国家自然科学基金项目(31460135)；广西自然科学基金项目（2020GXNSFAA297092）广西第十八批“十百千人才工程”专项资金；*通讯作者：Email: tghe118@163. com.
1.Agricultural Resources and Environment Research Institute,Guangxi Academy of Agricultural Sciences,Nanning;2.Landscape College,Hunan Polytechnic of Environment and Biology
Carbon (C), nitrogen (N) and phosphorus (P) stoichiometry in plants, litter, soil, and microbes in degraded vegetation communities were studied to provide a scientific basis for vegetation restoration and reconstruction for the karst area of southwest China. Five degraded vegetation communities in the karst area of northwest Guangxi were selected. C, N, and P contents of plant leaves, litter, soil and microbial biomass were determined. The stoichiometric characteristics of plant, litter, soil, microbial biomass and their relationships and the homeostasis of plant were analyzed. With the intensified degradation of the vegetation community, the leaf C, N, P content, N:P, litter N:P, and microbial biomass C decreased significantly, while the leaf C:N and C:P increased significantly and N:P of plant leaves was less than 14 in all communities. Litter N, P contents, soil C, N, P contents, microbial biomass N, P contents showed a trend of increase firstly and then significantly decreased with the intensified degradation degrees. There was no significant difference in soil N:P and microbial biomass C:N among communities with different degradation degrees. Leaf N and P were significant or extremely significantly positively correlated with soil N and P. Leaf C:P was significant or extremely significantly positively correlated with soil C:N,C:P, and N:P. The leaf N:P and litter N, N:P, as well as leaf C, N, P contents and microbial biomass C content were significantly positively correlated. The leaf N, P and soil C:P, N:P, leaf C:N and soil C, N, leaf C:P and soil N, P, leaf N:P and soil P showed significantly or extremely significantly negative correlations. The average values of the homeostasis index H of plant leaf N and P in the karst area were 2.74 and 2.31, respectively, which indicated the weak steady state. The H value of leaf N:P was 5.14, implying a steady state. Compared with N and P, the element ratio N:P had higher internal stability. The degradation of karst community caused the change of C, N, P contents and their stoichiometry. Plant N:P ratio showed somewhat homeostasis when soil nutrient changed, indicating that plants had a good adaptability to karst degraded ecosystem. The degradation resulted in increased limitation of plant growth by N. Our results suggest that soil N availability is critical for vegetation restoration in the karst areas of northwest Guangxi.
俞月凤,何铁光,曾成城,宋同清,彭晚霞,韦彩会,苏利荣,张野,范适.喀斯特区不同退化程度植被群落植物-凋落物-土壤-微生物生态化学计量特征.生态学报,,(). http://dx. doi. org/10.5846/stxb202007031730复制