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Effects of landscape structure on restoration success in tropical premontane forest. Sci Rep 2022; 12:13452. [PMID: 35927554 PMCID: PMC9352795 DOI: 10.1038/s41598-022-16542-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Accepted: 07/12/2022] [Indexed: 11/08/2022] Open
Abstract
Reversing large-scale habitat degradation and deforestation goes beyond what can be achieved by site-level ecological restoration and a landscape ecology perspective is fundamental. Here we assess the relative importance of tree cover and its configuration on forest-dependent birds and late-successional tree seedlings in restoration sites in southern Costa Rica. The abundance and species richness of birds increased in landscapes with more corridors, higher tree cover, and lower levels of fragmentation, highlighting the importance of riparian corridors for connectivity, and continuous tree cover as suitable habitat. Landscape variables affected abundance and species richness of seedlings similarly, but effects were weaker, possibly because seedlings face establishment limitation in addition to dispersal limitation. Moreover, the scale of landscape effects on seedlings was small, likely because proximal individual trees can significantly influence recruitment in restoration plots. Results underscore the importance of incorporating landscape-level metrics to restoration projects, as knowing the extent, and how the landscape may affect restoration outcomes can help to infer what kind of species will arrive to restoration plots.
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Abstract
The conservation field is experiencing a rapid increase in the amount, variety, and quality of spatial data that can help us understand species movement and landscape connectivity patterns. As interest grows in more dynamic representations of movement potential, modelers are often limited by the capacity of their analytic tools to handle these datasets. Technology developments in software and high-performance computing are rapidly emerging in many fields, but uptake within conservation may lag, as our tools or our choice of computing language can constrain our ability to keep pace. We recently updated Circuitscape, a widely used connectivity analysis tool developed by Brad McRae and Viral Shah, by implementing it in Julia, a high-performance computing language. In this initial re-code (Circuitscape 5.0) and later updates, we improved computational efficiency and parallelism, achieving major speed improvements, and enabling assessments across larger extents or with higher resolution data. Here, we reflect on the benefits to conservation of strengthening collaborations with computer scientists, and extract examples from a collection of 572 Circuitscape applications to illustrate how through a decade of repeated investment in the software, applications have been many, varied, and increasingly dynamic. Beyond empowering continued innovations in dynamic connectivity, we expect that faster run times will play an important role in facilitating co-production of connectivity assessments with stakeholders, increasing the likelihood that connectivity science will be incorporated in land use decisions.
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Edwards FA, Massam MR, Cosset CCP, Cannon PG, Haugaasen T, Gilroy JJ, Edwards DP. Sparing land for secondary forest regeneration protects more tropical biodiversity than land sharing in cattle farming landscapes. Curr Biol 2021; 31:1284-1293.e4. [PMID: 33482111 DOI: 10.1016/j.cub.2020.12.030] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 10/19/2020] [Accepted: 12/21/2020] [Indexed: 11/29/2022]
Abstract
Effectively managing farming to meet food demand is vital for the future of biodiversity.1,2 Increasing yields on existing farmland can allow the abandonment (sparing) of low-yielding areas that subsequently recover as secondary forest.2-5 A key question is whether such "secondary sparing" conserves biodiversity more effectively than retaining wildlife-friendly habitat within farmland ("land sharing"). Focusing on the Colombian Choco-Andes, a global hotspot of threatened biodiversity,6 and on cattle farming, we examined the outcomes of secondary sparing and land sharing via simulated scenarios that maintained constant landscape-wide production and equal within-pasture yield: (1) for species and functional diversity of dung beetles and birds; (2) for avian phylogenetic diversity; and (3) across different stages of secondary forest regeneration, relative to spared primary forests. Sparing older secondary forests (15-30 years recovery) promotes substantial species, functional, and phylogenetic (birds only) diversity benefits for birds and dung beetles compared to land sharing. Species of conservation concern had higher occupancy estimates under land-sparing compared to land-sharing scenarios. Spared secondary forests accumulated equivalent diversity to primary forests for dung beetles within 15 years and within 15-30 years for birds, highlighting the need for longer term protection to maximize the biodiversity gains of secondary sparing. Promoting the recovery and protection of large expanses of secondary forests under the land-sparing model provides a critical mechanism for protecting tropical biodiversity, with important implications for concurrently assisting in the delivery of global targets to restore 350 million hectares of forested landscapes.7,8.
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Affiliation(s)
- Felicity A Edwards
- Department of Animal and Plant Sciences, University of Sheffield, Western Bank, Sheffield S10 2TN, UK.
| | - Mike R Massam
- Department of Animal and Plant Sciences, University of Sheffield, Western Bank, Sheffield S10 2TN, UK
| | - Cindy C P Cosset
- Department of Animal and Plant Sciences, University of Sheffield, Western Bank, Sheffield S10 2TN, UK
| | - Patrick G Cannon
- Department of Animal and Plant Sciences, University of Sheffield, Western Bank, Sheffield S10 2TN, UK
| | - Torbjørn Haugaasen
- Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, Ås, Norway
| | - James J Gilroy
- School of Environmental Science, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | - David P Edwards
- Department of Animal and Plant Sciences, University of Sheffield, Western Bank, Sheffield S10 2TN, UK.
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Evaluating Forest Cover and Fragmentation in Costa Rica with a Corrected Global Tree Cover Map. REMOTE SENSING 2020. [DOI: 10.3390/rs12193226] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Global tree cover products face challenges in accurately predicting tree cover across biophysical gradients, such as precipitation or agricultural cover. To generate a natural forest cover map for Costa Rica, biases in tree cover estimation in the most widely used tree cover product (the Global Forest Change product (GFC) were quantified and corrected, and the impact of map biases on estimates of forest cover and fragmentation was examined. First, a forest reference dataset was developed to examine how the difference between reference and GFC-predicted tree cover estimates varied along gradients of precipitation and elevation, and nonlinear statistical models were fit to predict the bias. Next, an agricultural land cover map was generated by classifying Landsat and ALOS PalSAR imagery (overall accuracy of 97%) to allow removing six common agricultural crops from estimates of tree cover. Finally, the GFC product was corrected through an integrated process using the nonlinear predictions of precipitation and elevation biases and the agricultural crop map as inputs. The accuracy of tree cover prediction increased by ≈29% over the original global forest change product (the R2 rose from 0.416 to 0.538). Using an optimized 89% tree cover threshold to create a forest/nonforest map, we found that fragmentation declined and core forest area and connectivity increased in the corrected forest cover map, especially in dry tropical forests, protected areas, and designated habitat corridors. By contrast, the core forest area decreased locally where agricultural fields were removed from estimates of natural tree cover. This research demonstrates a simple, transferable methodology to correct for observed biases in the Global Forest Change product. The use of uncorrected tree cover products may markedly over- or underestimate forest cover and fragmentation, especially in tropical regions with low precipitation, significant topography, and/or perennial agricultural production.
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Zahawi RA, Reid JL, Fagan ME. Potential impacts of COVID-19 on tropical forest recovery. Biotropica 2020; 52:803-807. [PMID: 33173235 PMCID: PMC7646646 DOI: 10.1111/btp.12851] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Revised: 07/28/2020] [Accepted: 08/09/2020] [Indexed: 11/29/2022]
Abstract
COVID-19 has impacted humanity and the global environment in myriad ways, and more changes are on the horizon. Here we consider the impact of COVID-19 on our collective ability to restore degraded habitats and facilitate forest recovery in the tropics.
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Affiliation(s)
| | - J. Leighton Reid
- School of Plant and Environmental SciencesVirginia TechBlacksburgVAUSA
| | - Matthew E. Fagan
- Department of Geography and Environmental SystemsUniversity of MarylandBaltimore CountyBaltimoreMDUSA
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Moran MD, Monroe A, Stallcup L. A proposal for practical and effective biological corridors to connect protected areas in northwest Costa Rica. NATURE CONSERVATION 2019. [DOI: 10.3897/natureconservation.36.27430] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Habitat loss and increases in habitat isolation are causing animal population reductions and extirpations in forested areas of the world. This problem extends to protected areas, which, while often well-conserved, can be too small and isolated to maintain species that exist at low densities and require large contiguous areas of habitat (e.g. some large mammals). Costa Rica has been at the forefront of tropical forest conservation and a large proportion of the country’s land area is currently under some form of protection. One such area is the northwest portion of Costa Rica, which is an extremely biodiverse region with several noteworthy national and privately-owned protected areas. However, each protected area is an isolated island in a sea of deforestation. Within Costa Rica’s existing framework of biological corridors, we propose four sub-corridors as targets for restoration and full protection. These sub-corridors would link five major protected areas in northwest Costa Rica, with all of them linking to larger protected areas in the central portion of the country, while impacting a small number of people who reside within the corridors. After natural or active reforestation of the corridors, the result would be a contiguous protected area of 348,000 ha. The proposed sub-corridors would represent a 3.7% increase in protected area size in the region and only 0.2% of Costa Rica’s total land area. Using the jaguar (Panthera onca) as a model umbrella species, we estimated that each current isolated protected area could support between 8–104 individuals. Assuming lack of dispersal between protected areas (distance between each ranges from 8.1 to 24.9 km), these population sizes are unlikely to be viable in the long term. However, the combined protected areas, connected by biological sub-corridors, could support about 250 jaguars, a population size with a higher probability of surviving. Our study shows that focusing conservation efforts on a relatively small area of Costa Rica could create a large protected area derived from numerous small isolated preserves.
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Dickson BG, Albano CM, Anantharaman R, Beier P, Fargione J, Graves TA, Gray ME, Hall KR, Lawler JJ, Leonard PB, Littlefield CE, McClure ML, Novembre J, Schloss CA, Schumaker NH, Shah VB, Theobald DM. Circuit-theory applications to connectivity science and conservation. CONSERVATION BIOLOGY : THE JOURNAL OF THE SOCIETY FOR CONSERVATION BIOLOGY 2019; 33:239-249. [PMID: 30311266 PMCID: PMC6727660 DOI: 10.1111/cobi.13230] [Citation(s) in RCA: 90] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2018] [Revised: 09/29/2018] [Accepted: 09/30/2018] [Indexed: 05/25/2023]
Abstract
Conservation practitioners have long recognized ecological connectivity as a global priority for preserving biodiversity and ecosystem function. In the early years of conservation science, ecologists extended principles of island biogeography to assess connectivity based on source patch proximity and other metrics derived from binary maps of habitat. From 2006 to 2008, the late Brad McRae introduced circuit theory as an alternative approach to model gene flow and the dispersal or movement routes of organisms. He posited concepts and metrics from electrical circuit theory as a robust way to quantify movement across multiple possible paths in a landscape, not just a single least-cost path or corridor. Circuit theory offers many theoretical, conceptual, and practical linkages to conservation science. We reviewed 459 recent studies citing circuit theory or the open-source software Circuitscape. We focused on applications of circuit theory to the science and practice of connectivity conservation, including topics in landscape and population genetics, movement and dispersal paths of organisms, anthropogenic barriers to connectivity, fire behavior, water flow, and ecosystem services. Circuit theory is likely to have an effect on conservation science and practitioners through improved insights into landscape dynamics, animal movement, and habitat-use studies and through the development of new software tools for data analysis and visualization. The influence of circuit theory on conservation comes from the theoretical basis and elegance of the approach and the powerful collaborations and active user community that have emerged. Circuit theory provides a springboard for ecological understanding and will remain an important conservation tool for researchers and practitioners around the globe.
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Affiliation(s)
- Brett G. Dickson
- Conservation Science Partners Inc., 11050 Pioneer Trail, Suite 202, Truckee, CA, 96161, U.S.A
- Landscape Conservation Initiative, Northern Arizona University, Box 5694, Flagstaff, AZ, 86011, U.S.A
| | - Christine M. Albano
- Conservation Science Partners Inc., 11050 Pioneer Trail, Suite 202, Truckee, CA, 96161, U.S.A
| | | | - Paul Beier
- School of Forestry, Northern Arizona University, Box 15018, Flagstaff, AZ, 86011, U.S.A
| | - Joe Fargione
- The Nature Conservancy – North America Region, 1101 West River Parkway, Suite 200, Minneapolis, MN, 55415, U.S.A
| | - Tabitha A. Graves
- U.S. Geological Survey, Northern Rocky Mountain Science Center, 38 Mather Drive, West Glacier, MT, 59936, U.S.A
| | - Miranda E. Gray
- Conservation Science Partners Inc., 11050 Pioneer Trail, Suite 202, Truckee, CA, 96161, U.S.A
| | - Kimberly R. Hall
- The Nature Conservancy – North America Region, 1101 West River Parkway, Suite 200, Minneapolis, MN, 55415, U.S.A
| | - Josh J. Lawler
- School of Environmental and Forest Sciences, University of Washington, Box 352100, Seattle, WA, 98195, U.S.A
| | - Paul B. Leonard
- U.S. Fish & Wildlife Service, Science Applications, 101 12th Avenue, Number 110, Fairbanks, AK, 99701, U.S.A
| | - Caitlin E. Littlefield
- School of Environmental and Forest Sciences, University of Washington, Box 352100, Seattle, WA, 98195, U.S.A
| | - Meredith L. McClure
- Conservation Science Partners Inc., 11050 Pioneer Trail, Suite 202, Truckee, CA, 96161, U.S.A
| | - John Novembre
- Department of Human Genetics, Department of Ecology and Evolution, University of Chicago, 920 East 58th Street, Chicago, IL, 60637, U.S.A
| | - Carrie A. Schloss
- The Nature Conservancy, 201 Mission Street, San Francisco, CA, 94105, U.S.A
| | - Nathan H. Schumaker
- U.S. Environmental Protection Agency, 200 Southwest 35th Street, Corvallis, OR, 97330, U.S.A
| | - Viral B. Shah
- Julia Computing, 45 Prospect Street, Cambridge, MA, 02139, U.S.A
| | - David M. Theobald
- Conservation Science Partners Inc., 11050 Pioneer Trail, Suite 202, Truckee, CA, 96161, U.S.A
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Arroyo-Lambaer D, Chapman H, Hale M, Blackburn D. Conservation genetics of two threatened frogs from the Mambilla highlands, Nigeria. PLoS One 2018; 13:e0202010. [PMID: 30110399 PMCID: PMC6093670 DOI: 10.1371/journal.pone.0202010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Accepted: 07/26/2018] [Indexed: 11/23/2022] Open
Abstract
Amphibians are the vertebrate group with the highest number of species threatened with extinction, and habitat loss and fragmentation are considered to be among the leading causes of their declines and extinctions. Little is known of the population biology of amphibian species inhabiting montane forests in Central and West Africa, where anthropogenic activities such as farming and cattle raising are major threats to native biodiversity. We used Amplified Fragment Length Polymorphisms (AFLPs) to assess the population genetic structure of two poorly known species, Cardioglossa schioetzi and Leptodactylodon bicolor (both in the Arthroleptidae), in and around Ngel Nyaki Forest Reserve on the Mambilla Plateau in eastern Nigeria. The landscape comprises continuous forest on steep slopes and small riparian forest fragments in a grassland matrix. While increased fragmentation is well documented for these and other forests in the mountains of Cameroon and Nigeria over the past century, there are no previous assessments of the impact of forest fragmentation on montane amphibian populations in this region. Our estimates of genetic diversity are similar across populations within each species with levels of heterozygosity values consistent with local population declines. Except for a pair of populations (C. schioetzi) we did not observe genetic differentiation between forest and riparian forest fragment populations, nor across sites within continuous forest (L. bicolor). Our results demonstrate recent gene flow between forest fragments and the adjacent protected forests and suggest that small forest corridors connecting these may lessen the genetic consequences of at least 30 years of intense and severe fragmentation in Ngel Nyaki.
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Affiliation(s)
- Denise Arroyo-Lambaer
- Instituto de Biología, Universidad Nacional Autónoma de México, Ciudad Universitaria, Ciudad de México, México
| | - Hazel Chapman
- School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
- * E-mail:
| | - Marie Hale
- School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| | - David Blackburn
- Florida Museum of Natural History, University of Florida, Gainesville, Florida, United States of America
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Uriarte M, Chazdon RL. Incorporating natural regeneration in forest landscape restoration in tropical regions: synthesis and key research gaps. Biotropica 2016. [DOI: 10.1111/btp.12411] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- María Uriarte
- Department of Ecology, Evolution and Environmental Biology Columbia University 10th Floor Schermerhorn Extension, 1200 Amsterdam Ave. New York NY 10027 USA
| | - Robin L. Chazdon
- Department of Ecology and Evolutionary Biology University of Connecticut 75 N. Eagleville Road, Unit 3043 Storrs CT 06268‐3043 USA
- International Institute for Sustainability Estrada Dona Castorina 124, Horto Rio de Janeiro Brazil
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Chazdon RL, Guariguata MR. Natural regeneration as a tool for large‐scale forest restoration in the tropics: prospects and challenges. Biotropica 2016. [DOI: 10.1111/btp.12381] [Citation(s) in RCA: 250] [Impact Index Per Article: 31.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- Robin L. Chazdon
- Department of Ecology and Evolutionary Biology University of Connecticut 75 N. Eagleville Road, Unit 3043, 06269‐3043 Storrs CT USA
- International Institute for Sustainability Estrada Dona Castorina 124 Horto, 22460‐320 Rio de Janeiro Brazil
| | - Manuel R. Guariguata
- Center for International Forestry Research (CIFOR) Av. La Molina 1895 La Molina Lima Perú
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