Alterra, Landscape Center, POB 47, 6700 AA Wageningen, Netherlands.
Environ Pollut. 2010 Dec;158(12):3607-11. doi: 10.1016/j.envpol.2010.08.008. Epub 2010 Sep 15.
To study the pH preference of epiphytic lichens, the bark pH of Fraxinus, Tilia, Quercus and Ulmus trees in an urban environment was measured using a flat surface electrode. The total number of trees was 253. A survey was made of the lichens in a 40 × 40 cm quadrat surrounding the pH measurement point. Our data analysis using multivariate and univariate statistical techniques indicates that the tree species is the most important factor influencing lichen colonisation, and that bark pH alone is of less importance. We hypothesize that the changed pollution climate, with strong decreases in both sulphur dioxide and ammonia concentrations over the past two decades and a concomitant general increase in bark pH, has made epiphytes less sensitive to pH.
为了研究附生地衣的 pH 值偏好，使用平面电极测量了城市环境中 Fraxinus、Tilia、Quercus 和 Ulmus 树木的树皮 pH 值。树木总数为 253 棵。在 pH 值测量点周围 40×40cm 的正方形内对地衣进行了调查。我们使用多元和单变量统计技术的数据分析表明，树种是影响地衣定殖最重要的因素，而单独的树皮 pH 值则相对次要。我们假设，过去二十年来，二氧化硫和氨浓度的大幅下降以及树皮 pH 值的普遍升高，改变了污染气候，使附生植物对地衣的 pH 值不那么敏感。
