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Journal articleNash RK, Lambert B, NGuessan R, et al., 2021,
Systematic review of the entomological impact of insecticide-treated nets evaluated using experimental hut trials in Africa, Current Research in Parasitology & Vector-Borne Diseases, Vol: 1, Pages: 1-13, ISSN: 2667-114X
Resistance of anopheline mosquitoes to pyrethroid insecticides is spreading rapidly across sub-Saharan Africa, diminishing the efficacy of insecticide-treated nets (ITNs) – the primary tool for preventing malaria. The entomological efficacy of indoor vector control interventions can be measured in experimental hut trials (EHTs), where hut structures resemble local housing, but allow the collection of mosquitoes that entered, exited, blood-fed and/or died. There is a need to understand how the spread of resistance changes ITN efficacy and to elucidate factors influencing EHT results, including differences in experimental hut design, to support the development of novel vector control tools. A comprehensive database of EHTs was compiled following a systematic review to identify all known trials investigating ITNs or indoor residual spraying across sub-Saharan Africa. This analysis focuses on EHTs investigating ITNs and uses Bayesian statistical models to characterise the complex interaction between ITNs and mosquitoes, the between-study variability, and the impact of pyrethroid resistance. As resistance rises, the entomological efficacy of ITNs declines. They induce less mortality and are less likely to deter mosquitoes from entering huts. Despite this, ITNs continue to offer considerable personal protection by reducing mosquito feeding until resistance reaches high levels. There are clear associations between the different entomological impacts of ITNs, though there is still substantial variability between studies, some of which can be accounted for by hut design. The relationship between EHT outcomes and the level of resistance (as measured by discriminating dose bioassays) is highly uncertain. The meta-analyses show that EHTs are an important reproducible assay for capturing the complex entomological efficacy of ITNs on blood-feeding mosquitoes. The impact of pyrethroid resistance on these measures appears broadly consistent across a wide geographical area onc
Journal articleLilleskov EA, Kuyper TW, Bidartondo MI, et al., 2019,
Atmospheric nitrogen deposition impacts on the structure and function of forest mycorrhizal communities: a review, Environmental Pollution, Vol: 246, Pages: 148-162, ISSN: 0269-7491
Humans have dramatically increased atmospheric nitrogen (N) deposition globally. At the coarsest resolution, N deposition is correlated with shifts from ectomycorrhizal (EcM) to arbuscular mycorrhizal (AM) tree dominance. At finer resolution, ectomycorrhizal fungal (EcMF) and arbuscular mycorrhizal fungal (AMF) communities respond strongly to long-term N deposition with the disappearance of key taxa. Conifer-associated EcMF are more sensitive than other EcMF, with current estimates of critical loads at 5–6 kg ha−1 yr−1 for the former and 10–20 kg ha−1 yr−1 for the latter. Where loads are exceeded, strong plant-soil and microbe-soil feedbacks may slow recovery rates after abatement of N deposition. Critical loads for AMF and tropical EcMF require additional study. In general, the responses of EcMF to N deposition are better understood than those of AMF because of methodological tractability. Functional consequences of EcMF community change are linked to decreases by fungi with medium-distance exploration strategies, hydrophobic walls, proteolytic capacity, and perhaps peroxidases for acquiring N from soil organic matter. These functional losses may contribute to declines in forest floor decomposition under N deposition. For AMF, limited capacity to directly access complexed organic N may reduce functional consequences, but research is needed to test this hypothesis. Mycorrhizal biomass often declines with N deposition, but the relative contributions of alternate mechanisms for this decline (lower C supply, higher C cost, physiological stress by N) have not been quantified. Furthermore, fungal biomass and functional responses to N inputs probably depend on ecosystem P status, yet how N deposition-induced P limitation interacts with belowground C flux and mycorrhizal community structure and function is still unclear. Current ‘omic analyses indicate potential functional differences among fungal lineages and should be integrated
Journal articleRiutta T, Malhi Y, Kho LK, et al., 2018,
Tropical forests play a major role in the carbon cycle of the terrestrial biosphere. Recent field studies have provided detailed descriptions of the carbon cycle of mature tropical forests, but logged or secondary forests have received much less attention. Here we report the first measures of total net primary productivity (NPP) and its allocation along a disturbance gradient from old-growth forests to moderately and heavily logged forests in Malaysian Borneo. We measured the main NPP components (woody, fine root and canopy NPP) in old-growth (n=6) and logged (n=5) 1 ha forest plots. Overall, the total NPP did not differ between old-growth and logged forest (13.5 ± 0.5 and 15.7 ± 1.5 Mg C ha-1 year-1 , respectively). However, logged forests allocated significantly higher fraction into woody NPP at the expense of the canopy NPP (42% and 48% into woody and canopy NPP, respectively, in old-growth forest vs. 66% and 23% in logged forest). When controlling for local stand structure, NPP in logged forest stands was 41% higher, and woody NPP was 150% higher than in old-growth stands with similar basal area, but this was offset by structure effects (higher gap frequency and absence of large trees in logged forest). This pattern was not driven by species turnover: the average woody NPP of all species groups within logged forest (pioneers, non-pioneers, species unique to logged plots and species shared with old-growth plots) was similar. Hence, below a threshold of very heavy disturbance, logged forests can exhibit higher NPP and higher allocation to wood; such shifts in carbon cycling persist for decades after the logging event. Given that the majority of tropical forest biome has experienced some degree of logging, our results demonstrate that logging can cause substantial shifts in carbon production and allocation in tropical forests. This article is protected by copyright. All rights reserved.
Journal articlevan der Linde S, Suz LM, Orme CDL, et al., 2018,
Explaining the large-scale diversity of soil organisms that drive biogeochemical processes-and their responses to environmental change-is critical. However, identifying consistent drivers of belowground diversity and abundance for some soil organisms at large spatial scales remains problematic. Here we investigate a major guild, the ectomycorrhizal fungi, across European forests at a spatial scale and resolution that is-to our knowledge-unprecedented, to explore key biotic and abiotic predictors of ectomycorrhizal diversity and to identify dominant responses and thresholds for change across complex environmental gradients. We show the effect of 38 host, environment, climate and geographical variables on ectomycorrhizal diversity, and define thresholds of community change for key variables. We quantify host specificity and reveal plasticity in functional traits involved in soil foraging across gradients. We conclude that environmental and host factors explain most of the variation in ectomycorrhizal diversity, that the environmental thresholds used as major ecosystem assessment tools need adjustment and that the importance of belowground specificity and plasticity has previously been underappreciated.
Journal articleGray R, Ewers R, Boyle M, et al., 2018,
Effect of tropical forest disturbance on the competitive interactions within a diverse ant community, Scientific Reports, Vol: 8, ISSN: 2045-2322
Understanding how anthropogenic disturbance influences patterns of community composition and the reinforcing interactive processes that structure communities is important to mitigate threats to biodiversity. Competition is considered a primary reinforcing process, yet little is known concerning disturbance effects on competitive interaction networks.We examined how differences in ant community composition between undisturbed and disturbed Bornean rainforest, is potentially reflected by changes in competitive interactions over a food resource. Comparing 10 primary forest sites to 10 in selectively-logged forest, we found higher genus richness and diversity in the primary forest, with 18.5% and 13.0% of genera endemic to primary and logged respectively. From 180 hours of filming bait cards, we assessed ant-ant interactions, finding that despite considered aggression over food sources, the majority of ant interactions were neutral. Proportion of competitive interactions at bait cards did not differ between forest type, however, the rate and per capita number of competitive interactions was significantly lower in logged forest. Furthermore, the majority of genera showed large changes in aggression-score with often inverse relationships to their occupancy rank. This provides evidence of a shuffled competitive network, and these unexpected changes in aggressive relationships could be considered a type of competitive network re-wiring after disturbance.
Journal articleBrunner I, Frey B, Hartmann M, et al., 2017,
Historical datasets of living communities are important because they can be used todocument creeping shifts in species compositions. Such a historical data set exists foralpine fungi. From 1941 to 1953, the Swiss geologist Jules Favre visited yearly the regionof the Swiss National Park and recorded the occurring fruiting bodies of fungi >1 mm(so-called “macrofungi”) in the alpine zone. Favre can be regarded as one of the pioneersof alpine fungal ecology not least because he noted location, elevation, geology, andassociated plants during his numerous excursions. However, some relevant informationis only available in his unpublished field-book. Overall, Favre listed 204 fungal species in26 sampling sites, with 46 species being previously unknown. The analysis of his datarevealed that the macrofungi recorded belong to two major ecological groups, either theyare symbiotrophs and live in ectomycorrhizal associations with alpine plant hosts, or theyare saprotrophs and decompose plant litter and soil organic matter. The most frequentfungi were members of Inocybe and Cortinarius, which form ectomycorrhizas with Dryasoctopetala or the dwarf alpine Salix species. The scope of the present study was tocombine Favre’s historical dataset with more recent data, either with the “SwissFungi”database or with data from major studies of the French and German Alps, and with thedata from novel high-throughput DNA sequencing techniques of soils from the SwissAlps. Results of the latter application revealed, that problems associated with these newtechniques are manifold and species determination remains often unclear. At this point,the fungal taxa collected by Favre and deposited as exsiccata at the “Conservatoire etJardin Botaniques de la Ville de Genève” could be used as a reference sequence datasetfor alpine fungal studies. In conclusion, it can be postulated that new improved databasesare urgently necessary for the near future, partic
Journal articleSuz LM, Kallow S, Reed K, et al., 2017,
Pine mycorrhizal communities in pure and mixed pine-oak forests: Abiotic environment trumps neighboring oak host effects, Forest Ecology and Management, Vol: 406, Pages: 370-380, ISSN: 0378-1127
Scots pine (Pinus sylvestris) is frequently planted as a monoculture, but it is also grown in mixed plantations with other native trees such as pedunculate oak (Quercus robur). Both pine and oak form ectomycorrhizas that cover their roots and extend into the soil, facilitating tree water and nutrient uptake in exchange for photosynthetic carbon. Forming the interface between the soil and tree roots, mycorrhizal fungi are key drivers of biogeochemical cycling in terrestrial ecosystems and play an important role in the successful establishment of tree seedlings. They can, however, be susceptible to changes in the soil environment and in their hosts. Both environment and neighboring hosts affect how fungi colonize roots and may affect their host preference. Despite the importance of mycorrhizal fungi in forest ecosystems, little is known about the biodiversity and functional effects of mycorrhizal communities in mixed compared with monoculture plantations. Changes in mycorrhizal richness and composition can result in changes in functional groups with consequences for forest ecosystem stability and functioning. We compared pine mycorrhizas in eight mixed plantations of pine and oak and eight pine monocultures in two forests in England, and we investigated the main factors driving their taxonomic and functional composition. Geographical location and litter pH explained over 50% of the variation in pine mycorrhizal communities. Different environmental factors affected taxonomic and functional composition across stands, indicating functional redundancy. Pine tended to associate with more fungi in the presence of oak, but the abiotic environment exerted a stronger influence than oak presence on pine mycorrhizal diversity.
Journal articleWearn OR, Rowcliffe JM, Carbone C, et al., 2017,
Mammalian species abundance across a gradient of tropical land-use intensity: A hierarchical multi-species modelling approach, Biological Conservation, Vol: 212, Pages: 162-171, ISSN: 1873-2917
Recent work in the tropics has advanced our understanding of the local impacts of land-use change on species richness. However, we still have a limited ability to make predictions about species abundances, especially in heterogeneous landscapes. Species abundances directly affect the functioning of an ecosystem and its conservation value. We applied a hierarchical model to camera- and live-trapping data from a region in Borneo, and estimated the relative abundance (controlling for imperfect detection) of 57 terrestrial mammal species, as a function of either categorical or continuous metrics of land-use change. We found that mean relative abundance increased (by 28%) from old-growth to logged forest, but declined substantially (by 47%) in oil palm plantations compared to forest. Abundance responses to above-ground live tree biomass (a continuous measure of local logging intensity) were negative overall, whilst they were strongly positive for landscape forest cover. From old-growth to logged forest, small mammals increased in their relative abundance proportionately much more than large mammals (169% compared to 13%). Similarly, omnivores and insectivores increased more than other trophic guilds (carnivores, herbivores and frugivores). From forest to oil palm, species of high conservation concern fared especially poorly (declining by 84%). Invasive species relative abundance consistently increased along the gradient of land-use intensity. Changes in relative abundance across nine functional effects groups based on diet were minimal from old-growth to logged forest, but in oil palm only the vertebrate predation function was maintained. Our results show that, in the absence of hunting, even the most intensively logged forests can conserve the abundance and functional effects of mammals. Recent pledges made by companies to support the protection of High Carbon Stock logged forest could therefore yield substantial conservation benefits. Within oil palm, our results suppo
Journal articleWindram OPF, Rodrigues RTL, Lee S, et al., 2017,
The ability to program cellular behaviour is a major goal of synthetic biology, with applications in health, agriculture and chemicals production. Despite efforts to build ‘orthogonal’ systems, interactions between engineered genetic circuits and the endogenous regulatory network of a host cell can have a significant impact on desired functionality. We have developed a strategy to rewire the endogenous cellular regulatory network of yeast to enhance compatibility with synthetic protein and metabolite production. We found that introducing novel connections in the cellular regulatory network enabled us to increase the production of heterologous proteins and metabolites. This strategy is demonstrated in yeast strains that show significantly enhanced heterologous protein expression and higher titers of terpenoid production. Specifically, we found that the addition of transcriptional regulation between free radical induced signalling and nitrogen regulation provided robust improvement of protein production. Assessment of rewired networks revealed the importance of key topological features such as high betweenness centrality. The generation of rewired transcriptional networks, selection for specific phenotypes, and analysis of resulting library members is a powerful tool for engineering cellular behavior and may enable improved integration of heterologous protein and metabolite pathways.
Journal articleHudson LN, Newbold T, Contu S, et al., 2016,
The database of the PREDICTS (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems) project, Ecology and Evolution, Vol: 7, Pages: 145-188, ISSN: 2045-7758
The PREDICTS project-Projecting Responses of Ecological Diversity In Changing Terrestrial Systems (www.predicts.org.uk)-has collated from published studies a large, reasonably representative database of comparable samples of biodiversity from multiple sites that differ in the nature or intensity of human impacts relating to land use. We have used this evidence base to develop global and regional statistical models of how local biodiversity responds to these measures. We describe and make freely available this 2016 release of the database, containing more than 3.2 million records sampled at over 26,000 locations and representing over 47,000 species. We outline how the database can help in answering a range of questions in ecology and conservation biology. To our knowledge, this is the largest and most geographically and taxonomically representative database of spatial comparisons of biodiversity that has been collated to date; it will be useful to researchers and international efforts wishing to model and understand the global status of biodiversity.
Journal articleEwers RM, Andrade A, Laurance SG, et al., 2016,
A great challenge for ecologists is predicting how communities in fragmented tropical landscapes will change in the future. Available evidence suggests that fragmented tropical tree communities are progressing along a trajectory of ‘retrogressive succession’, in which the community shifts towards an early or mid-successional state that will persist indefinitely. Here, we investigate the potential endpoint of retrogressive succession, examining whether it will eventually lead to the highly depauperate communities that characterise recently abandoned agricultural lands. We tested this hypothesis by using neural networks to construct an empirical model of Amazonian rainforest-tree-community responses to experimental habitat fragmentation. The strongest predictor of tree-community composition in the future was its composition in the present, modified by variables like the composition of the surrounding habitat matrix and distance to forest edge. We extrapolated network predictions over a 100 yr period and quantified trajectories of forest communities in multidimensional ordination space. We found no evidence that forest communities, including those near forest edges, were converging strongly towards a composition dominated by just one or two early successional genera. Retrogressive succession may well be stronger in fragmented landscapes altered by chronic disturbances, such as edge-related fires, selective logging, or intense windstorms, but in this experimental landscape in which other human disturbances are very limited, it is unlikely that forest edge communities will fully revert to the species poor assemblages observed in very early successional landscapes.
Journal articleBladon AJ, Short KM, Mohammed EY, et al., 2016,
Journal articleTylianakis JM, Frost CM, Peralta G, et al., 2016,
Apparent competition drives community-wide parasitism rates and changes in host abundance across ecosystem boundaries, Nature Communications, Vol: 7, ISSN: 2041-1723
Species have strong indirect effects on others, and predicting these effects is a central challenge in ecology. Prey species sharing an enemy (predator or parasitoid) can be linked by apparent competition, but it is unknown whether this process is strong enough to be a community-wide structuring mechanism that could be used to predict future states of diverse food webs. Whether species abundances are spatially coupled by enemy movement across different habitats is also untested. Here, using a field experiment, we show that predicted apparent competitive effects between species, mediated via shared parasitoids, can significantly explain future parasitism rates and herbivore abundances. These predictions are successful even across edges between natural and managed forests, following experimental reduction of herbivore densities by aerial spraying over 20ha. This result shows that trophic indirect effects propagate across networks and habitats in important, predictable ways, with implications for landscape planning, invasion biology and biological control.
Journal articleDe Palma A, Purvis A, 2016,
Land-use change and intensification threaten bee populations worldwide, imperilling pollination services. Global models are needed to better characterise, project, and mitigate bees' responses to these human impacts. The available data are, however, geographically and taxonomically unrepresentative; most data are from North America and Western Europe, overrepresenting bumblebees and raising concerns that model results may not be generalizable to other regions and taxa. To assess whether the geographic and taxonomic biases of data could undermine effectiveness of models for conservation policy, we have collated from the published literature a global dataset of bee diversity at sites facing land-use change and intensification, and assess whether bee responses to these pressures vary across 11 regions (Western, Northern, Eastern and Southern Europe; North, Central and South America; Australia and New Zealand; South East Asia; Middle and Southern Africa) and between bumblebees and other bees. Our analyses highlight strong regionally-based responses of total abundance, species richness and Simpson's diversity to land use, caused by variation in the sensitivity of species and potentially in the nature of threats. These results suggest that global extrapolation of models based on geographically and taxonomically restricted data may underestimate the true uncertainty, increasing the risk of ecological surprises.
Journal articleGray CL, Hill SLL, Newbold T, et al., 2016,
Protected areas are widely considered essential for biodiversity conservation. However, few global studies have demonstrated that protection benefits a broad range of species. Here, using a new global biodiversity database with unprecedented geographic and taxonomic coverage, we compare four biodiversity measures at sites sampled in multiple land uses inside and outside protected areas. Globally, species richness is 10.6% higher and abundance 14.5% higher in samples taken inside protected areas compared with samples taken outside, but neither rarefaction-based richness nor endemicity differ significantly. Importantly, we show that the positive effects of protection are mostly attributable to differences in land use between protected and unprotected sites. Nonetheless, even within some human-dominated land uses, species richness and abundance are higher in protected sites. Our results reinforce the global importance of protected areas but suggest that protection does not consistently benefit species with small ranges or increase the variety of ecological niches.
Journal articleNewbold T, Hudson LN, Arnell AP, et al., 2016,
Land use and related pressures have reduced local terrestrial biodiversity, but it is unclear how the magnitude of change relates to the recently proposed planetary boundary (‘safe limit’). We estimate that land use and related pressures have already reduced local biodiversity intactness – the average proportion of natural biodiversity remaining in local ecosystems – beyond its recently-proposed planetary boundary across 58.1% of the world’s land surface, where 71.4% of the human population live. Biodiversity intactness within most biomes (especially grassland biomes), most biodiversity hotspots, and even some wilderness areas, is inferred to be beyond the boundary. Such widespread transgression of safe limits suggests that biodiversity loss, if unchecked, will undermine efforts towards long-term sustainable development.
Journal articleEmer C, Memmott J, Vaughan IP, et al., 2016,
AimAlien species alter interaction networks by disrupting existing interactions, for example between plants and pollinators, and by engaging in new interactions. Predicting the effects of an incoming invader can be difficult, although recent work suggests species roles in interaction networks may be conserved across locations. We test whether species roles in plant–pollinator networks differ between their native and alien ranges and whether the former can be used to predict the latter.LocationWorld-wide.MethodsWe used 64 plant–pollinator networks to search for species occurring in at least one network in its native range and one network in its alien range. We found 17 species meeting these criteria, distributed in 48 plant–pollinator networks. We characterized each species’ role by estimating species-level network indices: normalized degree, closeness centrality, betweenness centrality and two measures of contribution to modularity (c- and z-scores). Linear mixed models and linear regression models were used to test for differences in species role between native and alien ranges and to predict those roles from the native to the alien range, respectively.ResultsSpecies roles varied considerably across species. Nevertheless, although species lost their native mutualists and gained novel interactions in the alien community, their role did not differ significantly between ranges. Consequently, closeness centrality and normalized degree in the alien range were highly predictable from the native range networks.Main conclusionsSpecies with high degree and centrality define the core of nested networks. Our results suggest that core species are likely to establish interactions and be core species in the alien range, whilst species with few interactions in their native range will behave similarly in their alien range. Our results provide new insights into species role conservatism and could help ecologists to predict alien species impact at the communi
Journal articleCoux C, Rader R, Bartomeus I, et al., 2016,
Species roles in ecological networks combine to generate their architecture, which contributes to their stability. Species trait diversity also affects ecosystem functioning and resilience, yet it remains unknown whether species’ contributions to functional diversity relate to their network roles. Here we use 21 empirical pollen transport networks to characterise this relationship. We found that, apart from a few abundant species, pollinators with original traits either had few interaction partners or interacted most frequently with a subset of these partners. This suggests that narrowing of interactions to a subset of the plant community accompanies pollinator niche specialisation, congruent with our hypothesised trade-off between having unique traits vs. being able to interact with many mutualist partners. Conversely, these effects were not detected in plants, potentially because key aspects of their flowering traits are conserved at a family level. Relating functional and network roles can provide further insight into mechanisms underlying ecosystem functioning.
Journal articleBartomeus I, Gravel D, Tylianakis JM, et al., 2016,
1.Species interactions, ranging from antagonisms to mutualisms, form the architecture of biodiversity and determine ecosystem functioning. Understanding the rules responsible for who interacts with whom, as well as the functional consequences of these interspecific interactions, is central to predict community dynamics and stability.2.Species traits sensu lato may affect different ecological processes by determining species interactions through a two-step process. First, ecological and life-history traits govern species distributions and abundance, and hence determine species co-occurrence and the potential for species to interact. Second, morphological or physiological traits between co-occurring potential interaction partners should match for the realization of an interaction. Here, we review recent advances on predicting interactions from species co-occurrence, and develop a probabilistic model for inferring trait matching.3.The models proposed here integrate both neutral and trait-matching constraints, while using only information about known interactions, thereby overcoming problems originating from under-sampling of rare interactions (i.e. missing links). They can easily accommodate qualitative or quantitative data, and can incorporate trait variation within species, such as values that vary along developmental stages or environmental gradients.4.We use three case studies to show that the proposed models can detect strong trait matching (e.g. predator-prey system), relaxed trait matching (e.g. herbivore-plant system) and barrier trait matching (e.g. plant-pollinator systems).5.Only by elucidating which species traits are important in each process (i.e. in determining interaction establishment and frequency), can we advance in explaining how species interact and the consequences of these interactions for ecosystem functioning.
Journal articleNewbold T, Hudson LN, Hill SLL, et al., 2016,
Land use has large effects on the diversity of ecological assemblages. Differences among land uses in the diversity of local assemblages (alpha diversity) have been quantified at a global scale. Effects on the turnover of species composition between locations (beta diversity) are less clear, with previous studies focusing on particular regions or groups of species. Using a global database on the composition of ecological assemblages in different land uses, we test for differences in the between-site turnover of species composition, within and among land-use types. Overall, we show a strong impact of land use on assemblage composition. While we find that compositional turnover within land uses does not differ strongly among land uses, human land uses and secondary vegetation in an early stage of recovery are poor at retaining the species that characterise primary vegetation. The dissimilarity of assemblages in human-impacted habitats compared with primary vegetation was more pronounced in the tropical than temperate realm. An exploratory analysis suggests that this geographic difference might be caused primarily by differences in climate seasonality and in the numbers of species sampled. Taken together the results suggest that, while small-scale beta diversity within land uses is not strongly impacted by land-use type, compositional turnover between land uses is substantial. Therefore, land-use change will lead to profound changes in the structure of ecological assemblages.
Journal articlePfeifer M, Kor L, Nilus R, et al., 2016,
South East Asia has the highest rate of lowland forest loss of any tropical region, with logging and deforestation for conversion to plantation agriculture being flagged as the most urgent threats. Detecting and mapping logging impacts on forest structure is a primary conservation concern, as these impacts feed through to changes in biodiversity and ecosystem functions. Here, we test whether high-spatial resolution satellite remote sensing can be used to map the responses of aboveground live tree biomass (AGB), canopy leaf area index (LAI) and fractional vegetation cover (FCover) to selective logging and deforestation in Malaysian Borneo. We measured these attributes in permanent vegetation plots in rainforest and oil palm plantations across the degradation landscape of the Stability of Altered Forest Ecosystems project. We found significant mathematical relationships between field-measured structure and satellite-derived spectral and texture information, explaining up to 62% of variation in biophysical structure across forest and oil palm plots. These relationships held at different aggregation levels from plots to forest disturbance types and oil palms allowing us to map aboveground biomass and canopy structure across the degradation landscape. The maps reveal considerable spatial variation in the impacts of previous logging, a pattern that was less clear when considering field data alone. Up-scaled maps revealed a pronounced decline in aboveground live tree biomass with increasing disturbance, impacts which are also clearly visible in the field data even a decade after logging. Field data demonstrate a rapid recovery in forest canopy structure with the canopy recovering to pre-disturbance levels a decade after logging. Yet, up-scaled maps show that both LAI and FCover are still reduced in logged compared to primary forest stands and markedly lower in oil palm stands. While uncertainties remain, these maps can now be utilised to identify conservation win–win
Journal articleAlexander JS, McNamara J, Rowcliffe JM, et al., 2015,
Journal articleMilner-Gulland EJ, Sainsbury K, Burgess N, et al., 2015,
Journal articleMilner-Gulland EJ, Wallace A, Bunnefeld N, et al., 2015,
Quantifying the short-term costs of conservation interventions for fishers at Lake Alaotra, Madagascar, PLOS One, Vol: 10, ISSN: 1932-6203
Artisanal fisheries are a key source of food and income for millions of people, but if poorly managed, fishing can have declining returns as well as impacts on biodiversity. Management interventions such as spatial and temporal closures can improve fishery sustainability and reduce environmental degradation, but may carry substantial short-term costs for fishers. The Lake Alaotra wetland in Madagascar supports a commercially important artisanal fishery and provides habitat for a Critically Endangered primate and other endemic wildlife of conservation importance. Using detailed data from more than 1,600 fisher catches, we used linear mixed effects models to explore and quantify relationships between catch weight, effort, and spatial and temporal restrictions to identify drivers of fisher behaviour and quantify the potential effect of fishing restrictions on catch. We found that restricted area interventions and fishery closures would generate direct short-term costs through reduced catch and income, and these costs vary between groups of fishers using different gear. Our results show that conservation interventions can have uneven impacts on local people with different fishing strategies. This information can be used to formulate management strategies that minimise the adverse impacts of interventions, increase local support and compliance, and therefore maximise conservation effectiveness.
Journal articleMilner-Gulland EJ, mcnamara J, rowcliffe M, et al., 2015,
Landscapes in many developing countries consist of a heterogeneous matrix of mixed agriculture and forest. Many of the generalist species in this matrix are increasingly traded in the bushmeat markets of West and Central Africa. However, to date there has been little quantification of how the spatial configuration of the landscape influences the urban bushmeat trade over time. As anthropogenic landscapes become the face of rural West Africa, understanding the dynamics of these systems has important implications for conservation and landscape management. The bushmeat production of an area is likely to be defined by landscape characteristics such as habitat disturbance, hunting pressure, level of protection, and distance to market. We explored (SSG, tense) the role of these four characteristics in the spatio-temporal dynamics of the commercial bushmeat trade around the city of Kumasi, Ghana, over 27 years (1978 to 2004). We used geographic information system methods to generate maps delineating the spatial characteristics of the landscapes. These data were combined with spatially explicit market data collected in the main fresh bushmeat market in Kumasi to explore the relationship between trade volume (measured in terms of number of carcasses) and landscape characteristics. Over time, rodents, specifically cane rats (Thryonomys swinderianus), became more abundant in the trade relative to ungulates and the catchment area of the bushmeat market expanded. Areas of intermediate disturbance supplied more bushmeat, but protected areas had no effect. Heavily hunted areas showed significant declines in bushmeat supply over time. Our results highlight the role that low intensity, heterogeneous agricultural landscapes can play in providing ecosystem services, such as bushmeat, and therefore the importance of incorporating bushmeat into ecosystem service mapping exercises. Our results also indicate that even where high bushmeat production is possible, current harvest levels may
Journal articleNewbold T, Hudson LN, Hill SLL, et al., 2015,
Human activities, especially conversion and degradation of habitats, are causing global biodiversity declines. How local ecological assemblages are responding is less clear—a concern given their importance for many ecosystem functions and services. We analysed a terrestrial assemblage database of unprecedented geographic and taxonomic coverage to quantify local biodiversity responses to land use and related changes. Here we show that in the worst-affected habitats, these pressures reduce within-sample species richness by an average of 76.5%, total abundance by 39.5% and rarefaction-based richness by 40.3%. We estimate that, globally, these pressures have already slightly reduced average within-sample richness (by 13.6%), total abundance (10.7%) and rarefaction-based richness (8.1%), with changes showing marked spatial variation. Rapid further losses are predicted under a business-as-usual land-use scenario; within-sample richness is projected to fall by a further 3.4% globally by 2100, with losses concentrated in biodiverse but economically poor countries. Strong mitigation can deliver much more positive biodiversity changes (up to a 1.9% average increase) that are less strongly related to countries' socioeconomic status.
Journal articleWoodhouse E, Mills MA, McGowan PJK, et al., 2015,
Journal articleMaxwell SL, Milner-Gulland EJ, Jones JPG, et al., 2015,
Journal articlePeralta G, Frost CM, Didham RK, et al., 2015,
Journal articleMartinez-Garcia LB, Richardson SJ, Tylianakis JM, et al., 2015,
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