湿地松鹅掌楸混交林营养元素生物循环的研究

Nutrient Biocycling in Mixed Forest consisting of Pinus elliottii and Liriodendron chinense

分别对湿地松鹅掌楸人工混交林的乔木生物量及其养分 ,枯落物及其养分的生物循环等方面作了研究。结果表明 :不同林分生物量各营养元素的积累和分配各异 ,N、P、K、Ca、Fe、Zn元素的现存量均是混交林的大 ,Ca和Fe分别比松纯林高 2 74.9%和 10 2 .5 %。两种林分各元素分布顺序是 N>K>P>Mg>Fe>Zn,混交林中 Ca>P>Mg,湿地松纯林 P>Mg>Ca;混交林与松纯林相比各元素的吸收量 (除 Mg外 ) ,均以混交林为大。混交林各元素的归还总量为 132 .0 kg· hm- 2 ,纯松林仅为 6 5 .4kg· hm- 2 ;不同林分生产每 t干物质所需消耗各元素的量不同 ,除Ca、K外 ,元素的利用量以松纯林稍大。说明混交林地可较好地满足 N、P、Mg元素的需求 ,其归还的量较多 ,表明混交林既能满足林木生产对养分的需求 。

Biomass and nutrient contents of trees,Forest litter layer and its nutrient biocycling were investigated in the mixed forest consisting of Pinus elliottii and iriodendron chinesse(also in pure forest of P.elliottii).The results as follow:The nutrients anccumulation and distribution for different forests are not equivalent,the standing crop(of N、P、K、Ca、Mg、Zn)of trees in mixed forest were higher than those in pure forest respectively.The nutrients except Ca annual absorption in mixed forest were higher than those in pure forest,te total return of nutrients in mixed forest was 132.0kg·hm -2 ,but in pure forest was 65.4kg·hm -2 .The utilized rate of nutrients(except Ca、K)in mixed forest was lower than those in pure forest.