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Context: Understanding the complex interdependencies between nature and people is a major challenge for the sustainable management of social-ecological systems. Spatially explicit identification of these interdependencies is particularly relevant for managing biodiversity hotspots, such as Tropical Dry Forests (TDF). Objectives: We provided a methodology to spatially identify the components of social-ecological systems that have been shaped by both environmental conditions and management practices at three relevant decision-making scales: plots owned by individuals, plot owners, and governance units. To do so, we identified and characterized: (1) ecological clusters (EC), (2) social-management clusters (SC), and (3) social-ecological systems units (SESU) in a TDF in western Mexico. Methods: We used multivariate analysis to identify and characterize the ECs, SCs, and SESU at the respective decision-making scales. Results: We found four EC, SC, and SESU clusters. Differences between ECs were based on their elevation and land cover type. The SC differed according to the management intensity of cattle and forests. Differences between SESU were based on land management regime (individual vs collective), plot sizes, and time under private schemes. Conclusions: Our findings suggested that decision-makers (ejidatarios) are bounded by the topographical characteristics and the public policies that determine communal (or private) governance, also by the number of resources available to them. The methodology can be applied to other contexts and nested decision-making scales. The spatial identification of these interdependencies is critical for landscape planning since it can contribute to reconciling productive activities and biodiversity conservation. [ABSTRACT FROM AUTHOR]

Copyright of People & Nature is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Impacts of climate change require that society urgently develops ways to reduce amounts of carbon in the atmosphere. Tropical forests present an important opportunity, as they take up and store large amounts of carbon. It is often suggested that forests with high biodiversity have large stocks and high rates of carbon uptake. Evidence is, however, scattered across geographic areas and scales, and it remains unclear whether biodiversity is just a co-benefit or also a requirement for the maintenance of carbon stocks and uptake. Here, we perform a quantitative review of empirical studies that analyzed the relationships between plant biodiversity attributes and carbon stocks and carbon uptake in tropical forests. Our results show that biodiversity attributes related to species, traits or structure significantly affect carbon stocks or uptake in 64% of the evaluated relationships. Average vegetation attributes (community-mean traits and structural attributes) are more important for carbon stocks, whereas variability in vegetation attributes ( i.e., taxonomic diversity) is important for both carbon stocks and uptake. Thus, different attributes of biodiversity have complementary effects on carbon stocks and uptake. These biodiversity effects tend to be more often significant in mature forests at broad spatial scales than in disturbed forests at local spatial scales. Biodiversity effects are also more often significant when confounding variables are not included in the analyses, highlighting the importance of performing a comprehensive analysis that adequately accounts for environmental drivers. In summary, biodiversity is not only a co-benefit, but also a requirement for short- and long-term maintenance of carbon stocks and enhancement of uptake. Climate change policies should therefore include the maintenance of multiple attributes of biodiversity as an essential requirement to achieve long-term climate change mitigation goals. [ABSTRACT FROM AUTHOR]

Assessing the recovery of species diversity and composition after major disturbance is key to understanding the resilience of tropical forests through successional processes, and its importance for biodiversity conservation. Despite the specific abiotic environment and ecological processes of tropical dry forests, secondary succession has received less attention in this biome than others and changes in species diversity and composition have never been synthesised in a systematic and quantitative review. This study aims to assess in tropical dry forests 1) the directionality of change in species richness and evenness during secondary succession, 2) the convergence of species composition towards that of old-growth forest and 3) the importance of the previous land use, precipitation regime and water availability in influencing the direction and rate of change. We conducted meta-analyses of the rate of change in species richness, evenness and composition indices with succession in 13 tropical dry forest chronosequences. Species richness increased with succession, showing a gradual accumulation of species, as did Shannon evenness index. The similarity in species composition of successional forests with old-growth forests increased with succession, yet at a low rate. Tropical dry forests therefore do show resilience of species composition but it may never reach that of old-growth forests. We found no significant differences in rates of change between different previous land uses, precipitation regimes or water availability. Our results show high resilience of tropical dry forests in term of species richness but a slow recovery of species composition. They highlight the need for further research on secondary succession in this biome and better understanding of impacts of previous land-use and landscape-scale patterns. [ABSTRACT FROM AUTHOR]

• We analyzed social preferences and spatial perceptions of ecosystem services and biodiversity. • Exist bundles where biodiversity coexists with ecosystem services and others where agriculture threatens it. • The preferences and spatial patterns were strongly associated with supporting local livelihoods. • The biophysical factors and historical government policies shaped the current agricultural frontier. • The new, mixed methodology we developed can be implemented in a range of different contexts and scales. Tropical agricultural frontiers are rapidly changing and present unique opportunities to reconcile ecosystem services (ES) provision, biodiversity conservation, and livelihood maintenance of rural communities. To understand the dynamics of these frontiers, we analyzed preferences, reasons associated with importance, and spatial perceptions of ES and biodiversity in Mexico at two scales. In seven workshops and 42 interviews, participants ranked preferred ES and expressed reasons for their importance. They identified the relevant areas for ES and biodiversity. We used this data to create an index to obtain maps of perceived spatial patterns and perform a cluster analysis to identify ES bundles. A redundancy analysis highlighted the factors that help explain the spatial patterns and qualitative and quantitative methods were used to explore the reasons behind participants' rankings of relative importance. We found two contrasting bundles at the regional scale: the natural protected area, where biodiversity is highest, and the agricultural frontier, where agricultural services were highest. At the ejido scale, ejidos whose livelihoods are mainly centered on agriculture and those that develop diverse activities were grouped. Socio-ecological factors (e.g., ejido area, PES program, and indigenous population) further distinguished ejidos focused on agricultural expansion, those dominated by marginalized local inhabitants, and those focused on forest management. The most dominant reasons underlying ES rankings include having sufficient nutritious food and economic support linked to agricultural services. We discuss the role of conservation strategies, historical government decisions, and biophysical characteristics in shaping strong trade-offs between biodiversity conservation and agriculture—and the role of voluntary local conservation initiatives and a national PES scheme in supporting opportunities to reconcile some of these trade-offs. This study demonstrates the importance of integrating local community preferences and perceptions into spatially explicit products that can be used in inclusive conservation and landscape planning approaches for tropical landscapes worldwide. [ABSTRACT FROM AUTHOR]

Copyright of Revista Mexicana de Biodiversidad is the property of Universidad Nacional Autonoma de Mexico, Instituto de Biologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

1. In spite of the increasing amount of experimental evidence on the importance of plant species richness for ecosystem functioning at local scales, its role on the generation of ecosystem services at scales relevant for management is still largely unknown. To foster research on this topic, we assessed expert knowledge on the role of plant diversity in the generation of services at the landscape scale. 2. We developed a survey that included three levels of organization and seven components of plant diversity; four provisioning, six regulating and four cultural services; as well as three resources and three conditions among key abiotic factors that are likely to provide a contribution to service generation equalling that of plant diversity. Eighty experts in areas of biodiversity, ecosystem functioning and services answered the survey. 3. The experts identified species diversity within a community and diversity of communities within the landscape as the most important levels of organization for service generation, both with positive effects. Composition and number of species were considered to be the most relevant components of plant diversity, the latter with a positive effect on services. Water availability was identified as the most important abiotic resource. 4. Our results suggest different approaches to management for sustaining the generation of services at the landscape scale. Provisioning services were perceived as largely influenced by abiotic resources and less so (although positively) by plant diversity. Regulating services were expected to strongly depend on both plant diversity and abiotic factors. A particularly strong positive effect of plant diversity was expected for the generation of cultural services. Some variation in answers could be attributed to expert background. 5. Synthesis and applications. The expert survey generated detailed information and new hypotheses on the relationship between plant diversity and services at the landscape scale. Future research is needed to test these hypotheses, yet the areas of agreement identified in this study can be used immediately, with caution, as synthetic expert knowledge at spatial scales that are relevant for management, to guide technological and policy interventions ensuring the maintenance of biodiversity and ecosystem service delivery. [ABSTRACT FROM AUTHOR]

Quantitative scenarios are coming of age as a tool for evaluating the impact of future socioeconomic development pathways on biodiversity and ecosystem services. We analyze global terrestrial, freshwater, and marine biodiversity scenarios using a range of measures including extinctions, changes in species abundance, habitat loss, and distribution shifts, as well as comparing model projections to observations. Scenarios consistently indicate that biodiversity will continue to decline over the 21st century. However, the range of projected changes is much broader than most studies suggest, partly because there are major opportunities to intervene through better policies, but also because of large uncertainties in projections. [ABSTRACT FROM AUTHOR]