Knowledge about resource limitation to soil microbes is crucial for understanding ecosystem functions and processes, and for predicting ecosystem responses to global changes as well. Karst ecosystems are widespread in the world, and play a key role in regulating the global climate, however, the patterns of and mechanisms underlying microbial resource limitation in karst ecosystems remain poorly known. Here we investigated the microbial resource limitation in a karst region, by selecting four main land-use types, i.e. cropland, grassland, shrubland and secondary forest, in areas underlain by two lithology types, i.e. dolomite and limestone, in southwest China. Ecoenzymatic stoichiometry was used as an indicator of microbial resource limitation. Overall, soil microbes in karst ecosystems were more limited by carbon and phosphorus, rather than by nitrogen. Further analyses revealed that the patterns of carbon and phosphorus limitation were different among land-use or lithology types. Microbial carbon limitation was greatest in cropland and forest but lowest in grassland, and was greater under dolomite than under limestone. Microbial phosphorus limitation decreased from secondary forest to cropland under dolomite areas, but showed no difference among ecosystem types under limestone areas, indicating that lithology controls the pattern of microbial phosphorus limitation along the post-agriculture succession. Our study describes a general pattern of microbial resource limitation in karst ecosystems, and we suggest that lithologymay provide a new mechanism for explaining the variations of microbial resource limitation along the post-agriculture succession in different regions. (C) 2018 Elsevier B.V. All rights reserved.
1.Chinese Acad Sci, Inst Subtrop Agr, Key Lab Agroecol Proc Subtrop Reg, Changsha 410125, Hunan, Peoples R China 2.Chinese Acad Sci, Inst Subtrop Agr, Huanjiang Observat & Res Stn Karst Ecosyst, Huanjiang 547100, Guangxi, Peoples R China 3.Chinese Acad Sci, South China Bot Garden, Key Lab Vegetat Restorat & Management Degraded Ec, Guangzhou 510650, Guangdong, Peoples R China 4.Chinese Acad Sci, Guangdong Prov Key Lab Appl Bot, Guangzhou 510650, Guangdong, Peoples R China
Recommended Citation:
Chen, Hao,Li, Dejun,Mao, Qinggong,et al. Resource limitation of soil microbes in karst ecosystems[J]. SCIENCE OF THE TOTAL ENVIRONMENT,2019-01-01,650:241-248