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

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上升的影响方面的知识。然而，现有的研究偏向于温暖季节变暖的影响，尽管冬季气温上升的速度更快。事实上，物种对冬季气候变化的脆弱性很少被研究。尽管是最近的一项研究，但现有的关于冬季变暖对外温体(即冷血动物)影响的研究揭示了在吸温体中不太可能观察到的有害生理影响，并以某种方式证明了陆地外温体的脆弱性。体温依赖于保持在一定范围内的环境温度来维持关键的生理过程，包括生长和繁殖。因此，预计它们将对气候变化施加的热限制做出强烈反应。在外温类动物中，爬行动物特别容易受到环境条件快速变化的影响，因为它们的扩散能力往往有限。因此，由于气候变化，它们比其他类群更有可能遭受更高的灭绝率。研究的目的是调查冬季气温上升如何影响温带爬行动物的生理，并导致温带爬行动物物候和分布的转变。为了做到这一点，我们将使用入侵的壁蜥蜴(Podarcis Muralis，在冬季冬眠)，并整理英国爬行动物的长期数据来检查：1.在实验冬季条件下的生理和行为变化：我们将通过测量壁蜥蜴的繁殖成功并记录它们在冬眠过程中人工操纵的热条件下的荷尔蒙和行为反应，来评估冬季变暖对壁蜥蜴的生理影响。这将有助于我们理解气候变化的这一方面对个人健康的影响。2.与冬季变暖的历史模式相关的分布变化：我们将研究过去的温度变化--重点是冬季显著变暖的时期--与英国爬行动物的分布之间的关系，然后对它们的分布进行建模。这将帮助我们了解物种种群在未来气候情景下将如何相互作用。3.物候变化与冬季变暖的历史模式：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期变化的相关性，然后建立物候学模型。结合对分布变化的研究，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，并重点关注越冬温度的上升。它将带来更多关于冬季变暖对爬行动物的生理影响的信息，以及关于行为影响的第一个信息。此外，它将首次记录爬行动物在温和越冬条件下经历的物候和分布变化。这些信息目前没有包括在气候变化下对未来生物多样性损失的估计中，但可能是预测中需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.