2,159 research outputs found
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How much biodiversity loss is too much?
How much of something do we need to keep people safe and well? This question is frequently asked by those working in risk management. Across diverse sectors from flood protection to health care, practitioners assess risk as the product of the impact of a given event and the probability of its occurrence. Although these estimates are often uncertain, policy-makers must ultimately make spending decisions aimed at averting these risks, because the costs of inaction to society can be substantial. Biodiversity loss is a similarly critical, yet uncertain, issue. On page 288 of this issue, Newbold et al. (1) quantify global biodiversity losses, providing much-needed information on the encroachment of proposed “safe limits.
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The pitfalls of ecological forecasting
Ecological forecasting is difficult but essential, because reactive management results in corrective actions that are often too late to avert significant environmental damage. Here, we appraise different forecasting methods with a particular focus on the modelling of species populations. We show how simple extrapolation of current trends in state is often inadequate because environmental drivers change in intensity over time and new drivers emerge. However, statistical models, incorporating relationships with drivers, simply offset the prediction problem, requiring us to forecast how the drivers will themselves change over time. Some authors approach this problem by focusing in detail on a single driver, whilst others use ‘storyline’ scenarios, which consider projected changes in a wide range of different drivers. We explain why both approaches are problematic and identify a compromise to model key drivers and interactions along with possible response options to help inform environmental management. We also highlight the crucial role of validation of forecasts using independent data. Although these issues are relevant for all types of ecological forecasting, we provide examples based on forecasts for populations of UK butterflies. We show how a high goodness-of-fit for models used to calibrate data is not sufficient for good forecasting. Long-term biological recording schemes rather than experiments will often provide data for ecological forecasting and validation because these schemes allow capture of landscape-scale land-use effects and their interactions with other drivers
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The importance of including habitat-specific behaviour in models of butterfly movement
Dispersal is a key process affecting population persistence and major factors affecting dispersal rates are the amounts, connectedness and properties of habitats in landscapes. We present new data on the butterfly Maniola jurtina in flower-rich and flower-poor habitats that demonstrates how movement and behaviour differ between sexes and habitat types, and how this effects consequent dispersal rates. Females had higher flight speeds than males but their total time in flight was four times less. The effect of habitat type was strong for both sexes, flight speeds were ~2.5x and ~1.7x faster on resource-poor habitats for males and females respectively, and flights were approximately 50% longer. With few exceptions females oviposited in the mown grass habitat, likely because growing grass offers better food for emerging caterpillars, but they foraged in the resource-rich habitat. It seems that females faced a trade-off between ovipositing without foraging in the mown grass or foraging without ovipositing where flowers were abundant. We show that taking account of habitat-dependent differences in activity, here categorised as flight or non-flight, is crucial to obtaining good fits of an individual-based model to observed movement. An important implication of this finding is that incorporating habitat-specific activity budgets is likely necessary for predicting longer-term dispersal in heterogeneous habitats as habitat-specific behaviour substantially influences the mean (>30% difference) and kurtosis (1.4x difference) of dispersal kernels. The presented IBMs provide a simple method to explicitly incorporate known activity and movement rates when predicting dispersal in changing and heterogeneous landscapes
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Biodiversity generation and loss
Human activities in the Anthropocene are influencing the twin processes of biodiversity generation and loss in complex ways that threaten the maintenance of biodiversity levels which underpin human well-being. Yet, many scientists and practitioners still present a simplistic view of biodiversity as a static stock, rather than determined by a dynamic interplay of feedback processes that are affected by anthropogenic drivers. Biodiversity describes the variety of life on earth, from the genes within an organism, to ecosystem level. However, this article focusses on variation amongst living organisms, both within- and between- species. Within species, biodiversity is reflected in genetic, and consequent phenotypic variation between individuals. Genetic diversity is generated by germ line mutations, genetic recombination during sexual reproduction and immigration of new genotypes into populations. Across species, biodiversity is reflected in the numbers of different species present and also, by some metrics, in the evenness of their relative abundances. At this level, biodiversity is generated by processes of speciation and immigration of new species into an area. Anthropogenic drivers affect all these biodiversity generation processes, whilst the levels of genetic diversity can also feedback and affect the level of species diversity, and vice versa. Therefore, biodiversity maintenance is a complex balance of processes and the biodiversity levels at any point in time may not be at equilibrium.
A major concern for humans is that our activities are driving rapid losses of biodiversity, which outweigh by orders of magnitude the processes of biodiversity generation. A wide range of species and genetic diversity could be necessary for the provision of ecosystem functions and services (for definition see Braat 2016); for example in maintaining the nutrient cycling, plant productivity, pollination and pest control that underpin crop production. The importance of biodiversity becomes particularly marked over longer time periods and in particular under varying environmental conditions.
In terms of biodiversity losses, there are natural processes that cause roughly continuous low level losses, but there is also strong evidence from fossil records for transient events in which exceptionally large losses of biodiversity have occurred. These major extinction episodes are thought to have been caused by various large-scale environmental perturbations such as volcanic eruptions, sea level falls, climatic changes and asteroid impacts. From all these events, biodiversity has shown recovery over subsequent calmer periods, although the composition of higher level evolutionary taxa can be significantly altered. In the modern era, biodiversity appears to be undergoing another mass extinction event, driven by large-scale human impacts. The primary mechanisms of biodiversity loss caused by humans vary over time and by geographic region but include: overexploitation, habitat loss, climate change, pollution (e.g. nitrogen deposition) and the introduction of non-native species. It is worth noting that human activities may also lead to increases in biodiversity in some areas through species introductions and climatic changes, although these overall increases in species richness may come at the cost of loss of native species and with uncertain effects on ecosystem service delivery. Genetic diversity is also affected by human activities, with many examples of erosion of diversity through crop and livestock breeding or through the decline in abundance of wild species populations. Significant future challenges are to develop better ways to monitor both the drivers of biodiversity loss and biodiversity levels themselves, making use of new technologies, and improving coverage across geographic regions and taxonomic scope. Rather than treating biodiversity as a simple stock at equilibrium, developing a deeper understanding of the complex interactions— between environmental drivers, and between genetic and species diversity — is essential to manage and maintain the benefits that biodiversity delivers to humans, and to safeguard the intrinsic value of the Earth’s biodiversity for future generations
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Predicting resilience of ecosystem functioning from co‐varying species' responses to environmental change
Understanding how environmental change affects ecosystem function delivery is of primary importance for fundamental and applied ecology. Current approaches focus on single environmental driver effects on communities, mediated by individual response traits. Data limitations present constraints in scaling up this approach to predict the impacts of multivariate environmental change on ecosystem functioning.
We present a more holistic approach to determine ecosystem function resilience, using long‐term monitoring data to analyze the aggregate impact of multiple historic environmental drivers on species' population dynamics. By assessing covariation in population dynamics between pairs of species, we identify which species respond most synchronously to environmental change and allocate species into “response guilds.” We then use “production functions” combining trait data to estimate the relative roles of species to ecosystem functions. We quantify the correlation between response guilds and production functions, assessing the resilience of ecosystem functioning to environmental change, with asynchronous dynamics of species in the same functional guild expected to lead to more stable ecosystem functioning.
Testing this method using data for butterflies collected over four decades in the United Kingdom, we find three ecosystem functions (resource provisioning, wildflower pollination, and aesthetic cultural value) appear relatively robust, with functionally important species dispersed across response guilds, suggesting more stable ecosystem functioning. Additionally, by relating genetic distances to response guilds we assess the heritability of responses to environmental change. Our results suggest it may be feasible to infer population responses of butterflies to environmental change based on phylogeny—a useful insight for conservation management of rare species with limited population monitoring data.
Our approach holds promise for overcoming the impasse in predicting the responses of ecosystem functions to environmental change. Quantifying co‐varying species' responses to multivariate environmental change should enable us to significantly advance our predictions of ecosystem function resilience and enable proactive ecosystem management
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Are existing biodiversity conservation strategies appropriate in a changing climate?
Many countries have conservation plans for threatened species, but such plans have generally been developed without taking into account the potential impacts of climate change. Here, we apply a decision framework, specifically developed to identify and prioritise climate change adaptation actions and demonstrate its use for 30 species threatened in the UK. Our aim is to assess whether government conservation recommendations remain appropriate under a changing climate. The species, associated with three different habitats (lowland heath, broadleaved woodland and calcareous grassland), were selected from a range of taxonomic groups (primarily moths and vascular plants, but also including bees, bryophytes, carabid beetles and spiders). We compare the actions identified for these threatened species by the decision framework with those included in existing conservation plans, as developed by the UK Government's statutory adviser on nature conservation. We find that many existing conservation recommendations are also identified by the decision framework. However, there are large differences in the spatial prioritisation of actions when explicitly considering projected climate change impacts. This includes recommendations for actions to be carried out in areas where species do not currently occur, in order to allow them to track movement of suitable conditions for their survival. Uncertainties in climate change projections are not a reason to ignore them. Our results suggest that existing conservation plans, which do not take into account potential changes in suitable climatic conditions for species, may fail to maximise species persistence. Comparisons across species also suggest a more habitat-focused approach could be adopted to enable climate change adaptation for multiple species
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Developing a biodiversity-based indicator for large-scale environmental assessment: a case study of proposed shale gas extraction sites in Britain
1. Environmental impact assessments are important tools for predicting the consequences of development and changes in land use. These assessments generally use a small subset of total biodiversity – typically rare and threatened species and habitats – as indicators of ecological status. However, these indicators do not necessarily reflect changes in the many more widespread (but increasingly threatened) species, which are important for ecosystem functions. In addition, assessment of threatened species through field surveys is time-consuming and expensive and, therefore, only possible at small spatial scales. In contrast, planning changes in land use over large spatial scales (e.g. national infrastructure projects) require assessment and prioritization of biodiversity over large spatial extents.
2. Here, we provide a method for the assessment of biodiversity, which takes account of species diversity across larger spatial scales, based on occurrence records from 5553 species across 11 taxonomic groups. We compare the efficacy of the biodiversity-based indicator we developed against one based on threatened species only and then use it to consider spatial and temporal patterns in ecological status across Great Britain. Finally, we develop a case study to investigate biodiversity status in regions proposed for shale gas extraction in Great Britain.
3. Our results show a strong relationship between the ecological status of areas defined by all biodiversity versus only threatened species, although they also demonstrate that significant exceptions do exist where threatened species do not always accurately indicate the ecological status of wider biodiversity.
4. Spatial and temporal analyses show large variation in ecological status across Great Britain both within the area made available for shale gas licensing and within individual environmental zones. In total, however, 63% of hectads across Britain have suffered a net reduction in our biodiversity-based indicator since 1970.
5. Synthesis and applications. We provide a method and develop a biodiversity-based indicator for the assessment and prioritization of biodiversity at large spatial scales. We highlight the potential applications of this approach for the prioritization of areas that would benefit from conservation and restoration. We also emphasize the danger of insufficient consideration of more widespread species and not just rare and threatened species and habitats as indicators of ecological status when prioritizing large-scale national infrastructure projects. Our method should be a useful tool to complement existing environmental impact assessment methods
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Data on the movement behaviour of four species of grassland butterfly
This Data in Brief article describes data on the movement behaviour of four species of grassland butterflies collected over three years and at four sites in southern England. The datasets consist of the movement tracks of and recorded using standard methods and presented as steps distances and turning angles. Sites consisted of nectar-rich field margins, meadows, and mown short turf grasslands with minimal flowers. In total, 783 unique movement tracks were collected. The data were used for analysing the movement behaviour of the species and for parameterising individual-based movement models
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Integrating the influence of weather into mechanistic models of butterfly movement
Understanding the factors influencing movement is essential to forecasting species persistence in a changing environment. Movement is often studied using mechanistic models, extrapolating short-term observations of individuals to longer-term predictions, but the role of weather variables such as air temperature and solar radiation, key determinants of ectotherm activity, are generally neglected. We aim to show how the effects of weather can be incorporated into individual-based models of butterfly movement thus allowing analysis of their effects.
Methods: We constructed a mechanistic movement model and calibrated it with high precision movement data on a widely studied species of butterfly, the meadow brown (Maniola jurtina), collected over a 21-week period at four sites in southern England. Day time temperatures during the study ranged from 14.5 to 31.5⁰C and solar radiation from heavy cloud to bright sunshine. The effects of weather are integrated into the individual-based model through weather-dependent scaling of parametric distributions representing key behaviours: the durations of flight and periods of inactivity.
Results: Flight speed was unaffected by weather, time between successive flights increased as solar radiation decreased, and flight duration showed a unimodal response to air temperature that peaked between approximately 23⁰C and 26⁰C. After validation, the model demonstrated that weather alone can produce a more than two-fold difference in predicted weekly displacement.
Conclusions: Individual Based models provide a useful framework for integrating the effect of weather into movement models. By including weather effects we are able to explain a two-fold difference in movement rate of M. jurtina consistent with inter-annual variation in dispersal measured in population studies. Climate change for the studied populations is expected to decrease activity and dispersal rates since these butterflies already operate close to their thermal optimum
Applied Technological Direction of Power Plant Ash and Slag Waste Management when Kuznetsk Bituminous Coal is Burned
Currently a lot of power plants have a problem with storage of coal combustion solid by-products (ash and slag). Holding capacity of existing power plants available ash dumps were enlarged and modernized repeatedly. Many plants have two or even three of them. Today new ash dump construction is economically inconvenient due to need to assign new plots of land and their inconveniently big distance from a plant, which increase ash and slag transportation expenses. The goal of our research work is to find promising directions for ash and slag waste mass utilization based on Kuznetsk bituminous coals experimental data on ultimate composition and properties. The experimental research of ash, slag and their mixture samples from ash dumps brought us to conclusion that the most promising direction for these materials application in large quantities is construction industry including road construction. Be-sides, we lined up some other directions for ash, slag, and ash and slag mixture possible application. These directions might not provide mass utilization but they are promising from a point of view of the researched waste properties
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