Abstract:In order to understand the canopy effects of pioneer trees on seedling growth of other speciecs in rocky desertification area of southwestern Guangxi, the survival and growth traits of Cyclobalanopsis glauca and Lonicera maackii under three pioneer tree canopy, such as Delavaya toxocarpa, Leucaena leucocephala and Zenia insignis, were studied by field plot experiment. The results showed that the three pioneer trees could reduce the light intensity and improve soil physical characters, reduced soil bulk density, increased the total porosity and the field capacity, but they could not change soil chemical features. All the three pioneer trees had certain nurse effects on the survival and growth of C. glauca seedlings. Z. insignis and Leucaena leucocephala improved the survival but inhibited the growth of Lonicera maackii seedlings. D. toxocarpa decreased significantly the survival and growth of Lonicera maackii seedlings. Whether they improved or inhibited the seedling growth, the three pioneer trees had more effects on the seedling height and branch growth than those on basal diameter. Therefore, the pioneer trees D. toxocarpa, Leucaena leucocephala and Z. insignis could be selected as the nurse plants for C. glauca seedling in rocky desertification area in southwestern Guangxi, but Lonicera maackii should be planted outside the pioneer tree canopy to avoid shade effect.
