Climate change and defoliation interact to affect root length across northern temperate grasslands

1. Grassland plants, especially their root systems, are dynamic and can buffer changes resulting from exposure to multiple stressors; however, the interactive stressor effects on root dynamics and associated aboveground growth are poorly understood.

2. Here, we examine the effects of changed precipitation and air temperature, and defoliation intensity on root length dynamics and aboveground biomass using the third year data from a multifactor experiment conducted across three northern temperate grasslands.

3. We found that root length was more sensitive to the changes in environmental and management conditions than root mass, demonstrating the importance of root length as an indicator of rapid root system changes. Across all sites, warming, altered precipitation, and defoliation intensity interacted to affect root length while aboveground biomass was only affected by defoliation intensity, indicating that the root system was more responsive than aboveground biomass when climatic c...