Plant litter effects inversely on air and soil temperatures in Leymus chinensis grassland, Northeast China

Plant litter is an important component of grassland ecosystem, and has significantly reduced by human activities. These changes in natural systems cause variations in air and soil temperatures. This study described an experiment that different amounts of plant litter effect on air and soil temperatures in Songnen grassland, Northeast China. Plant litter reduction resulted in decreasing air temperature at 10 cm above surface and increasing soil temperature at 20 cm below soil surface in the growing season. The mean, maximum, and amplitude of air temperatures at 10 cm above soil surface of plots with plant litter were significantly higher than plots without litter. The mean, extreme, and amplitude of soil temperatures at 20 cm depth increased significantly as plant litter decreased in the growing season. Temperature differences between air and soil temperatures decreased significantly as plant litter decreased in the growing season. The results show that the soil and air temperatures respond differently to plant litter, and the changing temperature difference between air and soil temperatures has the potential to produce complex effects on grassland ecosystem.