【作者】 李兰花；

【导师】 朱金兆；

【作者基本信息】 北京林业大学 ， 水土保持与荒漠化防治， 2011， 博士

【摘要】 森林是人类赖以生存的重要自然资源,作为陆地生态系统的主体对调节生态平衡具有不可替代的作用。而森林质量的好坏直接关系到森林功能的发挥,随着造林数量的逐年增加,营林质量也逐渐被大家所重视。而北京市低山区由于人类活支干扰、造林技术不合理,立地条件所限等一系列因素,从而导致大量残次林的生成。为此,急需要对北京市低山区残次水土保持林进行一次全面的调查及质量的评价。为下一步提高林分质量提供理论依据。在北京低山区6个区县的典型区设置了40块标准样地,对油松、侧柏、刺槐、栎类、山杨、灌木丛林等群落个体进行每木调查,采用样方法调查了灌木、草本、幼苗更新状况、同时进行立地条件调查、土壤调查、水文调查等相关调查工作。主要研究结果兹分述如下：(1)北京低山区植被结构呈不稳定趋势从对北京市低山区进行植被调查可以看出,有相当一部分林分结果杂乱无章,无规律可循。这种情况一方面受树种或栽植技术影响,另一方面也受当地立地条件影响。在某种程度上,立地条件对其影响会更直接。(2)构建了合理的残次水土保持林的评价指标体系结合当地实际情况,运用数理统计方法及专家咨询筛选出三级共17个评价指标,评价指标涉及林分完整性、林分稳定性及其立地条件三项一级指标。运用模糊矩阵与数学方法相结合确定每一指标的标准。(3)建立了评价综合模型运用层次分析与专家分析相结合的方法,对每一评价指标确定一权重,利用SPSS数理统计学方法最终确定了残次水土保持林的评价模型。所建立的综合模型的公式为：s=(?)WiXi根据模型计算及前面所确定的每一指标的标准划分,再运用系统分析软件SPSS对评价得分综合值进行聚类分析。将残次林等级分为四级：①综合评价值大于8分的为优质林；②综合评价值在6-8分为一级残次林,属生长潜力型,即停止人为干扰,加以时日即可自行恢复；③综合评价值在4-6分为二级残次林,属抚育改造型,采用疏伐或其他一些措施即可恢复；④综合评价值在4分以下的为三级残次林,属砍伐重建型,将现有林分全部砍倒,再按合理树种及合理结构重新栽植。(4)运用评价体系及综合评价模型对所取40样地进行评价确定了所属北京6区县的40个样地的残次林等级,根据权重值中每一指标值分析残次林形成原因,为进一步采取改造措施提供理论依据。更多还原

【Abstract】 Forest plays very important role in adjusting ecosystem balance as the principal part of terrestrial ecosystem and important natural resource for people to live on. Moreover forestry quality has the direct relation to the play of forestry function,with the increase of the number of afforestation yearly, people pay more attention to the quality of forest increasingly. However, there were a large number of relict forest in low mountain areas of beijing because of the interference of human activity, unreasonable technology of afforestation, restriction of site conditions and so on.Therefore, in order to provide some theoretical foundation for promote forest quality, it’s time to make an all-around investigation and quality’s evaluation to relict water and soil conservation forests in Beijing low mountain.There have set up fourty standard plots in six countries’s typical areas in Beijing low mountain,and individuals to every wood for Pinus tabulaeformis, Platycladus orientalis, Robinia pseudoacacia, Quercus L, Populus davidiana, scrub forest and so on, investigate bush, herbaceous plant and seedling distribution situation simultaneously site condition investigation, soil survey, hydrology investigation and related investigations. The main research results this points as follows:(1) Beijing low mountain vegetation structure is not stable trendIn Beijing to low mountain from vegetation investigation can see, there are quite a few follow stand results desultorily, erratic. This situation by planting technology on tree or influence, on the other hand also influenced by local site condition the influence. To some extent, the effect will be the site conditions for more direct.(2)The reasonable construction machine of relict water and soil conservation forests evaluation index systemCombined with the local actual condition, using the mathematical statistics method and expert consultation screened level 3 total 17 evaluation index, evaluation index involving stand integrity, stability and site conditions stand three primary index. The fuzzy matrix combined with mathematical method to determine each index standards.(3) Establish a comprehensive model evaluationUsing the hierarchical analysis and expert analysis the method of combining the every evaluation index sure a weight and SPSS mathematical statistical methods to determine the final second water and soil conservation forests evaluation model. The comprehensive model established by the formula is: S＝(?)WiXiAccording to the model calculation and front of each indicator as determined by dividing the standards, systems analysis software SPSS again for comprehensive evaluation score value of clustering analysis. Will CanCiLin level into four levels:①the comprehensive evaluation value of more than eight points for high-quality forests;②in the comprehensive evaluation value into level 5-8 CanCiLin, belong to growth potential shape that stop human interference, try to time can restore automatically;③in the comprehensive evaluation value 2-5 into secondary CanCiLin, belong to tending transformation model, adopt thinning or some other measures can restore;④in the comprehensive evaluation value of two points below CanCiLin, belong to a category 3 type, will existing logging reconstruction stand all cut down, and then press reasonable tree species and reasonable structure to planting.(4) Use evaluation system and comprehensive evaluation model to take 40 sample which are evaluatedDetermine the subordinate counties in Beijing 40 of the six relict forest sample level, according to the weight value in each index analysis, and then relict forest formation reasons to take effective reform measures.更多还原