Climate change effects on biodiversity: impacts of increased overwinter temperatures on UK reptiles

要全面了解气候变化对生物多样性的影响，需要结合越冬和夏季气温升高的影响。然而，现有的研究偏向于暖季变暖的影响，尽管冬季气温正在以更快的速度上升。事实上，物种对冬季气候变化的脆弱性很少被研究。尽管暖冬对变温动物（即冷血动物）的影响是最近的研究方向，但现有的研究揭示了在恒温动物中不太可能观察到的有害生理影响，并在某种程度上证明了陆生变温动物的脆弱性。变温动物依靠保持在一定范围内的环境温度来维持包括生长和繁殖在内的关键生理过程。因此，预计它们将对气候变化带来的热约束做出强烈反应。在变温动物中，爬行动物由于其通常有限的传播能力，特别容易受到环境条件快速变化的影响。因此，由于气候变化，它们比其他分类群更有可能遭受更高的灭绝率。本研究的目的是研究冬季气温上升如何影响温带爬行动物的生理和诱导物候和分布的变化。为了实现这一目标，我们将使用入侵壁虎（Podarcis muralis，冬季冬眠），并整理英国爬行动物的长期数据进行研究：实验冬季条件下的生理和行为变化：我们将通过测量壁虎的繁殖成功率，记录它们在实验控制的冬眠温度条件下的激素和行为反应，来评估暖冬对壁虎生理的影响。这将有助于我们了解气候变化对个体适应性的影响。2. 与冬季变暖的历史模式相关的分布变化：我们将研究过去的热变化与英国爬行动物分布的关系，重点关注冬季变暖的显著时期，然后建立它们的分布模型。这将有助于我们了解物种种群在未来气候情景下如何相互作用。3. 与冬季变暖历史模式相关的物候变化：我们将测试过去冬季变暖时期与英国爬行动物冬眠期和繁殖季节变化的关联，然后开发物候模型。结合研究分布变化，这将有助于我们确定易受气候变化影响的物种和迫切需要采取保护行动的优先物种。从广义上讲，这项研究将有助于全面了解物种如何应对气候变化，重点关注越冬温度的升高。它将带来冬暖对爬行动物生理影响的额外资料，以及有关行为影响的第一手资料。此外，它将首次记录爬行动物在暖冬条件下所经历的物候和分布变化。这些信息目前没有包括在对气候变化下未来生物多样性损失的估计中，但可能是预测中要考虑的一个重要方面。

A comprehensive understanding of climate change effects on biodiversity would require a combination of knowledge from the impacts of increased overwinter and summer temperatures. However, existing studies are biased towards the effects of warm season getting warmer, though winter temperatures are increasing at a faster rate. Indeed, species' vulnerability to winter climate change has been rarely studied. Despite being a recent research track, existing studies on warming-winter effects on ectotherms (i.e. cold-blooded animals) revealed detrimental physiological effects that are unlikely to be observed in endotherms and somehow proved the vulnerability of terrestrial ectotherms. Ectotherms rely on ambient temperatures remaining within certain ranges to maintain critical physiological processes including growth and reproduction. As such, they are expected to react strongly to the thermal constraints imposed by climate change. Among ectotherms, reptiles are particularly vulnerable to rapid changes in environmental conditions given their often-limited dispersal abilities. Therefore, they are more likely to suffer higher extinction rates than other taxa due to climatic change.The aim of the study is to investigate how rising winter temperatures affect the physiology and induce shift in the phenology and distribution of temperate reptiles. To accomplish this, we will use the invasive wall lizard (Podarcis muralis, which hibernates during winter), and collate long-term data on UK reptiles to examine: 1. Physiological and behavioural shift under experimental winter conditions: We will assess the physiological effects of warming winter on wall lizards by measuring their reproductive success and recording their hormonal and behavioural response under experimentally manipulated thermal conditions during hibernation. This will help us to understand the effects of this aspect of climate change on individual fitness. 2. Distribution shifts associated with historical patterns of winter warming: We will examine the association of past thermal shifts - focusing on periods of significant winter warming - with the distribution of reptiles in the UK, then model their distribution. This will help us understand how species populations will interact under future climate scenarios. 3. Phenological shift associated with historical patterns of winter warming: We will test the association of past winter-warming periods on changes in the hibernation period and breeding season of UK reptiles, and then develop phenology models. In conjunction with studying distribution shifts, this will help us identify species vulnerable to climate change and priority species that urgently require conservation action. In broad terms, this study will contribute to bringing a comprehensive knowledge on how species may respond to climate change, with a strong focus on increased overwinter temperature. It will bring additional information on the physiological effects of winter-warming on reptiles as well as the first information on behavioural effects. Moreover, it will document for the first time the phenological and distribution shift undergone by reptiles under mild wintering conditions. Such information is not presently included in estimates of future biodiversity loss under climate change but could be an important aspect to consider in predictions.