Sardans J, Peñuelas J
Unitat d'Ecofisiologia CSIC-CEAB-CREAF, CREAF (Centre de Recerca Ecològica d'Aplicacions Forestals) Edifici C, Universitat Autònoma Barcelona, Bellaterra, Barcelona, Spain.
Environ Pollut. 2007 Jun;147(3):567-83. doi: 10.1016/j.envpol.2006.10.008. Epub 2006 Nov 28.
We conducted a field drought manipulation experiment in an evergreen oak Mediterranean forest from 1999 to 2005 to investigate the effects of the increased drought predicted for the next decades on the accumulation of trace elements that can be toxic for animals, in stand biomass, litter and soil. Drought increased concentrations of As, Cd, Ni, Pb and Cr in roots of the dominant tree species, Quercus ilex, and leaf Cd concentrations in Arbutus unedo and of Phillyrea latifolia codominant shrubs. The increased concentration of As and Cd can aggravate the toxic capacity of those two elements, which are already next or within the levels that have been shown to be toxic for herbivores. The study also showed a great reduction in Pb biomass content (100-135 gha(-1)) during the studied period (1999-2005) showing the effectiveness of the law that prohibited leaded fuel after 2001. The results also indicate that drought increases the exportation of some trace elements to continental waters.
1999年至2005年期间，我们在地中海常绿栎树林中进行了一项田间干旱控制实验，以研究未来几十年预计增加的干旱对动物可能有毒的微量元素在林分生物量、凋落物和土壤中的积累的影响。干旱增加了优势树种冬青栎根系中砷、镉、镍、铅和铬的浓度，以及草莓树和地中海刺叶桂樱这两种共优势灌木叶片中的镉浓度。砷和镉浓度的增加会加剧这两种元素的毒性，它们已经接近或处于对食草动物有毒的水平。该研究还表明，在研究期间（1999年至2005年），铅的生物量含量大幅下降（100 - 135 g·ha⁻¹），这表明2001年后禁止使用含铅燃料的法律是有效的。结果还表明，干旱会增加一些微量元素向陆地水体的输出。
