Fuel Management And Impact Assessment In Typical Coniferous Forests Of Beijing West Mountains

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.