Effects of litter, seed position, and water availability on establishment of seedlings for two semiarid grass species

Abstract

We conducted a field investigation and controlled experiments in a glasshouse to determine how litter, seed position, and/or water supply affect seedling emergence and the establishment of two native grass species (Leymus chinensis (Trin.) Tzvel. and Bromus inermis Leyss) in northern China. Both water supply and seed position dramatically influenced seedling emergence and growth, as well as the accumulation of biomass for these two species. For L. chinensis, the quantity of litter had a significant impact on seedling survival, height increment, and biomass production when grown in either the glasshouse or the field while that component had little influence on B. inermis seedling emergence or survival. The effects of litter were physical but not biological or chemical, suggesting that this component is important only in the first year of seedling establishment. Therefore, longer-term experiments are probably necessary to examine the biological and chemical impacts that litter has on seedling performance.