iES Landau, Institute for Environmental Sciences, RPTU Kaiserslautern-Landau, Fortstraße 7, D-76829 Landau in der Pfalz, Germany; University of Applied Sciences Trier, Environmental Campus Birkenfeld, Post Box 1380, 55761 Birkenfeld, Germany; University of Duisburg-Essen, Faculty of Biology, Universitätsstrasse 5, D-45141 Essen, Germany.
Environmental Archaeology Lab, Department of Historical, Philosophical and Religious Studies, Umeå University, Biblioteksgränd 3, 907 36 Umeå, Sweden; Norwegian Institute for Nature Research (NINA), Sognsveien 68, 0855 Oslo, Norway.
Sci Total Environ. 2023 Sep 1;889:164278. doi: 10.1016/j.scitotenv.2023.164278. Epub 2023 May 19.
Climate warming can lead to a replacement of species that favour cold temperatures by species that favour warm temperatures. However, the implications of such thermic shifts for the functioning of ecosystems remain poorly understood. Here, we used stream macroinvertebrate biological and ecological traits to quantify the relative contribution of cold, intermediate and warm temperature-adapted taxa to changes in community functional diversity (FD) using a dataset of 3781 samples collected in Central Europe over 25 years, from 1990 to 2014. Our analyses indicated that functional diversity of stream macroinvertebrate communities increased over the study period. This gain was driven by a net 39 % increase in the richness of taxa that favour intermediate temperatures, which comprise the highest share in the community, and to a 97 % increase in the richness of taxa that favour warm temperatures. These warm temperature-adapted taxa displayed a distinct and more diverse suite of functional traits compared to the cold temperature-adapted group and thus contributed disproportionately to local FD on a per-taxon basis. At the same time, taxonomic beta-diversity declined significantly within each thermal group, in association with increasing local taxon richness. This study shows that over recent decades, small low-mountain streams in Central Europe have experienced a process of thermophilization and increasing functional diversity at local scales. However, a progressive homogenisation occurred at the regional scale, with communities converging towards similar taxonomic composition. As the reported increase in local functional diversity can be attributed mostly to the intermediate temperature-adapted taxa and a few expanding warm temperature-adapted taxa, these patterns could mask more subtle loss of sensitive cold temperature-adapted taxa with irreplaceable functional traits. In light of increasing climate warming, preservation of cold habitat refuges, should be considered a priority in river conservation.
气候变暖可能导致喜低温物种被喜高温物种取代。然而，这种热转移对生态系统功能的影响仍知之甚少。在这里，我们使用溪流大型无脊椎动物生物和生态特征，使用 1990 年至 2014 年在中欧收集的 3781 个样本的数据集，量化了对社区功能多样性（FD）变化的冷、中温和暖温度适应类群的相对贡献。我们的分析表明，溪流大型无脊椎动物群落的功能多样性在研究期间增加。这种增益是由中间温度偏好类群的丰富度净增加 39%驱动的，中间温度偏好类群在群落中占比最高，而温暖温度偏好类群的丰富度增加了 97%。与适应寒冷温度的类群相比，这些适应温暖温度的类群表现出截然不同且更多样化的功能特征，因此在每个分类群的基础上对当地 FD 的贡献不成比例。与此同时，在每个热群内，分类多样性显著下降，与当地分类群丰富度的增加有关。这项研究表明，在最近几十年中，中欧的小低山水流经历了一个嗜热化过程和局部功能多样性的增加。然而，在区域尺度上发生了逐渐的同质化，随着群落向相似的分类组成趋同。由于报道的局部功能多样性增加主要归因于中间温度适应类群和少数扩张的温暖温度适应类群，这些模式可能掩盖了具有不可替代功能特征的敏感低温适应类群更微妙的损失。鉴于气候变暖的加剧，应优先考虑保护冷生栖息地，作为河流保护的重点。
