Using the Rainfall Exclusion Experiment (REX) within the KBS LTER, researchers found that nematode communities are more stable in early successional landscapes than agricultural ones during drought. This study highlights the importance of plant diversity for resilient soil ecosystems under environmental change.
As farmers adopt new strategies to cope with increasingly extreme weather events, such as heatwaves and droughts, understanding the mechanisms behind resiliency in agricultural systems is critical. While it’s well-established that drought harms crop production, less is known about how the soil community responds to these changes.
New research from the LTER, led by former MSU graduate student Tvisha Martin, investigated the effects of drought on free-living nematode communities (also known as roundworms).
Nematodes are important for two key reasons: 1) they are strong indicators of soil food web structure and broader ecosystem functions, such as nutrient cycling and resilience to disturbance, and 2) they are highly responsive to changes in management practices. These characteristics make nematodes an ideal model for examining how drought conditions might impact soil health and ecosystem function.
Dr. Martin used two land types in the Main Cropping Systems Experiment (MCSE) that represent different levels of plant biodiversity: early successional systems with many plant species present, and no-till annual row-crop systems with a single plant crop species present. She used rainout shelters from the Rainfall Exclusion Experiment (REX) to simulate drought in both systems. Nematode communities were surveyed before, during, and after drought conditions. The goal was to assess how plant biodiversity influences nematode resilience to drought and how the immediate alleviation of drought impacts nematodes in these contrasting systems.
The results show that early successional systems, where perennial plants and greater biodiversity are present, create conditions that support stable nematode communities. In these systems, nematode populations showed little to no change in response to drought. In contrast, in no-till annual systems, nematode communities underwent significant shifts during drought. This suggests that diverse plant communities foster underground communities that are more resilient to drought, and provide a more stable environment for nematodes compared to agricultural systems.
What does this mean for agriculture? To build more drought-resistant farming systems, we can’t rely solely on no-till practices. Integrating diverse, perennial plant communities – such as prairie strips – into agricultural management is key. Such practices are more likely to foster a stable soil food web, which in turn supports healthy, resilient agroecosystems capable of maintaining productivity under the pressures of climate change.
