The Influence Of Different Asexual Reprduction To Poplar In Bashang Region

Poplar is a very common tree with strong adaptability which mainly grows intemperate and cold temperate zones. Bashang region in Zhangjiakou is in high ground, andthe weather there is dry, clod and windy with short frost-free season, thus, the poplar is themajor suitable plant. However, lots of poplars there are in a degenerative and aging periodwithout preserving function, which need to be further improved. Therefore, it is crucial totransform and improve the current forest belt and land, moreover to choose a proper way offorest reproduction in the construction of the forest protection.In order to learn the features of man-made poplar forests and the general rules ofbiomass, and the influence of planting density, this research chooses Cathay poplarand Peking poplar from1960to1991as subjects, making comparative research in thegrowth process of height, DBH and volume of trees, accumulated and annual growthincrement by drawing the growth curve to study its growth process in Excel, and usingSPPS17.0to process data. After investigated on the vegetative propagation of CuttingWood、Root Pruning and Embedded Pile and the growth features of Grafting Beijing Popla,it can be concluded that:1. The height of Root Pruning is obvious superior in the process of height growth, andEmbedded Pile is ranking the second. In each phase of height growth Root Pruning isahead of Embedded Pile and Cutting Wood。2. DBH of Root Pruning is better than Embedded Pile, and much better than CuttingWood, and the growth differences is even bigger with age.The DBH growth of man-made Cutting Wood forest appears like a “S”, while RootPruning and M show an increasing trend, and Root Pruning’ DBH growth is more stablethan Embedded Pile and Cutting Wood.3. The volume increment of Root Pruning is better than Embedded Pile, and muchbetter than Cutting Wood, and the growth differences differs with age.The volume increment of Cutting Wood appears like “S” curve, and it fits the“slow-quick-slow” growth rules. The growth of volume increment of Root Pruning andEmbedded Pile are mainly in the later stage, and the curve appears like a “J”. RootPruning’s volume increment is obvious superior to Embedded Pile and its growth processis comparatively stable. 4. The growth of Root Pruning is not good at Grafting.From the average growth curve, the height of Root Pruning is better than Grafting ofPeking poplar. DBH of Grafting of Peking poplar is better than Root Pruning, and thegrowth differences is even bigger with age. The volume increment of Grafting of Pekingpoplar is better than Root Pruning, and the growth differences is even bigger with age.