Disentangling the drivers of decadal body size decline in an insect population
Disentangling the drivers of decadal body size decline in an insect population
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解开昆虫种群十年间体型下降的驱动因素
DOI：
10.1111/gcb.17014
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发表时间：
2023
影响因子：
11.6
通讯作者：
Ives, Anthony R.
中科院分区：
文献类型：
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作者：
Botsch, Jamieson C.;Zaveri, Aayush N.;Nell, Lucas A.;McCormick, Amanda R.;Book, K. Riley;Phillips, Joseph S.;Einarsson, Árni;Ives, Anthony R.
虽然人们普遍预测气候变暖会缩小变温动物的体型，但有关这一趋势的证据好坏参半。体型不仅取决于温度，还取决于其他因素，如食物质量和种内竞争。由于温度趋势或其他长期环境因素可能影响种群规模和食物来源，将平均体型的趋势归因于温度需要分离潜在的混杂效应。我们评估了1977年至2015年间冰岛Mývatn湖中部雅龄跗象体型的变化趋势和潜在的驱动因素（水温、种群规模和食物质量）。虽然温度在Mývatn升高，但与理论预期相反，成年蠓的体型只有轻微（不显著）下降。使用包含多个预测因子的状态空间模型，体型与水温和蠓种群丰度呈负相关，与蠓的13c富集呈正相关（这是有利食物条件的一个指标）。这些影响的程度是相似的，因此温度、丰度和碳稳定同位素特征的同时变化可以在长期的体型趋势中相互抵消。我们的研究结果说明了受全球变化影响的多种因素是如何相互作用影响变温动物的平均体型的。
While climate warming is widely predicted to reduce body size of ectotherms, evidence for this trend is mixed. Body size depends not only on temperature but also on other factors, such as food quality and intraspecific competition. Because temperature trends or other long‐term environmental factors may affect population size and food sources, attributing trends in average body size to temperature requires the separation of potentially confounding effects. We evaluated trends in the body size of the midgeTanytarsus gracilentusand potential drivers (water temperature, population size, and food quality) between 1977 and 2015 at Lake Mývatn, Iceland. Although temperatures increased at Mývatn over this period, there was only a slight (non‐significant) decrease in midge adult body size, contrary to theoretical expectations. Using a state‐space model including multiple predictors, body size was negatively associated with both water temperature and midge population abundance, and it was positively associated with13C enrichment of midges (an indicator of favorable food conditions). The magnitude of these effects were similar, such that simultaneous changes in temperature, abundance, and carbon stable isotopic signature could counteract each other in the long‐term body size trend. Our results illustrate how multiple factors, all of which could be influenced by global change, interact to affect average ectotherm body size.