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Since peatlands store up to 30% of the global soil organic carbon, it is important to understand how these ecosystems will react to a change in climate and management. Process-based ecosystem models have emerged as important tools for predicting long-term peatland dynamics, but their application is often challenging because they require programming skills. In this paper, we present NUCOMBog, an R package of the NUCOM-Bog model (Heijmans et al. 2008), which simulates the vegetation, carbon, nitrogen and water dynamics of peatlands in monthly time steps. The package complements the model with appropriate functions, such as the calculation of net ecosystem exchange, as well as parallel functionality. As a result, the NUCOMBog R package provides a user-friendly tool for simulating vegetation and biogeochemical cycles/fluxes in peatlands over years/decades, under different management strategies and climate change scenarios, with the option to use all the in-built model analysis capabilities of R, such as plotting, sensitivity analysis or optimization. 相似文献
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Leif Egil Loe Atle Mysterud Vebj?rn Veiberg Rolf Langvatn 《Proceedings. Biological sciences / The Royal Society》2009,276(1667):2581-2587
In species with polygynous mating systems, females are regarded as food-limited, while males are limited by access to mates. When local density increases, forage availability declines, while mate access for males may increase due to an increasingly female-biased sex ratio. Density dependence in emigration rates may consequently differ between sexes. Here, we investigate emigration using mark-recovery data from 468 young red deer Cervus elaphus marked in Snillfjord, Norway over a 20-year period when the population size has increased sixfold. We demonstrate a strong negative density-dependent emigration rate in males, while female emigration rates were lower and independent of density. Emigrating males leaving the natal range settled in areas with lower density than expected by chance. Dispersing males moved 42 per cent longer at high density in 1997 (37 km) than at low density in 1977 (26 km), possibly caused by increasing saturation of deer in areas surrounding the marking sites. Our study highlights that pattern of density dependence in dispersal rates may differ markedly between sexes in highly polygynous species. Contrasting patterns reported in small-scale studies are suggestive that spatial scale of density variation may affect the pattern of temporal density dependence in emigration rates and distances. 相似文献
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Maritime Spatial Planning (MSP) needs to incorporate spatial information on human impacts. As human activities and uses increase in marine and coastal waters around the world, pressures in ecosystems are also increasing, leading to multiple adverse effects on different species and habitats. The European Directive on MSP aims to achieve an integrated approach to marine governance, whilst securing and maintaining the healthy status of marine and coastal waters, in accordance with the Marine Strategy Framework Directive. The latter requires Member States to develop assessments not only on pressures and impacts, but also on the state of the marine environment and then take measures towards reaching a Good Environmental Status by 2020.The Portuguese Maritime Spatial Plan – Plano de Ordenamento do Espaço Marítimo (POEM) was developed between 2009 and 2012. In 2014 a law establishing the Basis for the Spatial Planning and Management of the National Maritime Space was enacted and in 2015 the framework for the elaboration of a new national Maritime Spatial Plan, named Situation Plan, was established. Portugal will face, in the next five years, the challenge of planning and managing its marine space, whilst promoting its sustainable use and protection.This study adapted a cumulative effects assessment model to understand how the impacts from multiple threats affect the marine and coastal ecosystems and, how this information can be used to improve the management process. Information was gathered on intensity and distribution of activities and uses for the Portuguese continental subdivision marine area, quantified and mapped their cumulative impacts in marine ecosystems, and overlapped with the POEM. Results show that impacts are spreading from the coast up to the Contiguous Zone. Higher scores appear in Transitional and Coastal Waters in the north (Viana do Castelo/Figueira da Foz), centre (Peniche/Setúbal) and south (Lagos/Faro). In some areas with higher ranks, statutes of nature conservation are already in place, but potential activities may still occur on top of existing ones. This study shows that the adapted model is a helpful tool to clarify ocean planning, identify areas of potential conflicts among users and support the decision making process. 相似文献
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The assessment of different policy options represents a major tool for decision-makers in Biosphere Reserves, to develop more-resilient strategies for sustainable development and to visualise unintended consequences of these policies.In this work we analyse eight measures proposed by different agents in order to meet the main objectives of environmental sustainability, included in the Action Plan of the Fuerteventura Biosphere Reserve (Spain). We quantified the effects of these measures in terms of the sustainability thresholds of 10 environmental indicators, also proposed by the Action Plan, which was integrated in the Fuerteventura Biosphere Reserve dynamic model. Their behaviours under these measures allow determination of whether the objectives will be met in the period 2012–2025. Although some indicators would improve under these measures, fitting certain objectives, some negative effects on other indicators confirm the existence of trade-offs among these objectives. For instance, grazing limitation would improve the proportion of high-quality vegetation but would negatively affect the Egyptian vulture population, which would even fall below its sustainability threshold. The definition of thresholds for each indicator allows decision-makers to establish a way to prioritise among the eight measures analysed. The results show that these measures are insufficient to meet the sustainability thresholds of four indicators (the landscape indicator, the proportion of renewable energy, the per capita primary energy consumption and carbon dioxide emissions). Focusing on the remaining six indicators and following the rule “Threshold out, measure out”, seven out of the eight measures would exceed some thresholds and should be avoided. Only one option, aimed at growing fodder to feed cattle on restored traditional agricultural lands, would not exceed any of these thresholds. However, this measure also presents certain negative effects regarding indicators related to flagship species (the houbara habitat and the Egyptian vulture population), which would require compensation measures. 相似文献