title: Spatial heterogeneity of plant-soil feedback affects root interactions and interspecific competition.
abstract: Plant-soil feedback is receiving increasing interest as a factor influencing plant competition and species coexistence in grasslands. However, we do not know how spatial distribution of plant-soil feedback affects plant below-ground interactions. We investigated the way in which spatial heterogeneity of soil biota affects competitive interactions in grassland plant species. We performed a pairwise competition experiment combined with heterogeneous distribution of soil biota using four grassland plant species and their soil biota. Patches were applied as quadrants of 'own' and 'foreign' soils from all plant species in all pairwise combinations. To evaluate interspecific root responses, species-specific root biomass was quantified using real-time PCR. All plant species suffered negative soil feedback, but strength was species-specific, reflected by a decrease in root growth in own compared with foreign soil. Reduction in root growth in own patches by the superior plant competitor provided opportunities for inferior competitors to increase root biomass in these patches. These patterns did not cascade into above-ground effects during our experiment. We show that root distributions can be determined by spatial heterogeneity of soil biota, affecting plant below-ground competitive interactions. Thus, spatial heterogeneity of soil biota may contribute to plant species coexistence in species-rich grasslands.
authors: Department of Experimental Plant Ecology, Institute for Water and Wetland Research, Radboud University Nijmegen, PO Box 9100, 6500, GL Nijmegen, the Netherlands.
authors: Marloes
authors: M
authors: Hendriks
authors: Department of Experimental Plant Ecology, Institute for Water and Wetland Research, Radboud University Nijmegen, PO Box 9100, 6500, GL Nijmegen, the Netherlands.
authors: Janneke M
authors: JM
authors: Ravenek
authors: Department of Experimental Plant Ecology, Institute for Water and Wetland Research, Radboud University Nijmegen, PO Box 9100, 6500, GL Nijmegen, the Netherlands.
authors: Annemiek E
authors: AE
authors: Smit-Tiekstra
authors: Department of Experimental Plant Ecology, Institute for Water and Wetland Research, Radboud University Nijmegen, PO Box 9100, 6500, GL Nijmegen, the Netherlands.|Nature Conservation and Plant Ecology, Wageningen University, PO Box 47, 6700 AA, Wageningen, the Netherlands.
authors: Jan Willem
authors: JW
authors: van der Paauw
authors: Department of Experimental Plant Ecology, Institute for Water and Wetland Research, Radboud University Nijmegen, PO Box 9100, 6500, GL Nijmegen, the Netherlands.
authors: Hannie
authors: H
authors: de Caluwe
authors: Department of Terrestrial Ecology, Netherlands Institute of Ecology, PO Box 50, 6700 AB, Wageningen, the Netherlands.|Laboratory of Nematology, Wageningen University, PO Box 8123, 6700 ES, Wageningen, the Netherlands.
authors: Wim H
authors: WH
authors: van der Putten
authors: Department of Experimental Plant Ecology, Institute for Water and Wetland Research, Radboud University Nijmegen, PO Box 9100, 6500, GL Nijmegen, the Netherlands.
authors: Hans
authors: H
authors: de Kroon
authors: Nature Conservation and Plant Ecology, Wageningen University, PO Box 47, 6700 AA, Wageningen, the Netherlands.
authors: Liesje
authors: L
authors: Mommer
mesh_terms: D018533:Biomass; D005246:Feedback; D018517:Plant Roots / Q000502:physiology*; D018520:Plant Shoots / Q000502:physiology; D006109:Poaceae / Q000502:physiology*; D012987:Soil; D013045:Species Specificity
chemical_list: D012987:Soil
keywords: coexistence; grasslands; plant-soil feedback; root competition; soil biota; soil heterogeneity