Pannek A, Duprè C, Gowing D J G, Stevens C J, Diekmann M
Department of Ecology, FB 2, Vegetation Ecology and Conservation Biology, University of Bremen, Leobener Str., 28359, Bremen, Germany,
Oecologia. 2015 Jan;177(1):39-51. doi: 10.1007/s00442-014-3120-6. Epub 2014 Nov 19.
Anthropogenic eutrophication impacts ecosystems worldwide. Here, we use a vegetation dataset from semi-natural grasslands on acidic soils sampled along a gradient in north-western Europe to examine the response of species frequency to nitrogen (N) deposition, controlling for the effects of other environmental variables. A second dataset of acidic grasslands from Germany and the Netherlands containing plots from different time periods was analysed to examine whether the results of the spatial gradient approach coincided with temporal changes in the abundance of species. Out of 44 studied species, 16 were affected by N deposition, 12 of them negatively. Soil pH and phosphorus (P) influenced 24 and 14 species, respectively, predominantly positively. Fewer species were related to the soil contents of NO3(-) or NH4(+), with no significant differences between the number of positive and negative effects. Whereas the temporal change of species was unrelated to their responses to pH, species responding negatively to N deposition, soil P and NO3(-) showed a significant decline over time in both countries. Species that were negatively affected by high N deposition and/or high soil P also showed a negative temporal trend and could be characterised by short stature and slow growth. The results confirm the negative role of N deposition for many plant species in semi-natural acidic grasslands. The negative temporal trends of species sensitive to high N deposition and soil P values clearly show a need for maintaining low soil nutrient status and for restoring the formerly infertile conditions in nutrient-enriched grasslands.
人为富营养化影响着全球的生态系统。在此，我们利用来自欧洲西北部沿梯度采样的酸性土壤上半天然草地的植被数据集，来研究物种频率对氮（N）沉降的响应，并控制其他环境变量的影响。分析了来自德国和荷兰的包含不同时间段样地的酸性草地的第二个数据集，以检验空间梯度方法的结果是否与物种丰度的时间变化一致。在所研究的44个物种中，16个受到氮沉降的影响，其中12个受到负面影响。土壤pH值和磷（P）分别影响了24个和14个物种，主要是正面影响。与土壤中NO3(-)或NH4(+)含量相关的物种较少，正负影响的数量没有显著差异。虽然物种的时间变化与其对pH值的响应无关，但在这两个国家中，对氮沉降、土壤P和NO3(-)有负面响应的物种随时间均呈现显著下降。受到高氮沉降和/或高土壤P负面影响的物种也呈现负面的时间趋势，其特征可能是植株矮小和生长缓慢。结果证实了氮沉降对半天然酸性草地中许多植物物种的负面作用。对高氮沉降和土壤P值敏感的物种的负面时间趋势清楚地表明，需要维持低土壤养分状态，并恢复养分富集草地以前的贫瘠状况。
