广西大青山杉木马尾松人工林近自然化改造试验研究

发布时间：2018-05-31 08:46

本文选题：近自然化改造 + 杉木　；参考：《中国林业科学研究院》2017年博士论文

【摘要】：在近自然森林经营的原则指导下,以桂西南地区14年生马尾松(Pinus massoniana)、杉木(Cunninghamia lanceolata)人工针叶纯林为对象,设置系列采伐强度和林下多树种套种开展近自然化改造研究。马尾松采伐强度设置为I(80%)、II(73%)、III(66%)和IV(59%);杉木为I(69%)、II(60%)、III(51%)、IV(40%),均以不采伐不套种处理为对照,套种大叶栎(Castanopsis fissa)、红椎(Castanopsis hystrix)、灰木莲(Manglietia glauca)、香梓楠(Michelia hedyosperma)、格木(Erythrophleum fordii)5个阔叶树种。通过保留木和套种树种生长、林下植被9年定位观测调查以及林地土壤的定期取样分析,揭示林木生长、林下植被多样性以及林地土壤化学性质的动态变化及其对采伐强度的响应,探明人工针叶林近自然化改造效果,为人工针叶纯林近自然化改造提供理论依据和科技支撑,从而加快人工针叶纯林向结构合理、生态功能强、景观效果好和经济效益高的近自然林演变。主要研究结果如下:(1)采伐强度显著影响马尾松和杉木保留木生长,其单株材积、胸径、冠面积的年均增长量随采伐强度的降低而减小,均显著高于对照(P0.05);林分蓄积量的年均增长量则随采伐强度的降低而递增,均显著低于对照(P0.05);但采伐强度对树高影响不显著(P≥0.05)。马尾松人工林生长对采伐的动态响应以树冠最敏感,冠面积首先急剧增大,进而引起胸径的快速生长;树高和枝下高年均增量变化相对平稳。而杉木人工林生长对采伐的动态响应以树冠和胸径最敏感,冠幅、胸径首先急剧增大,进而引起单株材积的快速生长。相同采伐处理下,马尾松林分冠面积年均增长量在采伐后第1~3年显著高于采伐后期;第3~5年胸径年均增长量最高。杉木冠幅、胸径和枝下高年均增量在采伐后第1~3年最大;单株材积、树高和林分蓄积的年均增量高峰出现在采伐后第3~5年。相同年份下,马尾松单株材积和胸径以处理I为最高,杉木单株材积和胸径则以处理III为最高,而两个树种的枝下高和蓄积均以对照为最高。采伐后第9年,马尾松处理II、III和IV的林分蓄积量与对照差异不显著,杉木处理III的林分蓄积量与对照差异不显著。根据单株材积和林分蓄积量比较认为,马尾松以采伐处理II(保留密度为300株·hm-2)为最佳,杉木以594株·hm-2(III)保留密度为宜。(2)马尾松、杉木林下套种第3年,大叶栎的胸径、树高和冠幅以及灰木莲的树高和冠幅、红椎的树高出现生长高峰;第5年,红椎、灰木莲、香梓楠的胸径出现生长高峰;第9年,格木的胸径、树高和冠幅以及香梓楠的树高和冠幅、红椎的冠幅增长量最大。从5个阔叶树胸径、树高和冠幅生长总体表现看,其生长速度为大叶栎红椎灰木莲香梓楠格木。套种后9年间,采伐强度显著影响马尾松林下套种阔叶树的生长,其中大叶栎和灰木莲的胸径、树高和冠幅以及红椎的胸径和冠幅的生长随采伐强度降低而减小;而香梓楠的胸径生长随采伐强度降低而增大;红椎、格木的树高生长受采伐强度影响不大;格木的胸径和冠幅以及香梓楠的树高和冠幅生长在套种前7年受采伐强度影响不大,此后其生长随采伐强度降低而减小。因此,马尾松林下套种香梓楠则宜采用保留密度为375株·hm-2和450株·hm-2套种,套种其他4个树种宜采用保留密度为225株·hm-2和300株·hm-2的采伐强度。杉木采伐强度对套种阔叶树的生长大多表现为中度采伐强度优于强度和弱度处理,但并未呈现明显规律。香梓楠的胸径、树高、枝下高和冠幅生长最慢,大叶栎则生长最快;大叶栎在采伐处理II(488株·hm-2)下套种优于其余3个采伐处理,格木则适合在采伐处理I(375株·hm-2)下套种,红椎、灰木莲和香梓楠适合在采伐处理III(594株·hm-2)下套种。(3)马尾松强度采伐后第1年,其林下植物种类数量显著增加,随时间的推移,林下植被多样性呈现一直减少的趋势;采伐后第1、5和9年,马尾松灌木层和草本层的Simpson多样性指数、Pielou均匀度指数分别以保留密度为300株·hm-2、375株·hm-2和225株·hm-2的林分为最高;物种数、Margalef丰富度指数和Shannon-Wiener指数随着采伐强度增加变化趋势较为平稳。杉木采伐后第1年,随着采伐强度的增加,灌木层和草本层物种数、Margalef丰富度指数、Shannon-Wiener多样性指数均呈递增趋势,但仅处理I显著高于对照;第5年,处理Ⅰ的各多样性指数与对照差异不显著,其余3个采伐处理的灌木层和草本层物种数、Margalef丰富度指数均显著小于对照,处理IV的草本层Shannon-Wiener多样性指数、Simpson多样性指数、Pielou均匀度指数显著高于对照;第9年,4个采伐处理灌木层Margalef丰富度指数显著低于对照,处理III草本层Margalef丰富度指数、Shannon-Wiener多样性指数、Simpson多样性指数、Pielou均匀度指数显著高于对照。(4)采伐和林下套种处理能够改善马尾松、杉木林地土壤养分状况,采伐后第3~9年,随着时间推移,O层土壤的有机质、全氮显著增加,土壤肥力上升,A层和B层土壤无显著变化,总体上土壤缺磷、缺钾严重;各土层养分含量均为O层高于A、B层。对于马尾松而言,4个采伐处理的土壤p H值、有机质含量等8个指标均随着时间的推移呈先降低随后逐渐升高的趋势;而杉木林地随着时间的推移,各处理的速效磷、全钾显著升高,而其余各项养分指标年际变化不大。土壤有机质和全氮含量与其他土壤养分含量显著相关,对马尾松和杉木林地土壤肥力具有明显的指示作用。马尾松土壤肥力综合指数随着时间的推移呈现先下降而后缓慢升高;采伐强度越大,肥力指数越低;采伐后第9年,处理IV(450株·hm-2)和对照的肥力指数显著高于其余3个采伐处理。杉木土壤肥力综合指数则为对照高于4个采伐处理;采伐后第3~9年,采伐处理I(375株·hm-2)和IV(732株·hm-2)的肥力指数高于处理II(488株·hm-2)和处理III(594株·hm-2)。采伐处理9年内4个采伐处理的土壤养分含量还未赶上对照处理,说明通过强度采伐和套种阔叶树来改良针叶纯林土壤养分状况是一个长期的过程。
[Abstract]:Under the guidance of the principles of natural forest management, with the 14 year old Pinus massoniana of Southwest Guangxi and the pure plantation of Chinese fir (Cunninghamia lanceolata) artificial coniferous forest, a series of cutting intensities and multi tree species under the forest were set up to carry out a close naturalization study. The cutting strength of Pinus massoniana was set to I (80%), II (73%), III (66%) and IV (59%). Cunninghamia lanceolata is I (69%), II (60%), III (51%) and IV (40%), which are controlled by non harvesting and intercropping, interplanting large leaf oak (Castanopsis fissa), red vertebra (Castanopsis hystrix), Lilia (Manglietia glauca), fragrant catalpa (Michelia hedyosperma), 5 broad-leaved tree species. The 9 year orientation observation survey and the regular sampling analysis of the woodland soil revealed the growth of forest trees, the diversity of the vegetation, the dynamic changes of the chemical properties of the soil and the response to the cutting intensity, and the effect of the near naturalization of artificial coniferous forests, which provided the theoretical basis and scientific support for the near naturalization of artificial coniferous forest. The main results were as follows: (1) the growth of Pinus massoniana and Sugiki Boruki was significantly affected by the cutting intensity, and the annual growth of single tree volume, diameter and crown area decreased with the decrease of cutting intensity. In contrast (P0.05), the annual growth of stand volume increased with the decrease of cutting intensity, which was significantly lower than that of the control (P0.05), but the effect of cutting intensity on tree height was not significant (P > 0.05). The dynamic response of Pinus massoniana plantation to cutting was most sensitive to the tree crown, and the crown area increased rapidly, and the tree growth was rapidly growing; The dynamic response of the high and lower branches is relatively stable. The dynamic response of the growth of Chinese fir plantation to cutting is the most sensitive to the crown and the breast diameter, the crown and the DBH first increase rapidly, which leads to the rapid growth of the individual volume. Under the same cutting treatment, the annual average growth of the crown area of the Pinus massoniana forest is significantly higher than that after the cutting in the 1~3 year after cutting. The annual average annual increment of DBH in 3~5 was the highest. The annual increment of Cunninghamia lanceolata crown, breast diameter and branch height was the largest in 1~3 year after cutting, and the annual average increment peak of individual volume, tree height and stand accumulation appeared in 3~5 year after cutting. Under the same year, the individual volume and chest diameter of Pinus massoniana were the highest, the individual volume and DBH of Cunninghamia lanceolata were located in the same year. III was the highest, and the height and accumulation of the two tree species were the highest. Ninth years after the harvesting, the difference in the stand volume of the stand of Masson Pine treated with II, III and IV was not significant. The difference of the stand volume between the stand and the control of the III was not significant. The optimum retention density is 300 plant hm-2. The suitable density of 594 plants and hm-2 (III) is suitable for Chinese fir. (2) Pinus massoniana, Cunninghamia lanceolata under third years, the diameter of oak, tree height and crown, the height and crown of the tree, the height of the tree height of the red vertebra; fifth years, the peak of the breast of the red vertebra, the grey wood lotus and the fragrant catalpa Phoebe; Ninth years, grig. The diameter of the DBH, the tree height and the crown, the height and the crown of the red vertebra were the largest. The growth rate of the 5 broadleaf trees, the tree height and the canopy growth, was the growth rate of the oak tree of the oak tree of the oak. After 9 years, the cutting intensity significantly affected the growth of the broad-leaved tree under the Masson pine forest. The DBH, tree height and crown, and the growth of the diameter and crown of the red vertebrae decreased with the cutting intensity, and the growth of the DBH was increased with the cutting intensity, and the height growth of the red and green trees was less affected by the cutting strength; the diameter and crown of the tree and the height and crown of the tree were growing in the interplanting. The first 7 years had little influence on the cutting intensity, and then its growth decreased with the decrease of cutting strength. Therefore, the preservation density of 375 plants, hm-2 and 450 hm-2 interplanting should be adopted in the undergrowth of Pinus massoniana, and the other 4 tree species should be harvested with the retention density of 225, hm-2 and 300 plant. The growth of leaf tree mostly showed that the moderate cutting strength was better than strength and weak degree treatment, but it did not show obvious rules. The diameter of the tree, the height of the tree, the height and the crown of the branch were the slowest, and the large leaf oak growth was the fastest. The large leaf oak was superior to the other 3 cutting treatments in the cutting treatment II (488 plant. Hm-2), and the tree was suitable for the harvesting and treatment of I (375). Under plant and hm-2, the red vertebra, the grey wood lotus and the fragrant catalpa Nana were suitable for interplanting under the cutting treatment of III (594 plant. Hm-2). (3) first years after the cutting of Pinus massoniana, the species number of the under forest plant species increased significantly. The vegetation diversity of the undergrowth showed a tendency to decrease with the time, and the 1,5 and 9 years after cutting, the Simp of the Masson Pine shrub layer and the herb layer. Son diversity index and Pielou evenness index were the highest in the stand density of 300 plant, hm-2375 plant, hm-2 and 225 plant. Hm-2. The number of species, Margalef richness index and Shannon-Wiener index were more stable with the increase of cutting intensity. After fir logging, the shrub layer and herb were increased with the increase of cutting intensity. The number of layers, the Margalef richness index and the Shannon-Wiener diversity index were all increasing, but the only treatment I was significantly higher than the control. Fifth years, the diversity index of the treatment I was not significantly different from the control. The number of shrub and herb layers and the Margalef richness index of the other 3 cutting treatments were significantly smaller than those of the control, and the IV herbs were treated. The Shannon-Wiener diversity index, the Simpson diversity index and the Pielou evenness index were significantly higher than those of the control. In the ninth year, the Margalef richness index of the 4 cutting shrubs was significantly lower than that of the control. The Margalef richness index of the III herb layer, the Shannon-Wiener diversity index, the Simpson diversity index and the Pielou evenness index were significantly higher than those of the control. (4) (4) cutting and subplanting treatment can improve the soil nutrient status of Pinus massoniana and Chinese fir woodland, after 3~9 year, the organic matter of the soil in the O layer increased significantly, the soil fertility increased, the soil fertility increased, the A layer and the B layer had no significant changes. In general, the soil soil was deficient in phosphorus and potassium deficiency was serious, and the nutrient content of each soil layer was O higher than A, B For Pinus massoniana, the 8 indexes, such as P H value, organic matter content and so on, decreased first and then gradually increased with the passage of time; and with the passage of time, the total potassium of each treatment was significantly increased with the passage of time, while the interannual changes of the other nutrients were not significant. Soil organic matter and total nitrogen were not changed. The content of soil fertility in Pinus massoniana and Chinese fir woodland was clearly indicated. The soil fertility index of Masson pine was first descended and then slowly increased with time, and the higher the cutting strength, the lower the fertility index; Ninth years after cutting, the fertility index of IV (450 plants.) and the control were treated. The soil fertility index of Cunninghamia lanceolata was higher than that of the other 3 cutting treatments. The soil fertility index of Cunninghamia lanceolata was higher than that of 4 cutting treatments, and the fertility index of I (375 plant. Hm-2) and IV (732 plant hm-2) after felling was higher than that of II (488 plant. Hm-2) and III (594 plant. Hm-2). The soil nutrient content of the harvesting treatment in 9 years was also higher than that of the treatment for 9 years. It is a long-term process to improve soil nutrient status of pure coniferous forest by intensity harvesting and interplanting broad-leaved trees.
【学位授予单位】：中国林业科学研究院
【学位级别】：博士
【学位授予年份】：2017
【分类号】：S756

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