Growth Evaluation of Phoebe bournei Mixed Forest in Afforestation Year

The growth of Phoebe bournei in different mixed ratios and mixed tree species in the afforestation year was investigated and analyzed.The results showed that the average survival rate of P.bournei in different mixed modes was 98.04%,which was 4.04% higher than that of P.bournei pure forest.The afforestation survival rate of mixed tree species Schima superba and Toona ciliata var.pubescens reached 100%,which was higher than that of Cunninghamia lanceolata and Liquidambar formosana.The ground diameter,maximum crown width,tree height and SPAD of P.bournei and its mixed tree species were the largest in the mixed mode of P.bournei∶Toona ciliata var.pubescens = 3∶1,and P.bournei reached 17.22 mm,76.50 cm,129.47 cm and 41.10 respectively,which were 16.59%,34.78%,11.12% and 8.50% higher than the average value,and 31.85%,57.73%,20.55% and 3.68% higher than the control.Toona ciliata var.pubescens reached 44.52 mm,148.40 cm,207.03 cm and 57.21 respectively,which were 103.85%,61.20%,65.61% and 19.06% higher than the average value.The effects of different mixed modes on the afforestation survival rate,the ground diameter,maximum crown width,tree height,branch height and SPAD of P.bournei and its mixed tree species were significantly different.The survival rate and tree height of P.bournei were significantly correlated with the survival rate and tree height of its mixed tree species,and the correlation coefficients were 0.70 and 0.76,respectively.According to the comprehensive evaluation,P.bournei ∶Toona ciliata var.pubescens = 2∶1 or 3∶1,P.bournei :Schima superba = 2∶1 or 1∶1,P.bournei∶Cunninghamia lanceolata = 2∶1,these five mixed modes have better growth in the first year of afforestation,and can be used as the main planting model in the early stage of mixed afforestation of P.bournei.