Greenhouse plant-soil feedback experiment at Cedar Creek Ecosystem Science Reserve

We conducted a reciprocal greenhouse experiment to examine how the growth of prairie grass species depended on the soil communities conditioned by conspecific or heterospecific plant species in the field. The source soil came from monocultures in a long-term competition experiment (LTCE, Cedar Creek Ecosystem Science Reserve, MN, USA). Within the LTCE, six species of perennial prairie grasses were grown in monocultures or in eight pairwise competition plots for 12 years under conditions of low and high soil nitrogen availability. In six cases, one species clearly excluded the other; in two cases, the pair appeared to coexist. In year 12, we gathered soil from all 12 soil types (monocultures of six species by two nitrogen levels) and grew seedlings of all six species in each soil type for seven weeks.