杉木纯林及杉木火力楠混交林林分结构及土壤养分分析

Stand Structure and Soil Nutrient of Cunninghamia lanceolata Pure Forest and Mixed Forest of Cunninghamia lanceolata and Michelia macclurei

以广西南宁市郊杉木纯林和杉木+火力楠混交林为研究对象,分析杉木纯林与杉木+火力楠混交林的生长与土壤养分之间的关系差异,以期为杉木人工林的营造提供数据参考。结果表明:杉木+火力楠混交林的平均胸径、平均树高和单株材积等生长量显著高于杉木纯林;混交林的径阶集中分布范围为18~22 cm,纯林主要集中分布在12~20 cm径阶范围内;杉木混交林径级离散度为0.593 3,杉木纯林径级离散度为0.929 3,混交林分化不明显而纯林分化明显。杉木混交林与杉木纯林土壤养分含量差异显著,混交林土壤中全N、氨态N、全P、全K、速效P、速效K含量均显著多于杉木纯林,且随着土层深度的增加,土壤养分含量均逐渐减少。混交林林分结构比纯林稳定,养分含量较高。

The difference between growth soil nutrients of Cunninghamia lanceolata pure forest mixed forest of Cunninghamia lanceolata Michelia macclurei was analyzed based on the mixed forest of Cunninghamia lanceolata Michelia macclurei in Nanning suburb of Guangxi Zhuang Autonomous Region. Result shows that the average DBH,tree height tree volume of mixed forest of Cunninghamia lanceolata Michelia macclurei are significantly higher than that of Cunninghamia lanceolata pure forest;diameter concentration range is 18-22 cm,the pure forest is mainly distributed in 12-20 cm diameter range;size dispersion of mixed forest of Cunninghamia lanceolata Michelia macclurei is 0. 593 3,size dispersion of Cunninghamia lanceolata plantation is 0. 929 3;differentiation of mixed forest is not obvious differentiation pure forest is obvious. The difference of soil nutrient content in pure forest mixed forest of Cunninghamia lanceolata is significant,content of total nitrogen,ammonia nitrogen,total phosphorus in soil are significantly higher than that of the mixed plantations,available phosphorus available potassium content of soil in Cunninghamia lanceolata plantations were significantly higher than the mixed forest,and with the thickness of the soil layer deepening,decrease of nutrient content in pure forest the soil is significantly higher than that in the mixed forest of Cunninghamia lanceolata. Therefore,the structure of mixed forest is more stable than the pure forest,and the nutrient content is higher.