LITTER DECOMPOSITIQN RATES IN HORQIN SANDY LAND, NORTHERN CHINA: EFFECTS OF HABITAT AND LITTER QUALITY.

Litters of three dominant shrubs were chosen to assess the influence of habitat and litter quality on litter decomposition rates in Horqin Sandy Land, Northern China. Litter in 20 x 25 cm litter bags of 2 x 2 mm mesh size were added to the depth of 0 cm and 10 cm in the sand soil along a habitat gradient of sand dune stabilization and restoration: mobile dune, semi-mobile dune, semi-fixed dune and fixed dune. Litter mass loss was measured five times to evaluate changes in decomposition rates. Results showed that litter decomposition rates increased along the habitat gradient of sandy dune restoration, and litter in fixed dune decomposed significantly faster than that in mobile dune. A. halodendron litter decomposed significantly faster than C. microphylla and S. gordejevii litter in sandy dunes. Litter decomposition rates increased about 5% per month from May to September. Litters buried 10 cm deep decomposed much faster than that on the soil surface. Pearson's correlation analysis showed that residual lignin content and the lignin:C ratio were significantly and positively correlated with decomposition rates, indicating that lignin content plays an important role in litter decomposition rates. [ABSTRACT FROM AUTHOR]