Common-garden experiments with populations sampled along natural thermal gradients help to reveal local adaptation, disentangle environmental and genetic effects, and ultimately predict, by analogy, future biotic responses to climate change. In this regard, geothermal habitats are useful model systems as they exhibit dramatic changes in soil temperature. The springtail Protaphorura pseudovanderdrifti has apparently coped with such local geothermal warming in Iceland, as this species occurs along a more than half-century-old geothermal gradient in a grassland and persists along a newly emerged temperature gradient in a previously non-geothermal planted spruce forest. We measured thermal reaction norms for development and walking speed and acute cold shock tolerance of P. pseudovanderdrifti originating from the grassland and forest geothermal gradients. Temperature-dependent juvenile development showed little variation among subpopulations from the recently warmed forest, probably due to insufficient evolutionary time, but springtails from the warmed grassland plots had significantly steeper reaction norms than their counterparts from the corresponding unwarmed plot. In contrast, cold tolerance and locomotory activity showed no conclusive clinal pattern despite significant within-habitat variation. There appeared to be significant differences between habitats, as springtails from the forest had more temperature-sensitive developmental rate and locomotory activity, walked faster, and exhibited more variable cold tolerance than grassland springtails did. The planting of a forest, therefore, seems to have exerted a stronger effect on the thermal phenotype of P. pseudovanderdrifti than the emergence of a geothermal gradient. Thus, habitat properties may be no less important in shaping thermal reaction norms than the mean temperature. These local-scale findings suggest that, in addition to warming per se, global transformation of communities may drive the evolution of thermal phenotypes to an extent comparable with the effect of rising environmental temperature.

中文翻译：

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来自两个地热变暖栖息地的亚北极跳虫的温度响应

对沿自然热梯度采样的种群进行的公共花园实验有助于揭示局部适应、解开环境和遗传影响，并最终通过类比预测未来生物对气候变化的反应。在这方面，地热栖息地是有用的模型系统，因为它们表现出土壤温度的巨大变化。跳虫 Protaphorura pseudovanderdrifti 显然已经应对了冰岛这种当地的地热变暖，因为该物种沿着草原中具有半个多世纪历史的地热梯度出现，并沿着先前非地热种植的云杉林中新出现的温度梯度持续存在. 我们测量了 P. 的发展和步行速度以及急性冷冲击耐受性的热反应规范。源自草原和森林地热梯度的伪范德瑞夫蒂。温度依赖的幼虫发育在最近变暖的森林亚群之间几乎没有变化，这可能是由于进化时间不足，但来自温暖草地地块的跳尾鱼的反应规范明显比来自相应未温暖地块的对应物更陡峭。相比之下，尽管存在显着的栖息地变化，但耐寒性和运动活动没有显示出确凿的临床模式。栖息地之间似乎存在显着差异，因为与草原跳虫相比，来自森林的跳虫具有更高的温度敏感发育速度和运动活动，行走速度更快，并且表现出更多可变的耐寒性。因此，植树造林 似乎比地温梯度的出现对 P.pseudovanderdrifti 的热表型产生了更强的影响。因此，栖息地特性在塑造热反应规范方面的重要性可能不亚于平均温度。这些局部尺度的研究结果表明，除了变暖本身之外，群落的全球转变可能会推动热表型的演变，其程度与环境温度升高的影响相当。