The role of the thermal niche in past warming worlds (ThermNiche)

热生态位在过去变暖世界中的作用（ThermNiche）

• 批准号: 424857030
• 负责人: Privatdozent Dr. Martin Aberhan
• 金额: --
• 依托单位: Museum für Naturkunde - Leibniz-Institut für Evolutions- und Biodiversitätsforschung (MfN)
• 依托单位国家: 德国
• 项目类别: Research Units
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/424857030?language=en
• 关键词: role; thermal; niche; past; warming

Understanding the dynamics of past and present ecosystems and predicting directional changes in response to climate change are long-standing challenges in (paleo-)ecology. We propose to apply the concept of the thermal niche to study the effects of climate warming on shifts in the latitudinal distribution of species and in the thermal structure of faunal assemblages. Using occurrence data of marine benthic macroinvertebrates and maps of seawater temperatures derived from oxygen isotopes and climate modelling, we address in detail the effects of climatic ups and downs during the Pliensbachian-Toarcian (Early Jurassic) time interval, and subsequently extend our analyses to the Phanerozoic eon. First, we test whether warming is narrowing the latitudinal ranges of species (hypothesis 1) alongside the hypothesis that warming preferentially results in poleward shifts of species. Second, we argue that the thermal structure of an assemblage determines its response to warming (hypothesis 2). Particularly we hypothesize that immigrants have warmer realized thermal niches than the pre-existing assemblage average; that extirpation prevails among species for which raised temperatures exceed their upper thermal limits; and that increase or decrease in the abundance of species is predicted by their respective pre-existing thermal niche. Third, we explore whether changes in the composition and thermal structure of faunal assemblages are most distinct at the warm edge accumulations of tropical and temperate species respectively (hypothesis 3). In this context, we predict that local population losses occurred preferentially in assemblages with high proportions of the warmest-affinity species, whereas immigrations are negligible; that a second maximum of population losses is located at the equatorward distribution edge of temperate species; and that this warm temperate zone also receives significant immigrations of tropical species resulting in peaks of faunal turnover within assemblages. Understanding the role of the thermal niche, we expect to contribute knowledge about the extent to which marine ecosystems remain cohesive or are transformed, involving replacements of incumbent species by immigrants or newly evolved species, in the face of climate change.

了解过去和现在生态系统的动态并预测应对气候变化的方向性变化是(古)生态学的长期挑战。我们建议应用热生态位的概念来研究气候变暖对物种纬度分布和动物群组合热结构的影响。利用海洋底栖大型无脊椎动物的出现数据以及氧同位素和气候模拟得出的海水温度图，我们详细地讨论了Pliensbchian-Toarcian(早侏罗世)时期气候起伏的影响，并随后将我们的分析扩展到显生宙。首先，我们测试变暖是否正在缩小物种的纬度范围(假设1)，以及变暖优先导致物种向极地转移的假设。其次，我们认为一个组合的热结构决定了它对气候变暖的反应(假设2)。特别是，我们假设，移民拥有比先前存在的群落平均水平更温暖的意识到的热生态位；升高的温度超过其温度上限的物种普遍存在灭绝；物种丰度的增加或减少是由它们各自先前存在的热生态位预测的。第三，我们探讨了植物群组合的组成和热结构的变化是否分别在热带和温带物种的暖缘堆积处最为明显(假设3)。在这方面，我们预测，当地种群损失优先发生在最温暖亲和性物种比例较高的群落中，而迁徙可以忽略不计；第二大种群损失位于温带物种向赤道方向的分布边缘；这一暖温带还接受热带物种的大量迁徙，导致群落内动物群周转的高峰。了解热生态位的作用，我们期望提供关于海洋生态系统在多大程度上保持凝聚力或发生转变的知识，包括在面对气候变化时，移民或新进化的物种取代现有物种。