Different inter-annual responses to availability and form of nitrogen explain species coexistence in an alpine meadow community after release from grazing
文献类型：SCI/SSCI论文
| 作者 | Song M. H. ; Yu F. H. ; Ouyang H. ; Cao G. M. ; Xu X. L. ; Cornelissen J. H. C. |
| 发表日期 | 2012 |
| 关键词 | aboveground biomass alpine meadow compensatory dynamics long-term experiment niche differentiation species richness terrestrial ecosystems niche complementarity nutrient limitation plant-communities organic nitrogen arctic tundra deposition grasslands diversity biodiversity |
| 英文摘要 | Plant species and functional groups in nitrogen (N) limited communities may coexist through strong eco-physiological niche differentiation, leading to idiosyncratic responses to multiple nutrition and disturbance regimes. Very little is known about how such responses depend on the availability of N in different chemical forms. Here we hypothesize that idiosyncratic year-to-year responses of plant functional groups to availability and form of nitrogen explain species coexistence in an alpine meadow community after release from grazing. We conducted a 6year N addition experiment in an alpine meadow on the Tibetan Plateau released from grazing by livestock. The experimental design featured three N forms (ammonium, nitrate, and ammonium nitrate), crossed with three levels of N supply rates (0.375, 1.500 and 7.500gNm-2yr-1), with unfertilized treatments without and with light grazing as controls. All treatments showed increasing productivity and decreasing species richness after cessation of grazing and these responses were stronger at higher N rates. Although N forms did not affect aboveground biomass at community level, different functional groups did show different responses to N chemical form and supply rate and these responses varied from year to year. In support of our hypothesis, these idiosyncratic responses seemed to enable a substantial diversity and biomass of sedges, forbs, and legumes to still coexist with the increasingly productive grasses in the absence of grazing, at least at low and intermediate N availability regimes. This study provides direct field-based evidence in support of the hypothesis that idiosyncratic and annually varying responses to both N quantity and quality may be a key driver of community structure and species coexistence. This finding has important implications for the diversity and functioning of other ecosystems with spatial and temporal variation in available N quantity and quality as related to changing atmospheric N deposition, land-use, and climate-induced soil warming. |
| 出处 | Global Change Biology |
| 卷 | 18 |
| 期 | 10 |
| 页 | 3100-3111 |
| 收录类别 | SCI |
| 语种 | 英语 |
| ISSN号 | 1354-1013 |
| 源URL | [http://ir.igsnrr.ac.cn/handle/311030/30779]  |
| 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 | Song M. H.,Yu F. H.,Ouyang H.,et al. Different inter-annual responses to availability and form of nitrogen explain species coexistence in an alpine meadow community after release from grazing. 2012. |
入库方式： OAI收割
来源：地理科学与资源研究所
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