桉树与厚荚相思混交林的生物量及对土壤影响研究

BIOMASS OF EUCALYPTS AND ACACIA CRASSICARPA MIXED FOREST AND ITS INFLUENCE TO SOIL

对雷州林业局营造桉树与厚荚相思混交林进行生物量测定及对土壤影响的分析结果表明∶尾叶桉（无性系ＭＬＡ）与厚荚相思混交林６年生地上部分群体生物量比尾叶桉纯林多３６．６％以上，单株叶量、细根行间混交的尾叶桉分别比纯林的尾叶桉多３８．４％，８２．８％；带状混交的尾叶桉比纯林的尾叶桉分别多１９．５％，４．７％，林分叶量带状混交林比纯林大４．９倍。４年生时混交林凋落物干重比纯林多３１％以上。混交林０～３０ｃｍ土层有机质、全氮、全钾含量分别比纯林多１７．２％，２６．９％，１９．３％。

The experiment was established in eucalypts and Acacia crassicarpa mixed forest in Leizhou Forestry Bureau. Biomass of forest was measured and the influence of mixed forest to soil was analysized also. It showed that the best mixed forest ( Eucalyptus urophylla+A. crassicarpa ) have over 36.6% forest biomass more than the pure eucalypts forest at 6 years old. The individual leave biomass and slender root quantity of E. urophylla inter row mixture forest increased by 38.4% and 82.8% each, and mixture by strip forest increased by 19.5% and 4.7% each compared with the pure ones. Dry weight of litter of mixed forest was over 31% more than the pure forest at 4 years old and the forest leave biomass was 4.9 times more than the pure ons. The content of organic material, total nitrogen, total potassium was increased by 17.2%, 26.9% and 19.3% respectlly compared with the pure forest.