【作者】 刘烁；

【导师】 周国模； 白尚斌；

【作者基本信息】 浙江农林大学 ， 森林经理学， 2010， 硕士

【摘要】 毛竹林是中国南方地区重要的森林类型,具有重要的经济价值,因此,目前对于竹林的研究主要集中在丰产栽培技术和丰产栽培模式等方面。但目前有研究表明,毛竹因其强大的分生能力,扩张情况明显,并不断纯林化,导致生物多样性的减少,景观结构单一。但关于其纯林形成的原因尚鲜见报道,而林木的生长、更新与光因子具有密切的关系,因此,研究毛竹林在蔓延过程中光环境的改变对其他木本植物的影响对于揭示毛竹纯林化具有重要的理论意义。同时对毛竹林的合理经营和保护区物种多样性的保护具有实践指导意义。本研究在天目山自然保护区内设置样地,利用照度计、无线传感器网络等手段监测了针阔混交林、针阔—毛竹混交林以及毛竹纯林内的光照强度的变化,并且利用Li-6400型光合速率仪测定三种林分类型的样地内主要的几种乔灌木的光补偿点,分析了光照强度的变化对主要几种乔灌木的光合作用的影响;同时利用UV-2550型分光光度计测定主要几种乔灌木叶绿色的吸光度,对比分析了它们与毛竹叶片的光谱吸收情况。研究结果表明:1.在光照强度的变化上,表现为以下三个特点:（1）单日内的光照强度变化在晴天表现为双峰曲线,峰值出现于下午14点和16点;（2）随着月份改变,到监测结束时,针阔混交林内光照强度下降了10μmol·m^-2.·s^-1,针阔—毛竹混交林内下降了37.6μmol·m^-2.·s^-1,毛竹纯林内下降了35μmol·m^-2.·s^-1;（3）不同林分内光照强度的结果为毛竹林>针阔—毛竹混交林>针阔混交林,针阔混交林内晴天日平均最低光照强度为9.8μmol·m^-2.·s^-1。2.在光补偿点方面,毛竹最高,其次为枫香、杉木、杉木幼苗、杜仲和油茶,分别为19.6μmol·m^-2.·s^-1、14.3μmol·m^-2.·s^-1、9.77μmol·m^-2.·s^-1、9.76μmol·m^-2.·s^-1、8.94μmol·m^-2.·s^-1、3.07μmol·m^-2.·s^-1。3.对比光照强度与主要乔灌木的光补偿点发现,在毛竹林蔓延过程中的光照强度并没有降至主要乔灌木的光补偿点之下,因此,它们的光合作用依然大于其呼吸作用,可以持续的补充有机物。光照强度的变化可能不会影响主要乔灌木的正常生长。然而,由于杉木幼苗独特的喜荫特性,光照的增强可能会影响到杉木的更新。4.光谱的吸收结果看出,由于所有植物对于可见光部分的吸收基本都集中在相同的波段范围内,且峰值也处于同样的665nm以及435nm处。但峰值的吸收程度不同,在两个峰值处均表现为杜仲>毛竹>枫香>杉木幼苗>杉木>油茶。这样毛竹蔓延可能会影响到吸收能力不及它的几种树种的生长,但是油茶能够吸收利用紫外部分的光,可能受到影响较小。更多还原

【Abstract】 Phyllostachys edulis is an important part of forest in southen area of China, and it has an imporantan economic value, so the reasrch focuses on high yield cultivation techniques and high yield mode and so on. But some study showed that phyllostachys edulis kept expansion and pure because of its strong proliferation, and this leaded to a reduction of biological diversity, and the single of landscape structure. But the study of the reasons of its pure is still rare, and the tree growth and renewal have a close relationship with light factors, so the influence of the changes of light environment on the woody plant in phyllostachys edulis stands is an important theoretical significance for the study of pure of phyllostachys edulis stands. It has practical significance for reasonable management of phyllostachys edulis forest and protection of species diversity in reserves.This study setted the plots in Tianmu mountain nature reserve, monitored the light intensity in needle board leaved mixed forest, needle board leaved-bamboo mixed forest and phyllostachys edulis forest with Quantum Meter and wireless sensor network（WSN）, detected the light compensation point （LCP） of the main trees and shrubs in three different plots with Li-6400 to analyse the influence of changes of light intensity on the photosynthesis of trees and shrubs; analysed their respective absorbance with Spectrophotometer UV-2550 to compare them with the absorption spectrum of bamboo leaves.The result shows:1. There are three characteristics in the Changes in lght intensity as the follow: （1） The variety of light intensity in a single sunny day was bimodal cure, the peak showed at 14:00 and 16:00; （2） The light intensity reduced 10μmol·m^-2.·s^-1 in needle board leaved mixed forest, 37.6μmol·m^-2.·s^-1 in needle board leaved-bamboo mixed forest and 35μmol·m^-2.·s^-1 in phyllostachys edulis forest as the month change; （3） The light intensity in different plots was phyllostachys edulis forest > needle board leaved-bamboo mixed forest > needle board leaved mixed forest, and the minimum of sunny average daily light insity was 9.8μmol m^-2 s^-1 in needle board leaved mixed forest.2. The light compensation point of Moso bamboo is the highest, followed by Liquidambar formosana, fir, fir seedlings, Eucommia ulmoides Oliver, and Camellia Oleifera. The light compensation point of these plant species are 19.6μmol·m^-2.·s^-1, 14.3μmol·m^-2.·s^-1, 9.77μmol·m^-2.·s^-1, 9.76μmol·m^-2.·s^-1, 8.94μmol·m^-2.·s^-1,and 3.07μmol·m^-2.·s^-1 respectively.3. Comparison of the light intensity and light compensation point of main plant species shows the light intensity is not under the light compensation point of main plant species during the process of phyllostachys edulis expansion. Therefore, the photosynthesis of main plant species is still stronger than their respiration, which means there is enough nutrition to sustain their growth. Change in light intensity has no influence on growth of main plant species. However, increase in light intensity will impact on fir regrowth because the fir seedlings are apt to shade condition.4. The plant absorbs the same range of visible light, and the peak values locate at 665nm and 435nm.The absorption was different, Eucommia ulmoides > phyllostachys edulis > Chinese sweet gum > China fir sapling > China fir > Camellia oleifera, at both the two peaks. The growth of plants that absorption ability was lower than phyllostachys edulis would be effected by the expansion of phyllostachys edulis. Camellia oleifera can absorb and use ultraviolet radiation, it may get less effect.更多还原