REFUGIAL POPULATIONS AT TRAILING-EDGE RANGE MARGINS: ATTRIBUTES, SURVIVAL AND CONSERVATION

许多物种目前作为局部的避难种群生存在过去气候条件更有利的地区。这些物种生存在局部栖息地和/或周围地区的非典型小气候中;例如，英国的冷适应物种可能在气候变暖时在当地寒冷的朝北地点生存。避难所对于物种在过去的气候变化中生存非常重要，并且在人为气候变化下可能再次如此。尽管如此，人们对支持人口避难所的当地条件知之甚少。因此，我们对物种在未来随着气候变化而持续存在的地点的属性（地点，栖息地，小气候）知之甚少。了解这些属性是至关重要的通知未来的保护政策，以及发展一个更深层次的基本科学了解物种的地理分布的动态。我们将利用人为气候变化带来的机会，通过研究英国四种分布在北方的蝴蝶，直接观察避难种群的形成。蝴蝶是这个项目的理想研究物种，因为在过去四十年的气候变化中，英国有很好的分布记录，而且当地的小气候和小栖息地条件影响着蝴蝶从出生到死亡的所有生命阶段。我们将重新调查英国自20世纪70年代以来的历史分布数据，以及我们在2004-05年重新调查的地点，以确定哪些物种幸存下来，哪些物种已经灭绝。我们将使用动态人口模型，将环境信息的物种，以确定当地的小气候和栖息地的人口生存的位置，因为在20世纪70年代的人为气候变化的特点。我们将通过研究其他北方无脊椎动物的气候避难所形成来检验我们蝴蝶研究结果的普遍性。然后，我们将使用我们的模型来预测未来气候变化的后果的物种，到2100年，并确定在何种程度上避难所与现有的保护区的位置在British.The拟议的工作将提供第一次调查，和预测模型，促进人口的持续性范围撤退物种的位置的属性。该项目将解决气候变化下物种分布动态的基本问题，并产生对决策者具有相当实际价值的结果。它将为了解气候变化对生物多样性的影响开辟一条新的研究途径，并提供一套具体的科学证据，为关于在气候变化下制定有效的保护战略的辩论提供信息。

Many species currently survive as localised, refugial populations in regions where they used to be more widespread under more favourable past climatic conditions. These species survive in localised habitats and/or microclimates that are atypical of the surrounding region; for example, a cold-adapted species in Britain might survive on a locally cold, north-facing site when the climate warms. Refugia have been extremely important in allowing species to survive past climatic changes, and are likely to be so again under anthropogenic climate change. Despite this, the local conditions that support population refugia are poorly understood. Thus we have little idea of the attributes (locations, habitats, microclimates) of sites where species may persist in future as the climate changes. Understanding these attributes is vital for informing future conservation policies as well as for developing a deeper fundamental scientific understanding of the dynamics of species' geographic distributions. We will take advantage of the opportunity presented by anthropogenic climate change to observe the creation of refugial populations directly, by studying four species of northerly-distributed butterflies in Britain. Butterflies are ideal study species for this project because there are excellent distribution records in Britain over the past four decades of climate change, and because local microclimate and microhabitat conditions affect all butterfly life stages, from birth to death. We will re-survey sites in Britain for which we have historical distribution data since the 1970s, and which we re-surveyed in 2004-05, to determine where species have survived, and where they have become extinct. We will use dynamic population models that incorporate environmental information for species to identify the local microclimatic and habitat characteristics of locations where populations have survived since the onset of anthropogenic climate change in the 1970s. We will examine the generality of our butterfly findings by studying climate refugial formation in other northern invertebrates. We will then use our models to project the consequences of future climatic changes for species, to the year 2100, and determine the degree to which refugia coincide with the locations of existing protected areas in Britain.The proposed work will provide the first investigation of, and predictive models for, the attributes of locations that promote population persistence in range retreating species. The project will address fundamental questions about the dynamics of species' ranges under climate change, as well as producing results of considerable practical value for policy makers. It will open up a new avenue of research on understanding the impacts of climate change on biodiversity, and provide a concrete body of scientific evidence to inform the debate on developing effective conservation strategies under climate change.