【作者】 陈晓燕；

【导师】 郭连生；

【作者基本信息】 内蒙古农业大学 ， 森林培育， 2010， 博士

【摘要】 本文研究了大青山前山区古路板与水磨试验区油松人工林等5个主要森林植被的植被特征、土壤水分动态、主要树种气孔导度、蒸腾和光合等生理生态特征变化及其对光照强度、土壤水分变化的响应,在此基础上应用BROOK90模拟研究了不同森林植被类型的水分平衡,进而研究了其土壤水分植被承载力。主要结果如下:(1)试验区土壤主要物理性质的测定研究表明,乔木林地土壤石砾含量、土壤容重小于灌木林地,田间持水量和最大持水量均大于灌木林地,土壤饱和导水率虎榛子灌木林最大(40.14mm/h)。结果表明乔木林地涵养水源的能力大于虎榛子灌木林。(2)土壤含水量的年际变化,季节变化与降雨趋势基本一致,其垂直分布随深度增加呈下降趋势,表明自然降水对该区土壤水分变动起控制作用,进而影响植被生长。生长季土壤含水量山杨次生林最大(23.16%),油松人工林最小,次生林中乔木林优于灌木林。(3)在立地、树龄等相似条件下,山杨干生物量比例最大,辽东栎枝生物量所占比例最大;油松叶生物量所占比例最大。油松单株地上生物量、单位面积生物量与林分密度的关系均可用方程:y=1/(k+a×e-bx),x为林分密度,y为单株地上生物量(或单位面积生物量)。叶面积指数30a油松人工林为4.88—10.95 m2/m2,白桦次生林为2.80—4.80 m2/m2,虎榛子灌木林为1.21—4.22 m2/m2。(4)林分消光系数的日变化与树干液流速率、气孔导度日变化的变化趋势基本一致。虎榛子灌木林消光系数最大(1.52),油松人工林消光系数变化幅度在0.10—0.21之间。(5)大青山几个主要树种的光合特征、叶绿素荧光特征与光照强度、土壤含水量的关系均可以模拟为方程:y=a+b(1-e-kx)(y,光合、荧光指标;x,光照强度、土壤含水量)。(6)林内降雨量、林冠截留量、树干径流量和地表径流量均与林外降雨量呈正相关关系。乔木林冠层截留率大于灌木林,山杨天然次生林林冠平均截留率最大,虎榛子最小。山杨次生林干流率(2.81%)明显大于其他被试森林植被。油松干流率变化在1.69%—4.94%。植被水分年供给、植被水分年消耗都与年最大叶面积指数呈线性相关,两直线交点对应的叶面积指数作为承载力衡量指标,虎榛子天然林为2.99 m2/m2,白桦天然林为4.75 m2/m2,油松人工林为10.65m2/m2,其相对应密度分别约为:557266株/hm2,2916株/hm2,3250株/hm2 ,其可作为该区森林培育和经营管理的依据。更多还原

【Abstract】 In this paper, the mian forest vegetation vegetation characteristics, soil water dynamic, stomatal conductance, transpiration, photosynthesis of main species, and the response of photosynthetic indexes to light intensity and soil water content were studied in Guluban and ShuiMo test areas of Daqing former mountain. Based on the environment characteristics of the area, BROOK90 was used to simulate the water balance of different vegetation types. Furthermore, vegetation carrying capacity of soil water was studied. The main results were as following:(1) The result of main physical properties of soil showed that the gravel content and soil bulk density of arbor forest were lower than that of shrub land. But the field capacity and maximum water capacity of arbor forest were higher. Soil saturated hydraulic conductivity of Ostryopsis davidiana Decaisne. was the highest(40.14 mm/h). Water conservation capacity of arbor forest was better than shrub land.(2) Soil water annual variation and seasonal variation had a consistent trend with precipitation. The vertical distribution showed a decline trend with the soil depth increased. It indicated that rainfall controlled soil water. In the growing season, soil water content of Populus davidiana Dode.was the highest(23.16%), but soil water content of Pinus tabulaeformis Carr. was the lowest. Water content of arbor forest was better than shrub land.(3) At the similar site condition and tree age, stem biomass of Populus davidiana was the biggest and branch biomass of Quercus liaotungensis Koidz. was the biggest. Equation y=1/(k+a×e-bx)can be used to express the relationship between aboveground biomass and stand density of Pinus tabulaeformis Carr.(x represented stand density, y represented aboveground biomass). Leaf area index of 30a Pinus tabulaeformis Carr. plantation, Betula platyphylla Suk. secondary forest and Ostryopsis davidiana Decaisne. shrub were 4.88—10.95 m2/m2 , 2.80—4.80 m2/m2 and 1.21—4.22m2/m2.(4) Stand extinction coefficient had a similar trend with stem sap flow rate and stomatal conductance daily variation. Stand extinction coefficient of Ostryopsis davidiana Decaisne. was the biggest. Stand extinction coefficient change range of Pinus tabulaeformis Carr. plantation was during 0.10—0.21.(5) Photosynthetic characteristics, chlorophyll fluorescence characteristics and light intensity, soil water content can be simulated by equation y=a+b(1-e-kx) (y represented photosynthetic or fluorescence; x represented light intensity or soil water content).(6) Rainfall under tree crown, canopy interception, stem flow and surface runoff showed positive correlation with rainfall outside of stands. Canopy interception rate of arbor forest were higher than that of shrub land. Canopy interception rate of Populus davidiana was the highest and canopy interception rate of Ostryopsis davidiana Decaisne. was the lowest. Stem flow rate of Populus davidiana secondary forest was 2.81%, which was higher than other tree species. Stem flow rate of Pinus tabulaeformis Carr. was in the range of 1.69% to 4.94%. The water balance result showed that year water supply and consumption showed linear correlation with maximum leaf area index. Maximum leaf area index of Ostryopsis davidiana Decaisne. shrub forest, Betula platyphylla Suk. secondary forest, Pinus tabulaeformis Carr. plantation were 2.99m2/m2, 4.75m2/m2 and 10.65m2/m2. The corresponding densities were 557266 stock/hm2, 2916 stock/hm2 and 3250 stock/hm2, which provided evidence for silviculture and management.更多还原