Degradation of Organic Matter from Terrestrial Plants in Hongfeng Lake Basin under Different Redox Conditions
Degradation of organic matter in plant residues is a major process of nutrient cycling in ecosystems.In this study,terrestrial plants in the Hongfeng Lake basin were selected to conduct one-year simulation experiments of organic matter degradation under differ-ent redox conditions.The Power model was used to characterize the degradation of organic matter and reveal the main factors affecting the degradation of organic matter in plant residues.Generally,the proportion of residual biomass from decomposed C3 plants in anoxic and oxic conditions differed very little,ranging respectively from 64％to 77.3％and 59.5％to 76.8％.The proportion of residual bio-mass from decomposed C4 plants ranged from 42.6％to 57.4％and 31.2％to 43.5％,showing a higher degree of degradation under oxic conditions than under anoxic conditions.The higher degradation degree and rate of C4 than C3 plant residues mainly reflected that C4 plants had higher hemicellulose,cellulose and lower lignin contents.The composition and structure of organic matter in plant resi-dues had significant effects on the degradation rate,among which the hemicellulose content had the most remarkable impact.The high-er the hemicellulose content was,the greater the plant degradation rate constant.The degradation rate constants of C3 plant residues differed considerably,showing a pattern of Masson pine＞Chinese parasol＞rice under different redox conditions.The degradation rates of C4 plant residues varied significantly with orders of corn＞Bermudagrass＞thatch under anoxic conditions and corn＞thatch＞Bermuda-grass under oxic conditions.
NETL
NSTL
万方数据
