Decreases in organic C reserves in soils can reduce the catabolic diversity of soil microbial communities
Decreases in organic C reserves in soils can reduce the catabolic diversity of soil microbial communities
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DOI：
10.1016/s0038-0717(99)00141-8
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发表时间：
2000-02-01
影响因子：
9.7
通讯作者：
Vojvodic-Vukovic, M
中科院分区：
文献类型：
--
作者：
Degens, BP;Schipper, LA;Vojvodic-Vukovic, M
了解影响土壤微生物多样性的主要因素对于预测当前土地利用趋势对陆地生物多样性的影响是必要的。我们使用微生物分解代谢均匀度作为衡量土壤微生物多样性的一个组成部分。通过测量土壤对一系列简单有机化合物的短期呼吸响应来评估分解代谢均匀性。牧场和其他土地利用在匹配的土壤分解代谢均匀度的差异有关的有机C库（总有机C，微生物生物量C，和潜在的可矿化C）的差异。这种方法能够比较土地利用对有机碳库的影响，在没有土壤类型的影响下，与分解代谢均匀度有关。一般来说，微生物分解代谢均匀度在牧场和土著植被下的土壤中最大（范围：19.7-23.3），在谷物/玉米/园艺作物下的土壤中最小（范围：16.4-19.6）。土壤混合种植土地利用的分解代谢均匀度介于这些极端之间（范围：17.7-20.5），但在松树林没有特征水平的均匀度（范围：15.1-22.3）。分解代谢均匀度与土壤有机碳库绝对值相关性较差（r（2）< 0.36）。然而，在牧场和其他土地利用之间的一系列配对比较中，微生物分解代谢均匀度的较大差异对应于有机C的较大差异（r（2）=0.76），并且在较小程度上，微生物生物量C（r（2）< 0.45）或潜在矿化C（r（2）< 0.13）的差异。因此，消耗土壤有机碳储量的土地利用可能会导致土壤微生物群落分解代谢多样性的下降。虽然这对微生物过程的影响是未知的，土壤有机碳的维护可能是重要的微生物多样性的保护。(C)2000爱思唯尔科技有限公司版权所有。
An understanding of the main factors influencing microbial diversity in soils is necessary to predict the effects of current landuse trends on terrestrial diversity. We used microbial catabolic evenness as a measure of one component of soil microbial diversity. Catabolic evenness was assessed by measuring the short-term respiration responses of soil to a range of simple organic compounds. Differences in catabolic evenness between pasture and other land-uses on matched soils were related to differences in organic C pools (total organic C, microbial biomass C, and potentially mineralizable C). This approach enabled comparison of land-use effects on organic C pools in relation to catabolic evenness without the effects of soil type. In general, microbial catabolic evenness was greatest in soils under pasture and indigenous vegetation (range: 19.7-23.3), and least in soils under cereal/maize/horticultural cropping (range: 16.4-19.6). Soils under mixed cropping land-uses had catabolic evenness that ranged between these extremes (range: 17.7-20.5), but under pine forestry there was no characteristic level of evenness (range: 15.1-22.3). Catabolic evenness correlated poorly with the absolute values of soil organic C pools (r(2) < 0.36). However, across a range of paired comparisons between pasture and other land-uses, greater differences in microbial catabolic evenness corresponded with greater differences in organic C (r(2)=0.76) and, to a lesser degree, with differences in microbial biomass C (r(2) < 0.45) or potentially mineralizable C (r(2) < 0.13). Therefore, land-uses that deplete organic C stocks in soils may cause declines in the catabolic diversity of soil microbial communities. Although the implications of this for microbial processes are unknown, maintenance of soil organic C may be important for preservation of microbial diversity. (C) 2000 Elsevier Science Ltd. All rights reserved.