Assisted restoration interventions drive functional recovery of tropical wet forest tree communities
Choosing appropriate forest restoration interventions is challenging. Natural regeneration can rapidly facilitate forest recovery in many situations. However, barriers such as dispersal limitation and competition with non-native species can require assisted restoration approaches to facilitate plant...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2022-08-01
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| Series: | Frontiers in Forests and Global Change |
| Subjects: | |
| Online Access: | https://www.frontiersin.org/articles/10.3389/ffgc.2022.935011/full |
| _version_ | 1828356147938066432 |
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| author | Leland K. Werden Leland K. Werden Sebastian Zarges Karen D. Holl Chad L. Oliver Federico Oviedo-Brenes Juan Abel Rosales Rakan A. Zahawi Rakan A. Zahawi |
| author_facet | Leland K. Werden Leland K. Werden Sebastian Zarges Karen D. Holl Chad L. Oliver Federico Oviedo-Brenes Juan Abel Rosales Rakan A. Zahawi Rakan A. Zahawi |
| author_sort | Leland K. Werden |
| collection | DOAJ |
| description | Choosing appropriate forest restoration interventions is challenging. Natural regeneration can rapidly facilitate forest recovery in many situations. However, barriers such as dispersal limitation and competition with non-native species can require assisted restoration approaches to facilitate plant community recovery. We used a study that has directly compared the outcomes of tropical wet forest restoration interventions across 11 replicate sites in southern Costa Rica. Within this framework, we examined the functional recovery trajectories of recruiting tree sapling communities across a gradient of restoration interventions including low (natural regeneration), intermediate (applied nucleation), and high (plantation) initial resource-investment, which we compared to remnant reference forest. We collated leaf and stem functional traits for tree species that comprised the bulk of recruiting saplings, then determined how community-weighted trait means and functional diversity metrics changed over a decade across treatments. Results show that assisted restoration approaches (applied nucleation, plantation) sped the development of more functionally diverse tree communities, more than tripling the functional richness (FRic) of recruiting communities when compared to natural regeneration. However, functional dispersion (i.e., the trait range of dominant species) was equivalent across interventions, and between 28 and 44% lower than remnant forest, indicating that increases in FRic under assisted restoration were driven by species recruiting in low abundances (<10 individuals across treatments). Recruits in assisted restoration treatments also had 10–15% tougher, less-palatable leaves, and leaves were even tougher in reference forest, which could be driven by increasing herbivory pressure along the gradient of interventions. Results show that tracking simple metrics such as species richness can mask a more mechanistic understanding of ecosystem recovery that is elucidated by taking a functional trait-driven approach toward evaluating outcomes. For example, our work identified a paucity of dense-wooded species recruiting across restoration interventions, wood density was 11–13% lower in restoration treatments than reference forests, underscoring such species as prime targets for enrichment planting. Overall, findings suggest that assisted restoration can catalyze the functional recovery of naturally recruiting tree communities in landscapes that are slow to recover naturally and highlight the importance of evaluating how different components of functional diversity shift over time to fully understand restoration outcomes. |
| first_indexed | 2024-04-14T02:54:48Z |
| format | Article |
| id | doaj.art-754b72745d534cfc831da59223609cd8 |
| institution | Directory Open Access Journal |
| issn | 2624-893X |
| language | English |
| last_indexed | 2024-04-14T02:54:48Z |
| publishDate | 2022-08-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Forests and Global Change |
| spelling | doaj.art-754b72745d534cfc831da59223609cd82022-12-22T02:16:10ZengFrontiers Media S.A.Frontiers in Forests and Global Change2624-893X2022-08-01510.3389/ffgc.2022.935011935011Assisted restoration interventions drive functional recovery of tropical wet forest tree communitiesLeland K. Werden0Leland K. Werden1Sebastian Zarges2Karen D. Holl3Chad L. Oliver4Federico Oviedo-Brenes5Juan Abel Rosales6Rakan A. Zahawi7Rakan A. Zahawi8Lyon Arboretum and School of Life Sciences, University of Hawai’i at Mānoa, Honolulu, HI, United StatesDepartment of Environmental Systems Science, ETH Zürich, Zurich, SwitzerlandFaculty of Forest Sciences and Forest Ecology, University of Göttingen, Göttingen, GermanyDepartment of Environmental Studies, University of California, Santa Cruz, Santa Cruz, CA, United StatesDepartment of Ecology and Evolutionary Biology, University of California, Santa Cruz, Santa Cruz, CA, United StatesLas Cruces Biological Station, Organization for Tropical Studies, San Vito, Costa RicaLas Cruces Biological Station, Organization for Tropical Studies, San Vito, Costa RicaLyon Arboretum and School of Life Sciences, University of Hawai’i at Mānoa, Honolulu, HI, United StatesCharles Darwin Foundation, Puerto Ayora, EcuadorChoosing appropriate forest restoration interventions is challenging. Natural regeneration can rapidly facilitate forest recovery in many situations. However, barriers such as dispersal limitation and competition with non-native species can require assisted restoration approaches to facilitate plant community recovery. We used a study that has directly compared the outcomes of tropical wet forest restoration interventions across 11 replicate sites in southern Costa Rica. Within this framework, we examined the functional recovery trajectories of recruiting tree sapling communities across a gradient of restoration interventions including low (natural regeneration), intermediate (applied nucleation), and high (plantation) initial resource-investment, which we compared to remnant reference forest. We collated leaf and stem functional traits for tree species that comprised the bulk of recruiting saplings, then determined how community-weighted trait means and functional diversity metrics changed over a decade across treatments. Results show that assisted restoration approaches (applied nucleation, plantation) sped the development of more functionally diverse tree communities, more than tripling the functional richness (FRic) of recruiting communities when compared to natural regeneration. However, functional dispersion (i.e., the trait range of dominant species) was equivalent across interventions, and between 28 and 44% lower than remnant forest, indicating that increases in FRic under assisted restoration were driven by species recruiting in low abundances (<10 individuals across treatments). Recruits in assisted restoration treatments also had 10–15% tougher, less-palatable leaves, and leaves were even tougher in reference forest, which could be driven by increasing herbivory pressure along the gradient of interventions. Results show that tracking simple metrics such as species richness can mask a more mechanistic understanding of ecosystem recovery that is elucidated by taking a functional trait-driven approach toward evaluating outcomes. For example, our work identified a paucity of dense-wooded species recruiting across restoration interventions, wood density was 11–13% lower in restoration treatments than reference forests, underscoring such species as prime targets for enrichment planting. Overall, findings suggest that assisted restoration can catalyze the functional recovery of naturally recruiting tree communities in landscapes that are slow to recover naturally and highlight the importance of evaluating how different components of functional diversity shift over time to fully understand restoration outcomes.https://www.frontiersin.org/articles/10.3389/ffgc.2022.935011/fullapplied nucleationcommunity assemblyCosta Ricafunctional diversitynatural regenerationtree plantation |
| spellingShingle | Leland K. Werden Leland K. Werden Sebastian Zarges Karen D. Holl Chad L. Oliver Federico Oviedo-Brenes Juan Abel Rosales Rakan A. Zahawi Rakan A. Zahawi Assisted restoration interventions drive functional recovery of tropical wet forest tree communities Frontiers in Forests and Global Change applied nucleation community assembly Costa Rica functional diversity natural regeneration tree plantation |
| title | Assisted restoration interventions drive functional recovery of tropical wet forest tree communities |
| title_full | Assisted restoration interventions drive functional recovery of tropical wet forest tree communities |
| title_fullStr | Assisted restoration interventions drive functional recovery of tropical wet forest tree communities |
| title_full_unstemmed | Assisted restoration interventions drive functional recovery of tropical wet forest tree communities |
| title_short | Assisted restoration interventions drive functional recovery of tropical wet forest tree communities |
| title_sort | assisted restoration interventions drive functional recovery of tropical wet forest tree communities |
| topic | applied nucleation community assembly Costa Rica functional diversity natural regeneration tree plantation |
| url | https://www.frontiersin.org/articles/10.3389/ffgc.2022.935011/full |
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