Soil texture affects soil microbial and structural recovery during grassland restoration
Soil texture affects soil microbial and structural recovery during grassland restoration
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DOI：
10.1016/j.soilbio.2010.08.014
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发表时间：
2010-12-01
影响因子：
9.7
通讯作者：
Six, Johan
中科院分区：
文献类型：
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作者：
Bach, Elizabeth M.;Baer, Sara G.;Six, Johan
许多生物和非生物因素影响长期干扰后土壤群落的恢复。我们使用美国内布拉斯加州粉质粘壤土和壤质细砂土上 0 至 19 年恢复的草地的两个时间序列，研究了土壤质地在土壤微生物群落结构恢复和微生物胁迫变化中的作用，以磷脂脂肪酸 (PLFA) 剖面为索引。所有恢复区以前都是耕地，通过美国农业部的保护储备计划播种了本土暖季草。粉质粘壤土中许多 PLFA 浓度的增加发生在时间序列上，包括总 PLFA 生物量、丰富度、真菌、丛枝菌根真菌、革兰氏阳性细菌、革兰氏阴性细菌和放线菌。粉质粘壤土中饱和：单不饱和和异：反异 PLFA 的比率随时间顺序下降，表明随着草地的建立，微生物群落的养分压力减少。对整个粉质粘壤土年代序列的整个 PLFA 剖面进行的多变量分析表明，微生物群落结构在朝向原生草原的轨迹上得到了恢复。相反，没有微生物群在壤质细沙时间序列上表现出方向性变化。土壤结构的变化也仅在粉质粘壤土年代序列中观察到。骨料平均加权直径（MWD）表现出指数上升至最大值，这是由于大骨料（>2000μm）比例呈指数上升至最大值，而微骨料（53μm）和粉砂和粘土部分（53μm）呈指数衰减。
Many biotic and abiotic factors influence recovery of soil communities following prolonged disturbance. We investigated the role of soil texture in the recovery of soil microbial community structure and changes in microbial stress, as indexed by phospholipid fatty acid (PLFA) profiles, using two chronosequences of grasslands restored from 0 to 19 years on silty clay loam and loamy fine sand soils in Nebraska, USA. All restorations were formerly cultivated fields seeded to native warm-season grasses through the USDA's Conservation Reserve Program. Increases in many PLFA concentrations occurred across the silty clay loam chronosequence including total PLFA biomass, richness, fungi, arbuscular mycorrhizal fungi, Gram-positive bacteria, Gram-negative bacteria, and actinomycetes. Ratios of saturated:monounsaturated and iso:anteiso PLFAs decreased across the silty clay loam chronosequence indicating reduction in nutrient stress of the microbial community as grassland established. Multivariate analysis of entire PLFA profiles across the silty clay loam chronosequence showed recovery of microbial community structure on the trajectory toward native prairie. Conversely, no microbial groups exhibited a directional change across the loamy fine sand chronosequence. Changes in soil structure were also only observed across the silty clay loam chronosequence. Aggregate mean weighted diameter (MWD) exhibited an exponential rise to maximum resulting from an exponential rise to maximum in the proportion of large macroaggregates (>2000 mu m) and exponential decay in microaggregates (53 mu m) and the silt and clay fraction (