桥山林区油松人工林营养元素分配与积累的研究

Nutrient distribution and accumulation pattern of Chinese pin e plantations in Qiaoshan forested region

在陕西省桥山林区 3块油松人工林样地中 ,对油松人工林生态系统各组分中N、P、K、Ca和Mg等 5种营养元素的含量、分配格局、积累规律以及它们与密度间的关系进行了研究 .结果表明 ,油松人工林不同器官中营养元素含量排序为树叶 >树枝 >树根 >树皮 >干材 ;在 2 6年生油松人工林现存量中 ,N、P、K、Ca、Mg总量分别为 2 14 44、2 2 91、15 8 88、167 3 6和 2 9 42kg·hm-2 ;乔木层、灌木层、草本层和死地被物层养分贮量分别为498 98、3 3 2、7 3 1和 83 40kg·hm-2 ;油松人工林N、P、K、Ca和Mg的富集系数分别为 3 98、4 2 8、5 69、1 0 8和 4 0 1;每生产 1t有机物质需要这 5种元素约 8 43～ 9 0 9kg·hm-2 ·a-1;乔木层中营养元素积累量为 2 88 2 6～ 60 6 0 7kg·hm-2 ,其中干材营养元素积累量约占乔木层的 14 1%～ 16 8% .

The contents,accumulation and distribution of 5 nutrient elements (N,P,K,Ca,Mg) were studied in 3 plots of Chinese pine plantations in Qiaoshan forested region in Shaanxi Province.The results showed that the nutrient content in various orga ns was in the order of needle>branch>root>bark>stem.In the 26 year plantati on ,the storage of N,P,K,Ca and Mg was 214.44,22.91,158.88,167.36 and 29.42kg·hm -2 .The total element accumulation was 498.98 kg·hm -2 in the tree laye r,3.32kg·hm -2 in the shrub layer,7.31kg·hm -2 in the herb layer and 8 3.40kg·hm -2 in dead soil covering layer.The enrichment ratios of N,P,K, Ca and Mg in Chinese pine plantation were 3.98,4.28,5 69,1.08 and 4.01.The net pr oduction of organic matter per ton needs a total five elements of 8.43～9.09kg· hm -2 ·yr -1 .The total nutrient elements accumulation in tree layer wa s 288.26～606.07kg·hm -2 ,of which stem accounted for 14.1～16.8%.