Macaulay Land Use Research Institute, Craigiebuckler, Aberdeen AB15 8QH, UK.
Environ Pollut. 2010 May;158(5):1296-302. doi: 10.1016/j.envpol.2010.01.015. Epub 2010 Feb 9.
The influence of applied nitrogen (N) concentration and load on thallus chemistry and growth of five terricolous alpine lichen species was investigated in a three-month N addition study. Thallus N content was influenced by both concentration and load; but the relative importance of these parameters varied between species. Growth was most affected by concentration. Thresholds for effects observed in this study support a low critical load for terricolous lichen communities (<7.5 kg N ha(-1) y(-1)) and suggest that concentrations of N currently encountered in UK cloudwater may have detrimental effects on the growth of sensitive species. The significance of N concentration effects on sensitive species also highlights the need to avoid artificially high concentrations when designing N addition experiments. Given the sensitivity of some species to extremely low loads and concentrations of N we suggest that terricolous lichens have potential as indicators of deposition and impact in northern and alpine ecosystems.
在为期三个月的氮添加研究中，研究了应用氮（N）浓度和负荷对五种陆生高山地衣物种藻体化学和生长的影响。藻体 N 含量受浓度和负荷的影响；但这些参数的相对重要性在物种之间有所不同。生长受浓度的影响最大。本研究中观察到的效应阈值支持陆生地衣群落的低临界负荷（<7.5 kg N ha(-1) y(-1))，并表明目前在英国云水中遇到的 N 浓度可能对敏感物种的生长产生不利影响。N 浓度对敏感物种的影响也凸显了在设计 N 添加实验时避免人为高浓度的必要性。鉴于一些物种对极低负荷和 N 浓度的敏感性，我们认为陆生地衣在地衣北部和高山生态系统中的沉积和影响方面具有潜在的指示作用。
