The role of dispersal in species' ability to respond to climate change

有一个正在形成的共识是，许多动物物种正在通过向北转移其分布来应对当前的气候变暖。然而，为了跟踪气候，物种必须能够通过已被人类活动大大改变的景观分散，繁殖栖息地往往是支离破碎的，分散在荒凉的城市和农业景观中。由于这种人类引起的栖息地丧失，许多传播能力差的物种无法改变它们的范围，无法到达它们目前范围边缘以外的新地点。预测为什么有些物种可以改变它们的活动范围以应对气候变化，而其他物种则不能，这对于改善我们对物种未来分布的预测至关重要。该项目将通过调查物种的扩散行为和能力来解决这一问题。即使温室气体排放量立即大幅减少，由于地球气候系统的惯性，仍然会发生更多的变暖。因此，无论采取何种减缓措施，都有可能导致未来变暖，在这方面，迫切需要采取适应措施。一种普遍建议的适应措施是创造更具渗透性的景观，使物种能够在退化的景观中移动，并帮助它们殖民新的地点。然而，改善生境连通性促进范围转移的有效性基本上是未经检验的。目前还没有数据研究物种的飞行行为对景观特征的反应如何影响它们在较长距离内分散的能力，殖民新的地点，从而改变它们的范围。然而，这些信息对于了解气候变化对生物多样性分布的影响至关重要。这项拟议中的工作将首次调查碎片化景观中的“日常”本地飞行行为如何转化为更长距离的传播和殖民成功。我们将专注于蝴蝶，并收集蝴蝶飞行路径特征（位移，飞行速度，方向性等）在繁殖栖息地，非繁殖栖息地，栖息地/非栖息地斑块边界的新的现场数据。我们将把运动信息和蝴蝶的行为（产卵，花蜜，等）到空间明确的动态模型，以估计运动在"真实的"研究景观。我们将测试我们的模型的可靠性，通过比较模拟的运动与独立的标记-再捕获数据获得相同的物种和研究景观。然后，我们将使用经过验证的模型来研究飞行行为和繁殖栖息地的可用性的变化如何影响研究景观中的运动概率。我们的模型还将使我们能够检查保护管理计划的有效性，以改善景观连通性（影响计划）。该项目将产生具有相当实际价值的结果，并解决有关物种分布范围扩散限制的基本问题。它将为了解和预测气候变化对生物多样性的影响开辟一条新的研究途径。保护战略必须包括适应战略，但保护主义者不确定该怎么做。拟议的工作将为这一辩论提供具体的科学证据。

There is an emerging consensus that many animal species are responding to current climate warming by shifting their distributions northwards. However, in order to track climate, species must be able to disperse through landscapes that have been greatly altered by human activities, and where breeding habitats are often fragmented and scattered across inhospitable urban and agricultural landscapes. Because of this human-induced habitat loss, many species with poor dispersal ability are failing to shift their ranges and are unable to reach new sites beyond their current range margin. Predicting why some species can shift their ranges in response to climate change whilst others cannot, is crucial for improving our projections of species' future distributions. This project will address this issue by investigating species' dispersal behaviour and capability. Even if greenhouse gas emissions were greatly reduced immediately, more warming would still occur due to inertia in the Earth's climate system. Thus, there is a commitment to future warming regardless of any mitigation and, in this context, adaptation measures are required urgently. One commonly suggested adaptation measure is the creation of more permeable landscapes that enable species to movement through degraded landscapes, and help them colonise new sites. However, the effectiveness of improving habitat connectivity for promoting range shifts is essentially untested. There are currently no data examining how species' flight behaviour in response to landscape features may affect their ability to disperse over longer-distances, colonise new sites, and hence shift their ranges. Yet such information will be crucial for understanding the impacts of climate change on the distribution of biodiversity. The proposed work will provide the first investigation of how 'everyday' local flight behaviour in fragmented landscapes translates into longer-distance dispersal and colonisation success. We will focus on butterflies and collect new field data on butterfly flight path characteristics (displacement, speed of flight, directionality, etc) within breeding habitats, within non-breeding habitats, and at habitat/non-habitat patch boundaries. We will incorporate movement information and butterfly behaviour (ovipositing, nectaring, etc) into spatially-explicit dynamic models to estimate movements in 'real' study landscapes. We will test the reliability of our models by comparing modelled movements with those obtained from independent mark-recapture data for the same species and study landscapes. We will then use validated models to examine how variation in flight behaviour and availability of breeding habitat affects the probability of movement in study landscapes. Our models will also allow us to examine the effectiveness of conservation management plans to improve landscape connectivity (Impact Plan). The project will produce results of considerable practical value, as well as addressing fundamental questions about dispersal limits to species ranges. It will open up a new avenue of research on understanding and predicting the impacts of climate change on biodiversity. Conservation strategies must include adaptation strategies, but conservationists are uncertain about what to do. The proposed work will provide a concrete body of scientific evidence to inform this debate.