朝阳地区油松不同林龄阶段生长与立地因子关系研究

发布时间：2018-04-13 00:35

  本文选题：朝阳地区 + 油松　； 参考：《沈阳农业大学》2017年硕士论文

【摘要】：辽西朝阳地区沙尘频繁、干旱多灾,生态失衡问题持续已久。据相关资料表明,该去立地条件复杂、立地环境恶劣是导致该地区造林成活率和保存率较低的重要原因,也是阻碍朝阳地区森林覆盖率快速、稳固提高的主要因素。油松(Pinus tabulaeformis)作为耐干旱、耐瘠薄的优秀树种,是目前该地的主要造林树种之一。为改善该地区生态环境现状,发掘探索该地区油松生长与立地因子的相关性,为朝阳地区油松的合理栽培及经营提供辅助性建议,本文以朝阳地区油松为研究对象,收集朝阳地区油松人工林共计27643个小班调查资料作为研究样本进行统计分析。以坡向(X1)、坡位(X2)、坡度(X3)、海拔(X4)、土层厚度(X5)、土壤质地(X6)为自变量,在划分林级的基础上采用主成分分析法及相关分析法,进行立地因子的主成分分析,并以主成分作为新自变量分别与油松平均树高、胸径和公顷蓄积进行相关性测定,确定影响油松平均树高、胸径以及公顷蓄积的主要立地因子,进而探索该地区油松随年龄增长其主要影响立地因子的变化,找寻影响各龄级油松不同生长量的主要立地因子。主要研究结果如下:(1)坡位及土壤质地对油松树高有较大的影响;在幼树时期油松胸径与土壤情况相关性较大,而随着林龄的增加,油松胸径受到海拔等地形因子的影响逐步增大;坡位是该地油松公顷蓄积的关键影响因子。(2)土壤质地和土层厚度是朝阳地区油松生长的主要影响因子,油松在幼龄时期受到土壤因子特别是土壤质地的影响比较大,近熟林和成熟林的林分生长也与土壤情况密切相关。次级影响因子为海拔、坡位、坡向。而坡度对油松生长情况影响效果不但较弱、而且呈间隔性地发生在个别年龄段。根据以上研究结果可知,栽种前进行整地是提高朝阳地区油松存活率和保存率的有效手段,森林经营过程应当侧重改善土壤状况。(3)坡位是另一个影响朝阳地区油松生长的重要立地因子,在油松进入快速生长发育期一直到发育至成熟林之前坡位对油松生长量变化起了重要影响作用,(4)与其他立地因子相比,坡度对朝阳地区油松生长情况影响效果最弱,即坡度的平峭对该地区油松生长影响较微。油松造林为朝阳地区大坡度地区进行荒山绿化和水土保持提供了可行性,对扩大朝阳地区绿化范围有重要意义。(5)朝阳地区油松从幼龄林到成熟林对其生长有重要影响的立地因子数量经历由少变多再变少的过程,在Ⅲ、Ⅳ龄级时受各立地因子影响最为明显且广泛,此段时期加强对油松人工林的经营和抚育力度,是保证油松林能健康发展到成熟林的有效途径。
[Abstract]:In Chaoyang area of western Liaoning Province, dust and dust are frequent, drought and disaster, ecological imbalance problem has been persistent for a long time.According to the relevant data, the condition of site removal is complex, and the bad site environment is the important reason leading to the low survival rate and preservation rate of afforestation in this area. It is also the main factor that hinders the rapid and steady improvement of forest coverage in Chaoyang area.Pinus tabulaeformis is one of the main afforestation species in this area.In order to improve the present situation of ecological environment, explore the correlation between the growth of Pinus tabulaeformis and site factors in Chaoyang area, and provide auxiliary suggestions for the rational cultivation and management of Pinus tabulaeformis in Chaoyang area, this paper takes Pinus tabulaeformis in Chaoyang area as the research object.A total of 27643 small classes of Pinus tabulaeformis plantation in Chaoyang area were collected for statistical analysis.Based on the independent variables of slope direction X _ 1, slope position X _ 2, gradient X _ 3N, elevation X _ 4N, soil thickness X _ 5N and soil texture X _ 6), principal component analysis (PCA) and correlation analysis (PCA) were used to analyze site factors on the basis of the classification of stand grade.With the principal component as the new independent variable, the correlation between the average tree height, DBH and hectare accumulation of Pinus tabulaeformis was determined, and the main site factors affecting the average tree height, DBH and hectare accumulation of Pinus tabulaeformis were determined.Furthermore, the changes of site factors of Pinus tabulaeformis in this area with the increase of age were explored, and the main site factors affecting the growth of Pinus tabulaeformis at different age levels were found.The main results are as follows: (1) the slope position and soil texture have great influence on the height of Pinus tabulaeformis.The DBH of Pinus tabulaeformis was gradually affected by elevation and other topographic factors, and the slope position was the key factor for the accumulation of Pinus tabulaeformis in this area. The soil texture and soil thickness were the main factors affecting the growth of Pinus tabulaeformis in Chaoyang area.Pinus tabulaeformis was influenced by soil factors, especially soil texture, and the stand growth of near mature forest and mature forest was closely related to soil condition.The secondary influencing factors were elevation, slope position and slope direction.The effect of slope on the growth of Pinus tabulaeformis was not only weak, but also occurred periodically in individual age groups.According to the above research results, land preparation before planting is an effective means to improve survival rate and preservation rate of Pinus tabulaeformis in Chaoyang area.The slope position is another important site factor affecting the growth of Pinus tabulaeformis in Chaoyang area.The slope position had an important effect on the growth of Pinus tabulaeformis during the period of rapid growth and development until the mature forest.) compared with other site factors, the slope had the weakest effect on the growth of Pinus tabulaeformis in Chaoyang area.In other words, the flat slope had little effect on the growth of Pinus tabulaeformis in this area.Afforestation of Pinus tabulaeformis provides feasibility for afforestation and soil and water conservation in large slope areas of Chaoyang area.In Chaoyang area, the number of site factors which have an important effect on the growth of Pinus tabulaeformis from young forest to mature forest has experienced the process of changing from less to more and then to less, in the third, the number of site factors of Pinus tabulaeformis var. tabulaeformis var. tabulaeformis has changed from less to more.The influence of site factors on 鈪，

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