本文選題：杉木人工林 + 間伐強(qiáng)度　； 參考：《中南林業(yè)科技大學(xué)》2017年碩士論文

【摘要】：目前,大面積杉木人工純林普遍存在林分結(jié)構(gòu)單一、地力衰退、生產(chǎn)力低下、生物多樣性下降、病蟲害加劇等一系列生態(tài)問題,嚴(yán)重制約了林地生態(tài)服務(wù)功能和可持續(xù)發(fā)展利用。因此,將現(xiàn)有的杉木純林改造為異齡針闊混交林是解決這一問題的關(guān)鍵,而在純林下補(bǔ)植闊葉樹為修復(fù)杉木純林生態(tài)服務(wù)功能提供了一條有效途徑。本文以福壽林場杉木人工中齡林為研究對象,采取隨機(jī)區(qū)組設(shè)計對杉木人工林進(jìn)行間伐和補(bǔ)植闊葉樹的經(jīng)營方式,于2012年開展試驗對試驗區(qū)內(nèi)的杉木人工林進(jìn)行3種間伐強(qiáng)度(20%、33%和56%)改造,林下補(bǔ)植3種闊葉樹大苗(深山含笑(Mchelia maudiaae)、馬褂木(LChiodendron Chinense)和欒樹(Koelreuteria paniculata)),以未間伐補(bǔ)植的純林為對照組,對照組和每個處理組設(shè)置3次重復(fù),每塊固定樣地面積為20m×30m,進(jìn)行連續(xù)定位監(jiān)測。通過分析間伐補(bǔ)植4a后杉木人工林林分的生長狀況、林分結(jié)構(gòu)以及干形質(zhì)量三方面,得出間伐補(bǔ)植闊葉樹大苗對杉木人工林生長的影響,為今后杉木人工林的撫育管理及多功能可持續(xù)經(jīng)營提供參考依據(jù)。主要結(jié)論如下:1.間伐補(bǔ)植改造對林木生長因子影響的結(jié)論為:(1)間伐補(bǔ)植改造對杉木林木的生長有促進(jìn)影響,均顯著提高了杉木的平均胸徑、樹高、冠幅、單株材積,并且隨著間伐強(qiáng)度的增強(qiáng)而增大,而每個處理組的杉木林分蓄積量卻顯著低于對照組。處理組C的杉木平均胸徑、樹高、冠幅、單株材積的生長效果最佳,在伐后第4a時,分別較間伐前增加了 63.43%、49.04%、102.24%、265.52%;而林分蓄積量較間伐前減少了 11.84%。(2)間伐強(qiáng)度對補(bǔ)植的深山含笑、欒樹、馬褂木生長沒有影響,但相比之下3種補(bǔ)植闊葉樹在處理組C中的胸徑和樹高均達(dá)到最大,且大小順序為深山含笑欒樹馬褂木。2.間伐補(bǔ)植改造對林木干形影響的結(jié)論為:(1)間伐補(bǔ)植后1-4a之間,枝下高、高徑比及胸高形數(shù)變化均隨間伐強(qiáng)度的增強(qiáng)而逐漸降低,而冠長率及尖削度隨著間伐強(qiáng)度的增強(qiáng)而增大;(2)在不同間伐補(bǔ)植的時期下,杉木枝下高、高徑比和胸高形數(shù)的年均生長率變化隨著間伐強(qiáng)度增強(qiáng)呈大致下降的趨勢,而冠長率的年均生長率隨著間伐強(qiáng)度增強(qiáng)而增大。3.間伐補(bǔ)植改造對林分結(jié)構(gòu)影響的結(jié)論為:(1)間伐補(bǔ)植在一定程度上有利于培育大徑階的杉木。間伐補(bǔ)植后1-4a之間,間伐補(bǔ)植林分胸徑有進(jìn)階生長,杉木胸徑在小徑階的分布有不同程度的減少,在10-12 cm之間的徑階株數(shù)上下波動,差異不大;在大徑階時隨間伐年限增長較快,徑階分布右移。(2)對照組杉木的最大相對直徑Rmax=1.1時,杉木株數(shù)所占百分?jǐn)?shù)達(dá)到最大;在處理組A、B的相對直徑分別為1.4和1.5時,杉木株數(shù)所占百分?jǐn)?shù)也都達(dá)到最大;對照組杉木的最大相對樹高Rmax=1.3時,杉木株數(shù)所占百分?jǐn)?shù)達(dá)到最大;處理組A和處理組B的杉木林分相對樹高分別為1.5和1.6時,杉木株數(shù)所占的百分?jǐn)?shù)為最大。
[Abstract]:At present, there are a series of ecological problems such as single stand structure, declining soil fertility, low productivity, decreasing biodiversity, increasing diseases and insect pests and so on in large area Chinese fir artificial pure forest. The ecological service function and sustainable development of forest land are seriously restricted. Therefore, the key to solve this problem is to transform the existing pure Chinese fir forest into mixed coniferous and broad-leaved forest of different ages, and to repair the ecological service function of pure Chinese fir forest by planting broad-leaved trees under pure forest. In this paper, the artificial middle age forest of Chinese fir in Fushou Forest Farm was used as the research object, and the management mode of thinning and replanting broadleaved trees of Chinese fir plantation was carried out by random block design. In 2012, three types of thinning intensity of Chinese fir plantations in the experimental area were reformed, including 33% and 56% of thinning intensity. Three species of broad-leaved tree seedlings (Mchelia maudiaaeae, LChiodendron Chinenseet) and Koelreuteria paniculata were replanted under the forest as control group. The control group and each treatment group were set up three times, each fixed sample area of 20 m 脳 30 m, for continuous location monitoring. By analyzing the growth status, stand structure and dry form quality of Chinese fir plantations after 4 years of thinning and supplementary planting, the effects of broadleaf plantlets planted by thinning on the growth of Chinese fir plantations were obtained. It provides reference for tending management and multi-function sustainable management of Chinese fir plantation in the future. The main conclusions are as follows: 1. The effect of thinning and replanting on the growth factors of Chinese fir trees was concluded as follows: (1) the effects of thinning and replanting on the growth of Chinese fir trees were improved, and the average DBH, height, crown width, volume of individual trees were significantly increased. With the increase of thinning intensity, the accumulation of Chinese fir in each treatment group was significantly lower than that in the control group. The average DBH, height, crown width and volume of individual tree in treatment group C were the best. At the 4th year after cutting, the average DBH, height, crown width and volume of individual tree in treatment group C were increased by 63.43 and 49.04 and 49.04%, respectively, compared with those before thinning, respectively, and the volume of stand volume was decreased by 11.84. 2) the intensity of thinning decreased 11.84. 2) the effect of thinning on the depth of the supplementary planting was higher than that before the thinning, and the effect of thinning on the growth of Cunninghamia lanceolata was higher than that before thinning. There was no effect on the growth of Luan tree and mandarin tree, but in contrast, the DBH and height of the three kinds of replanted broadleaved trees reached the maximum in treatment group C, and the order of size was. 2. The conclusion of the effect of thinning and replanting on tree stem shape was: (1) between 1 and 4 years after thinning, the changes of branch height, ratio of height to diameter and number of chest height decreased with the increase of thinning intensity. However, with the increase of thinning intensity, the average annual growth rate of the ratio of height to diameter and the number of breast height of Chinese fir increased with the increase of thinning intensity. The average annual growth rate of Chinese fir under branch height, height to diameter ratio and breast height number decreased with the increase of thinning intensity. The average annual growth rate of crown length increased with the increase of thinning intensity. The conclusion of the effect of thinning and replanting on the stand structure is: (1) to some extent, the thinning and replanting is beneficial to the cultivation of Chinese fir with large diameter order (Cunninghamia lanceolata). From 1 to 4 years after thinning, the DBH of the thinning and replanting stand had advanced growth, the distribution of DBH in the small diameter order of Chinese fir decreased to some extent, and the number of DBH in 10-12 cm fluctuated up and down, the difference was not significant. The maximum relative diameter of Chinese fir (Rmax=1.1) in the control group was higher than that in the treatment group, and the relative diameter of the treatment group was 1. 4 and 1. 5, respectively, and the relative diameter of the treatment group was 1. 4 and 1. 5, respectively, while the relative diameter of the treatment group was 1. 4 and 1. 5, respectively. The percentage of Chinese fir trees reached the maximum when the maximum relative height of Chinese fir was Rmax=1.3 in control group, and when the relative tree height of treatment group A and treatment B was 1.5 and 1.6, respectively, the percentage of Chinese fir trees reached the highest in the control group when the maximum relative tree height of Chinese fir was 1. 5 and 1. 6, respectively, and that of treatment group B was 1. 5 and 1.6, respectively. The percentage of the number of Chinese fir trees was the largest.
【學(xué)位授予單位】：中南林業(yè)科技大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：S791.27
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本文編號：1776203