Nitrogen Addition Regulates Soil Nematode Community Composition through Ammonium Suppression
文献类型：SCI/SSCI论文
| 作者 | Li Q.; Yu Q.; Li Q. |
| 发表日期 | 2012 |
| 关键词 | forest ecosystems plant-communities food-webs diversity mineralization biodiversity indicators deposition agroecosystems fertilization |
| 英文摘要 | Nitrogen (N) enrichment resulting from anthropogenic activities has greatly changed the composition and functioning of soil communities. Nematodes are one of the most abundant and diverse groups of soil organisms, and they occupy key trophic positions in the soil detritus food web. Nematodes have therefore been proposed as useful indicators for shifts in soil ecosystem functioning under N enrichment. Here, we monitored temporal dynamics of the soil nematode community using a multi-level N addition experiment in an Inner Mongolia grassland. Measurements were made three years after the start of the experiment. We used structural equation modeling (SEM) to explore the mechanisms regulating nematode responses to N enrichment. Across the N enrichment gradient, significant reductions in total nematode abundance, diversity (H' and taxonomic richness), maturity index (MI), and the abundance of root herbivores, fungivores and omnivores-predators were found in August. Root herbivores recovered in September, contributing to the temporal variation of total nematode abundance across the N gradient. Bacterivores showed a hump-shaped relationship with N addition rate, both in August and September. Ammonium concentration was negatively correlated with the abundance of total and herbivorous nematodes in August, but not in September. Ammonium suppression explained 61% of the variation in nematode richness and 43% of the variation in nematode trophic group composition. Ammonium toxicity may occur when herbivorous nematodes feed on root fluid, providing a possible explanation for the negative relationship between herbivorous nematodes and ammonium concentration in August. We found a significantly positive relationship between fungivores and fungal phospholipid fatty acids (PLFA), suggesting bottom-up control of fungivores. No such relationship was found between bacterivorous nematodes and bacterial PLFA. Our findings contribute to the understanding of effects of N enrichment in semiarid grassland on soil nematode trophic groups, and the cascading effects in the detrital soil food web. |
| 出处 | Plos One |
| 卷 | 7 |
| 期 | 8 |
| 收录类别 | SCI |
| 语种 | 英语 |
| ISSN号 | 1932-6203 |
| 源URL | [http://ir.igsnrr.ac.cn/handle/311030/30729]  |
| 专题 | 地理科学与资源研究所_历年回溯文献 |
| 推荐引用方式 GB/T 7714 | Li Q.,Yu Q.,Li Q.. Nitrogen Addition Regulates Soil Nematode Community Composition through Ammonium Suppression. 2012. |
入库方式： OAI收割
来源：地理科学与资源研究所
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