广西林朵林场栽针（杉）保阔混交造林的效果研究

EFFECTS OF FORESTATION BY KEEPING BROADLEAF TREES IN PLANTING CUNNINGHAMIA LANCEOLATA

摘要:

广西林朵林场栽针（杉）保阀混交造林试验表明：１９龄和３０龄混交林林分总蓄积量分别为１８４．７８和５１５．５８ｍ３ｈｍ（－２），比同龄杉木纯林的依次高２３．０％和２１．８％．混交林中主要树种杉木的树高、胸径和蓄积量随混交树种株数比例的增加而降低．混交林林地枯枝落叶层现存量平均为１５．１８ｔｈｍ（－２），Ｎ、Ｐ、Ｋ、Ｃａ和Ｍｇ５种元素的积累量平均为４２２．２２ｋｇｈｍ（－２），分别比杉木纯林的高２５．３％和３２．３３％．混交林林地土壤有机质、全氮、水解氮、有效磷和速效钾的平均含量以及孔隙度和持水量都高于杉木纯林．

Abstract:

The results of forestation with mixed broadleaf trees in planting Cunninghamia Ianceolata at Linduo Forest Farm in Guangxi Province showed that the total growing stocks in stands of 19-year-old and 30-year-old mixed forests were 184.78 and 515.58m3 hm(-2),respeCtively, which were by 23.0% and 21.8% higher than those of the same years old forests of pure Cunninghamia lanceolata, respectively. In mixed forests, the larger proportion of broadleaf species, the less became mean height, diameter and growing stocks of Cunninghamia lanceolata. The mean standing crop of litter on forest floor in mixed forests was 15.18t hm(-2), and the accumulation of nutrient elements (N, P, K, Ca, Mg) in the litter was 422.22kg hm(-2), being by 25.30% and 32.33% higher than those in pure Cunninghamia Ianceolata forest, respectively. The nutrient concentration of organic matter, total N,hydrolazable N, available P and rapidly available K in the soil, and soil porosity and water-holding capacity under mixed forest were higher than those under pure Cunninghamia Ianceolata forest.