本文選題：朝陽地區(qū) + 油松�。� 參考：《沈陽農(nóng)業(yè)大學(xué)》2017年碩士論文

【摘要】：遼西朝陽地區(qū)沙塵頻繁、干旱多災(zāi),生態(tài)失衡問題持續(xù)已久。據(jù)相關(guān)資料表明,該去立地條件復(fù)雜、立地環(huán)境惡劣是導(dǎo)致該地區(qū)造林成活率和保存率較低的重要原因,也是阻礙朝陽地區(qū)森林覆蓋率快速、穩(wěn)固提高的主要因素。油松(Pinus tabulaeformis)作為耐干旱、耐瘠薄的優(yōu)秀樹種,是目前該地的主要造林樹種之一。為改善該地區(qū)生態(tài)環(huán)境現(xiàn)狀,發(fā)掘探索該地區(qū)油松生長與立地因子的相關(guān)性,為朝陽地區(qū)油松的合理栽培及經(jīng)營提供輔助性建議,本文以朝陽地區(qū)油松為研究對象,收集朝陽地區(qū)油松人工林共計27643個小班調(diào)查資料作為研究樣本進行統(tǒng)計分析。以坡向(X1)、坡位(X2)、坡度(X3)、海拔(X4)、土層厚度(X5)、土壤質(zhì)地(X6)為自變量,在劃分林級的基礎(chǔ)上采用主成分分析法及相關(guān)分析法,進行立地因子的主成分分析,并以主成分作為新自變量分別與油松平均樹高、胸徑和公頃蓄積進行相關(guān)性測定,確定影響油松平均樹高、胸徑以及公頃蓄積的主要立地因子,進而探索該地區(qū)油松隨年齡增長其主要影響立地因子的變化,找尋影響各齡級油松不同生長量的主要立地因子。主要研究結(jié)果如下:(1)坡位及土壤質(zhì)地對油松樹高有較大的影響;在幼樹時期油松胸徑與土壤情況相關(guān)性較大,而隨著林齡的增加,油松胸徑受到海拔等地形因子的影響逐步增大;坡位是該地油松公頃蓄積的關(guān)鍵影響因子。(2)土壤質(zhì)地和土層厚度是朝陽地區(qū)油松生長的主要影響因子,油松在幼齡時期受到土壤因子特別是土壤質(zhì)地的影響比較大,近熟林和成熟林的林分生長也與土壤情況密切相關(guān)。次級影響因子為海拔、坡位、坡向。而坡度對油松生長情況影響效果不但較弱、而且呈間隔性地發(fā)生在個別年齡段。根據(jù)以上研究結(jié)果可知,栽種前進行整地是提高朝陽地區(qū)油松存活率和保存率的有效手段,森林經(jīng)營過程應(yīng)當(dāng)側(cè)重改善土壤狀況。(3)坡位是另一個影響朝陽地區(qū)油松生長的重要立地因子,在油松進入快速生長發(fā)育期一直到發(fā)育至成熟林之前坡位對油松生長量變化起了重要影響作用,(4)與其他立地因子相比,坡度對朝陽地區(qū)油松生長情況影響效果最弱,即坡度的平峭對該地區(qū)油松生長影響較微。油松造林為朝陽地區(qū)大坡度地區(qū)進行荒山綠化和水土保持提供了可行性,對擴大朝陽地區(qū)綠化范圍有重要意義。(5)朝陽地區(qū)油松從幼齡林到成熟林對其生長有重要影響的立地因子數(shù)量經(jīng)歷由少變多再變少的過程,在Ⅲ、Ⅳ齡級時受各立地因子影響最為明顯且廣泛,此段時期加強對油松人工林的經(jīng)營和撫育力度,是保證油松林能健康發(fā)展到成熟林的有效途徑。
[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，

本文編號：1742168