干扰强度对会同杉木林内环境特征的影响研究

发布时间：2018-04-20 13:48

本文选题：干扰强度 + 杉木人工林　；参考：《湖南大学》2016年博士论文

【摘要】：间伐干扰对人工林生态服务功能过程影响的研究是当今环境生态学研究的热点之一。本文以湖南会同县11年生杉木人工林为研究对象,按不同干扰强度设计了4种干扰措施(不干扰、15%弱度干扰、30%中度干扰、50%强度干扰),探讨了不同干扰强度对杉木人工林生态系统的林下植物多样性、水环境、土壤环境、凋落物、林分结构与碳动态特征,以期获得干扰措施提高杉木人工林生产力,改善人工林地的生态功能的准确数据,并为杉木人工林的优化提供理论依据。本文的具体研究工作及成果可以归纳为以下五个方面：(1)干扰强度对杉木林下生态系统(林下微环境、林下植物多样性和林下凋落物)的影响研究表明,不同干扰强度处理后的林下微环境因子随季节和时间变化明显,林下植物种类数量相对于对照区会明显增加。杉木林林下植被以灌木和草本为主,而小乔木是比较少的。林下植被中的生物量表现为随着干扰强度的增强而增大,并且与对照样相比生物量都增加。随着干扰强度的增强,灌木植物层和草本植物层的盖度和Shannon-Wiener指数都呈现增大的趋势。随着干扰强度的加大,林下凋落物的未分解层和半分解层单位面积生物量逐渐减小,然而林下凋落物分解层单位面积生物量随着干扰强度的增大而增大。(第3章)(2)干扰能有效降低酸沉降的危害和减小地表径流。会同杉木林生态观测站所在区域的酸沉降非常严重,干扰区域的地表和地下径流的pH值在干扰后会趋近于正常值,主要是由于干扰后的森林结构得到改善,并且林下植被层、枯叶层和土壤会有效缓解了酸沉降的造成的危害。在不发生大暴雨和特大暴雨的情形下,干扰能有效减小地表径流。在本研究范围内,减少地表径流和缓解酸沉降的效果随着干扰强度的增大而增大。(第4章)(3)在干扰作用下,土壤性质得到了明显的改良。干扰使土壤结构(孔隙度和容重)性质得到改善,从而使得土壤的通气性和透水性提高,进而提高了土壤肥力。干扰显著地增加了杉木林地土壤pH值,pH的提高可以增加营养元素的有效含量,从而增强土壤的肥力。同时,干扰能够引起土壤养分全量、土壤速效养分含量和土壤有机质含量的提高。在干扰作用下,过氧化氢酶、脲酶和蛋白酶活性都有不同程度的增加。干扰对土壤酶活的作用随季节的变化比较明显,夏季和秋季的下,干扰作用非常显著。干扰对土壤性质的作用在浅层土壤中更加明显,且在本研究中50%干扰强度的作用更加显著。(第5章)(4)通过研究不同干扰强度对杉木林林分生长因子、林分生物产量、林分郁闭度和叶面积指数的影响,表明采取人工干扰措施有利于杉木林的生长。干扰可以增加杉木林林分的单株材积,综合考虑株数以及单株材积,在不同干扰强度之下蓄积量表现为15%弱度干扰对照50%强度干扰30%中度干扰。不同干扰强度的林分树枝和树干材生物产量比未干扰林分大,在15%弱度干扰时树枝和树干材生物量占总生物产量的比率最大。(第6章)(5)不同的干扰强度对杉木林乔木层碳储量的影响具有显著差异。其中,单株碳储量随着干扰强度增加而增大,然而,单位面积的碳储量则随着干扰强度增加而下降。干扰后的灌木层和草本层的碳储量都显著地增加。同时,凋落物层碳储量增加较明显。随着干扰强度的增加,土壤总碳储量呈现增加的趋势。不同干扰强度作用下,杉木林中土壤的呼吸速率强度大小依次为50%干扰15%干扰未干扰30%干扰。杉木林中的土壤呼吸随季节的变化规律比较明显,从4月到12月呼吸速率呈现先增后减的趋势,在8月份的时候达到最大。(第7章)
[Abstract]:The study of the influence of thinning on the ecological service function process of plantation is one of the hotspots in the study of environmental ecology. In this paper, 4 kinds of interference measures (no interference, 15% weak interference, 30% moderate interference and 50% intensity interference) are designed for 11 year old Chinese Fir Plantation in Huitong County of Hunan. The intensity of the forest plant diversity, water environment, soil environment, litter, forest structure and carbon dynamic characteristics of Chinese fir plantation ecosystem, in order to obtain interference measures to improve the productivity of Chinese fir plantation, improve the ecological function of artificial forestland, and provide theoretical basis for the optimization of Chinese fir plantation. The work and results can be summed up in the following five aspects: (1) the effects of interference intensity on the sub forest ecosystem under forest (under forest micro environment, plant diversity under forest and litter under forest), the results show that the microenvironmental factors under different interference intensity changes with season and time, and the number of plant species under forest is relative to the control area. The lower vegetation in Cunninghamia lanceolata was dominated by shrubs and herbs, and small trees were less. The biomass in the undergrowth vegetation was increased with the enhancement of the interference intensity, and the biomass was increased. With the enhancement of the interference intensity, the coverage and Shannon-Wiener index of the shrub plant layer and herbaceous plant layer were both. With the increase of interference intensity, the biomass of undecomposed and semi decomposed layers in under forest litter decreased gradually, but the biomass of litter decomposition layer increased with the increase of interference intensity. (third) (2) interference could reduce the harm of acid deposition and reduce surface runoff. The acid settlement in the area where the forest ecological observation station is located is very serious. The pH value of the surface and underground runoff in the disturbed area will be close to the normal value after interference, mainly due to the improvement of the forest structure after interference, and the subsoil layer, the dead leaf layer and the soil will effectively alleviate the damage caused by acid settlement. In the case of heavy rainstorm, interference can effectively reduce surface runoff. In this study, the effect of reducing surface runoff and alleviating acid settlement increases with the increase of interference intensity. (fourth) (3) soil properties have been improved obviously under interference. Interference makes soil structure (porosity and bulk density) improved, so that interference can improve the properties of soil structure (porosity and bulk density). The soil fertility and soil fertility were improved, and soil fertility was enhanced. The soil pH value was significantly increased by interference. The increase of pH could increase the effective content of the nutrient elements and enhance the soil fertility. At the same time, the disturbance could cause the total soil nutrient, the content of soil soil available nutrients and the content of soil organic matter. Under interference, the activity of catalase, urease and protease increased in varying degrees. The effect of interference on soil enzyme activity was obvious with the change of season. The interference effect was very significant in summer and autumn. The effect of interference on soil properties was more obvious in shallow soil, and the effect of 50% interference intensity in this study More significant. (4) (fifth) (4) through the study of the effects of different interference intensity on the growth factor of Chinese fir forest, the biomass of stand, the canopy density and the leaf area index, it is shown that the artificial interference measures are beneficial to the growth of Chinese fir forest. The interference can increase the individual volume of the Chinese fir forest, considering the number of trees and the volume of individual trees, and not The storage volume under the same interference intensity is 15% weak degree interference and 50% intensity interference 30% moderate interference. The biomass of tree branches and tree stem wood with different interference intensity is larger than that of undisturbed forest. The ratio of tree stem and tree biomass to total biomass is the largest in 15% weak degree interference. (Sixth) (5) different interference intensity to Chinese fir forest There was a significant difference in the impact of carbon storage in the tree layer. Among them, the carbon reserves of single plant increased with the increase of interference intensity. However, the carbon reserves per unit area decreased with the increase of interference intensity. The carbon reserves in the shrub layer and the herb layer after interference increased significantly. Meanwhile, the carbon reserves in the litter layer increased significantly. With the interference intensity. In addition, the total soil carbon reserves showed an increasing trend. Under the effect of different interference intensity, the soil respiration rate in Chinese fir forest was 50% interference and 15% interference without interference of 30% interference. The change of soil respiration in Chinese fir forest was more obvious with the season, from April to December, the rate of respiration rate increased first and then decreased, in August. The time reaches the maximum. (the seventh chapter)

【学位授予单位】：湖南大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：S718.5

【参考文献】