西南桦与红椎混交造林模式评价

为了评价西南桦（Betula alnoides）与红椎（Castanopsis hystrix）混交造林模式的优劣，以单株形质指标、胸径分布、生长量、蓄积量、虫害和林下植被为指标，对25年生西南桦与红椎异龄混交林及13年生西南桦与红椎同龄混交林和相应的西南桦纯林的林分结构、生长量及健康状况进行研究。结果表明，西南桦与红椎混交造林，有利于西南桦干形塑造，提高西南桦生长量及单位面积总蓄积量，减少西南桦的感虫率及单株的虫孔密度，避免恶性杂草对林木生长的影响。

Evaluation of Mixed Plantation Regimes of Betula alnoides and Castanopsis hystrix

In order to evaluate the effectiveness of the afforestation modes of mixed planting,the stand structure,stand growth and forest healthy conditions of 25-year-old uneven-aged mixed plantation regimes of B.alnoides and C.hystrix,13-year-old even-aged mixed plantation of B.alnoides and C.hystrixand,as well as the corresponding pure stands of B.alnoides were examined by using the indexes of the morphology,diameter distribution,growth,growing stock,insect attack and undergrowth.The results indicated that planting B.alnoides mixed with C.hystrix was beneficial for improving stem form of B.alnoides,increasing growth and total volume per unit area,reducing infestation rate and borer density,and avoiding the influence of malignant weeds on tree growth.