PMID- 32564355 OWN - NLM STAT- MEDLINE DCOM- 20210223 LR - 20210223 IS - 1939-9170 (Electronic) IS - 0012-9658 (Linking) VI - 101 IP - 10 DP - 2020 Oct TI - Trait-environment relationships differ between mixed-species flocking and nonflocking bird assemblages. PG - e03124 LID - 10.1002/ecy.3124 [doi] AB - Hypotheses about the mechanisms of community assembly suggest that biotic and abiotic filters constrain species establishment through selection on their functional traits. It is unclear how differences in traits influence the niche dimensions of closely related bird species when they coexist in spatiotemporally heterogeneous environments. Further, it is necessary to take into account their participation in mixed-species flocks, social systems that can include both competition and facilitation. For 6 yr, we conducted counts of forest bird species and took measurements of environmental variables along an elevational gradient in the Nanling Mountains, China. To disentangle different deterministic and historical/stochastic processes between flocking and nonflocking bird assemblages, we first compared phylogenetic and functional structure, and community-weighted mean trait values (CWM). We further assessed elevational variations in trait-environment relationships. We found that the flocking and nonflocking bird assemblages were structured by environmental gradients in contrasting ways. The nonflocking assemblage showed a strong change from over-dispersed to clustered community structure with increasing elevations, consistent with the strong selective pressures of a harsh environment (i.e., environmental filtering). The nonflocking assemblage also displayed significant trait-environment relationships in bivariate correlations and multivariate ordination space, including specific morphological and foraging traits that are linked to vegetation characteristics (e.g., short trees at high elevations). By contrast, flocking birds were more resilient to habitat change with elevation, with relatively consistent community membership, and showed fewer trait-environment associations. CWM of traits that are known to be associated with species' propensity to join mixed-species flocks, including small body size and broad habitat specificity, were linked to the flocking assemblage consistently across the elevational gradient. Collectively, our trait-based analyses provide strong evidence that trait-environment relationships differ between flocking and nonflocking bird assemblages. Besides serving as bellwethers of changing environments, emergent properties of flock systems may increase the resilience of animal communities undergoing environmental change. Mixed-species flocks present an ideal model with which to explore cooccurrence of closely related species, because habitat filtering may be buffered, and the patterns observed are therefore the outcomes of species interactions including both competition and facilitation. CI - (c) 2020 by the Ecological Society of America. FAU - Zhang, Qiang AU - Zhang Q AUID- ORCID: 0000-0001-9440-2796 AD - Guangdong Key Laboratory of Animal Conservation and Resource Utilization, Guangdong Public Laboratory of Wild Animal Conservation and Utilization, Guangdong Institute of Applied Biological Resources, Guangdong Academy of Science, Guangzhou, 510260, China. FAU - Holyoak, Marcel AU - Holyoak M AD - Department of Environmental Science and Policy, University of California, Davis, California, 95616, USA. FAU - Goodale, Eben AU - Goodale E AD - Guangxi Key Laboratory of Forest Ecology and Conservation, College of Forestry, Guangxi University, Nanning, 530004, China. FAU - Liu, Zhifa AU - Liu Z AD - Nanling National Nature Reserve, Shaoguan, 512727, China. FAU - Shen, Yong AU - Shen Y AD - Guangdong Key Laboratory of Animal Conservation and Resource Utilization, Guangdong Public Laboratory of Wild Animal Conservation and Utilization, Guangdong Institute of Applied Biological Resources, Guangdong Academy of Science, Guangzhou, 510260, China. FAU - Liu, Jiajia AU - Liu J AUID- ORCID: 0000-0002-9778-060X AD - South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650, China. FAU - Zhang, Min AU - Zhang M AD - Guangdong Key Laboratory of Animal Conservation and Resource Utilization, Guangdong Public Laboratory of Wild Animal Conservation and Utilization, Guangdong Institute of Applied Biological Resources, Guangdong Academy of Science, Guangzhou, 510260, China. FAU - Dong, Anqiang AU - Dong A AD - College of Life Sciences, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, China. FAU - Zou, Fasheng AU - Zou F AD - Guangdong Key Laboratory of Animal Conservation and Resource Utilization, Guangdong Public Laboratory of Wild Animal Conservation and Utilization, Guangdong Institute of Applied Biological Resources, Guangdong Academy of Science, Guangzhou, 510260, China. LA - eng GR - 2018GDASCX-0107/GDAS Special Project of Science and Technology Development/ GR - 2020GDASYL-20200103098/GDAS Special Project of Science and Technology Development/ GR - 31670445/National Natural Science Foundation of China/ GR - 31672265/National Natural Science Foundation of China/ GR - 2020/Ecological Protection Engineering Program of Nanling National Nature Reserve/ GR - 2016A030310312/Guangdong Provincial Science and Technology Program/ GR - 2018B030324001/Guangdong Provincial Science and Technology Program/ GR - 2019A1515011003/Guangdong Provincial Science and Technology Program/ GR - 2019B121202006/Guangdong Provincial Science and Technology Program/ PT - Journal Article PT - Research Support, Non-U.S. Gov't DEP - 20200723 PL - United States TA - Ecology JT - Ecology JID - 0043541 SB - IM MH - Animals MH - *Birds MH - China MH - *Ecosystem MH - Phenotype MH - Phylogeny OTO - NOTNLM OT - Nanling Mountains OT - body size OT - community assembly OT - environmental filtering OT - habitat specificity OT - mixed-species bird flocks OT - positive interactions OT - trait convergence EDAT- 2020/06/22 06:00 MHDA- 2021/02/24 06:00 CRDT- 2020/06/22 06:00 PHST- 2020/01/01 00:00 [received] PHST- 2020/04/06 00:00 [revised] PHST- 2020/05/05 00:00 [accepted] PHST- 2020/06/22 06:00 [pubmed] PHST- 2021/02/24 06:00 [medline] PHST- 2020/06/22 06:00 [entrez] AID - 10.1002/ecy.3124 [doi] PST - ppublish SO - Ecology. 2020 Oct;101(10):e03124. doi: 10.1002/ecy.3124. Epub 2020 Jul 23.