Effects of nitrogen enrichment on soil microbial characteristics: From biomass to enzyme activities
Effects of nitrogen enrichment on soil microbial characteristics: From biomass to enzyme activities
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氮富集对土壤微生物特性的影响：从生物量到酶活性
DOI：
10.1016/j.geoderma.2020.114256
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发表时间：
2020-05-01
期刊：
影响因子：
6.1
通讯作者：
Yan, Weiming
中科院分区：
文献类型：
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作者：
Jia, Xiaoyu;Zhong, Yangquanwei;Yan, Weiming
土壤微生物在生态系统碳循环和养分循环中起着重要作用。氮素（N）富集对土壤微生物的影响是已知的，但是否有其他因素影响N富集对土壤微生物生物量和组成以及胞外酶活性（EEAs）的影响尚不清楚。在这项研究中，以评估土壤微生物特征，包括微生物生物量，微生物群落组成和EEAs的N富集的响应，我们进行了荟萃分析，使用1248个全球数据系列，从120篇已发表的论文在125个网站，涵盖全球5种类型的生物群落。结果表明，在所有研究中，增施氮肥显著降低了微生物量碳（MBC）和丛枝菌根真菌（AMF）。此外，土壤微生物的响应取决于氮素的富集速率，（微生物反应变化的氮速率）（64.85 kg N ha（-1）year（-1）），微生物量氮（MBN，57.00 kg N ha（-1）年（-1）），细菌生物量（106.75 kg N ha（-1）year（-1）），真菌生物量（70.50 kg N ha（-1）年（-1）），β-N-乙酰氨基葡萄糖苷酶施氮条件下，土壤氮素积累量为83.27kg/ha·a（-1），过氧化物酶活性为19.75kg/ha·a（-1）。土壤微生物对增氮的响应受生物群落类型、增氮速率和增氮类型、试验持续时间、降水量和土壤类型等因素的影响。此外，氮素富集还显著改变了土壤理化性质，从而影响了土壤微生物生物量和组成。我们的研究结果强调，氮富集降低了土壤微生物生物量，并表现出显着的影响，在所有陆地生态系统的土壤EEAs，观察到更明显的影响，增加氮率和持续时间。
Soil microbes play an important role in ecosystem processes, including carbon (C) and nutrient cycling. Nitrogen (N) enrichment is known to affect soil microbes, but whether other factors affect the impact of N enrichment on soil microbial biomass and composition and extracellular enzyme activities (EEAs) remains unclear. In this study, to evaluate the responses of soil microbial characteristics, including microbial biomass, microbial community composition and EEAs to N enrichment, we conducted a meta-analysis using 1248 global data series from 120 published papers at 125 sites that cover five types of biomes worldwide. The results showed that N enrichment significantly decreased microbial biomass carbon (MBC) and arbuscular mycorrhizal fungi (AMF) across all studies. In addition, the responses of soil microbes depended on the N enrichment rate, and different thresholds (the N rate at which the microbial response changes) of MBC (64.85 kg N ha(-1) year(-1)), microbial biomass nitrogen (MBN, 57.00 kg N ha (-1) year (-1)), bacterial biomass (106.75 kg N ha(-1) year (-1)), fungal biomass (70.50 kg N ha(-1) year(-1)), beta-N-acetyl-glucosaminidase (NAG) (83.27 kg N ha(-1) year(-1)) and peroxidase activity (19.75 kg N ha(-1) year(-1)) were observed under N enrichment. Moreover, the responses of soil microbes to N enrichment were affected by biome type, N enrichment rate and type, experimental duration, precipitation and soil type. Furthermore, the results showed that N enrichment significantly altered soil physical and chemical properties, which may affect soil microbial biomass and composition under N enrichment. Our findings highlight that N enrichment decreased the soil microbial biomass and showed a significant effect on soil EEAs across all terrestrial ecosystems, with more pronounced effects observed with increasing N rate and duration.