物种和基物偏好对河北太行山区六种地衣的元素含量的影响

为了解物种和基物偏好对地衣元素水平的影响,测定了采集于河北太行山区6个地点的6种地衣体内的16种元素（Al、Ba、Cd、Cr、Cu、Fe、Mn、Mo、Na、P、S、Sc、Sr、Ti、V和Zn）的含量。这6种地衣包括3种石生地衣（鸡冠胶衣Collema cristatum、中国石黄衣Xanthoria mandschurica和淡腹黄梅Xanthoparmelia mexicana）,2种土生地衣（莲座石蕊Cladonia pocillum和石果衣Endocarpon pusillum）,及1种树生地衣（毛边黑蜈蚣衣Phaeophyscia hispidula）。主成分分析（PCA）和费里德曼双向秩方差分析（Friedman检验）结果显示,物种和基物偏好对地衣体内元素含量的影响显著,而地点的影响不显著。树生地衣累积的大气源元素（P、S和Zn）高于土生和石生地衣。土生地衣体内的地壳源元素（Al、Ba、Fe、Mn、Mo、Na、Sc、Sr、Ti和V）和大气源元素Cr的含量最高。石生地衣的大气源元素（P、S和Zn）含量近于土生地衣,但地壳源元素含量较低;3种石生地衣在这些元素的含量方面差异不大。这些结果表明以地衣化学组成监测大气元素沉降的研究需慎重考虑物种及基物偏好的影响。

Effects of species and substrate preference on element concentration of six lichens in Taihang Mountains,Hebei, China

To test the effects of species and substrate preference on lichen element concentrations, sixteen chemical elements (Al, Ba, Cd, Cr, Cu, Fe, Mn, Mo, Na, P, S, Sc, Sr, Ti, V and Zn) were analyzed in six lichen species (three saxicolous lichens, Collema cristatum, Xanthoria mandschurica and Xanthoparmelia mexicana, two terricolous lichens, Cladonia pocillum and Endocarpon pusillum, and one corticolous lichen, Phaeophyscia hispidula) from six localities of the Taihang Mountains, Hebei, China. A combination of Principal Component Analysis (PCA) and Friedman test shows that species and substrate preference have high effects on element composition in lichen thalli, whereas locality has no significant effect. The corticolous lichen accumulates the highest level of atmospheric elements (P, S and Zn), while the terricolous lichens have the highest concentration for the crustal metals (Al, Ba, Fe, Mn, Mo, Na, Sc, Sr, Ti and V) and atmospheric metal Cr. As compared with the terricolous lichens, the saxicolous lichens are similar in levels of P, S and Zn, but are less affected by soil contamination. The three saxicolous lichens are roughly similar in concentration for these elements. These results suggest that atmospheric deposition biomonitoring with the aid of lichens should give consideration to the influence of species and substrate preference.