Phosphorus budget of a 70-year-old northern hardwood forest
Phosphorus budget of a 70-year-old northern hardwood forest
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DOI：
10.1007/bf00002757
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发表时间：
1992-07
期刊：
影响因子：
4
通讯作者：
R. Yanai
中科院分区：
文献类型：
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作者：
R. Yanai
最近的措施使修订和改进哈伯德·布鲁克实验林的磷收支成为可能，包括从森林地面和矿物土壤中分配植被对磷的吸收，并估计森林地面的净磷矿化。在这片70年生的北方阔叶林中，生物量和森林枯枝落叶层都在积累P(分别为1.3和0.16 kg P ha~(-1)/a)。每年植被吸收的磷中约有61%来自森林地面(占总磷9.6 kg ha-1yr-1的5.9 kg P ha-1yr-1)，尽管该池的P含量仅为矿质土壤中P含量的5%。林下土壤中P的周转速率为7%a-1，矿质土壤中P的周转速率为0.3%a-1。森林表层磷的再循环非常有效；在森林表层5.6公斤的P ha~(-1)净矿化中，只有0.3公斤P ha~(-1)渗入矿质土壤，其余的被植物吸收。磷的这种紧密循环很重要，因为在矿物土壤中，磷不像森林地面那样容易获得。
Recent measurements have made it possible to revise and improve the phosphorus budget of the Hubbard Brook Experimental Forest, including partitioning P uptake by vegetation from the forest floor and mineral soil and estimating net P mineralization in the forest floor. Both living biomass and forest floor are accumlating P (at rates of 1.3 and 0.16 kg P ha-1yr-1respectively) in this 70-yr old northern hardwood forest. About 61% of the P taken up by the vegetation each year comes from the forest floor (5.9 kg P ha-1yr-1of a total 9.6 kg P ha-1yr-1), even though the P content of this pool is just 5% of that in mineral soil. The turnover rate of P in the forest floor is 7% yr-1, while that of the mineral soil is 0.3% yr-1. Recycling of P in the forest floor is very efficient; of the 5.6 kg P ha-1yr-1net mineralization in the forest floor, only 0.3 kg P ha-1leaches into the mineral soil; the rest is taken up by plants. This tight recycling of P is important because P is less readily available in the mineral soil than in the forest floor.