湘西南酸枣、闽楠和蓝果树的营养元素含量及吸收规律

Characteristics of Nutrient Absorption in Nyssa sinensis, Phoebe bournei and Choerospondias axillaris from Xiangxi

摘要: 对湘西自治州森林生态站3个乡土珍贵树种——南酸枣、闽楠、蓝果树的营养元素含量及其分布进行了测定分析，结果表明：3树种各器官的营养元素总含量遵循树叶>树皮>树枝>树根>树干这一规律。叶中营养元素的含量顺序总体符合N > Ca > Mg > K > P > Mn > Fe > Zn > Cu。调查树种所在的森林生态站地处喀斯特地区，主要为石灰岩地区，该地区树种的Ca含量也较高。大量元素为蓝果树积累量最高，微量元素为闽楠积累量最高。不同的元素积累特点表现为Mg在常绿树种闽楠中远低于落叶树种南酸枣和蓝果树。叶片营养元素含量比值表明，南酸枣属于P制约型植物，闽楠和蓝果树为N、P共同影响生长型植物。相同植物类型的K、Ca、Mg元素之间的比值特征表明这些元素对相同生活类型树种起协同作用。不同元素含量的标准差和变异系数反映出3个乡土珍贵树种对Mn、Fe和Cu这3中元素有较大差异的选择性吸收。

Abstract: The nutrient elements of Nyssa sinensis, Phoebe bournei and Choerospondias axillaris from Xiangxi Ecology Station were investigated in this study. The results showed that the nutrient contents in the organs of three trees were leaf > bark > twig > root > trunk. The absorption of nutrient elements in the leaves were N > Ca > Mg > K > P > Mn > Fe > Zn > Cu. Calcium was determined as dominant nutrients in the leaves of the karst forest trees. C. axillaris was able to accumulate more macro-elements than other two trees, and the highest accumulation of micro-elements was found in P. bournei. N. sinensis and C. axillaris had an excellent ability to enrich Mg. N. sinensis was defined as the P limited plants based on the ratio of the elements in the leaves. The ratios of N/P, K/Ca and K/Mg in the leaves of the three species showed that a synergistic effect of K, Ca, Mg were found on The same type of species. The significant differences were observed in absorption of Mn, Fe and Cu based on statistical analysis.