubs. Leaves of some persistent bush honeysuckle can be seen. Bottom: Same woodland in June of 2019 after the addition of a seed mix in 2018. Photo: CCSD & SNR staff.

In both the seeded and non-seeded woodlands, the effect of management actions was very clear and positive, since both the number and cover of herbaceous species dramatically increased from the sample in 2017 to later sample dates. This is consistent with previous research showing that thinning the canopy, removing shrubs, and reintroducing fire promote restoration of herbaceous plants.

We also found substantial benefits from reintroducing species with seed mixes. The areas that received seed had about 10 more plant species present within a one square meter area, than the areas that did not get seed. We were also interested in the quality of the kinds of species that were establishing based on coefficients of conservatism, which denote how sensitive species are to human disturbances. We found that areas with seed added, contained fewer plants that were weedy ruderals, and more that were conservative and generally found only in high-quality intact habitat. Interestingly, areas that got seed additions were also more dominated by grasses and the areas that did not receive seed, although less rich in species, tended to have more abundant wildflowers (forbs). Specifically, common grasses that were sown at high rates tended to dominate areas that received seed additions, including river oats (Chasmanthium latifolium), hairy woodland brome (Bromus pubescens), and bottlebrush grass (Elymus hystrix). The restored areas that did not get a seed addition were dominated by ruderal (low conservatism) forbs such as jumpseed (Persicaria virginiana), white snakeroot (Ageratina altissima), and common yellow woodsorrel (Oxalis stricta).

A representative area that had seed added (top) and an area that did not (bottom) in June of 2019. In the non-seeded area, a large patch of the weedy native composite, giant ragweed (Ambrosia trifida), can be seen in the foreground. Photo: CCSD & SNR staff.

Our final goal was to examine the recruitment success of the over 100 different plant species that we added as seeds, to see if there were patterns in which kinds of species tended to establish best. Perhaps surprisingly, over half of the species we added were never detected in vegetation samples. These species might not have been sown into favorable conditions, or potentially, the quality of the seed might have been poor, since it came from wild populations and the seeds might not have been viable or mature. Still, some seeds may be dormant for many years, and more added species may break dormancy and recruit later. Among the species that did establish from added seeds, we found that recruitment was much higher for species that were sown at higher rates, suggesting that some species might have benefitted from a higher seeding rate. Both grasses and forbs tended to recruit well when sown at high rates, but the 25 sedge species we added had little or no recruitment success.

Based on our results, future research on woodland restoration should address why sedges are difficult to restore and methods to remedy this deficit. Additionally, it will be interesting to track the development of these herbaceous communities into the future, to examine how sown and unsown areas resist re-invasion by shrubs while they are continually managed with periodic burns. Our seed mixes dramatically improved the diversity and floristic quality of the herb layer in this woodland, however many species did not recruit, and key functional groups including sedges and forbs were underrepresented in their abundance. Future research should investigate what ratios of functional groups in seed mixes produce the best restoration outcomes, since conventions established for grassland restoration may not be the best approaches for restoring herbaceous species under a tree canopy. If you are interested in learning about this project in greater depth, the paper is freely accessible here. If you have any questions, feel free to contact Andrew (akaul@mobot.org).

Critical (ecological) care in the land of the dodo: invasive species removal

By Eva Colberg, postdoctoral fellow at Cornell University. Nearly all of Mauritius’s contemporary conservation plights are rooted in or exacerbated by the effects of invasive, non-native species. To see what restoration can do for the island’s few remaining forests, Dr. Eva Colberg joined members of the Tropical Island Biodiversity, Ecology & Conservation research group to visit (and weed) one of the island’s forest restoration sites.

Two of Mauritius’s prominent ecological invaders, a macaque and strawberry guava. Photo: Eva Colberg.

Red stems of strawberry guava (Psidium cattleyanum) form a wall dense enough to prevent walking through most of Mauritius’s remaining forests. Beyond impeding movement, the thick guava understory also reduces overstory tree fitness and disrupts native forest growth and succession. Originally from South America, strawberry guava is a classic case of a non-native, invasive species outcompeting and reducing habitat quality outside its native range (and islands are particularly vulnerable to invasion).

Litter basket ferns (Asplenium nidus) and other native species grow in the understory space freed up in a 20-ha area since the UNDP-funded removal of strawberry guava and other invasives in 1996. Photo: Eva Colberg.

Strawberry guava is far from the only invader threatening Mauritius’s flora and fauna. Alien ants disrupt pollination of native plants, an effect compounded by invasive plant presence. Conflicts between fruit farmers and a keystone seed disperser, the Mauritian flying fox (Pteropus niger), could be due to poor habitat quality and low native fruit production in invaded forests. Invasive macaques (Macaca fascicularis) further disrupt plant reproduction by breaking branches and eating fruits before they’re ripe, and eating and stealing nectar from native flowers without pollination.

Vincent Florens and an undergraduate student discuss the diversity of epiphytes found in a weeded section of forest at Black River Gorges National Park. Photo: Eva Colberg.

The ongoing onslaught of invasion means there’s no time to waste for restoration ecologists like F.B. Vincent Florens, Associate Professor at the University of Mauritius. “We have so many rare species on the brink of extinction [over 80% of the island’s endemic flowering plants are threatened], and have to work at the same time and learn as we go.” His life experience and ecological studies point to invasive species management as the island’s best hope for restoration and conservation, which he likens to healthcare. “First you save the person from dying and then you can treat the other issues.”

Although the views from Black River Gorges National Park are stunning, they also show the sparseness of the park’s forest overstory, with fewer and farther-between survivors.

Although avian re-introductions and rewilding small islets with tortoises are sexier solutions than mere weeding, the best way to keep Mauritius’s mainland forests from dying is through invasive plant removal. After weeding, native trees in all forest strata produce more flowers and fruit, woody plants increase in species richness and seedling density, and butterfly diversity and abundance also increase. These many benefits can be furthered and maintained by follow-up weeding and other subsequent measures (including the promise of biochar to suppress weed regeneration).

Recently described and known to only a few locations, the orchid (Polystachya jubaultii) grows in a weeded forest remnant at Black River Gorges National Park. Photo: Eva Colberg.

Despite decades’ worth of evidence pointing to the efficacy of invasive plant removal in Mauritius, it still isn’t widely implemented. Less than 5% of the island’s few remaining forests have been weeded of invasive plants, and even the best-protected forests are already dominated by invasive undergrowth. Frustratingly, some of the resources that could be used for invasive removal have instead hindered restoration via removal of native pioneer and nurse tree species. “We can do a lot of science, can come up with a lot of facts, but how do we get people to do what they don’t want to do?” Indeed, it’s far easier to uproot a small plant than to change someone’s mind, and Prof. Florens has an entire country to convince that saving their native forests is not only possible, but worth the effort.

Bunkered ex situ plant conservation and páramo biodiversity farms

By Iván Jiménez (Center for Conservation and Sustainable Development, Missouri Botanical Garden), Carlos A. Vargas (Herbario, Jardín Botánico de Bogotá José Celestino Mutis), Carlos I. Suárez (Colecciones Vivas, Jardín Botánico de Bogotá José Celestino Mutis), and Erika Benavides (Finca Milmesetas, Pasca, Sumapaz, Cundinamarca, Colombia)

As anthropogenic pressures on biodiversity mount, plant species conservation increasingly requires the integration of a variety approaches, including ex situ conservation: the maintenance of populations in intensively managed living collections. Conventional seed banking is commonly regarded as a particularly effective and efficient method of ex situ conservation, because a large number of seeds representing many species can be stored for long periods in relatively small spaces at seemingly low cost. It entails drying seeds to 15% relative humidity and storing them at −20 °C. For some “exceptional” species that cannot be easily represented in conventional seed banks, cryopreservation and associated methods are seen as good choices. In contrast, living collections of whole growing plants are often seen as relatively inefficient, requiring more space and care.

A particular problem with seed banks and cryopreservation projects, however, is that they may suffer from a “bunkered” conception of biodiversity conservation. By example, the Millenium Seed Bank is a “flood, bomb and radiation proof” underground facility designed as a “global insurance policy” to conserve seed diversity. Although focused on crops rather than wild plants, the Svalbard Global Seed Vault has a similar bunker ethos, aiming to guard against the loss of plant diversity due “not only to natural catastrophes and war, but also to avoidable disasters, such as lack of funding or poor management”. These bunker-like seed banks invite obvious questions: what protects them from lack of funding, miscalculation, poor management or extreme political ideology?

Both bunker-like seed banks are remarkable spatial concentrations of resources for ex situ conservation, seemingly at odds with the key biological insight according to which a large spatial spread decreases the probability of extinction. At the same time, these seed banks correspond to what Bruno Latour called “centers of calculation”, institutions where observations and specimens from faraway locations are amassed, organized and combined to produce scientific knowledge. Centers of calculation were foundational to the expansion of European colonialism. The Millenium Seed Bank and the Svalbard Global Seed Vault may be seen as contemporary extensions of the same colonial mindset, repurposed in the context of biodiversity conservation.

While other seed banks might not seem as obviously colonial, many do dislocate plant propagules from their original wild plant populations and human milieu. Most plant diversity in ex situ collections is held in the Global North, largely away from sources at the main centers of plant diversity. Even seed banks focused on nearby regional floras remove propagules from their immediate human and non-human environments.

And while not all seed banks boast about their bunker-like properties, many do sit well within the “ark paradigm”, whereby representative samples of species must be secured away (perhaps even in the back side of the moon, as suggested by a foundational paper) in preparation for a likely apocalyptic future of widespread extinction. The ark paradigm is clearly articulated in a chapter about the role of botanical gardens in ex situ plant conservation: “The primary goal of ex situ collections is to maintain a representation of the species as a source of material for restoration, should the species be lost in the wild, and this should be done as effectively and efficiently as possible”. This salvific post-extinction role for seed banks (let alone cryopreservation projects) seems to have little support in practice.

An alternative to the ark paradigm suggests that ex situ conservation can play a primary role before the extinction of wild populations. Ex situ collections may be used for research, training, education, awareness-raising and incentive programs that directly target the causes of primary threats to wild populations. In terms of this pre-extinction role, the conservation value of ex situ collections may be determined by their geographic location. The primary threats to many plant species are local. To address the causes of such threats, the most valuable living collections may be those able to engage the human communities coexisting with threatened plants. Bunkered living collections, removed from the human and non-human environment of the source plant populations, would likely be ineffective and inefficient at this task.

The alternative to the ark paradigm also suggests that ex situ conservation can play a central role in offsetting the effects of threats to wild populations, through the restoration of wild populations via reinforcement. Ex situ collections may provide plant stock for population management aimed at mitigating the effects of threats. Here, again, the geographic location of ex situ collections may determine their effectiveness and efficiency. Ex situ collections in the vicinity of threatened species would seem best for reinforcement programs. Moreover, issues related to propagation of whole growing plants would seem far more germane in this context than the worries about long-term storage prioritized by the ark paradigm and pursued in seed banks and cryopreservation projects.

An initiative adopting this alternative view of ex situ conservation is taking place in the páramo de Sumapaz, perched on the Eastern Colombian Andes. Páramos are high elevation ecosystems that are central for provisioning water to human populations in the tropical Andes. They are perilously affected by global change. The páramo de Sumapaz occupies about 315,000 hectares and, based on analysis of a recently compiled and edited database, hosts more than 3,000 plant species. Although the conservation status of 76% of these species has yet to be evaluated, currently 64 species are known to be threatened.

In this context, a group of researchers including local campesinos as well as staff and students from the Jardín Botánico de Bogotá, Parque Nacional Natural Sumapaz, Universidad Nacional de Colombia, Washington University in St. Louis, and the Missouri Botanical Garden, are engaged in participatory action research, with partial support from the Living Earth Collaborative. The aim is to develop the concept of “páramo biodiversity farms”, provisionally defined as properties in or near the páramo that derive economic benefits from at least one of four activities: i) biodiversity research, ii) education about biodiversity, iii) ex situ conservation of threatened plant species in living collections, and iv) plant stock production for population or ecosystem restoration.

A pilot páramo biodiversity farm began in 2019 at “El Carmen”, a 40-hectare property in the Sumapaz region. This pilot is focused on an ex situ collection of plants in the genus Espeletia (Asteraceae). Although páramo biodiversity farms would include work on many other plants, the focus on Espeletia at El Carmen is strategic. First, Espeletia are dominant “nurse-plants” in páramos and largely determine the physical structure of these ecosystems. Second, despite being locally dominant, several taxonomic species of Espeletia are threatened. Third, obtaining meaningful monitoring data for conservation is often difficult because the species boundaries in Espeletia are poorly understood and field identification is problematic.

Espeletia plants are dominant in páramos, as shown in the picture of the páramo de Sumapaz on the left. Orlando Romero, a campesino working for the Parque Nacional Natural Sumapaz, collects Espeletia seeds for the living collection at El Carmen. Photos by Iván Jiménez.

The living collection at El Carmen serves multiple purposes. First, it is a “common garden” experiment, designed to understand species boundaries and phenotypic characteristics of Espeletia species from Sumapaz. The experiment entails propagating plants from seeds sourced from +500 mother plants occurring across the páramo de Sumapaz, initially in a nursery and subsequently in an outdoor landscape. Second, the living collection serves as a facility to train local students in plant biology and conservation. Third, the collection conserves ex situ threatened Espeletia species that are endemic to the Sumapaz region. Finally, the living collection may serve as a seed-increase field providing Espeletia plant stock for future population or ecological restoration projects.

The picture on the left shows part of the living collection at El Carmen, including seedling trays (forefront), germination containers (right and back), and 3-year old plants in pots on the ground (back left). On the right Rudy Ortiz (left) and Natalia Beltrán, both biology students at the Universidad Nacional de Colombia, measure Espeletia seedlings at El Carmen. Photos by Erika Benavides.

A central theme of the project is the participation of local campesinos as co-investigators and managers, alongside researchers and officials from academic and environmental institutions. Achieving true participatory research and exchange of knowledge across these actors is far from trivial. Nonetheless, a concrete result of the project is that co-investigators, including campesinos, developed a sophisticated understanding of the phenotypic groups of Espeletia and their geographic distributions across Sumapaz, facilitating conservation monitoring programs. This increase in plant awareness among people coexisting with Espeletia plants is a key step towards addressing the causes of threats to páramo plant diversity. Campesino management of the ex situ collection at El Carmen (and the associated information) provides modest but direct economic benefits to a local family. We hope it also builds local capacity for the governance of biodiversity and collaborative relationships between campesinos and institutions focused on studying and managing biodiversity.

Jorge Penagos (left) and Erika Benavides, both campesinos from Sumapaz, record survival of Espeletia seedlings in the living collection at El Carmen. Photo by Rudy Ortiz.

The pilot biodiversity farm at El Carmen hints at how ex situ collections of whole growing plants may help prevent extinction of wild populations. This kind of collection is often thought to be inefficient because requirements of space and resources may be higher than for seed banks and cryopreservation. Collections of whole growing plants for ex situ conservation can indeed be costly when bunkered inside botanical gardens. But they can be more efficient when spread across lands owned by human communities coexisting with threatened plants. We suspect that páramo biodiversity farms may not be more costly than comparable seed banks in the Global North. And the benefits from páramo biodiversity farms would include ex situ collections that act not only as safeguards (the ark paradigm) but also as tools to prevent extinction in the wild and promote local (rather than colonial) biodiversity governance. Studies comparing costs and benefits, beyond back-of-the-envelope calculations, are needed to determine which approaches to ex situ conservation are more effective and efficient in different regions of the world.

“We planted a forest!” – The mental health benefits of ecological restoration: a pilot study

By Suzanne Hicks, Ecological Health Network, Gondwana Link. Suzanne Hicks is a clinical psychologist from Margaret River, Western Australia, with an interest in how nature influences our mental health. Here, she describes the evolution of an innovative pilot project involving disengaged young people in ecological restoration work with the intention of improving their mental health. The novel experimental design allowed her and her colleagues to test the hypothesis that there is a causal link between the observed improvements in social anxiety of the participants and the ecological restoration work undertaken by them.

An intriguing discussion in 2020 with James Aronson, of the global organisation Ecological Health Network (EHN), about the links between ecological restoration, soil health, and human health, whetted my curiosity to attend the second workshop in Hobart, Tasmania in February the following year. Although a clinical psychologist, rather than a scientist or ecologist, I have long been aware of the ways that being out and about in nature has a positive impact on mental wellbeing, both mine and that of my patients. But I wanted to learn more about the mechanisms by which this might occur, and also to be part of the growing movement involved in the regeneration of degraded landscapes and restoration of habitat.

In the days prior to the conference, we visited a site in the North East Bioregion of Tasmania where a group of unemployed people, brought together by Todd Dudley, president of the North East Bioregional Network, had undertaken ecological restoration at the site of a former pine plantation. Over 700 hectares of harvested, burned plantation land had been restored to the trajectory of a thriving native forest recovering from several cycles of clearing and pine plantations.

Landscape immediately following clearing of pine plantation in the North East Bioregion of Tasmania, Australia (left), and the same landscape four years after initiation of restoration of the endemic forest ecosystem.

The scale and success of the Tasmanian ecological restoration project was impressive, but equally intriguing from my point of view was the reported improvement in the physical and mental health of the participants. Accounts of changes from apathetic, disengaged and unhealthy unemployed people to enthusiastic and fit workers, some of whom went on to do further study in forest management and ecological restoration and regeneration, piqued my interest. However, what also stuck in my mind was a comment made by James Aronson. While applauding the success of the project, he also remarked that “It may as well not have happened”. Puzzled, I asked him why. His answer – because there was no empirical research data to support its outcomes. The intuitively obvious link between being involved ecological restoration and improvements in human health was purely anecdotal. I held that thought…

I felt somewhat out of my comfort zone at the start of the Hobart workshop, sitting among a high-powered group of public health researchers and environmental scientists from Australasia and the United States. While passionate about nature and very committed, through my work, to helping people improve their mental well-being, I certainly didn’t have deep scientific understanding of the nexus between the two. However, I was welcomed by the group and soon found myself intrigued and stimulated by what I was learning about ecological regeneration efforts being undertaken around Australia and Aotearoa New Zealand, and the ways that human health is impacted by natural environments and healthy biomes. The take-home message was clear: being in nature is good for people. In particular, the restoration of riverbanks may have the biggest bang for buck, improving water quality and the downstream health of the people who use the water. Yet, again and again, the need for empirical evidence was emphasized.

There is an abundance of data attesting to improvements in human health from being in nature, and also for the positive impacts on the environment of improving biodiversity. However, when it comes to support for the hypothesis that being actively involved in ecological regeneration, in and of itself, improves human health and wellbeing, EHN’s Adam Cross informed me there appears to be only a handful of published papers worldwide. Of these, almost all are correlational, and rely on subjective measures of well-being. There is, therefore, an urgent need for empirical data to guide ecological restoration endeavors, and further, in these times of escalating health budgets, to attract funding for ecological restoration as an important public health intervention.

On the plane back to my home in rural Margaret River, Western Australia, I mulled over what I had learned and wondered how I might bring it to bear in my community. My academic training as a clinical psychologist prompted me to speculate on the ways one might empirically research the hypothesized link between healing activities for impaired ecosystems and psychological health.

The Margaret River Program

I am a member of a recently-formed group of volunteers, who call ourselves Mindful Margaret River (MMR). We are working to improve the mental health and well-being of people in our town, which has had its fair share of recent natural disasters and tragedies: serious bushfires in 2011 and 2021 that burned numerous homes as well as large areas of national parks, and a multi-generational murder/suicide that took seven members of a single family. In addition, I belong to our local Nature Conservation group (NCMR). I wondered if, under the umbrella of MMR, I might develop a program, drawing on the resources of NCMR, whereby disengaged students from our local high school were invited to be part of a 20-week ecological restoration program aiming to improve both nature and the participants’ mental health. The novel part of the program would be to allocate students to one of two groups, the first involved in ecological restoration and the other to be in actively working in nature but not specifically participating in restoration activities. Researchers from the Psychology Department of University of Western Australia (UWA) would be invited to empirically evaluate the outcomes of the program.

In collaboration with my colleague Sandra Robertson, a community nurse at the local high school, a twenty-week program was developed taking students from school one day per week under the supervision of two teachers. The program would be assisted by NCMR staff in the practical aspects of restoration work. Volunteers from the Cape to Cape Walking Track  would guide the second group in maintenance of this long-distance coastal hiking track. The program would be under the formal custodianship of the local Indigenous Peoples, the Wandandi Peoples, who welcomed the students onto their Country (an Australian term referring to the ancestral Traditional lands of an Indigenous group) and accompanied them for a number of days throughout the program to teach them about Indigenous lore and culture, and about caring for Country. Additionally, a number of people working in environmental science and management such as rangers, scientists, and artists, were approached to talk to the students about nature-based career options, and on other occasions the students heard from experts in various components and aspects of local biodiversity.

Wandandi cultural custodian Zac Webb drawing a map of Country for the participants of the high school program.

Students of the program learning simple survey skills prior to beginning restoration work.

Over the course of 2020 we secured seed funding for the project from EHN Hub Gondwana Link, and subsequently full project funding from the Western Australian state-based grants body, Lotterywest, to operate the program for a further two years. Following this success, our pilot program was launched in 2021. Twenty-four year 10 and 11 students were selected, semi-randomly, for the two groups. There were 17 boys and seven girls, and four of the students were Indigenous. Their average age was sixteen. Sadly, due to behavioral issues, after 12 weeks the group involved in track maintenance was disbanded.

Students were excited to record different species of fungi during biological surveys.

The regeneration group completed the 20-week program and three questionnaire measures of their psychological wellbeing, taken at three points in the program, were obtained and analyzed by the UWA researchers. Taken together with focus group information, the researchers determined that there had been a statistically significant reduction in the students’ social anxiety over the course of the program, and that they had developed a greater sense of connection with nature and more appreciation of the actions they could take as individuals to help preserve their local environment.

The Boodja (“Country”) Regeneration crew, on Country during their 20-week program.

The Biddi (“Coastal path”) crew, on Country during the program.

After the challenges of the pilot stage, more work is now being undertaken to modify the research model of the program to fit more smoothly within the framework and timetabling of the school curriculum. However, even at this early stage we are pleased to be able to begin demonstrating empirically the benefits for mental health of being involved in ecological restoration activities. We hope that the next stage of the program will build our evidence base further, developing strong empirical support for the health benefits of engaging with nature and participating in ecological restoration—towards a vision where such activities might even become a central aspect of learning and education. In the meantime, it was a delight to have the enthusiastic endorsement of our young participants, captured in the comment from one of them – “We planted a forest!”

How does prescribed fire affect a threatened terrestrial orchid?

By Leighton Reid and Ryan Klopf

Leighton Reid is an assistant professor of ecological restoration in the School of Plant and Environmental Sciences at Virginia Tech. Ryan Klopf is the Mountain Region supervisor and natural areas science coordinator for the Virginia Natural Heritage Program. They describe a new research project that aims to understand how an important restoration tool impacts the population dynamics of federally threatened small whorled pogonia orchids. This project has an open PhD position available to start in January 2023; details can be found at the end of this post.

Deep in the heart of Virginia’s Shenandoah Valley, nestled against the western edge of the Blue Ridge Mountains, two clusters of small, green orchids grow in the dappled sunlight of a woodland understory. The orchids are small whorled pogonias (Isotria medeoloides) – a rare species that is considered threatened by the United States government because its population is declining so quickly that it could become endangered in the foreseeable future. We have monitored these populations for the past two summers, keeping tabs on every individual, to learn how this species is affected by one of the most important restoration tools in North America – prescribed fire.

A small whorled pogonia orchid with two flowers at Mount Joy Pond Natural Area Preserve. Photo: Lindsay Caplan.

Small whorled pogonia

As their name implies, small whorled pogonias are small (≤25 cm) and whorled (their leaves radiate outward from the stem). This species is a member of the Pogonieae, an orchid tribe that includes species in Asia and eastern North America. Its closest relative is the large whorled pogonia (I. verticillata) which sometimes grows alongside small whorled pogonia, but is distinguished by its purplish stem (small whorled pogonia has a whitish green, glaucous stem).

Small whorled pogonia (left) with a whitish, glaucous stem compared to large whorled pogonia (right) with a purplish stem base. Photos: Sara Klopf (left) & JL Reid (right).

Small whorled pogonias emerge from the leaf litter in late spring and in some years produce one or two solitary greenish yellow flowers, particularly when plants are exposed to more sunlight. Their flowers do not require any help with pollination; they produce the same amount of seed whether they are cross-pollinated or pollinate themselves.

The seeds themselves are tiny – like vanilla seeds, which are in the same orchid sub-family (Vanilloideae). The parent plant (which is usually both a mother and a father) provides almost no resources at all to its offspring. Each seed’s fate is closely linked to whether or not it finds a mycorrhizal fungus in the Russulaceae family to help it acquire the resources that it needs to survive and grow. In a typical relationship between plants and mycorrhizal fungus, the fungus scours the soil for nutrients like nitrogen and phosphorus and provides them to the plant in return for energy in the form of carbohydrates, which the plant produces through photosynthesis.

A developing fruit on a small whorled pogonia orchid at Mount Joy Pond Natural Area Preserve in June 2022. Photo: Andres Cunningham.

Fire and water at Mount Joy Pond

The story of this research project begins about 80 years ago, in a DuPont chemical plant in Waynesboro, Virginia. In the 1930s-1950s, the DuPont facility used mercury to produce rayon – a synthetic, silk-like fiber. Some of the mercury escaped from the plant and leaked into the South River – a tributary of the Shenandoah River. Mercury is a neurotoxin, and in the environment it can accumulate to dangerous levels in animals that are higher on the food chain, like fish. For many years, people living along the South River have been warned about the poor water quality and advised not to eat the fish.

In 2016, DuPont reached a $50 million USD settlement with the United States Department of Justice, the Department of the Interior, and the Commonwealth of Virginia to restore habitat for wildlife in the South River watershed, enhance water quality, and improve recreational areas. This settlement represented one of the largest environmental damage settlements in United States history.

Some of the DuPont settlement money was allocated to the Virginia Natural Heritage Program, a division of the Virginia Department of Conservation and Recreation that uses science-based conservation to protect Virginia’s plants and animals. Specifically, funds were provided to allow the Virginia Natural Heritage Program to protect and restore woodland habitat surrounding a unique wetland at the Mount Joy Pond Natural Area Preserve in Augusta County.

Briefly, Mount Joy Pond is a Shenandoah Valley Sinkhole community; that is, it is a groundwater-controlled wetland that floods intermittently when water percolates up through underlying carbonate rocks and then floods over the top of a clay lens perched in a layer of soil derived from the overlying sedimentary rocks. When this happens, the water becomes trapped, like water in a saucer. This unique situation creates wetland habitats which have persisted for the past 15,000 years and contain numerous rare and disjunct species, including the globally rare Virginia sneezeweed (Helenium virginicum). There are several dozen Shenandoah Sinkhole ponds, but only a handful of them are protected.

Virginia sneezeweed, an endemic species in the southeastern United States with disjunct populations in Virginia’s Shenandoah Valley sinkhole ponds and in a similar wetland situation in the Ozark Mountains of southern Missouri. Photo: JL Reid.

In the past, Mount Joy Pond filled with water every few years, but in recent decades it has filled up less and less often. To restore the wetland’s hydrology, the Virginia Natural Heritage Program set out to thin the surrounding forest and re-introduce fire to prevent fire intolerant trees, such as red maple, from regenerating. This may sound counterintuitive to some, but the logic is this:

• Each tree is like a drinking straw sucking water out of the ground and releasing it into the air via transpiration. If there are a lot of trees, the groundwater may stay too low to fill up the pond.
• Fire used to be much more common in the Shenandoah Valley. Prior to European colonization, Indigenous People burned the landscape and maintained much of it as savanna and open woodland – ecosystem types that have fewer trees than present day forests.
• By removing some trees and reintroducing a regular fire cycle, land managers at Mount Joy Pond Natural Area Preserve can restore an open woodland and raise the groundwater level, causing the pond to flood more often.

The Virginia Natural Heritage Program began to implement this restoration project in 2017, and the first thinning operations and burn were a success. In the years since, the groundwater level appears to have gone up, suggesting that the hydrological restoration plan is working.

Small whorled pogonia discovery

In the first spring after that first fire, a botanist was surveying the burned woods near the pond and found something unexpected – a small population of small whorled pogonia orchids, which had not been seen previously in the preserve despite extensive surveying by the Virginia Natural Heritage Program’s inventory team. Were the orchids there all along and nobody noticed them? Maybe. Or maybe the fire helped the orchid population emerge after years of suppression in the dense leaf litter in the shady understory.

Our team uses a grid sweep survey to search for new small whorled pogonia individuals in June 2022. Photo: JL Reid.

The story became more complicated later that summer when a more intensive search turned up a second population of small whorled pogonia orchids on the preserve – this one in an area that had not been burned.

The immediate consequence of discovering the new pogonia populations was that the United States Fish and Wildlife Service expressed concerns that future fire management might be detrimental to this threatened species. Nobody had studied how small whorled pogonia responds to fire, and there was a chance that burning could damage the population, even if it was good for the nearby pond’s hydrology. Of course, there was also a chance that not burning could damage the population. With fire, inaction is still an action.

To help settle the issue, the United States Fish and Wildlife Service agreed to sponsor a PhD student to study the small whorled pogonias at Mount Joy Pond and figure out how their population dynamics are impacted by prescribed fire.

Lindsay Caplan and Jimmy Francis monitor a population of small whorled pogonias at Mount Joy Pond Natural Area Preserve in June 2022. Photo: JL Reid.

Effects of prescribed fire on small whorled pogonia orchids

The main goal of our ongoing research is to understand how prescribed fire impacts small whorled pogonias. To do this, we will map and monitor the two subpopulations and the woodland plant communities in which they live. Over the next two years, one of the two subpopulations will be burned during a winter or early spring prescribed fire, and we will continue monitoring to document changes in plant vigor, reproduction, and population size. We will pay special attention to the light environment, which seems to be important for small whorled pogonia reproduction, and to the diversity and composition of soil fungi, which are important for small whorled pogonia emergence. We will also conduct annual surveys of the entire reserve to search for additional populations.

Ethan Dunn uses a canopy imager to measure canopy cover, photosynthetically active radiation, and leaf area index over a tiny small whorled pogonia individual in July 2021. Photo: JL Reid.

This project is just beginning. To date, we have monitored the two populations for two growing seasons (2021, 2022). There is still much work to be done. One of the next steps will be to produce an accurate map of each plant’s location, which will require centimeter-level precision using high-quality GPS equipment under a forest canopy.

We are currently seeking a PhD student to lead this research project starting in January 2023. A description of this opportunity is below. This project is an excellent opportunity for a student to develop expertise in ecological restoration and threatened species conservation from both a scientific perspective and an on-the-ground land management perspective.

Ultimately, the results of from this study will inform management of natural areas and small whorled pogonia restoration projects throughout the species’ wide range – from Ontario to Georgia.

A new perspective for plant translocation science: the International Plant Translocation Conference has been born

By Thomas Abeli, Department of Science, Roma Tre University

Many plant species around the globe are threatened with extinction or have already been extirpated from the wild as a result of habitat loss, pollution, alien invasive species, and climate change. Among the possibilities in the toolkit of conservation biologists to halt and reverse the loss of plant diversity, translocation is now a commonly used approach. Translocation is defined by the International Union for the Conservation of Nature (IUCN) as a deliberate transfer of species from one site to another for conservation purposes that includes different types of movements: population reinforcement of small and genetically depauperate populations, reintroduction of species within their native range in sites where they occurred in the past and from where have been extirpated, and conservation introduction of species outside their indigenous range. While the primary motivation for translocation is often the recovery of single species, translocation also plays a key role in ecosystem restoration – enabling the United Nations to achieve global goals for its 2020-2030 Decade of Ecosystem Restoration.

Reintroduction of Pyne’s ground-plum (Astragalus bibullatus) was featured in a talk by Dr. Matthew Albrecht on adaptive management in reintroduction programs at the first International Plant Translocation Conference in June.

Plant translocation is sometimes highly successful, sometimes dramatically discouraging and unsuccessful. Such variability in translocation outcome is rooted in the still poor understanding and standardization of techniques given that the field of translocation science remains in an early stage of scientific development. Translocation programs are challenging and complex, often requiring an interdisciplinary team that may include conservation biologists, restoration ecologists, taxonomists, geneticists, practitioners, policy makers, indigenous peoples, citizen scientists, and local community members.

It is common in science to organize periodical conferences where scientists from around the world meet and discuss recent findings and share ideas in a specific field. Although plant translocation is often discussed in national and international conservation biology conferences, we lacked a dedicated conference or forum to share experiences and improve plant translocation science and practice to deliver more effective conservation outcomes. With the aim of filling this gap, a group of field-leading scientists developed the 1^st International Plant Translocation Conference as a new forum to share ideas and advance the field of plant translocation.  After multiple delays over the past two years due to the COVID-19 pandemic, the Science Department of the Roma Tre University hosted the inaugural International Plant Translocation Conference (IPTC2022) from 20 to 23 June 2022 in Rome, Italy. Designed as a hybrid conference platform to promote global participation and inclusion, the conference included 71 participants (including online attendees) representing 19 countries and 5 continents.

Attendees and staff of the 1^st International Plant Translocation Conference (IPTC2022) in Rome.

With nine international keynote speakers from the International Union for Conservation of Nature (IUCN), the Center for Plant Conservation (United States), the Missouri Botanical Garden, the Curtin University (Australia), the Meise Botanical Garden (Belgium), the Liverpool John Moores University (United Kingdom), the University of Cagliari, the University of Pavia and the Botanical Garden of Rome (La Sapienza University), along with nearly 40 talks, a poster session, workshop, social events, and a field trip, the IPTC represented an outstanding opportunity for the global community of conservation biologists involved in plant translocation to present recent findings, best practices, learn from each other’s experiences, initiate new collaborations, and transfer knowledge to the next generation of conservation scientists and practitioners. The congress was organized around five thematic sessions covering topics related to translocation techniques, ex situ conservation approaches to support translocation, data sharing and ethics, and translocation case studies from the Mediterranean bioclimatic region.

Additionally, the congress discussed the controversial topics of assisted migration and de-extinction, which generate international news headlines. Assisted migrations are debated on one side for the opportunity they represent to save species threatened by climate change and, on the other side, for the risks they imply for recipient ecosystems. De-extinctions represent the last frontier of conservation. While still in the hypothetical stage, the idea of ​​reviving extinct species is fueling a wide scientific debate among supporters, opponents, and those who advocate conservation approaches that are more pragmatic. Research presented at the IPTC 2022 suggested that herbarium specimens and ex situ collections could support plant de-extinction perhaps more easily than resurrecting extinct animal species via back-breeding, cloning and synthetic biology.

Dr. Hong Liu from Florida International University presenting her research at the IPTC 2022.

The importance for scientists to meet in conferences has been exacerbated over the past two years when the COVID pandemic confined conferences to virtual online events. While virtual conferences remain an important vehicle for exchange of scientific knowledge, the lack of personal interactions through interactive workshops, brainstorming through informal discussions, and social events can stymie engagement and collaborative development. As one of the first post-pandemic congresses to meet in person, the number of new connections and collaborations developed during the IPTC conference should spur many advancements in translocation science.

IPTC2022 attendees relaxing and chatting during the field trip in Castelluccio di Norcia (Central Apennines, Italy).

For example, originating from informal discussions at social events a large group of IPTC attendees are now preparing a manuscript on best practice guidelines for mitigation translocations. The conference also revived discussion about developing a global interoperable register and database of plant translocation – a feature that would undoubtedly accelerate synthesis and meta-analysis and surely benefit the international community. Finally, a special issue of Plant Ecology entitled “Advances in Plant Translocation” will be dedicated to articles derived from IPTC talks.

More broadly, the achievement of the first IPTC and the following editions, are expected to contribute to the United Nations 2030 Agenda that outlines the medium-term strategy to reverse the trend of global biodiversity loss, to integrate policies of sustainable exploitation of natural resources on which the well-being of the growing world population depends, and to reduce and mitigate conflicts between man and the environment. In particular, the IPTC conference will impact the Sustainable Development Goal 15 “Life on Land”, as well as the more specific United Nations initiative “Decade of Ecosystem Restoration”. The organising committee of the IPTC2022 is already at work to identify a suitable location for the next IPTC conference, ideally within the next two/three years. Stay tuned for more exciting news and developments.

---

For more on translocations, see Translocating a threatened totem by Adam Cross

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

Madagascar’s unique history has created unique restoration challenges

Leighton Reid describes new research linking slow forest recovery to the ancient and protracted isolation that has made Madagascar a hotspot of global endemism – plus an example of working with local farmers to overcome these challenges and restore native rain forest.

Madagascar is a special place with a special history. Separated by ocean from Africa and India for the last 88 million years, this isolated tropical island has fostered the evolution of plants and animals found nowhere else on Earth. Lemurs, couas, and the plant family Sarcolaenaceae are all examples of organisms that evolved only in Madagascar. Collectively, such endemic species make up more than 80% of all plants and animals there.

Crested coua (Coua cristata), one of nine species in the genus Coua – all of which are found only in Madagascar. Photo credit: Olaf Oliveiero Riemer (CC BY-SA 3.0).

Madagascar also has special problems. Almost half of the island’s forest has been cleared for agriculture since 1953, and remaining forests are at imminent risk. One recent study projected that if deforestation rates do not diminish soon, 93% of eastern Malagasy rain forest could be gone by 2070.

The combination of a large proportion of endemic species and a high degree of habitat loss makes Madagascar a biodiversity hotspot. Some people call Madagascar one of the hottest hotspots because its endemism and habitat loss are so extreme.

This week, a new study led by UC Berkeley PhD student Kat Culbertson identified another special problem in Madagascar: following disturbance, Malagasy forests recovery very slowly. Compared to other tropical forests around the world, Malagasy rain forests recover only about a quarter (26%) as much biomass in their first 20 years of recovery. Dry forests in Madagascar also recover more slowly, recovering just 35% as much biomass as American tropical dry forests over the same time period.

Slow biomass recovery following disturbance in Madagascar (dark blue) compared to Central and South America (Neotropics), Africa (Afrotropics), and Asia (Asiatic tropics). Source: Katherine Culbertson et al. (2022) Biotropica.

Why do Malagasy forests recover more slowly than forests in other regions? The answer may be related to Madagascar’s unusual evolutionary history. Culbertson and her co-authors developed four hypotheses and reviewed an array of scientific literature to evaluate support for each one.

Four ways that Madagascar’s unique history could lead to slow forest recovery

1. Native Malagasy forests lack resilience to shifting nutrient and fire regimes from current farming practices. Many rural people across Madagascar practice tavy, a farming method that involves clearing forest, burning it, and then growing rice – a staple crop. After one or a few years of growing rice, the land is allowed to recuperate for several years before it is cultivated again. In other tropical forest locations, such as southern Mexico where humans have farmed for thousands of years, similar practices can coexist with native forests, but Malagasy forests seem to have little resilience to tavy, as least at the intensity with which it is practiced today. For example, in eastern Madagascar, a 3-5 year tavy cycle can cause a native forest to transition to permanent herbaceous vegetation in just 20-40 years. The soil nutrient stocks in that fallow field may be as little as 1-6.5% of soil nutrients stocks in intact forest.

2. Madagascar is an island, and islands tend to have more problems with invasive species. Goats in the Galapagos, brown tree snakes in Guam, acacia in Hawaii, and rats everywhere – these are just some of the ways that island ecosystems have been overwhelmed and transformed by invasive species. Madagascar is no exception. Rain forest regeneration at Ranomafana is stalled by invasive guava, eucalyptus, and rose apple, while dry forest regeneration at Berenty is inhibited by a vine – Cissus quadrangularis. People in Madagascar have many more anecdotes about problems with invasive species like silver oak and Melaleuca quiquenervia, although the extent and impact of these invaders on forest recovery have not yet been studied.

3. Old, weathered soils have favored the evolution of slow-growing native plants. Madagascar is not only an island, it is a very old island, and as such its soils have been weathered and depleted of important nutrients like phosphorus. It’s hard to separate the effect of inherently low nutrient availability due to being an old island from the effect of human-induced nutrient scarcity through tavy, but one comparison of phosphorus content in rice stalks showed that phosphorus content was 10× lower in Madagascar compared to the rest of sub-Saharan Africa. If native trees have evolved to grow more slowly in Madagascar because of low nutrient availability, then on average exotic tree species should grow faster than native Malagasy ones in the same gardens. This has been shown in a few cases, but a more compelling analysis would need more species.

4. Finally, Malagasy forests have dysfunctional seed dispersal. One way in which Madagascar is different from other tropical areas is that by and large its trees have evolved to have their fruits dispersed by lemurs. Unfortunately, many of the lemurs that could disperse Malagasy tree fruits are either extinct or endangered – in many cases due to a combination of hunting and habitat loss. Moreover, the lemurs that remain are reluctant to venture outside of forest fragments (perhaps with good reason) and so they are unable to disperse seeds to regenerating farmlands that most need them.

Black and white ruffed lemur (Varecia variegata) – a critically endangered seed disperser in eastern Madagascar. Photo credit: Tim Treuer.

In essence, the ancient and protracted isolation that has made Madagascar so unique has also made it uniquely vulnerable to contemporary changes like deforestation, fire, and agriculture. The result is an unfortunate combination: Madagascar not only has some of the highest deforestation rates, it is also one of the places least ecologically equipped to rebound from those disturbances.

A mosaic of mature tropical dry forest and forest restoration at Berenty in southern Madagascar. Photo credit: Ariadna Mondragon Botero.

The way forward – working with local people

Despite these challenges, Madagascar has committed to restoring four million hectares of lost habitat by 2030, an area nearly 7% the total national territory. This is a tall order in a country where technical difficulties are high and financial resources are often low, but it can be done, and the way forward, undoubtedly, is to work with local people.

One group that exemplifies bottom-up restoration is GreenAgain, a non-profit restoring native rain forest and supporting rural livelihoods in eastern Madagascar. GreenAgain is led and staffed by farmer-practitioners whose neighbors, family, and friends contract with GreenAgain to design, plant, and monitor diverse native forests on their lands. Last year, GreenAgain staff planted 20,000 trees across central eastern Madagascar, each one carried by hand, on foot, from one of eight regional tree nurseries. The rural farmers at GreenAgain collect rigorous data on tree survival and growth and collaborate with scientists to analyze and share the results of their tree planting experiments.

For example, one of the earliest experiments at GreenAgain was an assay of tree planting strategies intended to improve native tree seedling survival during plantings that occur in the dry season. Trees planted during the dry season typically have high mortality, sometimes in excess of 40%. One of the strategies that local farmers recommended to improve survival was to erect small teepees over each seedling using the leaves of a common fern, Dicranopteris linearis. These structures are temporary – they eventually dry out and blow away – but GreenAgain’s experiment showed that they reduced transplant shock (i.e., mortality in the first few weeks) by 75% compared to seedlings that were left to bake in the hot sun. In contrast, many of the other treatments had no discernable effect.

To analyze and publish these findings, GreenAgain partnered with an award-winning undergraduate researcher, Chris Logan, in my lab at Virginia Tech, who led a peer-reviewed paper that is now available at Restoration Ecology.

Leaf tent made with a ubiquitous fern, Dicranopteris linearis, placed over a native tree seedling. Photo credit: Catherine Hill.

Could technological solutions like hydrogels or irrigation systems produce greater improvements in dry season tree survival? Yes – they probably could for a certain price, but homegrown solutions like fern leaf shade tents are free and easily accessible to any person doing restoration across eastern Madagascar. They are also more likely to be used because they were developed by local people.

This study also showed that some native tree species are much better at coping with dry season stress than other species, so another possible solution for dry season plantings could be to plant only the tough survivors. Once those trees survive and begin to produce shade, fern leaf tents may not even be needed anymore to help more sensitive native species survive and grow.

To read more about ongoing restoration and ecological research in Madagascar, read our new review of how Madagascar’s evolutionary history limits forest recovery and our new open-access paper about strategies for dry season plantings in eastern Madagascar.

If you are in a position to support the work of local farmers restoring rain forests in eastern Madagascar, consider donating to GreenAgain at their website, greenagainmadagascar.org.

Identifying regional and restoration species pools for the Ozark Highlands

Andrew Kaul is a Restoration Ecology Post-doc in the Center for Conservation and Sustainable Development working with Matthew Albrecht at the Missouri Botanical Garden, and Michael Barash is a junior Biology major at Washington University in St. Louis. Here they describe Michael’s undergraduate research on commercial native seed availability for woodland restoration.

One of the largest barriers to restoration of degraded terrestrial habitats is availability of seed for use in reintroduction of desirable native plant species. Over the past few decades, the industry of native plant seed production has grown rapidly, but most native species in the US (and globally) are still not commercially available, and there can be strong biases in which types of species tend to be selected by seed producers.

In ecological parlance, a “species pool” represents all of the species which can colonize and occupy a certain region. Not all of the species in a regional species pool are available commercially, which is how many restoration practitioners acquire seeds, so the subset of species pool that contains only the species that are commercially available in a given region is sometimes called the “restoration species pool”.

For most ecosystems around the world, it is not well documented what proportion of the species pool is commercially available, and why these species have been selected for commercial trade. The few studies that have been conducted on commercial seed availability for restoration have found consistently that herbaceous (rather than woody) and rare species (rather than common ones) are less likely to be available, and there are strong taxonomic biases in which plant families are more represented. In the US, these studies have focused on open-canopy habitats with few trees, such as grasslands, rather than on more closed-canopy systems like woodlands and forests.

An open rocky glade (left), and a glade to woodland transition (middle), a woodland understory (right; Shaw Nature Reserve, Gray summit MO).

To address this information gap, we assessed the capacity of the native seed industry to support ecological restoration across terrestrial habitats in the Ozark region of the midcontinent USA. The use of seed additions to accelerate recovery of plant diversity in Ozark woodlands and forests is not well studied, and little information is available on how to best select species for reintroduction from seed. The specific goals of this project were to:

1) Identify the species pool of native herbaceous (non-woody) vascular plants appropriate for restoration of glades, woodlands, and forests in the Ozark Highlands;

2) Define the restoration species pool by identifying which of these species are commercially available;

3) Quantify biases in this restoration species pool with respect to growth form, rarity, habitat affinity, and a few important functional traits;

4) Identify candidate species which are not available from seed vendors, but should be a priority for seed production due to their importance for Ozark habitats.

The spatial scope of this study is the Ozark Highlands, level III ecoregion 39, which covers all of Southern Missouri, as well as parts of Northern Arkansas, and NE Oklahoma.

We began this project by developing a targeted species list of 1,178 herbaceous species native to upland habitats in the Ozark region, based on existing datasets from the Ecological Checklist of the Missouri Flora, the Flora of Missouri, and the Biota of North America Program (BONAP).

We predicted there would be selection, implicit or explicitly, by seed producers for species based on their growth form, conservatism score wetness rating, rarity, and functional traits. Each species’ physiognomy (growth form), conservatism score (that is, sensitivity to disturbance), and wetness ratings (a type of habitat affinity) were included in the Missouri Checklist. For each species in our pool, we compiled data on two measures of rarity including a qualitative measure –  the official Missouri State conservation ranking, and a quantitative measure – the range size of the species in the US, as measured by the number counties in the nation where there have been recorded occurrences in the BONAP database. We compiled trait data on height of adult plants, and bloom timing and duration from species descriptions in the Flora of Missouri. For each grass species, we compiled data on photosynthetic pathway from published literature.

We made predictions that species with certain growth strategies, traits, range sizes, and habitat preferences would be under- or over-represented in the pool of species produced by seed vendors. We predicted that compared to other growth forms, perennial forbs would be over-represented in the restoration species pool because the aesthetic value of restoration projects is often a high priority, and perennial forbs with their big flowers, are “showier” and will return year after year. Similarly, taller species, and those with a longer bloom period may be selected preferentially because their blooms are more noticeable. We expected that species which have a smaller range or are not abundant in sites where they do occur are less likely to be in demand by restoration practitioners, so are less likely to be commercially available. Based on this pattern we expected species with a lower conservatism score, larger range size, and higher conservation rank (less concern for conservation) to be more commonly produced by seed vendors.

We predicted that species with a larger range such as pale purple coneflower (Echinacea pallida; map on the left), would be more likely to be available from at least one producer than species with a smaller range, such as the related yellow coneflower (Echinacea paradoxa; right). Maps are from BONAP, and light green areas denote counties where the species has been reported.

The cottage seed industry for prairie plants has grown especially rapidly in recent years, so we expected that species which are generally found in more open habitats like glades, prairies, and savannas, would more likely to have been selected by at least one producer than the species which occur mostly in shady habitats like woodlands and forests. Similarly, since open habitats tend to have drier soils than shaded ones, we predicted there may be a bias toward species with a higher (drier) wetness rating. Many grass species that grow in open habitats have evolved a more efficient way of conducting photosynthesis under hot sunny conditions. There are fewer of these “warm-season” grasses than “cool-season” ones, but we predict that proportionally more warm-season grasses will be commercially available, because they are common in the prairie seed market.

Inflorescences of big bluestem (Andropogon gerardii), and Indian grass (Sorghastrum nutans) can be seen at this glade to woodland transition at Victoria Glades Conservation Area in Hillsboro, MO. These warm-season grasses are dominant in many prairies and common in glades, but generally do not occur under the canopy of wooded areas.

In order to test these predictions, we needed to compile information on which species in our pool are available from seed vendors. We identified ten seed vendors that are likely potential sources of seed materials for species native to the Ozark Highlands. These include five seed vendors within Missouri, four large regional seed vendors located in Iowa, Minnesota, and Kentucky, and one very large seed vendor that produces seed for regions all across all the US. We were able to get information on which species each vendor produces from their website, or if they did not have a website, then through personal communication. Many vendors sell a combination of seeds and potted plants, with most species only being available in one form or the other. For this study, we were only interested in seed products because restoration of herbaceous communities through seed additions is the most common and affordable approach.

Based on preliminary analyses, we found that 501 (43%) species were commercially available from at least one vendor. We found the strongest trends supporting the prediction that species differ in their likelihood of commercial availability based on physiognomy or “growth form”. Perennial species were twice as likely to be available as shorter-lived annual or biennial species, and as predicted, forbs were better represented in seed vendor catalogues than grasses or sedges.

We predicted that more common species would be better represented in the restoration species pool and our results somewhat support this prediction. Conservatism scores are assigned to species by expert botanists in each region, so they reflect how rare and how disturbance tolerant species are within local areas. In the US, these scores are often assigned at the state level. In order to avoid over-interpreting these designations, we binned scores into three groups including ruderal (0-3), matrix (4-6), and conservative (7-10) for use in our analysis. We found that “matrix” species with middling conservatism scores were more likely to be available than conservative or ruderal species. This may be because ruderal species can be somewhat weedy and may be expected to recruit into restored areas as volunteers. And on the other hand, highly conservative species may be difficult to grow for seed production, or have a small range, and thus limited restoration potential or demand. The state of Missouri has designations for the conservation concern of all native species. We found that species classified as “vulnerable” (S3), “imperiled” (S2), or “critically imperiled” (S1) were less likely to be available from seed vendors, as species classified as “secure” (S5) or “apparently secure” (S4). And finally, as predicted, we found that species with larger ranges are more likely to be commercially available.

We expected species which mostly occur in open habitats with little tree cover to be more likely to be commercially available. We classified each species as belonging to one of three habitat affinity groups, being an open habitat specialist, closed habit specialist, or a generalist. We found no bias in species availability based on habitat affinity or based on the wetness rating for Missouri. Based on the prediction that the prairie-focused seed market would promote availability of warm-season grasses, we thought they would have greater proportional representation in the seed market, but we also did not find evidence for that prediction. Warm and cool season grasses were equally likely to be available, with about a third of all species belonging to each group being available.

While we did not find that species with affinity to open habitats were more likely available from at least one producer than species from closed habitats, we did notice that the species which were sold by the most producers tended to be “prairie species” like butterfly milkweed (Asclepias tuberosa; left), which was available from 9 of the 10 vendors we surveyed, or stiff goldenerod (Solidago rigida; right), which was available from 8 vendors.

Traits of species may also contribute to seed vendors’ interest in propagating them. We found evidence that within perennial wildflowers (forbs), species with a taller maximum height are more likely to be available. We also predicted that species with a longer potential bloom period would be better represented in the seed market, but surprisingly our data shows a negative relationship, where species that can bloom for many months are less represented in the restoration species pool. This pattern may be driven by differences between functional groups or plant families and deserves further investigation.

The final goal of this project was to identify candidate species to recommend to seed producers as valuable for restoration potential. We identified such species based on the highly detailed descriptions provided in a keystone reference for this region, Paul Nelson’s The Terrestrial Natural Communities of Missouri (2005). This book describes the geologic, climatic, and natural features of natural community types in Missouri. We only considered habitats within the broad designations of forests, woodlands, savannas, prairies, and glades, and we narrowed our focus to only habitat types that occur within the Ozark Ecoregion. For each of these 37 Ozark habitats, this reference provides lists of plant species that are “dominant”, “characteristic”, or “restricted” to that habitat. We propose that a good starting place in assessing the capacity of the native seed industry to support ecological restoration across terrestrial habitats in the Ozark region is to examine whether all of the “dominant” plant species in habitats within the Ozarks are available from vendors. Of the 120 species identified by Nelson as “dominant” in Ozark habitats, 80 of them (66%) were commercially available. This is encouraging, since it is higher than the overall availability rate of 43%, however there are still 40 species which would be difficult for restoration practitioners to acquire without hand collecting from wild populations. This highlights how biases in the restoration species pool could potentially make assembling a high-quality seed mix more difficult, if the species for sale represent those which are easiest to cultivate, rather than being the ones which have the most biological significance to restoration.

Birdfoot violet (Viola pedata) is classified as a dominant species for dry sandstone woodlands and is common on dolomite glades. Fortunately, we found it is commercially available from two vendors. Two other violets, wood violet (Viola palmata), and arrowleaf violet (Viola sagittata) are dominant in other Ozark habitats, but are not available from any of the vendors we surveyed.

Here, we are only scratching the surface in terms of identifying ways in which the seed production industry may inadvertently be biasing the restoration species pool and consequently the diversity and composition of restored plant communities. In the future we recommend continued collaboration between seed producers, restoration practitioners, and conservation scientists, to identify the limitations of available seed stocks and better align supply and demand for native seeds. Most seed vendors do not label products at taxonomic designations below the species level. However, conservation goals are sometimes identified for subspecies or varieties. The extent to which these taxa are commercially available is difficult to assess. Additionally, many restoration projects call for seed from a local provenance, but obtaining information on ecotypes of native seed lots from vendors can be difficult. While nearly 40% of our species pool for restoration projects in the Ozark Highlands are commercially available, the proportion of those species that are available from an Ozark ecotype is likely much lower.

We are currently preparing this project for publication. If you are interested in learning more, or have any questions, feel free to email Andrew (akaul@mobot.org).

Ecological restoration operations in the French Mediterranean coastal environment to promote dusky grouper population recovery

By Gilles Lecaillon, Etienne Abadie, and Charlotte Soler (founder and CEO, Project Manager, and intern at Ecocean, Ltd.). Ecocean is a French company providing ecological restoration and engineering ideas and services since 2003, including habitat creation for juvenile fish in near-coastal marine ecosystems, and floating islands of vegetation for multiple ecosystem services in fresh water lakes, in Europe, Asia, and elsewhere.

Near-coastal marine ecosystems and their biodiversity are under great pressure from human activities. Ecosystem processes and functionality can be impacted and disrupted by our infrastructures or activities, resulting in losses of ecosystem health and delivery of ecosystem services. Over the past few decades, conservation, revised management, and ecological restoration activities have been designed and implemented with the aim to reduce and compensate for the impacts we have on marine ecosystems. By using technological innovation, ecological engineering, and ecological restoration approaches, we manage to enhance and support different ecological processes, resulting for example in diversification of food chains or complexification of habitats in the targeted aquatic ecosystems. As compared to some terrestrial ecosystems, the science and practice of ecological restoration in marine environments, and of its integration within long term social-economical projects, are still in their infancy. Ecocean, Ltd. and other companies and NGOs are pushing the envelope and the marine portion of the budding restoration sector continues to grow and gain experience.

Ecocean was launched in 2003 by two French marine biologists. Among the approaches developed, the Biohut® was one of the first artificial habitats to be designed anywhere to restore fish nursery functions. This metallic structure, consisting in a central module filled with a natural substrate (oyster shells) and two protective modules, provides food resources and shelter for juvenile fish, wherever essential nursery functions have been impacted by human infrastructures and activities. The Biohut structure provides a simple but efficient technological solution in order to mimic and provide ecological functions of nurseries in as many types of aquatic ecosystems as possible.

Biohut habitats installed on a dock wall In Marseille (France) to add habitat complexity and protect juvenile fish from predators. ©Rémy Dubas / Ecocean

After several successive research projects carried out along the French Mediterranean shoreline, led with the support of scientific partners from the University of Perpignan and Ifremer (the French National Institute for Ocean Science), the ecological value of the Biohut habitat for juvenile fish in port areas was validated (Bouchoucha et al. 2016, Mercader et al. 2017a, 2017b). Various adaptations for different contexts have since then been implemented as ecological restoration tools in order to enhance survival rate and food chain recovery for many species of coastal fish and invertebrates. Today, 40 ports and marinas are equipped with Biohuts to help restore and speed the recovery of nursery functions for juvenile fish, and over 4500 Biohut modules have been installed worldwide in ports, marinas, offshore substations, canals, floating photovoltaic platforms, outfalls at sea, etc. Monitoring is underway at least twice a year in more than 30 different locations.

Ongoing monitoring of the Biohut habitats, performed by scientific divers in order to assess the species colonizing the Biohut and their abundance, have allowed us to observe more than 100 different species of fish and more than 200 different species of invertebrates (crustaceans, mollusks, etc.) using these structures.

As mentioned above, it is critical to closely link ecological restoration and engineering interventions with awareness raising and education for local people and institutions, in order to involve local stakeholders and communities from the beginning of a project. Thus, the impact of restoration actions is not only at the scale of the habitat, but also reaches the social level, with chances of behavior changes that can enhance the gains and recovery made both by the target ecosystem,  the local human communities,  and human society as a whole.

Additionally, by involving local communities, especially young people, with dedicated activities, Ecocean aims to reach out and bring in these future stakeholders, and tries to influence them to commit themselves to aiding in the protection and restoration of biodiversity and ecosystems. Since 2017, more than 5000 children have been involved in such activities, helping them to reach a good level of implication and understanding of the ecosystems they live near and benefit from.

Awareness raising activities with children in Agde (France) exploring the organisms settled inside the substrate of a Biohut. © Sabrina Palmieri / Ecocean

Notes on cultural and natural history

The dusky grouper (Epinephelus marginatus) is an emblematic species throughout the Mediterranean Sea, where it lives near to rocky shorelines and in Posidonia seagrass meadows. Known to be an apex predator, it has a strong ecological role in these ecosystems.  Mature individuals can measure up to 1 m in length and have major cultural heritage value, since they are easy and fun to observe. However, because of their docile behavior towards people and the culinary quality of their flesh, groupers have been heavily impacted by fishing and spearfishing for a long time. Groupers are protogynous (female primary sex) hermaphroditic species with the first sexual maturation, as a female, between 2 and 5 years of age, followed by a sex reversal at approximately nine years of age (Faillettaz et al., 2018; Pollard & Francour, 2018). As a result of slow growth, long longevity, and late maturing, as well as a high site fidelity to shallow coastal waters, grouper populations are particularly sensitive to anthropogenic actions such as fishing (Hackradt et al., 2014).

In addition to the fishing pressure, the dusky grouper is subject to a drastic decline in the northwestern Mediterranean due to its unsuccessful recruitment (Bodilis et al., 2003) due to low reproductive success and low survival rate of post-larvae before their coastal settlement.

Adult male dusky grouper (1 m long) in its natural habitat. © Rémy Dubas / Ecocean

Since 2004, the dusky grouper has been classified as Endangered by the IUCN. It benefits from a fishing moratorium since 1993 that prohibits fishing or spearfishing. Recently, an increase in new, small (under 40 cm) dusky grouper individuals was observed along the French Mediterranean coast, but more help is needed to achieve real recovery.

Sexual activity and reproduction in this species have only been rarely observed by divers along the French Mediterranean coast and near Corsica. However, However, it is important to say that in their natural habitat, small juvenile dusky groupers are difficult to observe as they are cryptic and camouflage themselves very effectively.

Happily, we have recorded several juvenile dusky groupers sheltering in Biohut habitats deployed by Ecocean in Mediterranean ports and marinas. Since the first observations of four dusky groupers between 2013 and 2015 on artificial micro-habitats created by Ecocean (Mercader et al., 2017), more recently 19 new individuals have been sighted across 11 sites along the French Mediterranean coastline between 2016 and 2021. These dusky groupers measured between 4.5 and 15 cm. The increase of the observation of juveniles of this species in artificial habitats can be seen as a good sign for the populations.

Frontal view of a ~6 cm (3 months old) juvenile dusky grouper taking shelter in a Biohut. © Rémy Dubas / Ecocean

Other approaches being tried

In parallel, between 2013 and 2021, across 8 different sites along the Mediterranean French coast, 27 dusky grouper individuals were captured by a system called C.A.R.E (Collect by Artificial Reef Eco-friendly) light traps developed by Ecocean, during four scientific programs conducted by Ecocean, Villefranche’s Oceanographic Laboratory, Paul Ricard Oceanographic Institute, and a European Life + SUBLIMO project. The monitoring of presence/absence, and capture and examination of these juvenile groupers, even if in small numbers, helps to assess the effective reproduction of the species in the northern Mediterranean.

Juvenile dusky grouper (25 mm) after its capture with a light trap. © Isabelle Simonet / Ecocean

The other ecological restoration process developed by Ecocean consists in capturing fish post larvae with light traps, rearing the juveniles until they reach a safe size (7-10 cm) when they can be reintroduced to natural habitats. This process, called BioRestore, aims to enhance the survival rate of post-larvae juvenile fish, because they are captured at a life stage where their mortality rate is still very high, and this rate is reduced to less than 10% (due to disease and other causes) for the period of several months while they are kept in captivity.

BioRestore is already being implemented and has been refined since 2016 both in Marseille (in the CasCioMar project) and in Toulon (Orrea project) in order to capture and restock fish with enhanced survival rates.

Juvenile dusky grouper (12 cm long and- ~6 months old) being released in natural habitat after a few months of rearing. © Rémy Dubas / Ecocean

In order not to impact the structure of the communities of fish to which we are putting back rare and keystone species in the wild, all species are released in the same proportions and diversity as captured, so groupers are released 1-2 at a time, as compared to releases of hundreds of individuals from other, smaller species such as seabreams (Diplodus spp.), mullets (Mugilidae), and others.

Different species of coastal fish being released in the natural habitat after rearing from larvae. © Rémy Dubas / Ecocean

Therefore, despite a low reproductive potential on northwestern Mediterranean coasts, and more particularly in France, post-larval dusky grouper individuals have been observed to benefit from different restoration projects along the French Mediterranean shoreline.

In the natural environment, settled juveniles are difficult to encounter because there is a high larval mortality rate  and because newly settled juveniles are difficult to observe as they are quite cryptic.

Similar projects have been implemented by Ecocean divers in other locations, such as in the Marchica Lagoon in Morocco, and there we have also observed juvenile groupers from different species (Epinephelus marginatus and Mycteroperca rubra, among others) settling in the Biohut nursery habitats (Selfati et al. 2018). In addition to the ecological aspect of this implementation, local communities, local university students and professors, and fishers were all involved in the project, in order to have a solid local footprint on both society and environment.

In addition to that, Biohut habitats have been implemented in the French Caribbean islands of Saint Martin and Guadeloupe, and juveniles of other grouper species there have also been observed using Biohut® as their adopted habitat.

The observation of juvenile groupers in various ecosystems shows the potential of the tools described here for fish species with strong ecological value and cultural heritage in many parts of the world. They can provides juvenile with suitable growing conditions where nursery habitat functions have been impacted or the habitat completely destroyed.  Additionally, they can be very effective and compelling for communication and outreach to local communities regarding the importance of conservation, management, and where needed, reintroduction and reinforcement of natural populations of emblematic, apex predator fish such as the dusky grouper and many others. Ecocean and all its staff are committed to pushing this important work further.

References:

Bodilis, P., Ganteaume, A., & Francour, P. 2003. Presence of 1 year-old dusky groupers along the French Mediterranean coast. J. Fish Biology 62:242–246.

Bouchoucha, M. et al. 2016. Potential use of marinas as nursery grounds by rocky fishes: insights from four Diplodus species in the Mediterranean. Marine Ecology Progress Series 547:193-209.

Faillettaz, R., et al.  2018. First records of dusky grouper Epinephelus marginatus settlement-stage larvae in the Ligurian Sea. Journal of Oceanography, Research and Data 10:1–6.

Hackradt, C. W., et al.  2014. Response of rocky reef top predators (Serranidae: Epinephelinae) in and around marine protected areas in the Western Mediterranean Sea. PLoS ONE 9(6).              

Mercader, M., et al. 2017a. Small artificial habitats to enhance the nursery function for juvenile fish in a large commercial port of the Mediterranean. Ecological Engineering 105: 78-86.

Mercader, M., et al.  2017b. Observation of juvenile dusky groupers (Epinephelus marginatus) in artificial habitats of North-Western Mediterranean harbors. Marine Biodiversity 47:371–372.

Pollard, D.A & Francour, P. 2018. Mycteroperca rubra. The IUCN Red List of Threatened Species 2018:  e.T14054A42691814.

Selfati M., et al. 2018. Promoting restoration of fish communities using artificial habitats in coastal marinas. Biological Conservation 219:89-9.