Study On Garden Trees In Resistance To The Disastrous Weather In Hefei

With global climate changing exceptionally in recent years, disastrous weather occurs frequently, which attacked Hefei city in two consecutive years including wind damage, snow disaster and freeze injury, sparing neither urban landscape nor green space newly built in the urban construction with newly planted garden trees. In addition to great economic losses, it has caused broken branches, trunks and lodging of garden trees which would threaten people’s lives and property. Therefore, how garden trees can resist attacks by disastrous weather to function more efficiently has become an urgent problem.The damage situation was surveyed of garden trees which suffered from three disastrous weathers, freeze injury in early2008, wind disaster in early summer and snow disaster in mid-November in2009, to analyze the causes of the damage and how resistance of garden trees varies with species, ages, damaged parts and types of Green Space. The successful experience of resistance research to garden trees was studied with the correlation theory of urban ecology, which will provide a reference for taking protective measures for existing garden trees and selecting species of urban green space planning in the future. All the research means a lot to the sustainable development of urban landscape. Results of our analysis are as follows:1、The survey of the garden trees in Anhui Agricultural University shows there are17species damaged after wind damage. The ability in wind resistance for them is different, Cedrus deodara, Bischofia polycarpa show poor; Cinnamomum camphora, Robinia pseudoacacia, show relatively poor; Ligustrum lucidum, Sapium sebiferum, Platamts acerifolia get medium; Paulownia tomentosa, Acer buergeriamtm, Sophora japonica become strong. These species such as Camptotheca acuminate, Acer buergeriamtm, Platanus acerifolia with DBH21-40cm are week in wind resistance, while those with the other DBH are strong. The branches of most damaged trees and the trunks of Paulownia tomentosa, Bischofia polycarpa, Metasequoiaglyptostroboides have poor ability in wind resistance.2、The survey of the garden trees shows there are53species damaged after snow disaster in Hefei. The ability in anti-snow pressure for them is different, Cinnamomum camphora, Populus canadensis cv. I, Cedrus deodara show poor; Celtis tetrandra, Magnolia grandiflora, Acer palmatum cv.Dissecum show relatively poor; Primus ceraifera cv. Ateopurpurea, Ligustrum lucidum, Sophora japonica get medium; Ulmus pumila, Salix babylonica, Koelreuteria paniculata become strong. Among15common used garden tree species, Cinnamomum camphora, Platanus acerifolia and Cedrus deodara, with DBH below30cm have a poor ability in anti-snow pressure, while those with DBH above30cm are strong. The branches of Platanus acerifolia, Magnolia grandiflora and Cedrus deodara and the trunks of Populus canadensis cv. I, Sapium sebiferum, Metasequoia glyptostroboides have a poor ability in anti-snow damage. The garden trees were damaged seriously in Attached Green Space, Public Pack and Other Green Space, while in Green Buffer and Nursery were damaged lightly.3> The survey of the garden trees shows there are13species damaged after freeze injury in Hefei. Some damaged trees which planted newly have poorer frost resistance in worse growing environment than whose planted of years, such as Cinnamomum camphor, Magnoliagrandiflora, Elaeocarpus sylvestris, Michelia chapensis, Lorpetalum chinense var.rubrum, Pittosporum tobira, Camellia japonica, Pyracantha fortuneana, Bambusa multiplex, The frost resistance of elder trees is better than the younger trees in those freeze injured trees;The whole plant of young trees which planted newly or in nursery, and the leaves, branches and trucks of the trees which planted of years have a poor ability in anti-freeze injury, while the old branches, trucks and root of trees which planted of years are strong; From the analysis of the damage, we know that the broad-leaved, the evergreen and the exotic species are easily suffered from freeze injury,while the conifer species, the deciduous trees and the native trees are better.