Multidecadal changes in coastal benthic species composition and ecosystem functioning occur independently of temperature-driven community shifts

• Published in: Global Change Biology
• Main Authors: Armitage, Phoebe, Burrows, Michael T., Rimmer, James E.V., Blight, Andrew J., Paterson, David M.
• Other Authors: University of St Andrews.University of St Andrews, University of St Andrews.School of Biology, University of St Andrews.Scottish Oceans Institute, University of St Andrews.Sediment Ecology Research Group, University of St Andrews.St Andrews Sustainability Institute, University of St Andrews.Coastal Resources Management Group, University of St Andrews.Marine Alliance for Science & Technology Scotland
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2024
• Subjects: Biological indicators; Climate warming; Community ecology; Ecological shifts; Ecosystem dynamics; Ecosystem stability; Resilience; Thermal adaptation; Global and Planetary Change; Environmental Chemistry; Ecology; General Environmental Science; DAS; MCC; Arctic
• Online Access: https://hdl.handle.net/10023/30465; https://doi.org/10.1111/gcb.17482

Funding: The authors sincerely appreciate the support and contributions of two European Horizon Projects: ‘Ecological Tipping Cascades in the Arctic Seas’ (ECOTIP), Grant No 869383 and ‘Advancing understanding of Cumulative Impacts on European marine biodiversity, ecosystem functions and services for human wellbeing’ (ACTNOW), Grant No 101060072. Rising global temperatures are often identified as the key driver impacting ecosystems and the services they provide by affecting biodiversity structure and function. A disproportionate amount of our understanding of biodiversity and function is from short-term experimental studies and static values of biodiversity indices, lacking the ability to monitor long-term trends and capture community dynamics. Here, we analyse a biennial dataset spanning 32 years of macroinvertebrate benthic communities and their functional response to increasing temperatures. We monitored changes in species' thermal affinities to examine warming-related shifts by selecting their mid-point global temperature distribution range and linking them to species' traits. We employed a novel weighted metric using Biological Trait Analysis (BTA) to gain better insights into the ecological potential of each species by incorporating species abundance and body size and selecting a subset of traits that represent five ecosystem functions: bioturbation activity, sediment stability, nutrient recycling and higher and lower trophic production. Using biodiversity indices (richness, Simpson's diversity and vulnerability) and functional indices (richness, Rao's Q and redundancy), the community structure showed no significant change over time with a narrow range of variation. However, we show shifts in species composition with warming and increases in the abundance of individuals, which altered ecosystem functioning positively and/or non-linearly. Yet, when higher taxonomic groupings than species were excluded from the analysis, there was only a weak increase in the measured change in community-weighted average ...