Soil microbial community responses to long-term land use intensification in subtropical grazing lands
Soil microbial community responses to long-term land use intensification in subtropical grazing lands
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DOI：
10.1016/j.geoderma.2017.01.019
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发表时间：
2017-05
期刊：
影响因子：
6.1
通讯作者：
Sutie Xu;M. Silveira;K. Inglett;L. Sollenberger;S. Gerber
中科院分区：
文献类型：
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作者：
Sutie Xu;M. Silveira;K. Inglett;L. Sollenberger;S. Gerber
土地利用集约化往往导致植物复盖和养分投入的改变，从而对土壤微生物群落和组分的组成和结构产生潜在影响。本研究的目的是了解土地利用集约化(引入生产性植被类型、增加氮肥投入和放牧率)对佛罗里达州牧场土壤微生物群落组成和活性的长期(22年)影响。试验点由从本地牧场(最低)、林场(中等)到人工草地(最高)的管理强度梯度组成。从天然草地到播种地增加管理强度，促进了微生物的生物量和活性。在0-10 cm土层，人工草地的土壤微生物量碳浓度(334m g/kg−·1)高于森林草原和天然草地(分别为193m g/kg和232m g/kg−·1)。同样，潜在矿化C(PMC)也随着牧场集约化的增加而增加(人工牧场1.2mgCO2-C kg−和1D−1，原生牧场和森林牧场分别为0.5mgCO2-C kg−和0.6mgCO2-C kg−)。与本地牧场和森林牧场相比，播种的牧场表现出最高的β-葡萄糖苷酶活性(203nmolg−)和磷脂脂肪酸生物量(222nmolg−)。结果还表明，随着土地利用集约化程度的提高，从天然牧场到森林牧场或人工草地，细菌的相对丰度更高，真菌的相对丰度更低。研究表明，长期土地利用集约化影响了亚热带牧场土壤微生物群落的大小、活性和组成。
Land use intensification often results in modification in plant cover and nutrient inputs with subsequent potential effects on composition and structure of soil microbial community and fractions. The objective of this study was to understand the long-term (> 22 yr) impacts of land use intensification (introduction of productive vegetation type, greater N fertilizer input and stocking rate) on soil microbial community composition and activity in Florida grazing lands. Experimental sites consisted of a gradient of management intensities ranging from native rangeland (lowest), silvopasture (intermediate), to sown pasture (highest). Increasing management intensity from native rangeland to sown promoted microbial biomass and activity. At the 0–10 cm, soil microbial biomass carbon (MBC) concentration was greater in sown pasture (334 mg kg− 1) compared to silvopasture and native rangeland (193 and 232 mg kg− 1, respectively). Similarly, potentially mineralizable C (PMC) increased in response to grazing land intensification (1.2 mg CO2-C kg− 1d− 1for sown pastures vs. 0.5 and 0.6 mg CO2-C kg− 1d− 1for native rangeland and silvopasture, respectively). Sown pastures exhibited the greatest levels of β-glucosidase activity (203 nmol g− 1soil h.− 1) and phospholipid fatty acid (PLFA) biomass (222 μmol kg− 1soil) compared to native rangeland and silvopasture. Results also demonstrated greater relative abundance of bacteria and less fungi as land use intensification increased from native rangeland to silvopasture or sown pasture. Our study indicated that long-term land use intensification affected the size, activity, and composition of soil microbial community in subtropical grazing lands.