| 摘要: |
| [目的]探讨不同改造模式和经营措施对林分空间结构的影响,为合理经营森林提供依据.[方法]运用角尺度、混交度和大小比数等林分结构参数,对甘肃小陇山全面清理割灌改造华山松(模式1)、油松(模式2)和日本落叶松(模式3)以及带状割灌改造华山松(模式4)、油松(模式5)5种灌木林地改造模式林分的空间结构特征进行了分析.[结果]模式1～5林分的平均角尺度分别为0.459,0.431,0.388,0.514和0.472,抚育间伐对降低全面割灌造林林分林木个体分布的均匀性有一定作用,带状割灌造林能够减少均匀性而增加随机性,使林分更接近自然;模式1～5林分的平均混交度为0.347,0.291,0.291,0.323和0.324,属于弱度混交与中度混交的过渡类型.带状割灌造林和抚育间伐不仅均有利于提高林分的混交程度,而且还均能影响林分的直径分布结构,灌木林地改造后,其林分直径结构并未表现出纯林的直径结构特征;抚育间伐能对林木个体的大小分化程度产生深刻的影响,带状割灌造林能有效地改善林分的大小分化程度.[结论]带状割灌造林模式较全面清理割灌造林模式更有利于林分结构趋于合理. |
| 关键词: 林分 经营措施 空间结构 角尺度 混交度 大小比数 |
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| 基金项目:国家林业科技支撑计划项目（2006BAD03A08-03） |
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| Impacts of different management measures on spatial structure characteristics |
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| Abstract: |
| 【Objective】 The study was done in order to know the effects of different management measures and shrub transformation models on the spatial structure and provide evidences for reasonable management forest.【Method】 Using spatial structure parameters of the uniform angle index,mingling and neighborhood comparison index,the spatial structure characteristics of five different shrub transformation models were studied.The 5 models are cutting shrub transform Pinus armandi(Model 1),Pinus tabulaeformis(Model 2),Larix kaempferi(Model 3) and zonal cutting shrub transform Pinus armand, (Model 4)and Pinus tabulaeformis(Model 5).【Result】 The results show that the average value uniform angle indexes of models 1 to 5 were 0.459,0.431,0.388,0.514,0.472 respectively.Tending thinning had obvious impacts on decreasing the uniformity of individual distribution,which made the stands closer to natural;the average values mingling of models 1 to 5 were 0.347,0.291,0.291,0.323,0.324 respectively and they belonged to slight mingling.Zonal cutting transformation and tending thinning both were good to improve the stand mingling;both the zonal cutting shrub transformation and tending thinning had impacts on stand diameter distribution,while the stand diameter distribution lost the characteristic of plantation after transformation;tending thinning had profound impacts on the size differentiation of stand and the zonal cutting shrub plantation improve the size differentiation.【Conclusion】 The different shrub transformation models and management measures had different effects on the stands spatial structure,the zonal cutting shrub transformation was more benefitial to stands,more reasonable in structure than allover cutting shrub transformation. |
| Key words: stand management measure spatial structure uniform angel index mingling neighborhood comparison |
