南岭自然保护区常绿阔叶林优势树种叶片中11种化学元素含量特征

为探讨南岭自然保护区常绿阔叶林优势树种叶片营养特征及重金属含量水平，测定了保护区16个优势树种叶片中N、P、K、Ca、Al、Na、Mg、Mn、Ni、Cu和Pb共11种化学元素的含量，并分析了其在叶片中的变异特征和相关性。结果表明：该地区植物叶片N、P含量均低于我国陆生植物叶片含量的平均值，叶片Ca、K、Mg含量处于陆地植物叶片的正常范围，叶片Mn含量与广东植物叶片含量接近；16个优势树种叶片重金属含量均处于正常范围；南岭自然保护区优势树种受P限制强烈；尽管16个优势树种叶片暂未受到重金属和Al毒危害，但因华南地区酸沉降引发土壤重金属活化的风险仍存在，应加强对该地区森林土壤化学性质和树木叶片化学元素含量的定期监测研究。

Chemical Element Contents in Leaves of 16 Dominant Species from Evergreen Broad-leaved Forest at Nanling Nature Reserve

In order to evaluate the nutrient status and the heavy metal concentrations in the leaves of evergreen broad-leaved forest at Nanling Nature Reserve, the characteristics including contents, relationships and variations of N, P, K, Ca, Al, Na, Mg, Mn, Ni, Cu and Pb, were detected in the leaves of 16 dominant species in this reserve. The contents of N and P in leaves of the selected tree species were below the averages, while the concentrations of Ca, K and Mg were within its normal ranges of the terrestrial plants in China. The levels of Mn in the leaves detected were near the background values of Guangdong plants. Fortunately, the concentrations of Al, Ni, Cu, and Pb were within their respective normal ranges in plants. Based on the ratios of leaf N to P, the 16 species detected were all P-limited. Although these species are not suffering from Al, Ni, Cu and Pb at present, there is a potential risk from toxic metals activated by soil acidification caused by acid deposition in south China. Regular monitoring and research on the elemental concentrations in the leaves as well as forest soils in the reserve are scientifically necessary.