Detection of changes in litter nutrients in Caragana korshinskii following the decomposition process in desertified grassland ecosystems using the litter bag method

An investigation of the elemental nutrient residual rate of Cartagena korshinskii shrub litter was conducted using the litter bag method (4, 2, 0.01 mm) in Yanchi County, Ningxia. The results showed: 1) At 210 days, there was a " release” of litter N and K, whereas there was an " accumulation” of litter P and cellulose in C. korshinskii shrub litter within litter bags with three size meshes. Regarding lignin, there was an " accumulation” in the large shrub microhabitats, whereas there was a " release” in the microhabitats with very small-, small-, and medium-sized shrubs in the 0.01 mm mesh litter bags only. 2) There were no significant (P > 0.05) differences in residual rate in the litter between three types of meshes in the microhabitats of small, medium, and large-sized shrubs. In the microhabitats of very small-sized shrubs, however, the residual rate of litter N, P, and K was in the order of 0.01 mm (–32.99%, 121.03%, –2.04%) > 4 mm (–63.64%, 14.31%, –6.95%) > 2 mm (–75.47%, 9.79%, –36.32%), that of lignin was 0.01 mm (–10.56%) > 2 mm (–46.18%) > 4 mm (–49.59%), and that of cellulose was 2 mm (160.44%) > 4 mm (97.80%) > 0.01 mm (21.56%). It was concluded that there were similar changes in litter nutrient elements N, K, P, and cellulose in microhabitats of very small, small, medium, and large shrubs in all three mesh sizes. However, there were interactive effects of soil faunal groups and shrub canopy sizes on litter lignin following the decomposition process in desertified grassland ecosystems of Ningxia.