Neutral effect of nitrogen addition and negative effect of phosphorus addition on topsoil extracellular enzymatic activities in an alpine grassland ecosystem
Neutral effect of nitrogen addition and negative effect of phosphorus addition on topsoil extracellular enzymatic activities in an alpine grassland ecosystem
复制标题
高寒草地生态系统中氮添加和磷添加对表土细胞外酶活性的中性影响和负向影响
DOI：
10.1016/j.apsoil.2016.06.004
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发表时间：
2016-11-01
影响因子：
4.8
通讯作者：
He, Jin-Sheng
中科院分区：
文献类型：
--
作者：
Jing, Xin;Yang, Xiaoxia;He, Jin-Sheng
土壤氮、磷是高山生态系统中影响植物初级生产力的主要限制性营养元素，但由于其分解速率较低，人为活动增加了氮、磷的输入。关于增加氮和磷的有效性对地下微生物群落功能的影响知之甚少。为了确定土壤微生物对氮磷添加的响应，在青藏高原高寒草地生态系统中，研究了氮磷添加2年后植物初级生产力、土壤微生物生物量、土壤矿质氮有效性、土壤呼吸和土壤胞外酶活性的变化。研究结果表明，施氮对植物生物量、土壤微生物生物量、土壤呼吸和土壤胞外酶活性无显著影响。在0-10 cm土层中，磷的添加增加了植物生物量，但抑制了大多数活性碳循环酶的活性，对土壤微生物生物量和土壤呼吸的影响较小。此外，氮和磷添加量对这些变量没有交互作用。总的来说，N添加似乎并没有对植物初级生产力和微生物活性产生显着的影响，而P添加增加植物初级生产力，并倾向于抑制表土微生物活性后，两年的营养应用。(C)2016爱思唯尔B. V.保留所有权利。
Soil nitrogen (N) and phosphorus (P) are common limiting nutrients affecting plant primary productivity in alpine ecosystems due to the low decomposition rate, though anthropogenic activities have greatly increased their inputs into ecosystems. Little is known regarding the effects of increasing N and P availabilities on the functioning of belowground microbial communities. To determine how soil microorganisms respond to N and P addition, we measured plant primary productivity, soil microbial biomass, soil mineral N availability, soil respiration, and the activities of soil extracellular enzymes after two years of N- and P-addition in an alpine grassland ecosystem on the Tibetan Plateau. We observed no significant effect of N addition on plant biomass, soil microbial biomass, soil respiration, or the activities of soil extracellular enzymes. In contrast, P addition increased plant biomass but suppressed the activities of most labile-C-cycling enzymes at 0-10 cm of soil depth, although the effects on soil microbial biomass and soil respiration were minor. Moreover, there was no interaction between N and P addition on these variables. Overall, N addition does not appear to exert a significant effect on plant primary productivity and microbial activity, whereas P addition increases plant primary productivity and tends to suppress topsoil microbial activity after two years of nutrient application. (C) 2016 Elsevier B.V. All rights reserved.