A REVIEW OF THE IMPACT OF EXTREME ENVIRONMENTAL FACTORS ON EARTHWORM ACTIVITIES AND THE FEEDBACK ON THE CLIMATE

Abstract

Soils support a diverse range of organic life and provide several ecosystem functions and services that allow terrestrial life to thrive. Earthworms influence greenhouse gas (GHG) emissions from the soil both biologically (via respiration and litter modification) and physically (via increased macroporosity and altered air and water movement pathways). They improve soil carbon sequestration but also actively contribute to the release of major greenhouse gases. Shifting geographical ranges of earthworms due to changes in climatic conditions might affect the composition, structure and function of the soil ecosystem. This review examines the possible effects of the projected change in climate on earthworm communities and resulting implications for soil GHGs due to changes in environmental endpoints such as temperature and moisture. Earthworm activity, abundance, and biomass increase as soil moisture content increases, but drought and flooding reduce earthworm productivity. Climate change is likely to exacerbate earthworm invasions at higher latitudes and altitudes. However, because higher temperatures inhibit earthworm activities during droughts, anticipated warmer and drier climates may impede earthworm invasions. Climate change may disrupt the delicate balance between carbon sequestration and greenhouse gas emissions from soil in the coming century, but there are currently insufficient field studies to back up these prognostications.