Crown Characteristic And Effect To Regeneration Of Major Tree Species In The Mixed Broadleaved-Korean Pine Forest

Canopy structure is one of the most important factors that affect the structure and function of forest ecosystem,especially the closed canopy.This paper was based on the large fixed plots(9hm~2 )of the typical broad-leaved Korean pine forest of Xiaoxing'an mountains.We investigated the height of the trees that DBH≥2cm and drew crown map of every tree which height≥10m.From that we can get the canopy patches map of every species and the distribution of the trees under every canopy patch.We researched the basal character of tree crown for broadleaves-Korean pine mixed forest,the sapling distribution under tree crown;We analyzed the spatial patterns of crowns for major species and saplings in understory,also the spatial association between crowns and saplings to interpret the spatial pattern of populations in in broadleaves-Korean pine mixed forest.It offers science basis for the broadleaved-Korean pine mixed forest protection,management and regeneration succession.The distribution of major species is different in four height layer.The amount of Pinus koraiensis crowns occupy the 92.2%of the whole canopy.The density of the crowns showed single peak with height increasing for Betula costata,Pinus koraiensis,Abies nepholepis and Fraxinus mandshurica,reduced with increasing of tree height for Acer ukurudunse,Ulmus laciniata,Acer tegmentosum,Acer mono and Tilia amurensis.The patches of Pinus koraiensis have the largest area and covered the 30 percent of the plot.The covered area showed single peak with height increasing,other species showed L type.The average area of crowns is largest for Ulmus laciniata and of crown patches for Pinus koraiensis.The amounts of the crowns of Betula costata,Abies nepholepis and Fraxinus mandshurica reduced with the increase of area, others showed single peak.The amounts of canopy patches reduced with the increase of area of canopy patches.All of the major species showed positive association between crown area and DBH.The associations are higher for Betula costata,Fraxinus mandshurica and Ulmus laciniata,lower for others.The associations between crown area and tree height were not obvious for Acer ukurudunse and Acer tegmentosum and it showed positive associations for other species,but the degree is lower.The Acer species generates well in the broadleaved-Korean pine mixed forest.The amounts of their saplings are always the most under most canopy patches.The density of saplings of Pinus koraiensis,Abies nepholepis and Fraxinus mandshurica is the least in all of the major species.The crowns of Pinus koraiensis,Abies nepholepis,Acer mono and Tilia amurensis showed clustered according to results of point pattern analysis and the saplings of major species showed the same pattern.The saplings of major species showed different spatial associations with crowns of different species of Pinus koraiensis,Abies nepholepis,Acer mono and Tilia amurensis.