The effects of climatic fluctuations and extreme events on running water ecosystems

Research output: Contribution to journalArticle

Authors

  • Guy Woodward
  • Núria Bonada
  • Lee E. Brown
  • Russell G. Death
  • Isabelle Durance
  • Clare Gray
  • Sally Hladyz
  • Steve J. Ormerod
  • Ross M. Thompson
  • Samraat Pawar

Colleges, School and Institutes

External organisations

  • Imperial College London
  • Universitat Autònoma de Barcelona
  • University of Leeds
  • MASSEY UNIVERSITY
  • Cardiff University
  • School of Biological and Chemical Sciences Queen Mary University of London
  • Monash University
  • University of Fairbanks; Institute of Arctic Biology; Fairbanks Alaska 99611 USA
  • University of Canberra

Abstract

Most research on the effects of environmental change in freshwaters has focused on incremental changes in average conditions, rather than fluctuations or extreme events such as heatwaves, cold snaps, droughts, floods or wildfires, which may have even more profound consequences. Such events are commonly predicted to increase in frequency, intensity and duration with global climate change, with many systems being exposed to conditions with no recent historical precedent. We propose a mechanistic framework for predicting potential impacts of environmental fluctuations on running-water ecosystems by scaling up effects of fluctuations from individuals to entire ecosystems. This framework requires integration of four key components: effects of the environment on individual metabolism, metabolic and biomechanical constraints on fluctuating species interactions, assembly dynamics of local food webs, and mapping the dynamics of the meta-community onto ecosystem function. We illustrate the framework by developing a mathematical model of environmental fluctuations on dynamically assembling food webs. We highlight (currently limited) empirical evidence for emerging insights and theoretical predictions. For example, widely supported predictions about the effects of environmental fluctuations are: high vulnerability of species with high per capita metabolic demands such as large-bodied ones at the top of food webs; simplification of food web network structure and impaired energetic transfer efficiency; and reduced resilience and top-down relative to bottom-up regulation of food web and ecosystem processes. We conclude by identifying key questions and challenges that need to be addressed to develop more accurate and predictive bio-assessments of the effects of fluctuations, and implications of fluctuations for management practices in an increasingly uncertain world.

Details

Original languageEnglish
Article number20150274
JournalRoyal Society of London. Proceedings B. Biological Sciences
Volume371
Issue number1694
Publication statusPublished - 19 May 2016

Keywords

  • Biodiversity, Community assembly, Ecosystem functioning, Food webs, Metabolism, Resilience