Climate warming often results in species range shifts, biodiversity loss and accumulated climatic debts of biota (i.e. slower changes in biota than in temperature). Here, we analyzed the changes in community composition and temperature signature of stream invertebrate communities over 25 years (1990-2014), based on a large set of samples (n = 3782) over large elevation, latitudinal and longitudinal gradients in central Europe. Although warming was moderate (average 0.5 degrees C), we found a strong reorganization of stream invertebrate communities. Total abundance (+35.9%) and richness (+39.2%) significantly increased. The share of abundance (TA) and taxonomic richness (TR) of warm-dwelling taxa (TA: +73.2%; TR: +60.2%) and medium-temperature-dwelling taxa (TA: +0.4%; TR: +53%) increased too, while cold-dwelling taxa declined (TA: -61.5%,; TR: -47.3%). The community temperature index, representing the temperature signature of strearn invertebrate communities, increased at a similar pace to physical temperature, indicating a thermophilization of the communities and, for the first time, no climatic debt. The strongest changes occurred along the altitudinal gradient, suggesting that stream invertebrates use the spatial configuration of river networks to track their temperature niche uphill. Yet, this may soon come to an end due to the summit trap effect. Our results indicate an ongoing process of replacement of cold-adapted species by thermophilic species at only 0.5 degrees C warming, which is particularly alarming in the light of the more drastic climate warming projected for coming decades. (C) 2018 Elsevier B.V. All rights reserved.
1.Senckenberg Res Inst, Dept River Ecol & Conservat, Gelnhausen, Germany 2.Nat Hist Museum Frankfurt, Gelnhausen, Germany 3.Univ Duisburg Essen, Fac Biol, Essen, Germany 4.Goethe Univ, Inst Ecol Evolut & Divers, Frankfurt, Germany 5.Univ Canterbury, Sch Biol Sci, Christchurch, New Zealand 6.Univ Appl Sci Trier, Environm Campus Birkenfeld, Birkenfeld, Germany 7.Univ Duisburg Essen, Fac Biol, Dept Aquat Ecol, Essen, Germany
Recommended Citation:
Haase, Peter,Pilotto, Francesca,Li, Fengqing,et al. Moderate warming over the past 25 years has already reorganized stream invertebrate communities[J]. SCIENCE OF THE TOTAL ENVIRONMENT,2019-01-01,658:1531-1538