Climate Change Effects on Arbuscular Mycorrhizal Fungi and Prairie Plants Along a Mediterranean Climate Gradient
Wilson, H. E.. 2012. M.Sc. University of Oregon
Abstract
Arbuscular mycorrhizal fungi (AMF) provide numerousservices to their plant
symbionts. Understanding the effects of climate change on AMF, and the resulting plant
responses, is a crucial factor in predicting ecosystem responses on a global scale. We
used a manipulative climate change experiment embedded within a natural climate
gradient in Oregon and Washington to examine how the effects of future climate change
on AMF-plant symbioses are mediated by soil water availability, soil nutrient
availability, and vegetation dynamics.
Using structural equation modeling, we found that the direct effect of increasing
temperatures was to decrease AMF colonization. Indirect effects of temperature,
mediated through other variables, canceled each other out. However, future shifts in these
relationships could either exacerbate or mitigate the negative direct effect of temperature.
As ecosystems in Mediterranean climates experience more intense droughts and heavier
rains, decreases in AMF colonization could have substantial consequences for plant
communities and ecosystem function.
