The James Hutton Institute, Craigiebuckler, Aberdeen, AB15 8QH, UK.
The James Hutton Institute, Craigiebuckler, Aberdeen, AB15 8QH, UK.
Environ Pollut. 2018 Apr;235:956-964. doi: 10.1016/j.envpol.2017.12.086. Epub 2018 Feb 21.
The predicted long lag time between a decrease in atmospheric deposition and a measured response in vegetation has generally excluded the investigation of vegetation recovery from the impacts of atmospheric deposition. However, policy-makers require such evidence to assess whether policy decisions to reduce emissions will have a positive impact on habitats. Here we have shown that 40 years after the peak of SO emissions, decreases in SO are related to significant changes in species richness and cover in Scottish Calcareous, Mestrophic, Nardus and Wet grasslands. Using a survey of vegetation plots across Scotland, first carried out between 1958 and 1987 and resurveyed between 2012 and 2014, we test whether temporal changes in species richness and cover of bryophytes, Cyperaceae, forbs, Poaceae, and Juncaceae can be explained by changes in sulphur and nitrogen deposition, climate and/or grazing intensity, and whether these patterns differ between six grassland habitats: Acid, Calcareous, Lolium, Nardus, Mesotrophic and Wet grasslands. The results indicate that Calcareous, Mesotrophic, Nardus and Wet grasslands in Scotland are starting to recover from the UK peak of SO deposition in the 1970's. A decline in the cover of grasses, an increase in cover of bryophytes and forbs and the development of a more diverse sward (a reversal of the impacts of increased SO) was related to decreased SO deposition. However there was no evidence of a recovery from SO deposition in the Acid or Lolium grasslands. Despite a decline in NO deposition between the two surveys we found no evidence of a reversal of the impacts of increased N deposition. The climate also changed significantly between the two surveys, becoming warmer and wetter. This change in climate was related to significant changes in both the cover and species richness of bryophytes, Cyperaceae, forbs, Poaceae and Juncaceae but the changes differed between habitats.
大气沉降减少与植被测量响应之间的预测长期滞后时间通常排除了对大气沉降影响下植被恢复的研究。然而，政策制定者需要这样的证据来评估减少排放的政策决策是否会对生境产生积极影响。在这里，我们表明，在 SO 排放达到峰值 40 年后，SO 的减少与苏格兰钙质、中营养、Nardus 和湿地草地物种丰富度和盖度的显著变化有关。我们利用苏格兰植被调查数据，该数据于 1958 年至 1987 年首次进行，并于 2012 年至 2014 年进行了重新调查，研究了物种丰富度和苔藓、莎草科、草本植物、禾本科和灯心草科的盖度随时间的变化是否可以用硫和氮沉积、气候和/或放牧强度的变化来解释，以及这些模式在六种草地生境之间是否存在差异：酸性、钙质、黑麦草、Nardus、中营养和湿地草地。结果表明，苏格兰的钙质、中营养、Nardus 和湿地草地正在从 20 世纪 70 年代英国 SO 沉积峰值中开始恢复。草类盖度的下降、苔藓和草本植物盖度的增加以及更丰富的草丛的发展（SO 增加影响的逆转）与 SO 沉积减少有关。然而，在酸性或黑麦草草地中没有发现从 SO 沉积中恢复的迹象。尽管两次调查之间 NO 沉积有所下降，但我们没有发现增加的 N 沉积影响逆转的证据。气候在两次调查之间也发生了显著变化，变得更加温暖和湿润。这种气候变化与苔藓、莎草科、草本植物、禾本科和灯心草科的盖度和物种丰富度的显著变化有关，但不同生境之间的变化有所不同。
