Soil heterogeneity and species composition jointly affect individual variation of three forage grasses

Abstract

AimsIndividual variation (IV) plays an important role in driving the structure and function of plant communities, especially when plants growing in heterogeneous soils. However, the joint effects of soil heterogeneity and species composition on IV are still unclear. MethodsA controlled experiment was done, where four soil heterogeneity levels were developed by filling resource-rich and resource-poor substrates in pots with different patch sizes (i.e. fine, small, medium and large), and seven types of species compositions were derived from all the possible combinations of three forage grasses (i.e. Festuca elata, Bromus inermis and Elymus breviaristatus). Coefficient of variation (CV) of plant height and chlorophyll content were applied to quantify IV. ResultsCV first increased and then decreased with increasing patch size. Moreover, CV in monocultures was on average lower than mixtures. Furthermore, patch size and species composition jointly affected IV, where B. inermis growing together with E. breviaristatus had relatively higher CV of plant height than that in other compositions, while F. elata growing together with E. breviaristatus had relative higher CV of chlorophyll content than that in other compositions, and both of these patterns were found in pots with small patch size. ConclusionsSoil heterogeneity and species composition jointly affected individual variation of plants. More plant traits such as plant biomass should be considered to further explore the effects of soil heterogeneity on individual variation. Such results can be applied in the restoration of degraded grasslands.