Testing the Effect of Soil Heterogeneity on Arbuscular Mycorrhiza Fungi (AMF) Contribution to Plant Productivity

Most natural soils are heterogeneous and nutrient availability and soil structure change greatly over small distances. It is still unclear whether AMF are advantageous for plants under such hete-rogeneous soil conditions. The objective of this study was to determine whether diverse AMF com-munity support host plant community productivity in heterogeneous soil. It was also tested whe-ther soil heterogeneity affects plant productivity. This was carried out in a greenhouse experiment made up of two factors: soil heterogeneity and AMF richness. Soil heterogeneity was simulated by mixing three soil types (sand, field soil and organic soil) together (homogenous soil (HM)), mixing them partly (semi homogenous (SH)) or keeping the three soil types separate in three compart-ments within one pot (heterogeneous (HT)). AMF richness was simulated by adding no AMF, one of four different AMF species separately, or all four different AMF together. The pots were planted with a mixture of Trifolium pratense and Lolium multiflorum. There was no effect of soil heteroge-neity on total plant biomass. However, the biomass of the individual plant species was greatly af-fected by soil heterogeneity with Lolium being the most abundant in the heterogeneous soil and Trifolium being the most abundant in the homogenous soil. Total plant biomass did not increas