贵州省湄潭县狭叶方竹现状及退化防治对策

为保护利用湄潭县优良狭叶方竹资源,采用作业设计调查方法对全县狭叶方竹资源普查,结果表明：湄潭县狭叶方竹林呈469个斑块状分布于岩溶山地,生长于常绿阔叶林和常绿落叶阔叶混交林下,面积1372.1hm2,其中生长正常面积631.5hm2(46.02%)、退化面积740.6hm2(53.98%)。分析发现引起狭叶方竹林退化的原因是立地因子适宜性选择和群落环境因子适应性选择综合作用的结果,主要表现在不适宜土壤瘠薄和海拔极值过渡区气候条件、不适应群落上层林木郁闭度大于0.70或0.10以下环境条件、不承受人为过度采笋伐竹干扰,其它因素为局部损害。由此提出狭叶方竹林退化防治对策,一是调控上层林木郁闭度到0.20～0.50的合理区间；二是通过间伐或补植,使立竹度、竹龄结构趋于合理；三是积极改善山区竹林经营条件,引导林农自觉养林护竹；四是退耕还竹增加狭叶方竹林面积。

Status Quo and Degeneration Control Measures of Chimonobambusa angustifolia in Meitan County, Guizhou Province

To protect and utilize Chimonobambusa angustifolia in Meitan County of Guizhou Province, its resources were surveyed through designing survey method. The results showed that C. angustifolia had 469 patches in Meitan, grew in the evergreen broad-leaved forest and evergreen and deciduous broad-leaved mixed forest, and distributed in karst mountainous areas, the growth area was 631.5 hm2(46.02%) and the degradation area was 740.6 hm2(53.98%). The results showed that the reason for the degradation of C. angustifolia forest was the comprehensive effect of the site factor’s suitability selection and the community environmental factors’ adaptive selection, and mainly appeared as being unsuitable for barren soil and altitude extreme transition zone climate, unsuitable for the community overtop canopy density of 0.70 to 0.10, and unable to bear the excessive cutting of bamboo and bamboo shoots, while other factors caused local damage. Therefore, C. angustifolia degeneration control measures are suggested as controlling the canopy density of tree upper layers to 0.20- 0.50; rationalizing the density of bamboo plantation and bamboo age structure through thinning or replanting; improving the mountainous bamboo forests operating conditions and guiding farmers to cultivate and protect it of their own will; and converting cultivated land into bamboo forests to increase the area of C. angustifolia.