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Agricultural expansion is the primary driver of ecological degradation across the tropics. Set-asides—uncultivated parts of agricultural landscapes, often on steep slopes and alongside rivers—may alleviate environmental impacts but can reduce the area cultivated. Here we model an approach to configuring set-asides aimed at optimizing ecological outcomes (biodiversity, above-ground carbon storage and nutrient cycling) without reducing net cultivation area. We compare set-asides in an oil palm landscape where all plantations adopt the same configuration (‘uniform’ approach) with a scenario where there can be variation in configuration among plantations (‘variable’ approach). We find that all set-aside configurations support substantial ecological values but that the best strategies involve set-asides, particularly alongside rivers, that are spatially targeted and variable among plantations. This ‘variable’ approach can increase ecological outcomes twofold over the ‘uniform’ approach without reducing net cultivation area. Our findings underscore the potential importance of well-planned set-asides for enhancing agricultural sustainability.

Building trust in science and evidence-based decision-making depends heavily on the credibility of studies and their findings. Researchers employ many different study designs that vary in their risk of bias to evaluate the true effect of interventions or impacts. Here, we empirically quantify, on a large scale, the prevalence of different study designs and the magnitude of bias in their estimates. Randomised designs and controlled observational designs with pre-intervention sampling were used by just 23% of intervention studies in biodiversity conservation, and 36% of intervention studies in social science. We demonstrate, through pairwise within-study comparisons across 49 environmental datasets, that these types of designs usually give less biased estimates than simpler observational designs. We propose a model-based approach to combine study estimates that may suffer from different levels of study design bias, discuss the implications for evidence synthesis, and how to facilitate the use of more credible study designs., Randomised controlled experiments are the gold standard for scientific inference, but environmental and social scientists often rely on different study designs. Here the authors analyse the use of six common study designs in the fields of biodiversity conservation and social intervention, and quantify the biases in their estimates.

Agricultural expansion drives biodiversity decline in forested tropical regions. Consequently, it is important to understand the conservation value of remnant forest in production landscapes. In a tropical landscape dominated by oil palm we characterized faunal communities across eight taxa occurring within riparian forest buffers, which are legally protected alongside rivers, and compared them to nearby recovering logged forest. Buffer width was the main predictor of species richness and abundance, with widths of 40-100 m on each side of the river supporting broadly equivalent levels of biodiversity to logged forest. However, width responses varied markedly among taxa, and buffers often lacked forest-dependent species. Much wider buffers than are currently mandated are needed to safeguard most species. The largest biodiversity gains are achieved by increasing relatively narrow buffers. To provide optimal conservation outcomes in tropical production landscapes we encourage policymakers to prescribe width requirements for key taxa and different landscape contexts., Newton-Ungku Omar Fund (grants 216433953, 537134717) – delivered by the British Council and funded by the UK Department for Business, Energy and Industrial Strategy and the Malaysian Industry-Government Group for High Technology – as well as the UK Natural Environment Research Council (NE/K016407/1, NE/K016261/1; https://lombok.nerc-hmtf.info/). MJS was supported by a Research Leadership Award from the Leverhulme Trust.

Urbanization poses a serious threat to local biodiversity, yet towns and cities with abundant natural features may harbor important species populations and communities. While the contribution of urban greenspaces to conservation has been demonstrated by numerous studies within temperate regions, few consider the bird communities associated with different landcovers in Neotropical cities. To begin to fill this knowledge gap, we examined how the avifauna of a wetland city in northern Amazonia (Georgetown, Guyana) varied across six urban landcover types (coastal bluespace; urban bluespace; managed greenspace; unmanaged greenspace; dense urban; sparse urban). We measured detections, species richness and a series of ground cover variables that characterized the heterogeneity of each landcover, at 114 locations across the city. We recorded >10% (98) of Guyana’s bird species in Georgetown, including taxa of conservation interest. Avian detections, richness, and community composition differed with landcover type. Indicator species analysis identified 29 species from across dietary guilds, which could be driving community composition. Comparing landcovers, species richness was highest in managed greenspaces and lowest in dense urban areas. The canal network had comparable levels of species richness to greenspaces. The waterways are likely to play a key role in enhancing habitat connectivity as they traverse densely urbanized areas. Both species and landcover information should be integrated into urban land-use planning in the rapidly urbanizing Neotropics to maximize the conservation value of cities. This is imperative in the tropics, where anthropogenic pressures on species are growing significantly, and action needs to be taken to prevent biodiversity collapse.

Accelerating rates of urbanisation are contributing to biodiversity declines worldwide. However, urban green (e.g. parks) and blue spaces (e.g. coast) provide important habitat for species. Emerging evidence also shows that green and blue spaces can benefit human psychological wellbeing, although few studies originate from the Global South and it is unclear whether more biodiverse spaces offer greater wellbeing gains. We examine how bird diversity (abundance, species richness, Shannon diversity, and community composition) in green and coastal blue space in Georgetown, Guyana, is associated with people's wellbeing (positive and negative affect, anxiety) in situ, using point counts and questionnaires. Bird community composition differed between green and coastal sites, and diversity was significantly higher in green sites. Positive affect and anxiety did not differ between green and coastal sites, but negative affect was higher in coastal sites. Mixed-effect models showed no associations between biodiversity and wellbeing, implying other features are contributing to people's positive wellbeing. Despite no association between biodiversity and wellbeing, both green and coastal blue sites are important for wellbeing and supporting different bird communities. City planning authorities and public health professionals should ensure these social and environmental needs are met in developing cities in the Global South.

Intact forests provide diverse and irreplaceable ecosystem services that are critical to human well-being, such as carbon storage to mitigate climate change. However, the ecosystem functions that underpin these services are highly dependent on the woody vegetation-animal interactions occurring within forests. While vertebrate defaunation is of growing policy concern, the effects of vertebrate loss on natural forest regeneration have yet to be quantified globally. Here we conduct a meta-analysis to assess the direction and magnitude of defaunation impacts on forests. We demonstrate that real-world defaunation caused by hunting and habitat fragmentation leads to reduced forest regeneration, although manipulation experiments provide contrasting findings. The extirpation of primates and birds cause the greatest declines in forest regeneration, emphasising their key role in maintaining carbon stores, and the need for national and international climate change and conservation strategies to protect forests from defaunation fronts as well as deforestation fronts., The defaunation of vertebrates may disrupt forest functioning through the loss of plant-animal interactions, but impacts on forests remain unquantified. Here the authors show that seed dispersal is a key interaction and defaunation of primates and birds negatively impacts forest regeneration.

Agricultural expansion across the tropics is the primary driver of biodiversity declines and ecosystem service degradation. However, efforts to mitigate these negative impacts may reduce commodity production. We quantify trade-offs between oil palm cultivation and ecological outcomes (biodiversity, above-ground carbon storage and dung nutrient cycling) across different potential set-aside (uncultivated areas in agricultural landscapes) strategies. We show that all set-aside configurations yield substantial gains in ecological outcomes. The best strategy involves spatially targeted riparian reserves, such as those used in oil palm certification schemes, where species occurrence can be doubled without reducing overall cultivation area. Adopting this strategy throughout the 8 million hectares of plantations in Borneo would lead to extensive improvements in ecological outcomes without losses to production area, and consequently, enhancing agricultural sustainability.

Approaches to characterise and monitor biodiversity based on the sound signals of ecosystems have become popular in landscape ecology and biodiversity conservation. However, to date, validation studies of how well acoustic indices reflect observed biodiversity patterns have often relied on low levels of either spatial or temporal replication, while focussing on habitats with similar underlying anthropological and geophysical sound characteristics. For acoustic indices to be broadly applicable to biodiversity monitoring, their capacity to measure the ecological facets of soundscapes must be robust to these potential sources of bias. Using two contrasting recording approaches, we examined the efficacy of four commonly used acoustic indices to reflect patterns of observed bird species richness across a tropical forest degradation gradient in Northeast Borneo. The gradient comprised intact and logged forests, riparian forests, remnants, and oil palm plantations, thus providing a highly variable anthrophonic and geophonic soundscape. We compared the degree to which acoustic indices derived from automated versus point count recording methods detected variation in inter-habitat species richness, as well as their capacity to capture changes in species diversity as a consequence of forest degradation quantified by high-resolution LiDAR derived forest canopy heights. We found Acoustic Diversity Index was associated with forest canopy height as measured by both automated recorders and recordings from point counts, whereas the association between canopy height and Acoustic Complexity Index was only detected using point count recordings. For both types of recordings, Acoustic Complexity Index exhibited the strongest relationship with observed bird richness in old growth and logged forest, whereas Acoustic Diversity was not linked, suggesting avian richness does not drive its association with canopy height. No acoustic indices were associated with observed bird richness in oil palm riparian areas. Our findings underscore the potential utility of soundscape approaches to characterise biodiversity patterns in degraded tropical landscapes, and may be used as a proxy for human inventories of bird communities. However, we also show that for acoustic indices to be effective on landscape-wide studies of environmental gradients, adequate spatial replication is required, and care must be taken to control for non-target elements of soundscapes in different habitats.

The rise of palm oil as the world’s most consumed vegetable oil has coincided with exponential growth in palm oil research\ud activity. Bibliometric analysis of research outputs reveals a distinct imbalance in the type of research being undertaken, notably a\ud disproportionate focus on biofuel and engineering topics. Recognising the expansion of oil palm agriculture across the tropics and\ud the increasing awareness of environmental, social and economic impacts, we seek to re-orient the existing research agenda\ud towards one that addresses the most fundamental and urgent questions defined by the palm oil stakeholder community. Following\ud consultation with 659 stakeholders from 38 countries, including palm oil growers, government agencies, non-governmental\ud organisations and researchers, the highest priority research questions were identified within 13 themes. The resulting 279\ud questions, including 26 ranked as top priority, reveal a diversity of environmental and social research challenges facing the\ud industry, ranging from the ecological and ecosystem impacts of production, to the livelihoods of plantation workers and smallholder\ud communities. Analysis of the knowledge type produced from these questions underscores a clear need for fundamental science\ud programmes, and studies that involve the consultation of non-academic stakeholders to develop ‘transformative’ solutions to the\ud oil palm sector. Stakeholders were most aligned in their choice of priority questions across the themes of policy and certification\ud related themes, and differed the most in environmental feedback, technology and smallholder related themes. Our\ud recommendations include improved regional academic leadership and coordination, greater engagement with private and public\ud stakeholders of Africa, and Central and South America, and enhanced collaborative efforts with researchers in the major\ud consuming countries of India and China.

Urban land cover expansion and human population growth are accelerating worldwide. This is resulting in the loss and degradation of green and blue spaces (e.g. parks, waterways, lakes) in cities, which provide resources to sustain biodiversity and improve human wellbeing. The specific characteristics of these spaces (e.g. sounds, species, safety) that enhance or detract from wellbeing are underexplored, yet this knowledge is needed to inform urban planning, management and policies that will ultimately benefit both people and biodiversity. Research of this kind is rarely conducted in the Global South, where rapid urbanisation threatens biodiversity-rich ecosystems of worldwide significance. Here, we examine how perceptions of green, waterway, and dense urban spaces relate to wellbeing in Georgetown, Guyana. Specifically, we use mediation models to test how perceptions of sound, bird species richness, naturalness, and safety concerns contribute to sites being perceived as restorative which, subsequently, influences wellbeing. We assess the accuracy of these site perceptions with objective measures of sound (using a bioacoustic sound index), bird species richness, and percent coverage of vegetation, water, and impervious surfaces. Results showed that if sites were perceived as species rich, containing natural sounds like birdsong, natural rather than artificial, and safe, they were perceived as more restorative, resulting in improved wellbeing. In general, people's perceptions were consistent with objective measures. Green, compared with waterway and dense urban sites, contained more biophonic sounds, higher species richness, greater vegetation and water coverage. Although waterways were biodiverse, they were dominated by anthrophonic sounds, so were perceived as artificial and non-restorative. We shed light on how city planners might augment specific characteristics to improve the wellbeing of urban dwellers, with implications for biodiversity conservation. Our findings provide a scientific evidence base for urban design and management plans that could deliver multiple co-benefits, particularly in biodiversity-rich cities in neotropical regions.

Seedling growth and survival are critical for tropical rainforest regeneration. Alterations to natural disturbance regimes, such as those brought about by logging, have the potential to shift relative species abundances and the community composition of forests, resulting in population declines for commercially valuable species. Timber operations therefore need to minimise such changes if long-term sustainability is to be achieved within the industry. Reduced-impact logging (RIL) has been promoted widely as an alternative management strategy to conventional selective logging, as it employs practices that decrease the negative impacts of logging within forests. However, the long-term sustainability of RIL, including the influence it has on the regeneration of species targeted for timber extraction, is still uncertain. Here we undertake a comparative study in Iwokrama forest, Guyana, examining seedling densities of four commercially valuable and two pioneer tree species in unlogged, 1.5 years and 4.5 years postharvest forest plots to ascertain how seedling regeneration is effected by RIL. We find that RIL had either a neutral or positive impact on the density of seedlings of timber species when compared to unlogged forest, with pioneer species densities remaining rare. We conclude that the forestry practices associated with RIL have little effect on the natural regeneration rates of key commercially valuable tree species in logged neotropical forests.

Species of bats in the subfamilies Stenodermatinae and Carolliinae are primarily frugivores, and through the ingestion of fruit and\ud defecation of seeds, they play a crucial role in their environment through the dispersal of early successional and pioneer plants contributing to reforestation. These ecosystem services provided by frugivorous bats are becoming more critical with time, as anthropogenic habitat destruction continues to rise. The objective of this study was to survey the plant species dispersed by frugivorous bats in a tropical rainforest in Guyana. Fecal samples were taken from captured frugivorous bats and stomach contents were taken from a representative collection. The four most common bats were Artibeus planirostris, A. obscurus, A. lituratus, and Carollia perspicillata, which accounted for 67% of total captures in mist nets set in the forest understory. Twenty plant species were identified in fecal and stomach content samples with the most abundant (Ficus nymphaeifolia, Piper bartlingianum, Cecropia latiloba, and C. sciadophylla) accounting for 60% of the total. Cecropia latiloba, which is an early colonizer of floodplains throughout the Guiana Shield and Amazon River Basin was previously unknown to be bat dispersed. Seven plant species were documented as being dispersed by nine bat species for the first time. These results enhance our understanding of seed dispersal by Neotropical bats, specifically by revealing previously unknown bat/plant relationships.

Most countries have committed to protect 17% of their terrestrial area by 2020 through Aichi Target 11 of the Convention on Biological Diversity, with a focus on protecting areas of particular importance for biodiversity. This means national-scale spatial conservation prioritisations are needed to help meet this target and guide broader conservation and land-use policy development. However, to ensure these assessments are adopted by policy makers, they must also consider national priorities. This situation is exemplified by Guyana, a corner of Amazonia that couples high biodiversity with low economic development. In recent years activities that threaten biodiversity conservation have increased, and consequently, protected areas are evermore critical to achieving the Aichi targets. Here we undertake a cost-effective approach to protected area planning in Guyana that accounts for in-country conditions. To do this we conducted a stakeholder-led spatial conservation prioritisation based on meeting targets for 17 vegetation types and 329 vertebrate species, while minimising opportunity costs for forestry, mining, agriculture and urbanisation. Our analysis identifies 3 million ha of priority areas for conservation, helping inform government plans to double the current protected area network from 8.5 to 17%. As part of this, we also develop a new technique to prioritise engagement with local communities whose lands are identified as important to conservation. Our study both provides a scientifically robust, politically acceptable protected area expansion strategy for Guyana, and illustrates the importance of conservation planning at the country-scale to translate international commitments into national action.

Dung beetles (Scarabaeidae: Scarabaeinae) are sensitive to habitat perturbations and are easily studied, making them an ideal taxonomic group with which to evaluate the effects of low-intensity anthropogenic disturbances such as Reduced-Impact Logging. Here we examine the effect of a certified Reduced-Impact Logging operation on dung beetles, and demonstrate their suitability for use in rapid ecological impact studies. We sampled dung beetle assemblages, environmental variables and timber extraction rates across four treatment groups in closed canopy and canopy gaps in logged and unlogged forest in Guyana. Community analysis revealed that logged forest supported a more uniform dung beetle assemblage compared to unlogged forest. Differences in assemblage structure were driven by dissimilarity between closed canopy treatments, as plots in artificial and natural canopy gaps supported comparable assemblages. Indicator analyses were conducted across treatments, using a new approach (CLAM) and two well-established methods (IndVal, SIMPER). Two species respectively were classified as indicators of logged (Hansreia affinis and Eurysternus caribaeus) and unlogged forest (Canthidium aff. centrale and Deltochilum (Calhyboma) carinatum). BIO-ENV analysis demonstrated that tree extraction intensity, bare ground cover, and ground cover by leaf material were key factors influencing dung beetle assemblages. Despite the relatively low-impact of Reduced-Impact Logging reported by previous studies, we find that dung beetles are sensitive to even small changes in environmental conditions as a result of this form of anthropogenic disturbance. As dung beetles are a highly responsive taxonomic group, we illustrate that they represent a valuable taxon that can be used to critically evaluate best practice forestry operations and other disturbance activities, particularly in time constrained studies (e.g., rapid monitoring and environmental impact assessments). However, we recommend the use of multiple indicator analyses to monitor potential changes in assemblage composition, due to a lack of congruence between methods.

Vertebrate population densities were quantified in lowland central Guyana using line-transect censuses at three forest sites subjected to reduced-impact logging (RIL), and three adjacent unlogged sites. We censused a range of forest vertebrate species including large canopy-dwelling and terrestrial birds, three primates, one rodent and one tortoise. Two 4 km transects at each site were repeatedly surveyed during the wet season of 2008 to derive population density estimates on the basis of a cumulative survey effort of 416 km. RIL had ended within 16 months, and sites had been subjected to a mean extraction rate of 3.9 m3 ha−1, equivalent to only 1.1 trees ha−1. Three of the 15 vertebrate species examined here exhibited significantly different abundances at forest RIL sites, two of which were negative. Large frugivores such as primates were less abundant in sites subject to RIL, whereas smaller frugivores, granivores, folivores and insectivores were more common in logged sites. We are unable to reliably distinguish between responses of different taxonomic groups, since robust abundance metrics could only be estimated for four mammal species. Despite this, species traits including dietary guild, body mass, home range size and vertical stratification of forest use are used to explain varying responses. Our findings suggest that responsible reduced-impact logging practices in neotropical forests can be considered as a relatively benign form of forest management that can coexist with the requirements of both local economies and biodiversity conservation. However, our study sites experienced comparably low extraction rates, and detrimental effects such as hunting were low. Our results therefore provide an opportunity to scrutinise the effects of best practice logging systems, though do not necessarily represent typical circumstances across tropical forests.

Summary Tropical forests are selectively logged at 20 times the rate at which they are cleared, and at least a fifth have already been disturbed in this way [1]. In a recent pan-tropical assessment, Burivalova et al. [2] demonstrate the importance of logging intensity as a driver of biodiversity decline in timber estates. Their analyses reveal that species richness of some taxa could decline by 50% at harvest intensities of 38 m 3 ha -1 . However, they did not consider the extraction techniques that lead to these intensities. Here, we conduct a complementary meta-analysis of assemblage responses to differing logging practices: conventional logging and reduced-impact logging. We show that biodiversity impacts are markedly less severe in forests that utilise reduced-impact logging, compared to those using conventional methods. While supporting the initial findings of Burivalova et al. [2], we go on to demonstrate that best practice forestry techniques curtail the effects of timber extraction regardless of intensity. Therefore, harvest intensities are not always indicative of actual disturbance levels resulting from logging. Accordingly, forest managers and conservationists should advocate practices that offer reduced collateral damage through best practice extraction methods, such as those used in reduced-impact logging. Large-scale implementation of this approach would lead to improved conservation values in the 4 million km 2 of tropical forests that are earmarked for timber extraction [3].

Conservation management can no longer rely on protecting pristine habitats, but must consider the\ud wider landscape. This is especially true on oceanic islands where endemic species are believed to be\ud particularly susceptible to the extinction risks that accompany land conversion. Despite this, there is a\ud paucity of studies examining how endemic communities on oceanic islands may be distributed across\ud such human-modified habitats. Taking Príncipe Island in West Africa as a case study, we investigate how\ud avian communities vary across the habitats (primary forest, secondary forest, agricultural areas) of this\ud globally important centre of endemism. Here, recent policy reforms aimed at poverty alleviation and\ud increased food production are rapidly altering the current land-use mosaic. Across all habitats, 27 bird\ud species were encountered. Survey points in secondary forest and agricultural areas were, on average,\ud more diverse and held higher overall abundances of birds than those within primary forest. This was\ud true for both the entire avian assemblage and the endemic species alone. Nevertheless, two IUCN-listed\ud species were restricted to primary forest, and many other endemics occurred at higher densities within\ud this habitat. We demonstrate that agricultural areas and novel habitats, such as secondary forest, can\ud hold high abundances of endemic species and thus have the potential to act as a resource for biodiversity\ud conservation. A double-stranded approach to conservation is therefore required that both protects the\ud integrity of the primary forest and controls the rapid changes in agricultural land-use to ensure that it\ud continues to support a large component of the endemic avifauna.

Fishes were collected from the rivers in and around the Iwokrama Forest during January–February and November–December 1997. Four hundred species of fish were recorded from forty families in ten orders. Many of these fishes are newly recorded from Guyana and several are thought to be endemic. The number of species recorded for the area is surprising given the low level of effort and suggests that this area may be particularly important from a fish diversity perspective. This paper focuses on species of particular interest from a management perspective including those considered economically important, rare or endangered. The paper is also the basis for developing fisheries management systems in the Iwokrama Forest and Rupununi Wetlands.

Biodiversity continues to decline in the face of increasing anthropogenic pressures such as habitat destruction, exploitation, pollution and introduction of alien species. Existing global databases of species' threat status or population time series are dominated by charismatic species. The collation of datasets with broad taxonomic and biogeographic extents, and that support computation of a range of biodiversity indicators, is necessary to enable better understanding of historical declines and to project - and avert - future declines. We describe and assess a new database of more than 1.6 million samples from 78 countries representing over 28,000 species, collated from existing spatial comparisons of local-scale biodiversity exposed to different intensities and types of anthropogenic pressures, from terrestrial sites around the world. The database contains measurements taken in 208 (of 814) ecoregions, 13 (of 14) biomes, 25 (of 35) biodiversity hotspots and 16 (of 17) megadiverse countries. The database contains more than 1% of the total number of all species described, and more than 1% of the described species within many taxonomic groups - including flowering plants, gymnosperms, birds, mammals, reptiles, amphibians, beetles, lepidopterans and hymenopterans. The dataset, which is still being added to, is therefore already considerably larger and more representative than those used by previous quantitative models of biodiversity trends and responses. The database is being assembled as part of the PREDICTS project (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems - www.predicts.org.uk). We make site-level summary data available alongside this article. The full database will be publicly available in 2015. The collation of biodiversity datasets with broad taxonomic and biogeographic extents is necessary to understand historical declines and to project - and hopefully avert - future declines. We describe a newly collated database of more than 1.6 million biodiversity measurements from 78 countries representing over 28,000 species, collated from existing spatial comparisons of local-scale biodiversity exposed to different intensities and types of anthropogenic pressures, from terrestrial sites around the world. © 2014 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd.