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Agricultural landscapes cover >60% of terrestrial landscapes. While biodiversity conservation and crop productivity have been seen as mutually exclusive options for a long time, recent research suggests that agricultural landscapes represent significant opportunities for biodiversity conservation outside of traditional protected areas.Here, we use a unique dataset that includes annual monitoring of 12,300 permanent 25‐ha plots over two decades across Spain to assess how agricultural landscapes are changing over time. We focus particularly on landscape composition and configuration variables such as the diversity of crops grown within a landscape, average plot size or the cover of natural habitats and assess how changes to these variables affect the ability of agricultural landscapes to ensure high yields.We find potential synergistic strategies that are good for biodiversity conservation and can also lead to increasing crop yields. Specifically, we find that management practices that favour increasing biodiversity values such as maintaining small field sizes and high crop richness values at the landscape scale actually led to the greatest average yield values across 54 crops, 41% of which depend on pollinator activity for reproduction.Policy implications: While our analysis does not factor in economic costs and benefits, we show that synergy scenarios that are good for biodiversity conservation and crop productivity are possible, yet not as widespread as they could be. [ABSTRACT FROM AUTHOR]

Many insect species provide essential pollination services. However, the amount of pollen deposited onto a stigma when visiting a flower ('single visit pollen deposition', SVD) can vary greatly among taxa depending on morphological traits of pollinators. Further, SVD is commonly measured using one of two methods ('static': waiting for an insect to visit a flower present on plant, and 'active': removing the flower and presenting it to a flower visitor) that may also differ in their effectiveness.To gain a more comprehensive understanding of how SVD compares among pollinators, we conducted a hierarchical meta‐analysis using data from 28 studies identified by a systematic review. These contained SVD data for 94 bee and 33 fly taxa (hereafter 'wild pollinators'), across 30 plant species from which we included 127 observations. In the analysis of each study, we used the western honey bee Apis mellifera as a comparator species.Wild pollinators deposited more pollen onto stigmas per single visit than honeybees, and those with larger body deposited significantly more pollen than smaller ones. Of the two methodological approaches to assess SVD, 'static' versus 'active', we found no significant difference regarding the amount of deposited pollen.Synthesis and applications. Our meta‐analysis highlights the breadth of wild pollinators that contribute to pollination effectiveness via their delivery of pollen to many crop and non‐crop plant species. However, just 25% of the observations assessed the amount of pollen deposited by fly species. Our findings point to the need to further quantify the pollination effectiveness of non‐bee pollinators as studies have largely focused on managed and wild bee species. [ABSTRACT FROM AUTHOR]

The unwanted development of dense understorey vegetation composed of resource‐acquisitive, tall plant species competing strongly with tree regeneration can pose formidable problems for managers attempting to regenerate temperate forests. Despite many studies on the effects of understorey removal, no comprehensive review has summarised and quantified its effects on subsequent life stages of tree regeneration in temperate forests.We synthesised data from 32 experimental studies from temperate forest regions. We used meta‐analytic techniques to find general patterns in terms of the characteristics of the understorey, overstorey and characteristics of the regenerating tree species, which are most responsible for possible positive understorey removal effects on early life stages of tree regeneration, i.e. emergence, survival and growth.Both seedling survival and growth increased in response to understorey removal; emergence did not show a clear pattern. Seedlings growing free from competition mainly increased their biomass growth (total and above‐ground), whereas diameter and height growth responded less. These positive effects were largest when removing denser understorey vegetation and under more open overstorey conditions. Multiple management options influenced the regeneration responses to understorey removal. For instance, growth of older, planted seedlings responded less to removal, whereas protection against large browsers increased growth responses.Tree species with differing strategies responded differently to understorey removal. Growth and survival responses of early‐successional species responded more strongly to understorey removal than mid‐ or late‐successional tree species.Synthesis and applications. Our study showed that understorey removal can have strong positive effects on tree regeneration across temperate forest contexts. The magnitude of these effects depended on overstorey and understorey conditions, but also on the type of tree species that is regenerated. Our results can support forest managers in their decision‐making and help assess under what conditions understorey removal will be most justified. [ABSTRACT FROM AUTHOR]

The management of crops outside the regular cropping calendar can improve profits when supply is low and prices are high, but we do not know how induced, early flowering impacts the pollination services that crops require.This study examines the effects of flowering time and pollinator management, including managed honeybee colonies and ground flower cover, on the pollination of the tropical fruit tree, longan (Dimocarpus longan Lour.), comparing between in‐season flowering (naturally) and off‐season flowering (chemically induced) in Northern Thailand.Visitation rates of flower visitor groups significantly differed among treatments: for in‐season flowering, wild bees were the most frequent pollinator group, whereas in the off‐season flowering, there were no wild bees, and instead dipterans were the most frequent pollinator group. Some off‐season plantations have honeybee hives present and in this situation honeybees were the most frequent pollinator group.We show that temporal variation in the pollinator community significantly alters the pollination efficiency of longan crops. Consequently, longan production from off‐season longan farms generates lower net profit in the absence of managed bees and wild bees, and wild bees produced higher seed‐sets than either honeybees or dipterans.Synthesis and applications. Wild bees were the main pollinator group of longan in the in‐season flowering resulting in high fruit production; whereas in the off‐season flowering honeybees and dipterans were the main pollinator group. Longan production from off‐season longan farms without managed bee produced less net profit. The farmers practicing off‐season with honeybee hives management gain the largest net profit. Developing mechanisms to promote and maintain pollinator abundance and diversity is likely to increase the resilience of the system in addition to profit in the long term; thus, efforts should be made to provide more nesting habitat and reduce pesticide use. [ABSTRACT FROM AUTHOR]

Grassland ecosystems are imperiled by agricultural activity world‐wide. Restoring grassland habitat is important to conserving grassland fauna and preserving ecosystem services, but more knowledge is needed on the impact that local and landscape factors have on patterns of diversity. We focused on whether prairie grassland restorations along a gradient of increasing agricultural cover in the surrounding landscape would be inhabited by less diverse and/or more homogenous native bee communities. Native bees are a specific target for many grassland restoration efforts, and supporting their local and β‐diversity in reconstructed habitats is of mounting interest. We also investigated if higher floral resource richness within restorations could help ameliorate negative effects of agricultural landscapes.We sampled 16 prairie restorations in Minnesota (USA) that varied along a gradient of increasing agricultural land cover around the site. We characterized floral resource richness at all sites beginning in mid‐May and ending in mid‐September. We used GLMMs and multivariate analyses to disentangle how floral resource richness and percentage of surrounding land cover in agricultural production are associated with the local and β‐diversity of bee communities.Local bee diversity increased with increasing local floral resource richness, independent of the surrounding landscape. Bee β‐diversity was not impacted by local floral resource richness or percentage of agricultural cover in the surrounding landscape, indicating local and landscape factors are not substantially impacting the homogeneity of bee communities across restorations.Synthesis and applications. We found that, regardless of agricultural cover in the surrounding landscape, more florally rich plantings attract more diverse bee communities. We recommend that habitat plantings prioritize local scale diversity, and that potential sites where the landscape is dominated by agricultural production should not be overlooked for restoration. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Applied Ecology 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.)

Tropical dry forests are among the most threatened ecosystems in the world. Rapid loss, degradation and fragmentation of these native ecosystems in a changing climate have driven a time‐sensitive need to improve our understanding and management of remaining dry forests.We used advanced remote sensing technologies, combined with extensive field data and machine learning, to better understand how spatial drivers (e.g. climate, fire, human) of canopy species composition vary in importance and correlate with forest cover (total, native and non‐native), within an endangered Hawaiian tropical dry forest.Past introductions of non‐native, drought‐tolerant tree species into this Hawaiian dry forest have created a new forest canopy composition and a loss of native forest biodiversity and connectivity at the landscape scale.Synthesis and applications. Our findings help to spatially visualize the loss and transition of native Hawaiian forests and provide a new conservation planning tool. Conservation and restoration efforts can now be informed by spatial maps of canopy composition, connectivity and determinants of forest cover for the region. For example, our models identified a climatic transition zone between 800 and 1,000 m where native forests exist in high densities, and non‐native forests are not yet dominant. This area may be optimal for cost‐effective conservation and targeted management. Ecosystems are changing globally at unprecedented rates. The methods presented in this study provide a framework that can be adapted to monitor these changes around the world. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Applied Ecology 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.)

Evaluation of conservation incentive programme outcomes is needed to direct future investment, however, monitoring of large‐scale programmes is relatively rare. Research in this area has frequently relied on space‐for‐time substitution or similar designs, rarely controlling for counterfactual trends or potential learning or leakage effects using repeated measures taken before and after intervention at impact and independent control sites.Using a Before‐After‐Control‐Impact (BACI) monitoring design, we investigate the ecological impact of a conservation stewardship programme, where landholders set their own contract price through a reverse auction. In order to maintain or increase species and structural diversity of remnant native vegetation, contracted landholders agreed to manage grazing pressure (from stock and feral animals), control weeds and retain fallen logs. We test whether impact sites (private land under contract) changed over a 9–10 year period relative to control sites (independently managed, non‐contracted private land) and reference sites (public conservation areas).Modest improvements were detected in native plant species richness, log abundance and grazing pressure at impact sites compared with background changes observed at control sites. While log abundance and grazing pressure were directly managed at impact sites, the improvement in native plant species richness was assumed to be influenced by reduction in multiple pressures such as grazing pressure and weed abundance.No significant intervention effects were detected in other variables including regeneration, plant litter cover, weed cover and canopy dieback. However, these variables did show changes over time which were likely due to weather, particularly an extended period of drought followed by unusually high rainfall.Policy implications. This study shows that revealed‐price incentive contracts can produce biodiversity improvement compared with the business‐as‐usual scenario of native vegetation management on private land. The use of a Before‐After‐Control‐Impact monitoring design enabled the separation of treatment effects from background changes such as those linked to climate and weather, demonstrating the importance of this approach for programme evaluation. We recommend the allocation of appropriate resources for monitoring and also highlight the need for the collection of baseline data prior to contract establishment at both impact and independently managed control sites. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Applied Ecology 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.)

The effective number of species (ENS) has been proposed as a robust measure of species diversity that overcomes several limitations in terms of both diversity indices and species richness (SR). However, it is not yet clear if ENS improves interpretation and comparison of biodiversity monitoring data, and ultimately resource management decisions.We used simulations of five stream macroinvertebrate assemblages and spatially extensive field data of stream fishes and mussels to show (a) how different ENS formulations respond to stress and (b) how diversity–environment relationships change with values of q, which weight ENS measures by species abundances.Values of ENS derived from whole simulated assemblages with all species weighted equally (true SR) steadily decreased as stress increased, and ENS‐stress relationships became weaker and more different among assemblages with increased weighting.The amount of variation in ENS across the fish and mussel assemblages that was associated with environmental gradients decreased with increasing q.Synthesis and applications. Species diversity is valued by many human societies, which often have policies designed to protect and restore it. Natural resources managers and policy makers may use species richness and diversity indices to describe the status of ecological communities. However, these traditional diversity measures are known subject to limitations that hinder their interpretation and comparability. The effective number of species (ENS) was proposed to overcome the limitations. Unfortunately, our analyses show that ENS does not improve interpretability of how species diversity responds to either stress or natural environmental gradients. Moreover, incorporating the relative abundance of individuals in different species (evenness) into diversity measures as implemented in ENS can actually weaken detection of diversity responses. Natural resources managers and policy makers therefore need to be cautious when interpreting diversity measures, including ENS, whose values are jointly influenced by richness and evenness. We suggest that both researchers and practitioners measure and report three aspects of diversity (species richness, evenness, and composition) separately when assessing and monitoring the diversity of ecological communities. Species diversity is valued by many human societies, which often have policies designed to protect and restore it. Natural resources managers and policy makers may use species richness and diversity indices to describe the status of ecological communities. However, these traditional diversity measures are known subject to limitations that hinder their interpretation and comparability. The effective number of species (ENS) was proposed to overcome the limitations. Unfortunately, our analyses show that ENS does not improve interpretability of how species diversity responds to either stress or natural environmental gradients. Moreover, incorporating the relative abundance of individuals in different species (evenness) into diversity measures as implemented in ENS can actually weaken detection of diversity responses. Natural resources managers and policy makers therefore need to be cautious when interpreting diversity measures, including ENS, whose values are jointly influenced by richness and evenness. We suggest that both researchers and practitioners measure and report three aspects of diversity (species richness, evenness, and composition) separately when assessing and monitoring the diversity of ecological communities. [ABSTRACT FROM AUTHOR]

Liana cutting is a management practice currently applied to encourage seedling regeneration and tree growth in some logged tropical forests. However, there is limited empirical evidence of its effects on forest demographic rates in Southeast Asia.We used 22 four‐hectare plots in the Sabah Biodiversity Experiment (a reduced impact logging site) enrichment line planted with 16 dipterocarp species to assess the effects of complete liana cutting on tree growth and survival. We compared plots where lianas were only cut along planting lines (standard enrichment line planting) with those with one (2014) or two rounds (2011 and 2014) of complete liana cutting.We found increased seedling growth following the first complete liana cut in 2011 relative to the enrichment line planting, consistent with previous studies. The response after 3 years to the cutting in 2014 depended on whether lianas had been previously cut or not: in twice‐cut plots, seedling growth was not significantly different from the standard enrichment planting controls, whereas growth in plots with only one complete cut in 2014 was significantly slower. Seedling survival decreased through time for both once‐ and twice‐cut liana treatments but remained stable in controls.Sapling growth after the 2014 liana cutting showed a similar pattern to seedling growth, while tree growth following the 2014 liana cutting was significantly lower than controls regardless of whether lianas were cut twice (2011 and 2014) or once (2014).Differences in response between the two rounds of liana cutting were likely due to changes in precipitation—2011 was followed by consistent rainfall while 2014 was followed by two severe droughts within 2 years.Synthesis and applications. Our results generally support the widely reported positive effects of liana cutting on tree growth and survival. However, reduced growth and survival after the 2015/2016 El Niño suggests that drought may temporarily undermine the benefits of liana cutting in logged tropical forests. Managers of similar areas in SE Asia should consider halting liana cutting during El Niño events. In other tropical areas, seedling survival should be monitored to assess to what extent results from SE Asia are transferable. Our results generally support the widely reported positive effects of liana cutting on tree growth and survival. However, reduced growth and survival after the 2015/2016 El Niño suggests that drought may temporarily undermine the benefits of liana cutting in logged tropical forests. Managers of similar areas in SE Asia should consider halting liana cutting during El Niño events. In other tropical areas, seedling survival should be monitored to assess to what extent results from SE Asia are transferable. [ABSTRACT FROM AUTHOR]

Tropical forests store and sequester large quantities of carbon, mitigating climate change. Lianas (woody vines) are important tropical forest components, most conspicuous in the canopy. Lianas reduce forest carbon uptake and their recent increase may, therefore, limit forest carbon storage with global consequences for climate change. Liana infestation of tree crowns is traditionally assessed from the ground, which is labour intensive and difficult, particularly for upper canopy layers.We used a lightweight unmanned aerial vehicle (UAV) to assess liana infestation of tree canopies from above. It was a commercially available quadcopter UAV with an integrated, standard three‐waveband camera to collect aerial image data for 150 ha of tropical forest canopy. By visually interpreting the images, we assessed the degree of liana infestation for 14.15 ha of forest for which ground‐based estimates were collected simultaneously. We compared the UAV liana infestation estimates with those from the ground to determine the validity, strengths, and weaknesses of using UAVs as a new method for assessing liana infestation of tree canopies.Estimates of liana infestation from the UAV correlated strongly with ground‐based surveys at individual tree and plot level, and across multiple forest types and spatial resolutions, improving liana infestation assessment for upper canopy layers. Importantly, UAV‐based surveys, including the image collection, processing, and visual interpretation, were considerably faster and more cost‐efficient than ground‐based surveys.Synthesis and applications. Unmanned aerial vehicle (UAV) image data of tree canopies can be easily captured and used to assess liana infestation at least as accurately as traditional ground data. This novel method promotes reproducibility of results and quality control, and enables additional variables to be derived from the image data. It is more cost‐effective, time‐efficient and covers larger geographical extents than traditional ground surveys, enabling more comprehensive monitoring of changes in liana infestation over space and time. This is important for assessing liana impacts on the global carbon balance, and particularly useful for forest management where knowledge of the location and change in liana infestation can be used for tailored, targeted, and effective management of tropical forests for enhanced carbon sequestration (e.g., REDD+ projects), timber concessions, and forest restoration. Unmanned aerial vehicle (UAV) image data of tree canopies can be easily captured and used to assess liana infestation at least as accurately as traditional ground data. This novel method promotes reproducibility of results and quality control, and enables additional variables to be derived from the image data. It is more cost‐effective, time‐efficient and covers larger geographical extents than traditional ground surveys, enabling more comprehensive monitoring of changes in liana infestation over space and time. This is important for assessing liana impacts on the global carbon balance, and particularly useful for forest management where knowledge of the location and change in liana infestation can be used for tailored, targeted, and effective management of tropical forests for enhanced carbon sequestration (e.g., REDD+ projects), timber concessions, and forest restoration. [ABSTRACT FROM AUTHOR]

The relative importance of bottom‐up versus top‐down control of population dynamics has been the focus of much debate. In infectious disease biology, research is typically focused on the bottom‐up process of host resistance, wherein the direction of control flows from the lower to the higher trophic level to impact on pathogen population size and epidemiology. However, the importance of top‐down control by a pathogen's natural enemies has been mostly overlooked.Here, we explore the effects of, and interaction between, host genotype (i.e., genetic susceptibility to pathogen infection) and infection by a hyperparasitic fungus, Ampelomyces spp., on the establishment and early epidemic growth and transmission of a powdery mildew plant pathogen (Podosphaera plantaginis). We used a semi‐natural field experiment to contrast the impacts of hyperparasite infection, host‐plant resistance and spatial structure to reveal the key factors that determine pathogen spread. We then used a laboratory‐based inoculation approach to test whether the field experiment results hold across multiple pathogen–host genetic combinations and to explore hyperparasite effects on the pathogen's later life‐history stages.We found that hyperparasite infection had a negligible effect on within‐host infection development and between‐host spread of the pathogen during the onset of epidemics. In contrast, host‐plant resistance was the major determinant of whether plants became infected, and host genotype and proximity to an infection source determined infection severity.Our laboratory study showed that, while the interaction between host and pathogen genotypes was the key determinant of infection outcome, hyperparasitism did, on average, reduce the severity of infection. Moreover, hyperparasite infection negatively influenced the production of the pathogen's overwintering structures.Synthesis and applications. Our results suggest that bottom‐up host resistance affects pathogen spread, but top‐down control of powdery mildew pathogens is likely more effective against later life‐history stages. Further, while hyperparasitism in this system can reduce early pathogen growth under stable laboratory conditions, this effect is not detectable in a semi‐natural environment. Considering the effects of hyperparasites at multiple points in pathogen's life history will be important when considering hyperparasite‐derived biocontrol measures in other natural and agricultural systems. Our results suggest that bottom‐up host resistance affects pathogen spread, but top‐down control of powdery mildew pathogens is likely more effective against later life‐history stages. Further, while hyperparasitism in this system can reduce early pathogen growth under stable laboratory conditions, this effect is not detectable in a semi‐natural environment. Considering the effects of hyperparasites at multiple points in pathogen's life history will be important when considering hyperparasite‐derived biocontrol measures in other natural and agricultural systems. [ABSTRACT FROM AUTHOR]