Resource limitation of soil microbes in karst ecosystems
Resource limitation of soil microbes in karst ecosystems
复制标题
喀斯特生态系统土壤微生物的资源限制
DOI：
10.1016/j.scitotenv.2018.09.036
复制
发表时间：
2019-02-10
影响因子：
9.8
通讯作者：
Wang, Kelin
中科院分区：
文献类型：
--
作者：
Chen, Hao;Li, Dejun;Wang, Kelin
了解土壤微生物的资源限制对于理解生态系统的功能和过程，以及预测生态系统对全球变化的响应至关重要。喀斯特生态系统分布广泛，在全球气候调节中发挥着关键作用，但喀斯特生态系统微生物资源限制的模式和机制尚不清楚。本文以中国西南地区白云岩和石灰岩两种岩性为基础，选取了耕地、草地、灌丛和次生林四种主要土地利用类型，研究了喀斯特地区微生物资源的有限性。采用生态酶化学计量学作为微生物资源限制指标。总体而言，喀斯特生态系统中土壤微生物受碳和磷的限制大于氮。进一步分析表明，不同土地利用类型和不同岩性的土壤碳磷限制模式存在差异。微生物碳限制在农田和森林中最大，在草地中最低，在白云岩下比在石灰岩下更大。白云岩区微生物磷限制由次生林向农田递减，而灰岩区不同生态系统类型间无差异，说明岩性控制了农业后演替过程中微生物磷限制的格局。我们的研究描述了喀斯特生态系统中微生物资源限制的一般模式，我们认为岩性可能为解释不同地区微生物资源限制随农业后演替的变化提供了新的机制。(C) 2018 Elsevier B.V.版权所有
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.