永仁县云南松天然次生林生长过程分析

Analysis of Growth Process Pinus yunnanensis Natural Secondary Forests in Yongren County of Yunnan Province

采用德国近自然经营技术,将林木分为特优木、优势木、中庸木和被压木,应用永仁县云南松天然次生林的试验样地数据和树干解析资料,分析云南松天然次生林的生长过程。结果表明,云南松林分的生长过程中优势木株数只占林分总株数的27.34%,但材积占林分总材积的比例达66.58%;25年生优势木的单株平均材积是中庸木和被压木的2.91倍和10.46倍。11年生时云南松树高连年生长量最大,为0.83 m,高生长主要在3～11年;33年生时胸径连年生长量最大,为2.065 cm。胸径生长主要在11～33年,此期间林分应适度间伐,可促进其快速生长。46年生时材积连年生长量最大,为0.053 693 m3;53年后明显下降;材积生长主要在32～53年期间;60年时连年生长量和平均生长量相等,说明进入数量成熟阶段,可以主伐。云南松天然次生林的经营期长,建议引入德国近自然经营技术,提高林分质量和缩短大径级培育时间。

The growth process of Pinus yunnanensis natural secondary forests in Yongren county of Yunnan province was studied based on the tree growth investigation and analytical wood analysis. Using the stand management idea of close-to-nature from Germany, the trees of Pinus yunnanensis at study site were classified into super-dominance tree, dominance tree, co-dominance tree, suppressed tree. It was found that the number of dominance tree was only 27.34 % of the total tree number, however accounted for 66.58 % of the total volume of the stand. As far as the average volume of 25 years old tree was concerned, the individual average volume was 2.91 times and 10. 46 times of co-dominance tree and suppressed tree respectively. The current annual height increment of 11 years old tree reached the highest value, which was 2. 065 cm. The obvious growth of DBH occurred from 11 years old to 33 years old, proper intermediate cutting was suggested in this stage so as to promote the fast growth of stand. The volume increment mainly occurred from 32 to 53 years old, and obviously decreased after 53 years old. At the age of 60 year, the current annual increment was equal to the average growth increment, which indicated the stand was in the stage of mature, and suitable for cutting. Pinus yunnanensis natural secondary forests were characterized by long management stage, it was suggested to introduce close-to-nature management idea and technology from Germany, to improve the stand quality and shorten the cultivation time of big diameter wood.