Plant clustering generates negative plant-soil feedback without changing the spatial distribution of soil fauna

The spatial distribution of resources affects ecological processes at alllevels of biological organization. However, it remains to be tested how thespatial configuration of belowground resources affects the communitydynamics of soil organisms and resulting plant-soil feedbacks. We used Agrostis stolonifera plants in different spatial configurations inmesocosms to study the dispersal patterns of soil nematodes and rotifers.Plant-soil feedbacks were later assessed by re-sowing the mesocosms withLolium perenne and Plantago lanceolata after removing all the initial A. stolonifera plants from the mesocosms. Bacterial-feeding nematodes androtifers spread fast, whereas plant-feeding nematodes barely dispersed fromthe release sites. These spread patterns of nematodes and rotifers dependedon the life-history traits and not on the spatial pattern of the plants.However, more clustered plants developed a higher total biomass and caused a reduced growth of the subsequent vegetation. Our results demonstrate that the mere spatial pattern of a single plantspecies can alter the strength of plant-soil feedbacks. This has importantimplications for understanding the impact of planting or replanting schemesand other changes in the spatial configuration of plants on long-termvegetation development and succession.

Automated summary

The spatial configuration of belowground resources can affect the community dynamics of soil organisms and resulting plant-soil feedbacks. The spread patterns of nematodes and rotifers were determined by their life-history traits rather than the spatial pattern of the plants. However, more clustered plants resulted in a higher total biomass and reduced growth of subsequent vegetation. These findings have important implications for understanding the impact of spatial configuration changes on long-term vegetation development and succession.