A study published today in Nature Ecology and Evolution sheds new light on the evidence for how climatic warming affects the seasonal timing within terrestrial, freshwater and marine food webs.
The study synthesises over 100 terrestrial and aquatic studies around the world that quantify the changes in seasonal timing (phenology) of predator and prey in a warming climate.
Global warming is often suggested to lead to changes in phenology that differ between trophic levels, leading to the asynchronous appearance of predator and prey. Mismatched seasonal timing has long been thought to impact negatively on predator populations. The new work systematically examined the evidence for this so-called “match-mismatch hypothesis” and found surprisingly few studies had actually measured all of its components.
Dr Angus Atkinson from Plymouth Marine Laboratory, who contributed to the study, explains: “The shift in the seasonal timing of annually occurring events, such as nesting in birds and migrations in fish, is one of the prevailing responses to a warming climate – the tendency is for these to become earlier under warming. But we still don’t properly know how these shifts affect food webs; some ecologists suggest that they de-synchronise the coupling between predators and prey. Our study shows that while this is sometimes the case, the evidence is very incomplete and we make a series of recommendations on how the evidence base can be improved”
The study also notes that almost all the reviewed research was conducted in Europe and North America and most were focused on terrestrial secondary consumers. The paper concluded with six research priorities for the future: studies to consider the full causal chain; increase evidence for aquatic systems; consider other environmental drivers; increase the geographic spread of studies; enhance the role of citizen scientists to contribute to studies, and establish a common language.
This study was a collaboration between University of Edinburgh, PML, University of Leeds, UK Centre for Ecology & Hydrology, Aarhus University, University of Exeter, RSPB Centre for Conservation Science, Lund University, British Trust for Ornithology, University of Cambridge, Norwegian University of Science and Technology, University of Bergen, University of Sheffield, University of Oxford & the Zoological Society of London.