生态学报2018，Vol.38Issue(2)：678-688,11.DOI:10.5846/stxb201612132559
生物土壤结皮演替对土壤生态化学计量特征的影响
The effects of biological soil crust succession on soil ecological stoichiometry characteristics
摘要
Abstract
Biological soil crusts (biocrusts) are ubiquitous living surface covers in arid and semi-arid regions.The succession of biocrusts exerts significant influence on soil nutrient cycles owing to their functions of carbon and nitrogen fixation.Therefore,soil ecological stoichiometry characteristics are likely to be affected by the succession of biocrusts.To explore the effects of biocrusts on the contents of organic carbon (C),total nitrogen (N),total phosphorus (P),and their stoichiometric characteristics,biocrusts in six successional stages,totaling 59 sites,were chosen from the hilly Loess Plateau region.Biocrusts and subsoils (0-2 cm,2-5 cm,and 5-10 cm) were sampled at each site.The contents of C,N,and P were analyzed and their ratios were calculated.The results showed that biocrusts significantly affected the contents of C,N,and P,and their ratios,which resulted in differences between biocrusts and the soils beneath them.Further,the differences increased with the succession of the biocrusts.The contents of C,N,and P significantly increased in the biocrust layers,which were significantly higher than that of the subsoils (0-10 cm).The contents of C,N,and P in biocrusts increased by 161％,127％,and 9％,respectively,in the later successional stage compared with that in the earlier stage.The ratios of C/N,C/P,and N/P in biocrusts were all significantly higher than in the soils beneath them (0-10 cm).Variances of C/N were lower than that of C/P and N/P,with a range from 10.0 to 11.8.The C/P and N/P ratios in the later successional stage of biocrusts were 2.4 and 2.1 times as high as that in the earlier successional stage,respectively.The slope aspect was the major influencing factor for the ecological stoichiometry characteristics of biocrusts.The ratios of C/N,C/P,and N/P were positively correlated with moss biomass and negatively correlated with soil bulk density.The recovery of topsoil nutrients was improved owing to the succession of biocrusts and the improvement of recovery appeared to be limited to a maximum depth of 2 cm under the biocrusts.Owing to the significant influences of biocrust succession on soil nutrients and their stoichiometric characteristics,and the differences between biocrusts and their subsoil,biocrusts play a crucial role for ecological restoration in arid and semi-arid regions.The results reveal the contribution of biocrusts to nutrient cycles from the perspective of soil stoichiometric characteristics and the study provides scientific basis to the ecological restoration and management in arid and semi-arid regions.关键词
藓/藻/碳/氮/磷/生态恢复/干旱半干旱地区Key words
moss/cyanobacteria/carbon/nitrogen/phosphorus/ecological restoration/arid and semi-arid regions引用本文复制引用
高丽倩,赵允格,许明祥,孙会,杨巧云..生物土壤结皮演替对土壤生态化学计量特征的影响[J].生态学报,2018,38(2):678-688,11.基金项目
国家自然科学基金(41571268,41271298) （41571268,41271298）
