The Research On CanopyLight Distribution Law And Growth Influennce On Pinus Sylverstris Artificial Stand

This research aims to abtain the characteristics indexes of plant canopy structure accurately, fast and efficiently, effectively forecast canopy characteristic parameters, better artificial stand structure, promote community regeneration and provide scientific basis. By using a new type canopy analyzer WinsCanopy2006a and taking photos on the spot of 15 Pinus sylverstris artifical stand of Maoershan Forest in Hei Longjiang Province, investigating the basic situation of plots, analyzing by the use of its own software, the results of canopy characteristic related parameters come out. The relationship between canopy characteristics and illumination shows as following:1. WinsCanopy2006a could be applied in Pinus sylverstris artifical stand canopy structure and light distribution analysis. The measured results of canopy characteristic parameters(mean value) are void content is 15.90%, canopy openness is 14.92%, leaf area index is 3.57, mean leaf angle is 18.93 degree, synthesis light environment coefficient is 26.12, growing season crown on the light and total radiation is 48.29 mol·m-2·d-1, direct radiation under crown is 11.35 mol·m-2·d-1, indirect radiation under crown is 1.26 mol·m-2·d-1, whole radiation under crown is 12.62 mol·m-2·d-1, extinction codfficient (k) is 0.53. It indicates the most important radiation way is direct one.2.In the same site quality, the light radiation is declining with the growth of stand age, from 8.8 to 12.32 mol·m-2·d-1, accounting for 25.31% in the top of canopy whole radiation, gradually enhancing absorbency to light, it becomes stable when the age is 30 years. The range of canopy openness is from 10.78% to 21.66%, and different age represents significant difference among communities, going down with the growth of stand age. The leaf area index ranges from 2.29 to 3.47, and different age represents no significant difference. The extinction coefficient (k) ranges from 0.47 to 0.63, the power enhancing with the growth of stand age. And canopy structure has certain effect to the change of extinction along with the change of stand age.3.In the same site quality, planting density and forest growth exsits obvious relevance, it is the vital factor to the growth of Pinus sylverstris. High density needs to use up more water and nutrient, and this causes fierce intra specific compitition. The DHB and height of trees decreases when density increases, and the death rate and density is positive correlation.4.The relevance of canopy characteristic parameters among Pinus sylverstris artifical stand of Maoershan Forest shows, leaf area index and void content, canopy opening, direct light site codfficient, scatter light site codfficient, synthesis light environment coefficient, direct radiation under crown, indirect radiation under crown is significant negative correlation. Mean leaf angle and canopy width is no significant. Mean leaf angle and leaf area index is significant negative correlation. Mean leaf angle and light environment coefficient, radiation under crown is positive correlation. canopy opening and light environment coefficient It indicates that the change of canopy width and leaf area index has an significant influence on other canopy characteristic parameters and light distribution in the forest.