Responses of Macroinvertebrate Assemblages to Flow in the Qinghai‐Tibet Plateau: Establishment and Application of a Multi‐Metric Habitat Suitability Model

• Published in: Water resources research 2022-05, Vol.58 (5), p.n/a
• Main Authors: Zhou, X. D., Xu, M. Z., Lei, F. K., Zhang, J. H., Wang, Z. Y., Luo, Y. Y.
• Format: Article
• Language: English
• Subjects: Alpine environments; alpine rivers and streams; Anthropogenic factors; Aquatic ecosystems; Biota; Climate change; Climate models; Conservation; Datasets; Ecosystem conservation; Ecosystem services; Ecosystems; Environmental conditions; flow variations; habitat suitability index; Habitats; Human influences; Hydrodynamics; Instream flow; integrated river management; Macroinvertebrates; Modelling; Plateaus; Regression analysis; River management; Rivers; species‐environment relationships; Statistical analysis; Streams; Taxa; Zoobenthos
• ISSN: 0043-1397; 1944-7973
• DOI: 10.1029/2021WR030909

Anthropogenic impacts and climate change modify instream flow, altering ecosystem services and impacting on aquatic ecosystems. Alpine rivers and streams on the Qinghai‐Tibet Plateau (QTP) are especially vulnerable to disturbance owing to limited taxonomic complexity. The effects of flow have been studied using specific taxa, yet the flow‐biota relationships of assemblages are poorly understood. A multi‐metric habitat suitability model (MM‐HSM) was developed using integrated measures of entire macroinvertebrate assemblages to substitute for habitat suitability indices derived from individual taxa. The MM‐HSM was trained using macroinvertebrates data from three alpine rivers on the QTP, including the Yarlung Tsangpo, the Nujiang, and the Bai rivers, and then validated using data from a forth alpine river (the Lanmucuo). The model produced predictions using the training data set (R2 = 0.587) and the validation data set (R2 = 0.489). By coupling the MM‐HSM with hydrodynamic simulations, the relationship between weighted usable area and flow (0.11–1.99 m3 s−1) for macroinvertebrate assemblages was established, whereby a unimodal response pattern was observed for the Lanmucuo River. This contrast with monotonically positive or negative relationships observed for individual indicator taxa further supported our hypothesis that the response pattern of entire macroinvertebrate assemblages to flow would differ from responses of individual indicator taxa. The MM‐HSM provides a novel framework to quantify flow‐biota relationships, which is a useful approach for integrated river management. Plain Language Summary Anthropogenic impacts and climate change modify the flow of rivers. Aquatic ecosystems in alpine rivers, such as those on the Qinghai‐Tibet Plateau (QTP), are especially vulnerable to flow variations. Effects of flow on the fauna have been studied mostly in individual species, whereas the response of entire communities to flow is poorly understood. In this study, we collect macroinvertebrates and measure environmental conditions in four alpine rivers on the QTP. We propose an index to describe the integrated status of macroinvertebrate communities by using multivariate statistical and regression analyses, and couple this index with the hydrodynamic simulation to model how entire macroinvertebrate communities respond to flow in a representative alpine river. Our results show that macroinvertebrates respond first positively then negatively to flow, yielding a su