Abstract:

In order to understand the spatial structure of Larix principis-rupprechtii forest in Guandi mountain Nature Reserve and explore the correlation of Larix principis-rupprechtii,10 sample plots of 30m × 30m were set up randomly.All the standing timbers entering the caliper step in the sample land were measured by each wooden ruler.The tree species,diameter,height,crown width,geographic coordinates and environmental factors were measured,the spatial structure analysis was maked based on the angular scale,mixed degree and size ratio,and the correlation analysis between forests and species was carried out by O-ring function.The results showed that:(1) most of the pure forest samples of Larix principis-rupprechtii were randomly distributed,and the mixed forests has obvious cluster distribution.(2) Larix principis-rupprechtii forests showed less correlation at different scales.The fewer the number of Larix principis-rupprechtii in the mixed forest,the more obvious of interspecific association.The research shows that Larix principis-rupprechtii forest is in the transition from moderate to inferior currently,and is beginning to decline from the top community,but Larix principis-rupprechtii is still dominant in the competition of this community,belonging to the dominant population.

Key words: Guandi mountain, Larix principis-rupprechtii forest, spatial structure, interspecific correlation, O-ring function