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The relevance of species diversity and composition in restoration plantings: a case study in the Atlantic Forest in Brazil

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By Dr. Ricardo Viani

Ricardo Viani is a professor at the Universidade Federal de São Carlos, Brazil, where he coordinates the LASPEF (viani@ufscar.br)

The Atlantic Forest in Brazil is a highly diverse tropical forest, listed as a global hotspot for biodiversity conservation. It is also the home of the two biggest Brazilian cities, São Paulo and Rio de Janeiro, and it is where most Brazilians live; around 150 million people inhabit and depend on the Atlantic Forest for the provision of ecosystem services.

Originally covering about 1.2 million square kilometers (297 million acres), the Atlantic Forest now covers less than 20% of its original area because of centuries of degradation. It is no wonder that the Atlantic Forest stands out globally as a region where forest restoration is urgently needed and is being taken seriously. In recent decades, many large-scale Atlantic Forest restoration programs have been implemented and, in 2009, the Pacto (Atlantic Forest Restoration Pact), a coalition of hundreds of institutions working for Atlantic Forest restoration, was launched. For its work, the Pacto was recognized as a World Restoration Flagship by the United Nations Decade on Ecosystem Restoration, highlighting it as a global example of an ongoing, large-scale, and long-term ecosystem restoration effort.

Landscapes where forest restoration plantings are usually done in the Atlantic Forest in Brazil. A sugarcane plantation (left, photo: Paulo Molin) and a pasture matrix (right, photo: Ricardo Viani), with variable levels of scattered remaining forest.

After decades of Atlantic Forest restoration efforts, it is time to evaluate what we have done so far, not only to assess the outcomes but also to inform other large-scale restoration initiatives worldwide. Thus, we recently investigated which tree species were included in 1,073 forest restoration plantings implemented from 2002 to 2018 in the Brazilian Atlantic Forest by restoration programs carried out by the NGO SOS Mata Atlântica.

Overall, 423 tree species were included in the evaluated plantings, which represent less than 8% of the Atlantic Forest tree flora. In comparison with remaining forest patches, restoration plantings skewed towards nitrogen-fixing, non-animal-dispersed, and pioneer species. Plantings had poorly included endangered and endemic species as well as species that were previously indicated as priority for restoration based on their ecological interactions, carbon storage, and conservation values.

However, the more striking result is that restoration initiatives are planting the same set of limited tree species across the whole Atlantic Forest. Although the Atlantic Forest has three types of forests (the Araucaria Forest, the Rainforest, and the Seasonal Forest), each one with their own singular floristics, restoration plantings are overall more similar in species composition to each other than to the remnants of the type of forest of the region where they exist. In other words, we plant the same species without considering spatial variation in local and regional floras.

This pattern raises an uncomfortable question. Is large-scale restoration via tree planting contributing to biotic homogenization, that is, the tendency for distinct places to become more similar?

A tropical forest restoration planting in the Atlantic Forest in Brazil. Plantings tend to be done with a similar set of species across the whole Atlantic Forest. Photo: Ricardo Viani

Why should we pay attention to the trees we plant for tropical forest restoration?

One may say that our role in tropical forest restoration is to trigger ecological succession, and it is not relevant if we plant just a few tree species across a wide, diverse region. Actually, some argue that we should plant the same species everywhere, by selecting and planting the best species to accelerate early forest development . This is one explanation for the overrepresentation of pioneer trees in restoration plantings, and a reason to increase the representation of generalist animal-dispersed trees, which attract native fauna to restoration sites and favor natural regeneration under planted trees. Another argument may be that evaluating what we plant for forest restoration is not so important because non-planted species will naturally colonize planting sites later on and change their floristic composition. However, this statement and the previous one are acceptable only if regional tree species can colonize restoration sites in fragmented landscapes – a questionable premise in typical landscapes of southeastern Brazil.

The few studies available in rich tropical forests show that many non-planted trees species colonize restoration plantings, which is good news. However, some functional groups, such as slow-growing tree species dispersed by gravity or by larger animals tend to be bad colonizers, especially in fragmented or defaunated landscapes. In other words, if they are not planted, many tree species will not reach restoration sites on their own, and we should pay more attention to their inclusion in restoration plantings.

Finally, we need also to consider that restoration is a strategy to promote in situ tree species conservation. The Atlantic Forest has more than 4,000 native tree species, almost half of them endemic, and dozens threatened by extinction. However, few endemic and threatened tree species are included in restoration plantings and some of the ones that are included are only used infrequently and in low abundance. Probably, some of them are also rare, absent in fragmented landscapes, and not good colonizers, which increases the importance of their planned and careful inclusion in restoration efforts.

A practitioner planting a slow-growing tree in the understory of previously planted pioneer trees. This is part of an experiment in the Atlantic Forest in Brazil, aiming to answer when it is better to plant slow-growing species: together with pioneer trees or under their shade. Photo: Ricardo Viani

The way forward

Restoration initiatives have done great work for the Atlantic Forest in recent decades, but there are always points that could be improved, such as the representation of regional flora and of some groups of species currently underrepresented in plantings (e.g., animal-dispersed, endangered, high value species for conservation, etc.). Solving this issue involves much more than just recommending their inclusion in restoration initiatives. Many of these species are rare, lots of them do not have seeds or seedlings available for restoration and, many, if not most, are slow-growing trees. Knowing how restoration practitioners perceive the importance of species diversity, selection, and composition for restoration plantings and potential trade-offs in prioritizing diversity representation versus fast early recovery may give insights on strategies to overcome this challenge.

In addition, as many underrepresented species in tropical forest restoration plantings are slow-growing, it is worth studying ways of introducing these species in restoration plantings. For instance, should we plant slow-growing trees under full-sun or under the canopy of previously planted pioneer trees? How can we balance the composition of restoration plantings to include slow-growing species without losing the benefits of rapid forest development promoted by fast-growing species? All these questions are still to be answered and part of my ongoing research project Optimizing high-diversity restoration: perceptions and approaches to add tree diversity in tropical forest restoration plantings.

 We are on our way, but there is still a long path to go before restoration will truly represent the diversity of complex and unique biomes.

For more information, read our paper recent paper in Forest Ecology and Management or contact Dr. Viani (viani@ufscar.br).

Part of an Atlantic Forest restoration experiment in Brazil where different abundances of fast and slow-growing species are being assessed aiming to find the best strategy to add slow-growing trees in tropical forest restoration plantings. Photo: Paulo Molin

Land Abandonment, Succession, and Restoration: The Wolf Run Grassland Restoration Project at the Missouri Botanical Garden’s Shaw Nature Reserve

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By: Mike Saxton and Calvin Maginel

Mike Saxton (mike.saxton@mobot.org) is the Manager of Restoration and Land Stewardship, and Calvin Maginel (cmaginel@mobot.org) is the Ecological Resource Scientist at Shaw Nature Reserve. 

Since 1950, over 1-billon acres of agricultural land have been abandoned worldwide. In certain landscape contexts, unassisted spontaneous recovery of high levels of native biodiversity in abandoned fields is possible while in others, like the Midwest USA, fallow fields rarely develop into biologically rich habitats. To achieve the ambitious goals of the UN Decade of Ecosystem Restoration, land managers and ecologists need to better understand how to assist the regeneration and ecological restoration of these highly altered landscapes. 

In 1925, the Missouri Botanical Garden purchased 1,300 acres of battered farm ground in Gray Summit, MO – approximately 35 miles (56 km) west of St. Louis – to escape the deleterious impact urban air pollution was having on horticultural collections in St. Louis City. The intended uses of this acreage were to: (1) propagate and grow plants, trees, and shrubs for the main Garden’s displays and (2) establish an arboretum focusing on woody plant collections. The site was officially named the Shaw Arboretum in 1933. After decades of development, many non-essential operations at the Arboretum were eliminated in 1958 and many fields were abandoned to allow spontaneous successional change. In 2000, the Shaw Arboretum was renamed Shaw Nature Reserve to reflect its contemporary mission to demonstrate, test, and inspire responsible stewardship practices through education, restoration, and protection of natural habitats and public enjoyment of the natural world. Today the Nature Reserve consists of 2,400 acres of varied habitat in various stages of restoration and revised management, including the use of prescribed fire.  

Prior to European settlement, the natural plant communities and ecosystems of the area were fire adapted, open oak-hickory woodlands and xeric glades with gallery forests along riparian corridors. Post-settlement, woodlands were clear-cut with some woodlots left to passively regenerate while others were converted to row crop agriculture. 

Wolf Run Grassland Restoration 

In 2016, Nature Reserve staff set an ambitious goal to bring all 2,400 acres of the site into active management to promote native biodiversity by the year 2030. This effort will include restoring open pastures and former row crop fields, a relatively simple process. A much more challenging effort will be reclaiming 120 acres of old fields with 60+ year successional development, which is our current Wolf Run Grassland Restoration project. The 120 acre project area was initially “wasted farm ground” that had erosion gullies “where a freight train could pass without you seeing it”, according to August Beilmann, former Arboretum Director from 1941 to 1956. The entire project area was re-sculpted and smoothed by a bulldozer in 1953 and then converted to bluegrass (Poa pratensis). “Every piece of this land that looks so likely to be just right was laboriously rebuilt,” said Beilmann in a 1974 interview.

Wolf Run Grassland Restoration project area in ca. 1945 showing open fields (light green) maintained through cattle grazing and mowing with trees occupying wet-weather streams and ditches (dark green). Photo: MBG Archives.

Since 1958 when areas including the Wolf Run Grassland Restoration were removed from mowing and grazing, the site was encroached upon and became dominated by eastern red cedar (Juniperus virginiana), the non-native invasive shrubs Amur honeysuckle (Lonicera maackii), and border privet (Ligustrum obtusifolium), as well as slippery elm (Ulmus rubra), shingle oak (Quercus imbricaria) and ash (Fraxinus) species, the latter of which which are in severe decline due to the emerald ash borer. 

These degraded woodlands had little native ground flora and were highly infested with non-native shrubs. Tree abundance and species composition had no historic analog. When setting ecological restoration goals for the area, staff determined that much of the site could not be managed as an open oak-hickory woodland, which would have existed at the site pre-settlement.  A new vision was needed. 

Goals for the Wolf Run Grassland Restoration project

  • Establish a mosaic of 80 acres (~32 ha) of prairie, 15 acres (~6 ha) of savanna and 25 acres (~10 ha) of oak-hickory woodlands
  • Maximize native flora diversity and aggressively control invasive shrub species 
  • Manage with periodic, dormant-season prescribed fire 

In 2021, Nature Reserve staff marked hundreds of native trees to retain including white, red, bur and black oaks (Quercus alba, Q. rubra, Q. macrocarpa, Q. velutina) and shagbark hickory (Carya ovata) and bitternut hickory (C. cordiformis). Drainages and wet weather streams were left with a 50 ft. (~15 m)  untreated buffer zone while a perennial creek flowing through the unit retained a 150 ft. (~46 m) untouched buffer. A logger removed unmarked trees from the area, with the commercial value of the timber offsetting the cost of the removal. Following US Fish and Wildlife Service recovery management guidelines for the Indiana bat (Myotis sodalis) — a federally endangered species — trees were only removed from November 1st to April 1st.

Wolf Run Grassland Restoration project area pre-thinning (2021), approximately 60 years after land abandonment. Note the dark green areas are dominated by eastern red cedar (Juniperus virginiana), a native tree that rapidly colonizes abandoned or disturbed lands in the Midwest. Historically, this fire-sensitive tree species primarily occurred on rocky outcrops and bluffs that served as refugia from periodic fires that were common in the pre-European settlement landscape. Photo: ESRI
Wolf Run Grassland Restoration project area post-thinning (2023). Photo: ESRI
Forestry contractor equipment was used to remove most woody biomass greater than 4.5 in. (~11 cm) in diameter and left behind mostly small-diameter slash. A bulldozer was used to collect the debris into 600 piles that were subsequently burned. Photo: Mike Saxton

The Restoration team has spent the last 9 months focusing on the removal of stumps for the project area. Stumps can be a substantial hazard for vehicles, equipment and staff safety. To seed native species and effectively manage the area for invasive species in perpetuity, the stumps must be ground down or cut flush to the ground.

Skid loader mounted stump grinder removing stumps. Photo: M. Saxton

Concurrent to this effort has been the site preparation step of chemically treating all of the invasive species and the disturbance driven annual vegetation that emerged post-land clearing [primarily fireweed (Erechtites hieraciifolius), mare’s tail (Erigeron canadensis), ragweed (Ambrosia artemisiifolia) and fox tail (Setaria pumila)]. This step is necessary because diverse, healthy native plant communities have not existed in these areas in more than 100 years. Consequently, there is no native seedbank to support the unassisted spontaneous recovery of native perennial herbaceous species in these highly degraded acres. 

In areas where stumps have not been cleared, traditional equipment (tractor boom sprayers and UTV mounted spray rigs) for applying herbicide are ineffective. The Nature Reserve hired a contractor that specializes in drone-assisted aerial herbicide applications. The drone flies 12 ft. (~37 m) above vegetation and can self-navigate around trees and other hazards. The unit carries a total of 8 gallons (~30 L) and sprays approximately 3 gallons of herbicide per acre. The effective width of each pass is 25 ft. (~8 m). A single battery powers the drone, with a flight time of 7.5 minutes and a re-charge time of 6 minutes. When the herbicide tank runs out, the drone re-deploys to the fill up location, is refilled by the contractor, and then returns to where it left off. 

Aerial drone sprayer used to eliminate undesirable vegetation. Photo: M. Saxton

The last step after the undesirable trees have been removed, biomass/debris has been burned, the stumps have been ground and invasive species have been controlled, is the final ground preparation. Currently, in 2023, we are again smoothing out erosion gullies and clearing away the last remnants of woody debris with a bulldozer. This effort will ensure effective seed-to-soil contact when we sow native seed in January 2024 and will enhance our ability to successfully search for invasive species in the coming years by eliminating deep ruts and rills.  

Above: Bulldozer in 1953 eliminating erosion rills in Wolf Run Grassland Restoration project area. Below: Bulldozer completing site preparation for native seed addition (2023).  Top Photo: St. Louis Globe Democrat, Bottom Photo: M. Saxton

Native Seeding and Experimentation to promote Biodiversity Recovery 

During the growing season of 2023, the Restoration team at the Nature Reserve has been feverishly collecting seed for this 2024 seeding effort. More than 1,100 lbs. (~500 kg) of bulk, milled seed from ~200 locally collected native tallgrass prairie and open oak-hickory woodland species will be used in the restoration planting. Additionally, these acres are enrolled in the Environmental Quality Incentives Program, EQIP – part of the Natural Resources Conservation Service, and we must purchase viability-tested seed to meet the minimum required specifications of the contract. The hand-collected seed together with the pure live seed (PLS) – percentage of viable seed in a seed lot – purchased from commercial vendors will provide us with ample species and volume of seed to effectively cover the 40 acres (~16 ha) to be planted this winter. 

Concurrent with the preparation effort, we initiated a research study, which will help inform our work and the broader research community on plant recruitment amongst scraped soils that have been inoculated with mycorrhizal fungi and those that have not. This study includes paired species from the same genus that have different CC-values, short for coefficients of conservatism, which represents a species’ tolerance of environmental degradation, or its fidelity to intact remnant or long-restored habitats, as determined by local botanical experts. Ecologists generally expect species that are dependent on stable intact communities (higher CC-values) to be more reliant on mycorrhizae connections to establish and flourish. Species with high CC-values tend to establish poorly in restoration sites, which is one of the reasons to pursue this study. Some examples from the ten herbaceous pairs of native species include sedges (Carex bushii [CC = 4] and Carex bicknellii [CC = 10]), grasses (Sporobolus compositus [CC = 3] and Bouteloua curtipendula [CC = 7]), and forbs (Oligoneuron rigidum [CC = 5] and Oligoneuron album [CC = 9]).

We added all 20 species at the same rate of pure live seed to provide each species an equal opportunity to establish. Initial analyses after one growing season indicate that low CC-value species germinated more successfully, producing more seedlings and greater percent cover than the high CC-value species, regardless of inoculation. We expect the addition of mycorrhizal fungi to have the greatest effects on species during the first couple of years after germination. If the mycorrhizae associate with the roots of the high-CC species more than the low-CC species, this may help them grow faster or be more resistant to future stress. Future monitoring will show us if there are long-term effects of inoculation.

To check for updates on restoration activities and results from experimental studies, please visit our webpage.

Barrels of hand-collected seed connected to a seed dryer, which pumps air through tubes into the barrels to eliminate mold & moisture. Photo: M. Saxton

Understanding the contributions of restored forests for nature and people: The NewFor Project

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By Dr. Pedro Brancalion

Dr. Brancalion is an associate professor of tropical forestry in the Department of Forest Sciences at the Luiz de Queiroz College of Agriculture (ESALQ) of the University of São Paulo. A leading expert in tropical forest restoration, Dr. Brancalion coordinates the Laboratory of Tropical Forestry (LASTROP), is partner at Re.green – a restoration company, is the Director of Innovation of the Center for Carbon Research in Tropical Agriculture, and member of the coordination board of the Center of Studies Sustainable Amazon.

Forest Landscape Restoration (FLR) emerged as a promising approach to revitalize degraded and deforested landscapes, by recovering their biodiversity, ecosystem services, and economic value. The Bonn Challenge is a pivotal FLR initiative, with an overarching goal of restoring 350 million hectares of degraded land by 2030. Over 210 million hectares have been pledged so far, by more than 60 nations, mostly across the tropics. Given its importance for mitigating some of the most pressing environmental crises of our time, like climate change and the sixth mass extinction, the Bonn Challenge and other FLR initiatives are strongly connected to other environmental and restoration programs, such as the Paris Climate Agreement, the United Nations’ Decade on Ecosystem Restoration and the UN Sustainable Development Goals. In spite of great promises and expectations, the implementation of these pledges has lagged behind schedule, highlighting the need to better engage local people by promoting FLR approaches that maximize desired benefits and overcome critical barriers for implementation.

FLR can be implemented through several reforestation approaches, including natural forest re-growth, mixed plantations of native species, monoculture tree plantations, and agroforestry. Planning the distribution of these approaches over space and time is a critical step towards effective FLR, and it depends on local socioecological conditions, targeted benefits, and stakeholders’ perceptions of the potential of each FLR approach to deliver these expected benefits. The aim of FLR is to establish multipurpose landscapes, where different FLR approaches are implemented in different areas to maximize various benefits.

Two contrasting farms in Colombia: On the left, a traditional cattle ranching farm in which most of the landholding area, even the riparian buffers, is occupied by planted pastures. The variation of color of the pastures (light green in the lower lands where soil is more fertile, and brownish at the slopes where soil is shallow, and erosion is high) is a clear indication that only a small portion of the land is productive. On the right, a restored farm, which had a similar initial condition to the neighbor farm but was submitted to FLR interventions over the past 20 years by a non-governmental organization, CIPAV. Degraded pastures in the slopes were abandoned for natural forest regeneration, a eucalyptus woodlot was planted to supply wood and fencing poles, a silvopastoral system was established in the lowlands, and restoration plantations were employed to protect riparian buffers (such plantations are not shown in the photo). Photo: P. Brancalion.

FLR relies on the increase in landscape heterogeneity for recovering multiple environmental benefits. However, nearly half of the FLR pledges to the Bonn Challenge are composed of monoculture tree plantations, which maximize financial returns in the short term but undermine the optimal recovery of biodiversity and ecosystem services. Rather than promoting landscape heterogeneity, some of these FLR initiatives may have promoted the opposite process, a form of forest landscape degradation that may magnify the impacts of climate change and the biodiversity crisis. A critical step to shift the direction is to better understand the pros and cons of different FLR approaches for delivering contributions for nature and people.

The NewFor Project

The Atlantic Forest of Brazil is a top global hotspot for the restoration of tropical rainforest landscapes. Since mid-2010’s, there has been a net increase in native forest cover and a fast expansion of eucalypt plantations, indicating that his region is rapidly transitioning to a mosaic of agricultural, forest, and urban landscapes. However, rather than the old-growth native forest remnants that once covered the region before deforestation, the new forest cover is now composed of a heterogeneous mosaic of different tree cover types. My colleagues and I believe it is important to understand how different tree cover types in different socioecological contexts influence human wellbeing and conservation. Doing so will allow us to develop new landscape-scale rules of thumb for FLR and will inform a menu of FLR options available to restoration practitioners to help them achieve their goals. At the same time, it would allow us to decipher some guidelines for restoration practice and offer a more robust menu of options for restoration practitioners to select the restoration approaches that better match their restoration conditions and expected benefits.

With these premises in mind, the project “Understanding restored forest benefits for nature and people – NewFor” was established initially as a partnership between the University of São Paulo (Brazil) and Wageningen University and Research (The Netherlands), financially supported by the São Paulo Research Foundation (FAPESP) and the Dutch Research Council (NWO). However, what was initially established as a research project between two universities rapidly transformed into a broad network of research organizations, NGOs (10), private companies (13), governmental agencies (5), and farms (over 50), which greatly increased the financial and logistical support of the project and allowed us to scale up our FLR project evaluations. These organizations have actively collaborated in the co-production of knowledge with researchers, an essential step towards more effective and transformative restoration.

The NewFor team. Photo: Gehard Waller.

The NewFor Project was initiated in 2020 based on the application of a protocol for evaluating forest multifunctionality (soil carbon, chemical and physical evaluations, soil water infiltration, litter and dead wood stocks, forest inventory of trees with diameter at breast height ≥5 cm, counting of regenerating individuals with height ≥2 m and diameter <5 cm, in 30 x 30 m plots) in different tree cover types (natural forest re-growth, mixed species restoration plantations, monoculture tree plantations, agroforests, forest remnants and agropastoral land uses as a control) distributed across a broad range of age and biophysical conditions (soil and climate types, relief, neighboring land uses, landscape connectivity). Further, the field plots were integrated into remote sensing evaluations based on lidar and hyperspectral sensors carried on drones and airplanes. The study area is the state of São Paulo, in southeastern Brazil, where most of the biophysical gradients of interest were present and restoration projects abound.

The NewFor Project has been implemented through the following step:

  • identification of a local partner who knows the region and can help identify and access different types of tree cover;
  • evaluation of aerial and satellite images to create land use/cover maps, which are validated with a local partner and further used to randomly allocate the position of the field plot;
  • field checking of the land use/cover, allocation of the permanent plots in the field with plastic tubes at the corners and high-precision geolocation;
  • implementation of the protocol, tagging each tree with a metallic tag;
  • flights over the field plot and the polygon with the tree cover type where the plot is located;
  • processing of the samples in laboratory; and
  • organization, storage, and validation of the data and metadata.

So far, the project accumulated data for more than 700 plots, which includes nearly 1,200 tree species, ~80,000 stems and ~50,000 trees, and obtained lidar data for ~400,000 hectares.

Field work by the NewFor team. Photos: Pedro Brancalion

Activities of the geospatial team: high-precision geolocation of the plots with a GNSS GPS equipment, field checking of the delimitation of the boundaries of the polygon composed by the tree cover type of interest where the field plots are established, and flight over the polygon and plot with a drone equipped with a lidar and hyperspectral sensor. Photos: Paulo Molin

Although few results of the project have been published in the literature so far, the bulk of data analysis, publications, and policy recommendations are about to start, as data collection has finished, and the dataset is ready to use. One of the most immediate – and perhaps most important – impacts of the NewFor Project was the inspiration for creating a similar nation-wide initiative by the Ministry of Science, Technology and Innovation, the Regenera Brasil initiative, which will employ a similar monitoring approach across all Brazilian regions and vegetation types, with the support of local research and outreach organizations. The Regenera Brasil project is about to start, which may make Brazil the first country to have a national restoration inventory.

To learn more about the NewFor Project, visit our blog and read our scientific papers about distinguishing between different FLR-related tree cover types and monitoring the outcomes of FLR interventions using UAV-based remote sensing, or contact the author. Also, follow us in social media: Instagram, YouTube, LinkedIn, and Facebook.

For additional information, contact Pedro Brancalion: pedrob@usp.br

Environmental DNA (eDNA): a new tool for monitoring terrestrial ecosystems

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Case studies involving tree hollow users and plant–animal interactions in Southwestern Australia

Joshua Newton, Bill Bateman, Paul Nevill (Curtin University) and Adam Cross (Curtin University and Ecological Health Network) describe environmental DNA (eDNA), a new tool for monitoring terrestrial ecosystems, and discuss some of the implications for ecological restoration.

The terrestrial ecosystems we know, and love are under increasing pressure. Habitat loss and fragmentation, species declines, and subsequent reductions in ecosystem services emphasize a need for effective strategies to preserve, manage, and restore these areas into the future. Central to these efforts is robust monitoring, a cornerstone for informed decision-making. However, we are often hindered by a lack of reliable data on species distributions, habitat associations, and community dynamics. While traditional monitoring techniques like direct observations and traps remain essential, the urgency and scale of the global threats demands innovation.  Rapid terrestrial biomonitoring approaches are needed to enable frequent monitoring, able to quantify the causes and effects of changes to terrestrial environments. Enter environmental DNA (eDNA), a new tool for monitoring terrestrial ecosystems.

What is eDNA?

Animals continuously shed cells containing DNA into the environment, and this DNA is largely an untapped source of information on evolution, biodiversity, and ecosystem health. However, over the past 15 years we have seen the rapid emergence of a new interdisciplinary field that fuses traditional ecology with molecular methods and advanced computational skills, exploiting this DNA or what we now know as environmental DNA (eDNA). Simply, eDNA is DNA that is collected from any environmental sample such as soil, water, air, the surface of plants, and even spider webs, rather than directly sampled from an individual organism. By testing environmental samples for the presence of eDNA, we remove the need to observe, collect, and visually identify organisms, and can obtain a rapid and simultaneous assessment of entire communities across taxonomic groups from an environmental sample.

With the DNA collected originating from species living in the surrounding environment and containing information on their identity, the potential uses of eDNA for biomonitoring are broad. It is possible to detect cryptic, rare, or threatened species, and large-scale eDNA-based biodiversity assessments are possible thanks to the emergence of high throughput DNA sequencing technology (sequencing of millions of DNA fragments), combined with DNA metabarcoding that allows for the simultaneous identification of many taxa within the same environmental sample. Beyond ‘basic’ biodiversity assessments, eDNA can offer insight into many important ecological and biological questions including aspects of animal behaviour and plant-animal interactions. And, while in its infancy, there is also the opportunity to obtain population-level genetic information from eDNA samples. This information becomes instrumental in the effective management and restoration of ecosystems, marking a significant advancement in our ability to understand and address environmental challenges.

Simon Cherriman of iNSiGHT Ornithology 30 meters high in a tuart tree (Eucalyptus gomphocephala) taking both sediment and swab eDNA samples from a hollow in the Tuart Forest National Park in the South West region of Western Australia. Photo: Joshua Newton.

eDNA case study 1: Revealing vertebrate tree hollow user biodiversity with eDNA metabarcoding

Across Australia, numerous vertebrate species use tree hollows for breeding, nesting, and protection. But these trees are being lost, and natural or restored tree recruitment tends to lag far behind this loss due to hollow development taking upwards of 100 years. As a result, tree hollows have become a limiting resource for many of our native species, who are also often bumped off the ‘property ladder’ by introduced species. Knowing who uses or has used hollows is critical if we want to conserve critical hollow-bearing trees and the native species that rely on them. Unfortunately, this can be difficult and time consuming to do by direct observation. But eDNA offers a solution. Testing environmental samples for the presence of eDNA, we successfully collected eDNA from 93 tuart tree (Eucalyptus gomphocephala) hollows throughout National Park and urban settings.  Thirty-four vertebrate species were detected: 10 mammals and 24 birds, allowing us to compile a species list of hollow users that has the potential to be more wide-ranging, rapid, and complete than that which would come from direct observation. The sensitivity of eDNA metabarcoding allowed for the detection of a variety of taxa including common species (e.g., Galah), cryptic species (e.g., brushtail phascogale), endangered species (e.g., ringtail possum), and invasive species (e.g., Rainbow Lorikeet), highlighting the wide range of possible applications for this new technique. This molecular tool serves not only as a comprehensive biodiversity assessment method but also as a sensitive approach for detecting individuals that may be elusive using other methods. Looking ahead, eDNA metabarcoding of tree hollows could be used to improve species distribution models of hollow users, identify vital habitat trees in need of conservation, and detect range expansion of invasive hollow-using species, enhancing our understanding of the ecology of vertebrate hollow users and supporting the development of informed management strategies that preserve vital hollow-bearing trees and the species that rely on them.

The critically endangered western ringtail possum (Pseudocheirus occidentalis) occupying a hollow and that was detected using eDNA methods within a tuart tree (Eucalyptus gomphocephala) in the Tuart Forest National Park in the South West region of Western Australia. Photo: Simon Cherriman

eDNA case study 2: Environmental DNA metabarcoding of flowers to detect plant–animal interactions.

Plant-animal interactions play a crucial role in the functioning of natural ecosystem and are fundamental in maintaining biodiversity and ecological balance. These interactions occur in various forms, including pollination, herbivory, and mutualistic and parasitic relationships. Monitoring these interactions is essential for the conservation of biodiversity, understanding ecosystem dynamics, and developing informed strategies for the management and restoration of terrestrial environments. However, studying these complex interactions using conventional methods is often difficult, labour intensive and requiring substantial taxonomic expertise for morphological identification of species, a field that is in decline globally. The use of eDNA to detect a variety of these ecological interactions, such as plant pollinators and predators, has recently been explored (as reviewed in Banerjee et al., 2021), and is providing an alternative approach to understanding these complex relationships. One such study conducted within the Helena and Aurora Range (or, in the local Kalamaia language, “Bungalbin”) of Western Australia, tested the use of eDNA in conjunction with visual surveys, on seven native flowering species. These plants represented a range of species with different flower morphologies and different assumed pollinators, many of the plants being of conservation concern and for which little information on pollinating taxa was currently available.

This eDNA metabarcoding survey was the first to simultaneously identify the interaction of insect, mammal, and bird species with flowers, and recorded more animal species visiting flowers than did visual surveys of the same species. In fact, the difference between the methods was remarkable; while eDNA identified 59 taxa, visual surveys identified only 16. This is in part due to eDNA metabarcoding not exclusively detecting pollinators. Non-pollinator taxa such as phytophagous insects (e.g., thrips and aphids), gall inducers (e.g., Cecidomyiidae), predators (e.g., spiders), and large mammals (e.g., kangaroo and horse) were also detected. This is because eDNA metabarcoding of flowers is unable to distinguish between animals that simply come into contact with flowers versus those that act as pollinators. While this might suggest a limitation, it also highlights opportunities for further applications such as the detection of pests and invasive species that interact with plants.

It also must be noted that visual surveys captured native bee species that remained undetected in DNA surveys, highlighting that while powerful and versatile, the use of eDNA metabarcoding, like all survey methods come with certain limitations. However, the use of eDNA metabarcoding of flowers did assist with detecting nocturnal species often missed using visual surveys. This included nocturnal moth species and the presence of a flower visit from a western pygmy possum (Cercartetus concinnus), arguably the cutest Australian marsupial, for which nectar is an important food resource. This suggests that employing both concurrently is the most effective approach for gaining accurate insights into plant-animal interactions. Surveying animal assemblages in remote locations and identifying the species associated with rare or infrequently visited plants can be challenging and it is difficult to capture the full flower-visitor cohorts for rarely visited flowering plants with short visual surveys. Here, eDNA collected from flowering material provided a complementary tool to help survey and monitor plant–animal interactions. Although not all of these organisms detected are likely to affect pollination, eDNA from flowers is able to provide a general overview of the flower-visitor community and potential pests for plant species of interest, and may provide information that would otherwise not be available.

Meet the western pygmy possum (Cercartetus concinnus): a tiny treasure of Southwestern Australia.  Photographer: Christine Cooper

Future of eDNA monitoring

As we delve deeper into the potential of eDNA, it becomes increasingly evident that this technology has the capacity to revolutionize our approach to studying ecological systems. But it’s not without limitations. Currently, it is not able to provide information on an organism’s age, condition, or breeding status, crucial factors for examining the population biology of a target species. Various abiotic factors, such as temperature and UV radiation impacting the degradation of DNA, as well as biotic factors varying DNA deposition rates between taxa, can also influence the efficiency of eDNA methods and need to be further understood. Additionally, the classification of species based on genetic material relies on reference sequence databases, which are still incomplete. For this reason, in many scenarios further baseline studies are still necessary before eDNA methods can be confidently implemented in terrestrial systems. However, as these challenges are addressed and the technology continues to advance, the potential of employing eDNA metabarcoding for monitoring terrestrial systems becomes increasingly probable, offering a transformative and non-invasive tool able to meaningfully contribute to future conservation, natural capital management and restoration efforts. Monitoring of restored biota across the tree of life and active management of restoration is necessary to improve restoration processes and outcomes, and provide evidence to stakeholders that targets are being achieved. Increasingly, eDNA metabarcoding is used as a restoration monitoring tool because it is able to generate biodiversity data rapidly, accurately, non-destructively, and reliably, on a wide breadth of organisms from soil microbes to mammals.

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

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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

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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

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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

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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?

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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

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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 1st 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 1st 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