Abstract: Ba on the observed data of the crown structure of artificial Latix olgensis stands and larix olgensis-northeast China ash mixed stands, we established the crown cone model of larix and northeast China ash. By observing the sun radiation in the two forestry communities, from physical basic law of absorbtion, reflection and transmission of electromagnetic wave, we calculate the sunlight utilization ratio of the two forestry communities respectively. and get the result that the sunlight utilization ratio of the double strata mixed stands is larger than that of the one single stratum pure stands.

Key words: Tree-crown model cone, Sun radiation, Absorbtivity