【作者】 何中华；

【导师】 刘晓东；

【作者基本信息】 北京林业大学 ， 生态学， 2013， 硕士

【摘要】 本文基于北京西山林场典型针叶林可燃物分布特征,提出可燃物调控技术,并对调控后林下植被的生态环境效应进行研究。选取典型林分设置人工针叶林：油松(Pinus tabulaeformis)、侧柏(Platycladus orientalis)各4块样地。调查可燃物特征,包括可燃物种类、负荷量等,应用统计及对比分析方法对可燃物负荷量的分布特征进行研究,提出以修枝和割灌为主的可燃物调控技术,并针对不同调控后的林下植被进行光合作用以及生物多样性的研究。研究结果表明：(1)可燃物垂直分布特征。选取的四块油松样地可燃物主要分布在0-3m和4-6m层。其中,四块样地在0-3m层的可燃物负荷量分别为：851.7g/m2,898.92g/m2,1381.77g/m2,1072.24g/m2,主要可燃物类型：地表枯落物和乔木下层活枝；在4-6m层,主要可燃物为乔木活枝。四块侧柏样地可燃物均主要分布在0-3m层,分别为：1136.79g/m2,1670.80g/m2,1273.29g/m2,1119.33g/m2,主要可燃物类型为：地表枯落物和灌木。(2)油松林、侧柏林调控措施。针对油松林,我们选取四个不同调控措施,分别为CK(对照)；P1：割灌：P2：修枝(3m以下)和割灌；P3：修枝(3.5m以下)和割灌。针对侧柏林,我们选取的四个不同调控措施,分别为CK(对照)；P1：修枝(2.5m以下)；P2：修枝(2.5m以下)和割灌：P3：修枝(3.5m以下)和割灌。(3)调控后林下植被光合特性。不同调控后,两类林分林下灌木光合特征指数呈现如下规律：①最大净光合速率、光饱和点、光补偿点、暗呼吸速率与对照相比均增大；②表观量子效率与对照相比均减小；存在个别情况与规律不一致。(4)调控后林下群落生物多样性研究。油松样地：可燃物调控改变了林下群落生物多样性,其中P3调控对林下灌木多样性影响明显,三种调控措施对林下草本多样性影响明显。侧柏样地：可燃物调控改变了林下群落生物多样性,其中P2和P3调控对林下草本多样性影响明显,三种调控对林下灌木多样性影响均不明显。本研究将可燃物调控技术与生态效应相结合,为研究地区针叶林可燃物调控技术规程的制定提供了一定的科学依据。更多还原

【Abstract】 Based on the fuel distribution characteristics in Beijing West Mountains Forest Farm, the specific fuel adjustment and control measures were developed, and the impact assessment of these fuel management approaches were evaluated. The typical coniferous forest type were selected, including4Pinus tabulaeformis forest plots and4Platycladus orientalis forest plots under the stand terrain characteristics. The characteristics of sample were investigated such as fuel types and fuel load. The statistical methods and a comparison method were applied to study the distribution characteristics of the fuel Load, and the fuel control technology were put forwarded. The photosynthesis attributes and biodiversity of understory vegetation under different fuel management measures were studied, then the results of ecological impact were analyzed, the main conclusions can be summarized as follows:(1)Vertical Distribution Characteristics of fuel. Analyze Fuel Load of four Pinus tabulaeformis stands, the fuel are mainly distributed in the layer of0-3meter and4-6meter, the fuel load of0-3meters in these stands were:851.7g/m2,898.92g/m2,1381.77g/m2,1072.24g/m2respectively, and the mainly fuel type were surface death fuel and live branch fuel. In the layer of4～6meter, the live branch fuel have a relatively larger load. As to the Fuel Load of Platycladus orientalis, the fuel mainly distributed in the layer of0-3meters, the fuel load in the four stands were1136.79g/m2,1670.80g/m2,1273.29g/m2,1119.33g/m2, respectively, and the main fuel type were surface death fuel and shrub fuel, with the potential to easily cause the surface fire to crown fire.(2)The fuel management measures of Pinus tabulaeformis and Platycladus orientalis forests. For the forest of Pinus tabulaeformis, four different fuel management measures were selected, the measures included CK(contrast),P1-cutting shrub,P2-pruning(less than3meters)and cutting shrub,P3-pruning(less than3.5meters)and cutting shrub. For the forest of Platycladus orientalis, the measures were CK(contrast),P1-pruning(less than2.5meters),P2-pruning(less than2.5meters)and cutting shrub,P3-pruning(less than3.5meters)and cutting shrub.(3)The photosynthesis characteristics of understory vegetation under different fuel management measures were measured and analyzed. the results of the photosynthesis characteristics index of the dominant shrub showed:①Compared with the contrast, the maximum net photosynthetic rate, light saturation point, light compensation point and dark respiration rate were greater than the contrast.②Generally speaking, compared with the contrast, the apparent quantum yield was reduced.(4)The biodiversity research of the understory communities. For the shrub layer of Pinus tabulaeformis, Compared with the contrast, the fuel management measures(treatment) of P3changed the biodiversity of shrub significantly, but the treatment of P1and P2less change the biodiversity of shrub. For the grass layer of Pinus tabulaeformis, Compared with the contrast, the treatment of P1,P2and P3change the biodiversity of shrub layer significantly. For the shrub layer of Platycladus orientalis, Compared with the contrast, the treatment of P1,P2and P3less change the biodiversity of shrub. For the grass layer of Platycladus orientalis, the control measures of P2and P3change the biodiversity of shrub significantly.This research conducted the fuel management technology and evaluated the ecological effects of fuel management measures. The results will provide a scientific basis for the fuel management.更多还原