湿地松林抚育间伐与修枝技术

对立地、密度、林龄基本一致的湿地松林分采取不同强度的抚育间伐和修枝试验，确定了湿地松林第1次间伐和修枝年龄为7～8a；林分标准郁闭度达0．85以上时，胸径连年生长量已下降，株数间伐强度以不超过30%为宜。第2次间伐应根据培育目的和经营管理水平确定强度，一般林分间伐强度不超过35％；间伐间隔期为5～6a。以培育大径级建筑用材林的林分，应进行第3次间伐，每公顷保留600～680株为宜。间伐后应进行修枝，修枝强度第1次以树高的1／3为宜，第2次以树高的1／2为宜，间隔期为3～5a，时间以深秋至早春为好。

Techniques of Thinning and Pruning in Plantations of Pinus ellottii

Based on the investigation and experimental trials for thinning and pruning on same site,planting densities and stand age,the first time for thinning and pruning of Pinus ellottii plantation was at 7~8 years old.While standard degree of closing of the plantation reached 0.85,current annual increment of DBH started to decline,and the intensity of thinning should not exceed 30%.The second time of thinning should be based on the silvicultural purpose and management intensity,usually intensity of thinning should not exceed 35%,and thinning interval was about 5~6 years.If the culture aims are for the large diameter of construction commercial forest,the third thinning should be carried out,and 600~680 tree/hm~2 should be reserved for harvest.Pruning should be practiced after thinning,and intensity of pruning is 1/3 of tree height for the first time,while 1/2 of tree height is for the second time.The pruning interval is about 3~5 years,and pruning times are the best from early spring to deep autumn.