中国东部主要松林营养元素循环的比较研究

 中国的松林主要分布在亚热带和温带地区，在亚热带和温带地区东部主要是马尾松林、华山松林、油松林、红松林和樟子松林。松林由于树种、起源和年龄的差别，其生物量的变化幅度较大，在65～200t·hm-2之间(东北地区的原始红松林最高生物量可达360t·hm-2)，松林的生物量表现出区域分异的特点。即从南到北随着纬度的增加，林分的生物量有逐渐降低的趋势。松树针叶中5种主要营养元素含量表现为N]>K]≥Ca]>Mg]≥P]，而且营养元素表现出因种而异，N的含量为华山松≥马尾松>油松≥红松>樟子松，而P和K在油松和红松针叶中含量较高；Ca的含量表现出较大的波动，与其母岩关系密切。松林主要营养元素(N、P、K、Ca、Mg)的积累量中N一般占25％～40％，松林营养元素循环速率受生境，树种、年龄的影响，但总的来说，亚热带地区松林营养元素的循环速率高于温带地区松林。

A STUDY ON NUTRIENT CYCLING OF PINE STANDS IN EASTERN PART OF CHINA

In China pine forest are mainly distributed in the subtropical zone and the temperate zone. In the eastern part of the subtropical and temperate zone,there are Pinus massoniana forest, P. armandii forest P. tabulaeformis forest, P. koraiensis forest,and P. sylvestris var. mongolica forest. Because of differences in species,origination and age of pine stands, their biomass is about 65～200 t·hm-2 and decreases with increasing of latitude. The contents of main nutrient elements in needles of pine tree are as follows: N]>K]≥Ca]> Mg]≥P]. At the same time, the contents of the nutrient elements differed among the species. Interspecific difference in nitrogen content of the needles was as follows : Pinus armandii > P. massoniana > P. tabulaeformis > P. koraiensis>P, sylvestris var. mongolica. Phosphorus and potassium contents were higher in needles of P. tabulaeformis and P. koraiensi. Calcium content fluctuation was big and dependent on rock from which the soil developed. The nitrogen accumulation, among the five elements (N, P, K, Ca,and Mg),was about 25 %～40% of all in pine stands. Habitat, species and plant age affected the rate of nutrient element cycling. In general, the cycling rate of the nutrient elements of the pine stands in the subtropical zone was higher than that of the pine stands in the temperate zone.