Spatial structure and nutrient utilization of mixed forest of Phoebe bournei and Schima superba

In order to explore the interspecific relationship between Phoebe bournei and Schima superba in mixed forest, and to determine whether S. superba can be used as the companion tree species of P. bournei to build a healthy and efficient mixed forest of P. bournei and S. superba.

The mixed forest of P. bournei and S. superba, and pure forest of P. bournei and pure forest of S. superba which were grown in Jindong Forest Farm for 16 years were taken as research objects, and probes into the interspecific relationship between the aboveground and underground parts of the mixed forest of P. bournei and S. superba by analyzing the root distribution characteristics and the spatial structure characteristics of the forest. The relationship of nutrient utilization between P. bournei and S. superba was clarified by analyzing the dynamic laws of leaf nutrients of P. bournei and S. superba in different phenological periods.

1) In the mixed forest of P. bournei and S. superba of 16a, the root distribution of P. bournei and S. superba partially overlapped within 1.5 m around P. bournei, but P. bournei still occupied the dominant position. There was competition but not intense in underground growth space and nutrient absorption and utilization between P. bournei and S. superba; 2) On the spatial structure of the overall stand, the pure forest of P. bournei and pure forest of S. superba were slightly better than the mixed forest of P. bournei and S. superba, which indicated that the growth characteristics and ecological characteristics of the mixed forest were different, and the stand homogeneity would be poorer, so the structural adjustment was more difficult than that of the pure forest. In the mixed forest, S. superba had formed a certain competitive advantage to P. bournei; 3) In the mixed forest of P. bournei and S. superba, the absorption and utilization of nutrients were not synchronous in part on the phenophase, and there is a relatively favorable complementary relationship; From all phenological periods, the N, P, and K contents in the leaves of P. bournei were higher than those of S. superba in most periods, indicating that the mixed cropping of P. bournei and S. superba was more beneficial to the absorption and utilization of nutrients by P. bournei, and S. superba had lower demand for nutrients; 4) The growth rates of P. bournei and S. superba in 16 years mixed forest were better than those of their corresponding pure forest, which indicated that early stage competition promoted the growth of forest stand.

The mixture of P. bournei and S. superba was beneficial for P. bournei to obtain more nutrients, and moderate competition promoted the growth of trees. S. superba was a good companion tree of P. bournei.