Climatic effects on the synchrony and stability of temperate headwater invertebrates over four decades

Important clues about the ecological effects of climate change can arise from understanding the influence of other Earth-system processes on ecosystem dynamics but few studies span the inter-decadal timescales required. We, therefore, examined how variation in annual weather patterns associated with the North Atlantic Oscillation (NAO) over four decades was linked to synchrony and stability in a metacommunity of stream invertebrates across multiple, contrasting headwaters in central Wales (UK).
Prolonged warmer and wetter conditions during positive NAO winters appeared to synchronise variations in population and community composition among and within streams thereby reducing stability across levels of ecological organisation. This climatically-mediated synchronisation occurred in all streams irrespective of acid-base status and land use, but was weaker where invertebrate communities were more functionally diverse. Wavelet linear models indicated that variation in the NAO explained up to...