【作者】 徐娟；

【导师】 余新晓；

【作者基本信息】 北京林业大学 ， 水土保持与荒漠化防治， 2010， 硕士

【摘要】 本研究以北京山区三种典型林分类型油松、刺槐、侧柏人工林枯落物层为研究对象,通过对三种林分枯落物层现存量,碳和养分的分析,持水特性的研究,保水保土功能的研究,分析得出三种林分类型枯落物层水文功能的异同,并创新性的对三种林分类型枯落物化感物质及相互之间的化感作用进行了系统的研究,分析得出初步结论,为三种林分类型混交提供可行性建议。油松、刺槐、侧柏三种林分类型下枯落物储量有一定差别,依次为油松林、刺槐林,侧柏林储量最小。枯枝落叶层中叶养分储量均以N为最高,P浓度最低。地表养分周转率用凋落物养分年归还量与枯枝落叶层养分贮量的比值表示,其中油松林地表N和K的周转率最大,P周转率最大值(1.48)出现在侧柏林。油松林枯落物层碳储量最高,均大于刺槐林和侧柏林,而侧柏林枯落物层的碳周转率较油松、刺槐林稍高。三种林分枯落物的最大持水量有所不同。刺槐林枯落物的最大持水量最大,侧柏林最小,枯落物最大持水率排序依次为：刺槐林>侧柏林>油松林。枯落物持水量与浸泡时间具有一定的相关关系,三种林分枯落物各层持水量与浸泡时间的关系进行回归分析,得出该时段内持水量与浸泡时间之间存在如下关系：Q=aln(t)+b式中：Q—枯落物持水量(g／kg)；t—浸泡时间(h)；a—方程系数；b—方程常数项。三种林分枯落物的吸水速率表现出一定的规律性。对三种林分不同层次枯落物吸水速率与浸泡时间进行拟合,发现其关系如下：V=Ktn式中：V—枯落物吸水速度(g·kg-1·h-1)；t—浸泡时间(h)；k—方程系数；n—指数。从有效拦蓄率看,三种林分枯落物未分解层均大于半分解层,呈现相同的变化规律。综合枯落物未分解层和半分解层的变化规律可知,三种林分中刺槐林枯落物的拦蓄能力最强。三种林分枯落物层的阻滞径流速率的效应十分显著,在同等的条件下,随着坡度的增加,开始产流时间依次缩短,产流速率依次增大。裸地与有枯落物覆盖产沙产流量有明显的差异。三种林分枯落物中化学成分主要有醇、烷、酯、酚、烯等,三种林分枯落物中的化学成分有相似的成分,但同时也有各自特有的化学成分。通过对三种浓度枯落物水浸液对种子生长的影响分析,探讨三种树种的种间关系。更多还原

【Abstract】 This research takes three typical planted forest floor in Beijing mountainous area,by studying on three typical planted forest floor,the carbon and the nutrient pool analysis,water retaining capacity,the function of the water and soil conservation,the analysis obtains three kind of forest floor ecology function the similarities and differences,and the innovative research is on allelochemicals to three kinds of forest floor and allelopathy effect between them,the analysis has drawn the preliminary conclusion to provide the feasible suggestion on three kinds of trees types mixes the junction. The paper main results are as follows:The litter total storage capacity of three typical planted forest are different,the order is:the Pinus tabulaeformis forest> the Robinia pseudoacacia forest> the Platycladus orientalis forest.The nutrient of the Pinus tabulaeformis,the Robinia pseudoacacia,the Platycladus orientalis,three kind of planted forest floor take N as highest, P is lowest.The surface nutrient cycling rate with withers and falls the nutrient year restore quantity and forest floor nutrient pool ratio indicated that Pinus tabulaeformis forest surface N and the K cycling rate is biggest,the P cycling rate maximum value (1.48) appears in the Platycladus orientalis forest. The Pinus tabulaeformis forest forest floor carbon reserves is highest, is bigger than the Robinia pseudoacacia and the Platycladus orientalis forest,but Platycladus orientalis’s carbon cycling rate compares the Pinus tabulaeformis and the Robinia pseudoacacia forest to be slightly high.The maximum water capacity of the Pinus tabulaeformis,the Robinia pseudoacaci,the Platycladus orientalis forest floor are different. The maximum water capacity of Robinia pseudoacacia is highest, the Platycladus orientalis to be smallest. The rate of maximum water capacity is in turn:the Robinia pseudoacacia> the Platycladus orientalis> the Pinus tabulaeformi.Semi-decomposition litter and undecomposition litter reached saturation in 8h or 10h,on the regression analysis between each water capacity to 0.5-24h and the soaking time relations,obtains in this time interval between the water capacity and the immersion time has the following relations:the relationship of water holding capacity and soaking time is Q=aln(t)+b.In first half-hour,the absorption rate is the largest,the rate was obviously slowed down after 4 h,the relationship of absorption rate and immersion time is V= ktn.The modified interception amount of three kind of forest litter presents the same change rule,that is undecomposition litter to be bigger than semi-decomposition litter.The litter of Robinia pseudoacacia forest is the biggest.With the increase of the slope,it is more obvious to retard effect on runoff and reduce effect on the sediment and runoff yield. The bare land with has withers and falls the cover to produce the sand to produce the current capacity to have the obvious difference.The chemical composition of the Pinus tabulaeformis,the Robinia pseudoacacia,the Platycladus orientalis forest litter mainly to have the mellowness, the alkane,the ester,the phenol,the alkene.The chemical composition of the Pinus tabulaeformis,the Robinia pseudoacacia,,the Platycladus orientalis forest litter to have the similar ingredient, but simultaneously also has respectively the unique chemical composition.Effect of different concentration extract of three forest litter on seed absolute germination percentage, the absolute germination tendency,the root,the embrionic axial length has the varying degree to suppress the influence.更多还原