Grasses, litter, and their interaction affect microbial biomass and soil enzyme activity
Grasses, litter, and their interaction affect microbial biomass and soil enzyme activity
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DOI：
10.1016/j.soilbio.2007.03.018
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发表时间：
2007-09-01
影响因子：
9.7
通讯作者：
Dornbush, Mathew E.
中科院分区：
文献类型：
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作者：
Dornbush, Mathew E.
植物对生态系统过程的影响是通过地下植物-微生物相互作用来调节的，而土壤酶分析通常被用来直接将微生物活动与生态系统过程联系起来。活植物通过根际过程和碎屑输入的差异影响微生物的生物量和活动。在因子温室实验中，我利用6种不同凋落物化学成分的草种来评估活植物和碎屑输入对底物诱导呼吸(SIR，活性微生物生物量的衡量标准)、基础呼吸、溶解有机碳(DOC)以及β-葡萄糖苷酶、β-氨基葡萄糖苷酶和酸性磷酸酶活性的相对影响。为了尽量减少混杂的变量，我使用了不含有机物质的盆栽介质，保持土壤水分恒定，并每周施肥。枯枝落叶处理的SIR和酶活性是植物添加处理的2-15倍。活植物与凋落物的结合并没有刺激微生物的生物量或活性高于仅使用凋落物的处理，并且β-葡萄糖苷酶的活性显著低于仅使用凋落物的处理。凋落物N(%)和植物生物量的物种差异分别与β-氨基葡萄糖苷酶和酸性磷酸酶活性的差异有关，但对β-葡萄糖苷酶、SIR或基础呼吸没有明显影响。DOC与凋落物C：N呈负相关，与植物生物量呈正相关。在刺激微生物活性方面，物种特性和活植物并不像增加凋落物那样重要，这表明植物对土壤酶活性的影响主要是由碎屑输入驱动的，尽管凋落物影响的强度可能会受到生长植物的影响。(C)2007爱思唯尔有限公司。保留所有权利。
Plant effects on ecosystem processes are mediated through plant-microbial interactions belowground, and soil enzyme assays are commonly used to directly relate microbial activity to ecosystem processes. Live plants influence microbial biomass and activity via differences in rhizosphere processes and detrital inputs. I utilized six grass species of varying litter chemistry in a factorial greenhouse experiment to evaluate the relative effect of live plants and detrital inputs on substrate-induced respiration (SIR, a measure of active microbial biomass), basal respiration, dissolved organic carbon (DOC), and the activities of beta-glucosidase, beta-glucosaminidase, and acid phosphatase. To minimize confounding variables, I used organic-free potting media, held soil moisture constant, and fertilized weekly. SIR and enzyme activities were 2-15 times greater in litter-addition than plant-addition treatments. Combining live plants with litter did not stimulate microbial biomass or activity above that in litter-only treatments, and beta-glucosidase activity was significantly lower. Species-specific differences in litter N (%) and plant biomass were related to differences in beta-glucosaminidase and acid phosphatase activity, respectively, but had no apparent effect on beta-glucosidase, SIR, or basal respiration. DOC was negatively related to litter C:N, and positively related to plant biomass. Species identity and living plants were not as important as litter additions in stimulating microbial activity, suggesting that plant effects on soil enzymatic activity were driven primarily by detrital inputs, although the strength of litter effects may be moderated by the effect of growing plants. (C) 2007 Elsevier Ltd. All rights reserved.