Costimulation of soil glycosidase activity and soil respiration by nitrogen addition
Costimulation of soil glycosidase activity and soil respiration by nitrogen addition
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DOI：
10.1111/gcb.13402
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发表时间：
2017-03-01
影响因子：
11.6
通讯作者：
Zhou, Lingyan
中科院分区：
文献类型：
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作者：
Chen, Ji;Luo, Yiqi;Zhou, Lingyan
在过去的世纪中，氮素在生态系统中的沉积达到了前所未有的水平，这将对微生物介导的土壤呼吸产生级联效应。胞外酶在土壤有机质降解过程中起着重要作用，其活性的测定可作为土壤有机质降解的潜在指标。然而，氮素胁迫下土壤胞外酶活性与土壤有机质降解之间的关系尚不明确。因此，我们进行了荟萃分析，从62个出版物，合成土壤EEAs和SR的反应，以提高氮。氮添加显著提高了葡萄糖苷酶（GA）活性13.0%，α-1，4-葡萄糖苷酶（AG）活性19.6%，β-1，4-葡萄糖苷酶（BG）活性11.1%，β-1，4-木糖苷酶（BX）活性21.9%，β-D-纤维二糖酶（CBH）活性12.6%。GA的增加更明显的持续时间长，高速率，有机和混合N添加（有机和无机N添加的组合），以及从农田的研究。GA的反应比（RR）与SR-RR呈正相关，即使单独评估AG、BG、BX和CBH时也是如此。GA-RR和SR-RR之间的这种正相关性保持了大多数类型的植被和土壤，以及不同的N添加方法。我们的研究结果提供了第一个证据表明，GA是连接到SR下N除了在一系列的生态系统，并强调需要进一步研究其他土壤EEAs的响应各种全球变化因素及其对生态系统功能的影响。
Unprecedented levels of nitrogen (N) have been deposited in ecosystems over the past century, which is expected to have cascading effects on microbially mediated soil respiration (SR). Extracellular enzymes play critical roles on the degradation of soil organic matter, and measurements of their activities are potentially useful indicators of SR. The links between soil extracellular enzymatic activities (EEAs) and SR under N addition, however, have not been established. We therefore conducted a meta-analysis from 62 publications to synthesize the responses of soil EEAs and SR to elevated N. Nitrogen addition significantly increased glycosidase activity (GA) by 13.0%, alpha-1,4-glucosidase (AG) by 19.6%, beta-1,4-glucosidase (BG) by 11.1%, beta-1,4-xylosidase (BX) by 21.9% and beta-D-cellobiosidase (CBH) by 12.6%. Increases in GA were more evident for long duration, high rate, organic and mixed N addition (combination of organic and inorganic N addition), as well as for studies from farmland. The response ratios (RRs) of GA were positively correlated with the SR-RRs, even when evaluated individually for AG, BG, BX and CBH. This positive correlation between GA-RR and SR-RR was maintained for most types of vegetation and soil as well as for different methods of N addition. Our results provide the first evidence that GA is linked to SR under N addition over a range of ecosystems and highlight the need for further studies on the response of other soil EEAs to various global change factors and their implications for ecosystem functions.