Tropical forests disappear rapidly because of deforestation, yet they have the potential to regrow naturally on abandoned lands. We analyze how 12 forest attributes recover during secondary succession and how their recovery is interrelated using 77 sites across the tropics. Tropical forests are highly resilient to low-intensity land use; after 20 years, forest attributes attain 78% (33 to 100%) of their old-growth values. Recovery to 90% of old-growth values is fastest for soil (<1 decade) and plant functioning (12 decades). Network analysis shows three independent clusters of attribute recovery, related to structure, species diversity, and species composition. Secondary forests should be embraced as a low-cost, natural solution for ecosystem restoration, climate change mitigation, and biodiversity conservation. © 2021 American Association for the Advancement of Science. All rights reserved.
Tag: biodiversity
Learning pathway: Course flows & blueprint
This course is a pivotal contribution to FAO’s vision of fostering a Better Environment, particularly focusing on Biodiversity for food and agriculture. Aligned with FAO’s strategic initiatives, the course is fortified by the approval of the FAO Strategy on Mainstreaming Biodiversity Across Agricultural Sectors and the 2021-23 Action Plan, emphasizing the importance of targeted policies and practices for sustainable use, conservation, and restoration of ecosystems.
Even small forest patches increase bee visits to flowers in an oil palm plantation landscape
Pollination sustains biodiversity and food security, but pollinators are threatened by habitat degradation, fragmentation, and loss. We assessed how remaining forest influenced bee visits to flowers in an oil palm-dominated landscape in Borneo. We observed bee visits to six plant species: four crops (Capsicum frutescens L. “chili”; Citrullus lanatus (Thunb.) Matsum & Nakai “watermelon”; Solanum lycopersicum L. “tomato”; and Solanum melongena L. “eggplant”); one native plant Melastoma malabathricum L. “melastome”; and the exotic Turnera subulata Smith “turnera”. We made one local grid-based and one landscape-scale transect-based study spanning 208 and 2130 m from forest, respectively. We recorded 1249 bee visits to 4831 flowers in 1046 ten-min observation periods. Visit frequency varied among plant species, ranging from 0 observed visits to S. lycopersicum to a mean of 0.62 visits per flower per 10 min to C. lanatus. Bee visitation frequency declined with distance from forest in both studies, with expected visitation frequency decreasing by 55% and 66% at the maximum distance from forest in each study. We also tested whether the distance to the nearest oil palm patch, with a maximum distance of 144 m, influenced visitation, but found no such associations. Expected visitation frequency was 70%–77% lower for plants close to a 200 ha forest fragment compared with those near large continuous forests (>400 ha). Our results suggest that, although found throughout the oil palm-dominated landscape, bees depend on remaining forests. Larger forests support more bees, though even a 50 ha fragment has a positive contribution.
FTA Highlight No.4 – Forest and Landscape Restoration
Forest and landscape restoration (FLR) provides a framework for implementing restorative interventions that collectively address major environmental challenges such as soil and land degradation, biodiversity loss, water scarcity, lack of sustainable rural livelihoods, and climate change mitigation and adaptation. Restorative interventions can take many forms, which vary in cost, trajectory and specific economic and social outcomes; likewise, their benefits accrue to various actors and stakeholders. Over the last decade, the CGIAR Program on Forests, Trees and Agroforestry (FTA) has undertaken innovative basic and applied research across different scientific disciplines on the multiple dimensions of FLR for improving policy and practice and facilitating the uptake of new knowledge, tools and approaches — both from the top down and the bottom up. This publication presents key FTA outputs on forest and landscape restoration from 2011 to 2021. Many of them have contributed to informing the implementation of FLR interventions at multiple scales of work. These outputs are presented according to five broad areas of influence: (1) contributions to restoration science; (2) contributions to global narratives and discourses; (3) contributions to policy and governance; (4) focusing on actors on the ground; and (5) contributions to national and international dialogues. The last section (6) discusses ways to move forward.
Predicting landscape-scale biodiversity recovery by natural tropical forest regrowth
Natural forest regrowth is a cost-effective, nature-based solution for biodiversity recovery, yet different socio-environmental factors can lead to variable outcomes. A critical knowledge gap to inform forest restoration planning is how to predict where natural forest regrowth is likely to recover high levels of biodiversity, as an indicator of conservation value and potential for provisioning of diverse ecosystem services. In this study, we predicted and mapped landscape-scale biodiversity recovery of species richness and total abundance of vertebrates, invertebrates, and plants in tropical and subtropical second-growth forests to inform spatial restoration planning. First, we conducted a global meta-analysis that quantified the extent to which recovery of species richness and total abundance of vertebrates, invertebrates, and plants in second-growth forests deviated from biodiversity values in reference old-growth forests found within the same landscape. We then employed a machine learning algorithm and a comprehensive set of socio-environmental factors to spatially predict and map this landscape-scale deviation. We found that landscape-scale biodiversity recovery in second-growth forests: (i) can be spatially predicted using socio-environmental landscape factors (human demography, land use/cover, anthropogenic/natural disturbances, ecosystem productivity, and topography/soil); (ii) was higher for species richness than for total abundance for vertebrates and invertebrates but not for plants (which showed a similar recovery for both metrics); and (iii) was positively correlated for total abundance of plant and vertebrate species. Our approach can help identify tropical and subtropical forest landscapes with high potential for biodiversity recovery through natural forest regrowth.
Upscaling tropical restoration to deliver environmental benefits and socially equitable outcomes
The UN Decade on Ecosystem Restoration offers immense potential to return hundreds of millions of hectares of degraded tropical landscapes to functioning ecosystems. Well-designed restoration can tackle multiple Sustainable Development Goals, driving synergistic benefits for biodiversity, ecosystem services, agricultural and timber production, and local livelihoods at large spatial scales. To deliver on this potential, restoration efforts must recognise and reduce trade-offs among objectives, and minimize competition with food production and conservation of native ecosystems. Restoration initiatives also need to confront core environmental challenges of climate change and inappropriate planting in savanna biomes, be robustly funded over the long term, and address issues of poor governance, inadequate land tenure, and socio-cultural disparities in benefits and costs. Tackling these issues using the landscape approach is vital to realising the potential for restoration to break the cycle of land degradation and poverty, and deliver on its core environmental and social promises. © 2021 Elsevier Inc.
Shade tree identity rather than diversity influences soil macrofauna in cacao-based agroforestry systems
Humanity is facing a rapid decline in global biodiversity, caused mainly by tropical deforestation through industrial and smallholder agriculture. However, smallholder agriculture landscapes host areas containing home gardens and other agroforestry systems (AFS) proved highly relevant for soil and biodiversity conservation. The positive interactions between aboveground and belowground biodiversity probably constitute a key element to promote the efficiency of these agro-ecosystems. To determine whether a relationship exists between tree and soil macrofauna diversity and composition, we compared cacao AFS with contrasted tree diversity along a topography and forest cover gradient in Talamanca, Costa Rica. To determine which components of the shade tree species, community structure (density, richness, Shannon, Pielou), and agroforest floor best explain the macrofauna community composition and structure, we constructed the “best models” based on the tree composition, tree structure, and agroforest floor as explanatory matrices in redundancy analyses. Macrofauna composition was best explained by a mix of tree species and litter attributes (R2=26.5 %), whereas macrofauna and vegetation co-vary significantly with topography (R2=12 %). Macrofauna structure is best explained by a selection of seven tree species (R2=41.2 %). The co-variation with topography remained low (R2=10.9 %). Tree evenness (Pielou index) explained only 7 % of macrofauna community structure while other diversity indices were not correlated with macrofauna composition or structure. The soil macrofauna was therefore more influenced by tree identity and litter composition than by the overall diversity of the tree community. This information is important for designing the optimal combinations of species for the intensification of production and provision of ecosystem services in cacao-based AFS.
Creating a National Biodiversity Database in Gabon and the Challenges of Mobilizing Natural History Data for Francophone Countries
Language is a major barrier for researchers wanting to digitize and publish collection data in Africa. Despite being the fifth most spoken language on Earth and the second most common in Africa, resources in French about digitization, data management, and publishing are lacking. Furthermore, French-speaking regions of Africa (primarily Central/West Africa and Madagascar) host some of the highest biodiversity on the continent and therefore are of great importance to scientists and decision-makers. Without having representation in online portals like the Global Biodiversity Information Facility (GBIF) and Integrated Digitized Biocollections (iDigBio), these important collections are effectively invisible. Producing relevant/applicable resources about digitization in French will help shine a light on these valuable natural history records and allow the data-holders in Africa to retain the autonomy of their collections. Awarded a GBIF-BID (Biodiversity Information for Development) grant in 2021, an international, multilingual network of partners has undertaken the important task of digitizing and mobilizing Gabon’s vertebrate collections. There are an estimated 13,500 vertebrate specimens housed in five institutions in different parts of Gabon. To date, the group has mobilized >4,600 vertebrate records to our recently launched Gabon Biodiversity Portal (https://gabonbiota.org/). The portal also hosts French guides for using Symbiota-based portals to manage, georeference, and publish natural history databases. These resources can provide much-needed guidance for other Francophone countries—in Africa and beyond—working to maximize the accessibility and value of their biodiversity collections.
Drivers of Biodiversity Conservation in Sacred Groves: A Comparative Study of Three Sacred Groves in Southwest Nigeria
Globally, sacred groves represent a traditional form of community-based conservation system, recognized for their capacity to preserve areas that are of cultural and religious importance to local people. In most cases, the entire community takes on a watchdog role to guard against encroachment and unauthorized access either by its members or outsiders who might desecrate such sites. Our paper investigates the effects of different governance arrangements on three sacred groves in southwest Nigeria⎯Osun Osogbo Sacred Grove (UNESCO World Heritage Site); Idanre Hills (Nigerian National Monument) and Igbo-Olodumare (local cultural site)⎯on their socio-economic and religio-cultural benefits and contribution to biodiversity conservation. Using a mixed-methods design of a semi-structured questionnaire (n=167), key informant interviews (n=2), and focus groups (n=7), we collected data from local community members, traditional priests, sacred grove devotees and tourism officials. We found that customary institutions have guided reverence for sacralized spaces and wise utilization of their unique resources. The growing recognition of sacred groves has paved the way for socioeconomic rewards for individuals and government as cultural tourism increases. We found that the involvement of formal institutions alongside customary institutions in sacred grove management reinforces compliance with conservation laws within the sacred groves, especially where traditional norms are weak or may be disregarded. We discuss the implications of these observations and offer suggestions to improve community engagement, uphold traditional ecological knowledge, and develop ecotourism within the groves. We conclude that the co-existence of community-based conservation through a system of established traditional norms and prohibitions as well as formal government legislation and management, offers assurance for the long-term preservation of sacred groves and their biodiversity.
Scientific foundations for an ecosystem goal, milestones and indicators for the post-2020 global biodiversity framework
Despite substantial conservation efforts, the loss of ecosystems continues globally, along with related declines in species and nature’s contributions to people. An effective ecosystem goal, supported by clear milestones, targets and indicators, is urgently needed for the post-2020 global biodiversity framework and beyond to support biodiversity conservation, the UN Sustainable Development Goals and efforts to abate climate change. Here, we describe the scientific foundations for an ecosystem goal and milestones, founded on a theory of change, and review available indicators to measure progress. An ecosystem goal should include three core components: area, integrity and risk of collapse. Targets—the actions that are necessary for the goals to be met—should address the pathways to ecosystem loss and recovery, including safeguarding remnants of threatened ecosystems, restoring their area and integrity to reduce risk of collapse and retaining intact areas. Multiple indicators are needed to capture the different dimensions of ecosystem area, integrity and risk of collapse across all ecosystem types, and should be selected for their fitness for purpose and relevance to goal components. Science-based goals, supported by well-formulated action targets and fit-for-purpose indicators, will provide the best foundation for reversing biodiversity loss and sustaining human well-being. © 2021, Springer Nature Limited.