海莲红树林氮磷的累积和循环

主要讨论55年生海莲林的氮、磷元素累积和循环。测定结果表明:现存量中含有氮、磷总量分别为 142.74 g/m~2 和16.57 g/m~2 。其中地上部分别为 75.31 g/m~2 和 7.82g/m~2,地下部分别为 67.43 g/m~2 和 8.75g/m~2 。该群落氮、磷元素生物循环中,年吸收量分别为19.0 g/m~2 和 2.41 g/m~2 ,存留量分别为 7.53 g/m~2 和 1.01 g/m~2 ,归还量分别为 11.47 g/m~2 和1.40 g/m~2 。它们的氮含量均大于磷含量,周转期氮需 13年比磷需12年为慢。

Accumulation and Biological Cycle of N and P Elements in the Bruguiera sexangula Mangrove Forest in Hainan, China

This paper is a part of the studies of the mangrove forest in the Dongzhai harbour of Hainan Island. China. It deals mainly with the accumulation and biological cycle of N and P elements of 55-year-old Bruguiera sexangula community. The main results of the measurement were as follows: 1 .)The amounts of N and P in the standing crop of this community were 1427.4 kg / ha and 165.7 kg / ha, in which the amounts of the two elements in the biomass of above ground were 753.1 kg/ha for N and 78.2 kg / ha for P, and in the biomass of underground were (kg / ha) 674.3 for N and 87.5 for P respectively. 2.) In biological cycle of N and P of this stand, the annual values of the vegetation mineral uptake were (kg / ha ?yr) 190.0 for N and 24.1 for P, of its retention were 75.3 for N and 10.1 for P, and of its return were 114.7 for N and 14.0 for P respectively. 3.)The turnover periods of N and Pwere 13 and 12 years respectively.