Research On The Canopy Structure Characteristics Of Mountain Broad-leaved Forest In The South-West

Mountain broad-leaved forest is formed after a long succession of fairly stable forest community, widely distributed, types, floristic composition and abundance, canopy as the forest interior and the external environment interaction the most direct and most active interface layer, the research of forest canopy structure characteristics has important significance to the construction of water conservation, ecological environment protection in the whole region and the restoration of forest ecosystem productivity.The purpose of this study was through the comparison of different successional process of the formation of broad-leaved forest (natural forest, secondary forest) of the canopy structure characteristics analysis in the natural reserve of Liziping, Ya'an City, we studied the broad leaved forest through sample plot investigating method, got the stand basic factor, and the canopy structure characteristic parameters were obtained by using hemispherical images. By drawing the crown projection, correlation analysis, trend analysis, spatial heterogeneity analysis, comparing the comparison of two types of broadleaf forest canopy structure characteristics, for further understand the canopy structure and light interception and community dry matter accumulation relationship between canopy, light radiation and forest under the relationship between vegetation and forest canopy of material circulation providing certain theoretical reference, for the rational management of the mountain broad leaved forest providing reference. we got the following conclusions:(1) The crown projection map of spatial distribution intuitively reflected the basic situation of two forest plots of forest, the natural forest plantation more complex than the secondary forest, the secondary forest grew neatly, crown projection area was smaller, the radiation parameters were higher than that of the original forest, were able to receive more solar radiation;(2) Two kinds of forest, there was a strong linear correlation between the Leaf area index and the Openness, Gap-Fraction, the correlation relationship was not strong between the leaf area index with Indirect Site Factor and PPFD Diffuse Under Per Day, Openness and Indirect Site Factor had a strong linear relationship (R2>0.7), indicating that the forest surface scattering was mainly affected by the Openness;(3) Trend analysis showed that the trend of canopy parameters in the North-South direction was obvious in the direction of the East-West, the canopy parameters showed a rising trend from North-South except the leaf area index and there was no obvious trend in the direction of the East-West, and according to the analysis of the heterogeneity, it was known that the canopy parameters were more likely to be influenced by solar radiation in the north and south direction;(4) In the natural forest, Leaf area index, Indirect Site Factor and PPFD Diffuse Under Per Day had a strong spatial autocorrelation in the lag distance 18-30 meters, Openness and Gap-Fraction had a strong spatial autocorrelation in the lag distance 20-85 meters, in the secondary forest, the MLA had a strong spatial autocorrelation in the lag distance 20 meters, so in the small scale range, the natural forest was more obvious heterogeneity than the secondary forest;(5) Different from the secondary forest, the natural forest was more obvious heterogeneity, strong correlation, large spatial difference, so the canopy structure was more complex, The results can provide a reference for the rational management of the mountain broad-leaved forest.