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CONTENTS: I. II. III. IV. V. VI. VII. References SUMMARY: The Brazilian Atlantic Forest hosts one of the world's most diverse and threatened tropical forest biota. In many ways, its history of degradation describes the fate experienced by tropical forests around the world. After five centuries of human expansion, most Atlantic Forest landscapes are archipelagos of small forest fragments surrounded by open‐habitat matrices. This ‘natural laboratory’ has contributed to a better understanding of the evolutionary history and ecology of tropical forests and to determining the extent to which this irreplaceable biota is susceptible to major human disturbances. We share some of the major findings with respect to the responses of tropical forests to human disturbances across multiple biological levels and spatial scales and discuss some of the conservation initiatives adopted in the past decade. First, we provide a short description of the Atlantic Forest biota and its historical degradation. Secondly, we offer conceptual models describing major shifts experienced by tree assemblages at local scales and discuss landscape ecological processes that can help to maintain this biota at larger scales. We also examine potential plant responses to climate change. Finally, we propose a research agenda to improve the conservation value of human‐modified landscapes and safeguard the biological heritage of tropical forests.

Global climate change alters the dynamic of natural ecosystems and directly affects species distributions, persistence and diversity. The impacts of climate change may lead to dramatic changes in biotic interactions, such as pollination and seed dispersal. Life history traits are extremely important to consider the vulnerability of a species to climate change, producing more robust models than those based primarily on species distributions. Here, we hypothesized that rising temperatures and aridity will reduce suitable habitats for the endemic flora of the Caatinga, the most diverse dry tropical forest on Earth. Specifically, species with specialized reproductive traits (e.g. vertebrate pollination, biotic dispersal, obligatory cross-pollination) should be more affected by climate change than those with generalist traits. We performed two ecological niche models (current and future) to simulate the effects of climate change on the distribution area of endemic species in relation to life-history traits. We used the MIROC-ESM and CCSM4 models for both intermediate (RCP4.5) and highest predicted (RCP8.5) GHG emission scenarios, with a resolution of 30' (~1 km2). Habitat with high occurrence probability (>80%) of endemic species will be reduced (up to ~10% for trees, ~13% for non-arboreous, 10-28% for species with any pollination/reproductive system), with the greatest reductions for species with specialized reproductive traits. In addition, the likely concentration of endemic plants in the extreme northeastern portion of the Caatinga, in more mesic areas, coincides with the currently most human-modified areas of the ecosystem, which combined with climate change will further contract suitable habitats of endemic species. In conclusion, plant species endemic to the Caatinga are highly vulnerable to even conservative scenarios of future climate change and may lose much of their climatic envelopes. New protected areas should be located in the northeastern portion of the Caatinga, which hosts a more favorable climate, but is currently exposed to escalating agricultural intensification.

Drastic changes in vegetation structure caused by exceeding ecological thresholds have fueled the interest in tropical forest responses to climate and land-use changes. Here, we examine the potential successional trajectories experienced by the largest dry tropical forest region in South America, driven by climate conditions and human disturbance. We built potential distribution models for vertebrate taxa associated with forest or shrub habitats to estimate natural vegetation cover. Distribution patterns were compared to current vegetation across the entire region to identify distinct forest degradation levels. Our results indicate the region has climatic and soil conditions suitable for more forest cover than is currently found, even in some areas with limited precipitation. However, 11.04% of natural cover persists across such an immense region, with only 4.34% consisting of forest cover. Forest degradation is characterized by the dramatic expansion of shrubland (390%), farming, and non-vegetation cover due to changes in land-use, rather than climatic conditions. Although different climate conditions have been the principal drivers for natural forest distribution in the region, the forest seems unable to resist the consequences of land-use changes, particularly in lower precipitation areas. Therefore, land-use change has exceeded the ecological thresholds for the persistence of forests, while climate change may exacerbate vegetation-type transitions.

Summary Competitor, stress‐tolerator, ruderal (CSR) theory is a prominent plant functional strategy scheme previously applied to local floras. Globally, the wide geographic and phylogenetic coverage of available values of leaf area (LA), leaf dry matter content (LDMC) and specific leaf area (SLA) (representing, respectively, interspecific variation in plant size and conservative vs. acquisitive resource economics) promises the general application of CSR strategies across biomes, including the tropical forests hosting a large proportion of Earth's diversity. We used trait variation for 3068 tracheophytes (representing 198 families, six continents and 14 biomes) to create a globally calibrated CSR strategy calculator tool and investigate strategy–environment relationships across biomes world‐wide. Due to disparity in trait availability globally, co‐inertia analysis was used to check correspondence between a ‘wide geographic coverage, few traits’ data set and a ‘restricted coverage, many traits’ subset of 371 species for which 14 whole‐plant, flowering, seed and leaf traits (including leaf nitrogen content) were available. CSR strategy/environment relationships within biomes were investigated using fourth‐corner and RLQ analyses to determine strategy/climate specializations. Strong, significant concordance (RV = 0·597; P < 0·0001) was evident between the 14 trait multivariate space and when only LA, LDMC and SLA were used. Biomes such as tropical moist broadleaf forests exhibited strategy convergence (i.e. clustered around a CS/CSR median; C:S:R = 43:42:15%), with CS‐selection associated with warm, stable situations (lesser temperature seasonality), with greater annual precipitation and potential evapotranspiration. Other biomes were characterized by strategy divergence: for example, deserts varied between xeromorphic perennials such as Larrea divaricata, classified as S‐selected (C:S:R = 1:99:0%) and broadly R‐selected annual herbs (e.g. Claytonia perfoliata; R/CR‐selected; C:S:R = 21:0:79%). Strategy convergence was evident for several growth habits (e.g. trees) but not others (forbs). The CSR strategies of vascular plants can now be compared quantitatively within and between biomes at the global scale. Through known linkages between underlying leaf traits and growth rates, herbivory and decomposition rates, this method and the strategy–environment relationships it elucidates will help to predict which kinds of species may assemble in response to changes in biogeochemical cycles, climate and land use. Lay Summary

Habitat fragmentation and forest management have been considered to drastically alter the nature of forest ecosystems globally. However, much uncertainty remains regarding the causative mechanisms mediating temperate forest responses, such as forest physical environment and the structure of woody plant assemblages, regardless of the role these forests play for global sustainability. In this paper, we examine how both habitat fragmentation and timber exploitation via silvicultural operations affect these two factors at local and habitat spatial scales in a hyper-fragmented landscape of mixed beech forests spanning more than 1500 km2 in SW Germany. Variables were recorded across 57 1000 m2 plots covering four habitats: small forest fragments, forest edges within large control forests, as well as managed and unmanaged forest interior sites. As expected, forest habitats differed in disturbance level, physical conditions and community structure at plot and habitat scale. Briefly, diversity of plant assemblages differed across all forest habitats (highest in edge forests) and correlated with integrative indices of edge, fragmentation and management effects. Surprisingly, managed and unmanaged forests did not differ in terms of species richness at local spatial scale, but managed forests exhibited a clear signal of physical/floristic homogenization as species promoted by silviculture proliferated; i.e. impoverished communities at landscape scale. Moreover, functional composition of plant communities responded to the microclimatic regime within forest fragments, resulting in a higher prevalence of species adapted to these microclimatic conditions. Our results underscore the notion that forest fragmentation and silvicultural management (1) promote changes in microclimatic regimes, (2) alter the balance between light-demanding and shade-adapted species, (3) support diverse floras across forest edges, and (4) alter patterns of beta diversity. Hence, in human-modified landscapes edge-affected habitats can be recognized as biodiversity reservoirs in contrast to impoverished managed interior forests. Furthermore, our results ratify the role of unmanaged forests as a source of environmental variability, species turnover, and distinct woody plant communities.

Habitat loss and degradation, mainly driven by agricultural expansion and intensification, alter ecological processes, ecosystem services and human well-being at a global scale. Pollinator populations in degraded agricultural areas tend to collapse, which in turn can reduce the effective pollination of agricultural crops and food production, particularly in leading food producing countries, such as Brazil. We sought to understand how the vulnerability to pollinator failure and the economic value of pollination (EVP) are associated with farmland size, farmer income, habitat loss, and the size of the human footprint. We also examine socioeconomic predictors related to income inequality levels across Brazilian municipalities and phytogeographic domains. We show that 58% of all leading crops in Brazil are dependent to some degree on animal pollination, and agricultural production in 96.8% of all municipalities is at least partly vulnerable to pollinator failure. Soybean, coffee, cotton, tomato and cocoa accounted for 84% of the total economic valuation of cropland pollination in Brazil, with soybean alone representing more than half of this value. Including soybean, vulnerability and EVP were positively correlated with the Human Development Index (HDI), Gross Domestic Product (GDP), habitat loss, and farmland size. On the other hand, these key indicators were negatively associated with the human footprint and the proportion of low-income farmers. Excluding soybean, however, vulnerability increased across low-income municipalities, particularly across the Atlantic Forest, Cerrado, and Caatinga, revealing strong biome contrasts. Overall, EVP was consistently reduced in areas under heavier human footprint, suggesting that anthropogenic pressures reduce pollination benefits. Our results also show that soybean cultivation masks underlying social and regional disparities in agricultural vulnerability. Thus, the evaluation of pollination risks can be masked by commodity production. Enhancing ecological processes and promoting diversified, pollinator-friendly agriculture may strengthen food production, particularly for tropical low-income farmers in vulnerable regions, while contributing to ecosystem service provision and human well-being.

1. Secondary forests are increasingly dominant in human-modified tropical landscapes, but the drivers of forest recovery remain poorly understood. Soil conditions influence plant community composition, and are expected to change over a gradient of succession. However, the role of soil conditions as an environmental filter driving community assembly during forest succession has rarely been explicitly assessed. 2. We evaluated the role of stand basal area and soil conditions on community assembly and its consequences for community functional properties along a chronosequence of Atlantic forest regeneration following sugar cane cultivation. Specifically, we tested whether community functional properties are related to stand basal area, soil fertility and soil moisture. Our expectations were that edaphic environmental filters play an increasingly important role along secondary succession by increasing functional trait convergence towards more conservative attributes. 3. We sampled soil and woody vegetation features across 15 second-growth (3-30 years) and 11 old-growth forest plots (300 m² each). We recorded tree functional traits related to resource-use strategies (specific leaf area, SLA; leaf dry matter content, LDMC; leaf area, LA; leaf thickness, LT; and leaf succulence, LS) and calculated community functional properties using the community-weighted mean (CWM) of each trait and the functional dispersion (FDis) of each trait separately and all traits together. 4. With exception of LA, all leaf traits were strongly associated with stand basal area; LDMC and SLA increased, while LT and LS decreased with forest development. Such changes in LDMC, LT and LS were also related to the decrease in soil nutrient availability and pH along succession, while soil moisture was weakly related to community functional properties. Considering all traits, as well as leaf thickness and succulence separately, FDis strongly decreased with increasing basal area and decreasing soil fertility along forest succession, presenting the lowest values in oldgrowth forests. 5. Synthesis. Our findings suggest that tropical forest regeneration may be a deterministic process shaped by soil conditions. Soil fertility operates as a key filter causing functional convergence towards more conservative resource-use strategies, such as leaves with higher leaf dry matter content.

Urbanization has rapidly increased in recent decades and the negative effects on biodiversity have been widely reported. Urban green areas can contribute to improving human well-being, maintaining biodiversity, and ecosystem services (e.g. pollination). Here we examine the evolution of studies on plant–pollinator interactions in urban ecosystems worldwide, reviewing also research funding and policy actions. We documented a significant increase in the scientific production on the theme in recent years, especially in the temperate region; tropical urban ecosystems are still neglected. Plant–pollinator interactions are threatened by urbanization in complex ways, depending on the studied group (plant or pollinator [generalist or specialist]) and landscape characteristics. Several research opportunities emerge from our review. Research funding and policy actions to pollination/pollinator in urban ecosystems are still scarce and concentrated in developed countries/temperate regions. To make urban green spaces contribute to the maintenance of biodiversity and the provision of ecosystem services, transdisciplinary approaches (ecological–social–economic–cultural) are needed.

Despite evidence about the contribution of Indigenous Peoples and local communities (IPLCs) to conservation, prevailing strategies still seek their separation from nature, often triggering conflicts. Current pledges to expand global protected area coverage suggest a need for the critical analysis of governance quality and the way conservation interacts with the well‐being of IPLCs. We present the case of Catimbau National Park in the Caatinga dry forest of northeast Brazil, where we explored connections between the well‐being of IPLCs and landscape through different values, practices and institutions, and perceptions of how environmentally just the park's governance has been. The well‐being of IPLCs is inextricably connected with the Caatinga landscape, through multiple place‐based relational values that, although differing between Indigenous and non‐indigenous inhabitants, have in both cases developed over generations. Although often framed as degraders, IPLCs exhibit a strong motivation to conserve, reflected through local institutions including forest gardens, sustainable use regulations, restoration activities and prevention of external encroachment. The strict form of protected area implemented at Catimbau, instead of a locally led or sustainable use reserve, explicitly targeted the resettlement of IPLCs and livelihood reorientation. These imposed objectives have clashed with a way of life in this peopled landscape and precluded local stewardship on a larger scale. Long‐term conflict arose through governance deficiencies which sparked multidimensional injustices. These include not only the misrecognition of local values and customary institutions but also the lack of procedures for consent or decision‐making influence, plus distributional harms including tenure insecurity and denied development assistance. Development and conservation strategies must reject narratives about poor, resource‐dependent rural communities and embrace the opportunities that local knowledge and institutions bring for effective conservation. As conservation efforts are expanded post‐2020, the people of the Caatinga and beyond must be recognised as embedded and a key part of any solution. In strict protected areas like Catimbau, where social conflict constrains their ability to function, seeking legal changes in governance type can be onerous. However, we describe other local‐level actions to build relationships and agency that may foster transitions towards better governance, and just treatment of IPLCs. A free Plain Language Summary can be found within the Supporting Information of this article. Resumo Apesar das evidências sobre a contribuição dos Povos Indígenas e Comunidades Locais (PICLs) para a conservação, as estratégias predominantes ainda buscam sua separação da natureza, muitas vezes desencadeando conflitos. As promessas atuais de expandir a cobertura global de áreas protegidas sugerem a necessidade de uma análise crítica da qualidade de governança e da maneira como a conservação interage com o bem‐estar das PICLs. Apresentamos o caso do Parque Nacional do Catimbau na floresta seca da Caatinga no nordeste do Brasil, onde exploramos as conexões entre o bem‐estar das PICLs e a paisagem por meio de diferentes valores, práticas e instituições, e percepções de quão ambientalmente justa tem sido a gestão do parque. O bem‐estar das PICLs está intrinsecamente ligado à paisagem da Caatinga, por meio de múltiplos valores relacionais de base local que, embora diferentes entre indígenas e não indígenas, em ambos os casos se desenvolveram ao longo de gerações. Embora muitas vezes classificadas como degradantes, as PICLs exibem uma forte motivação para conservar, refletida por meio de instituições locais, incluindo cultivos florestais, regulamentações de uso sustentável, atividades de restauração e prevenção de invasões externas. A forma inflexível de área protegida implementada no Catimbau, em vez de uma reserva localmente controlada ou de uso sustentável, visava explicitamente o reassentamento das PICLs e a reorientação dos meios de subsistência. Esses objetivos impostos colidiram com um modo de vida nesta paisagem povoada e impediram a gestão local em uma escala maior. O conflito de longo prazo surgiu por meio de falhas de gestão que geraram injustiças multidimensionais. Isso inclui não apenas o não reconhecimento de valores locais e instituições de usos e costumes, mas também a falta de procedimentos para consentimento ou influência na tomada de decisões, além de danos distributivos, incluindo insegurança de posse e negação de assistência ao desenvolvimento. As estratégias de desenvolvimento e conservação devem rejeitar narrativas sobre comunidades rurais pobres e dependentes de recursos e abraçar as oportunidades que o conhecimento local e as instituições trazem para uma conservação eficaz. À medida que os esforços de conservação são expandidos pós‐2020, o povo da Caatinga e além deve ser reconhecido como uma parte fundamental de qualquer solução. Em áreas estritamente protegidas como o Catimbau, onde o conflito social restringe sua capacidade de funcionamento, buscar mudanças legais do tipo de gestão pode ser dispendioso. No entanto, descrevemos outras ações em nível local para construir relacionamentos e ações que possam promover transições para uma melhor gestão e tratamento justo de PICLs. A free Plain Language Summary can be found within the Supporting Information of this article.