Investigation Of Ancient And Famous Trees In Lanzhou City And Their Conservation Techniques

Ancient and famous trees and their subsequent resources are one of the unrenewable valueles resources left by nature, which are scarce and nonrenewable resources. They record climatic change, testify the course of city development, engrave epoch stamp, They are often named "Green Antique" and "Live Cultural relic" by having high ecological, social, economic value, scientific research, high ornamental and tourist, and historical memorial meaning.In this study, the ancient, famous trees and ancient wood groups in Lanzhou city were studied based on field survey by looking into literatures, historical data and interviewing. Ancient trees culture was investigated systematically by conservation technique and regeneration technique of ancient and famous trees, and then the electronic file was established. The current situation and problems of the ancient and famous trees were also mentioned in this article, and some corresponding protective methods were suggested. Meanwhile, some references for the protection of ancient and famous trees in Lanzhou and heritage of ancient trees culture were provided. The main results were as follows:1. According to the survey, there are 322 old and famous trees with sporadic distribution. They belong to 19 families, 26 generas and 30 species. Among them 30, 44 and 238 trees are categorized as class I, II and III old trees respectively. One comprehensive file of ancient and famous trees was also established.2. The remaining pear orchards are mainly distributed in some valleys along the Yellow River in Lanzhou, such as Anning, Shichuan, Qingcheng vallys and so on. There are only 2570 pear trees remained and covering with an area of 183 hm~2 in Lanzhou according to survey. But these trees are faced with predicament of occupying, felling, and decaying, therefore, some important measures will be taken to protect these tree groups in future.3. The culture of ancient trees in Lanzhou city was surveyed and analyzed in this study, which includs city tree Sophora japonica L and culture of Sophora japonica, Lanzhou "Zuo gong liu", ancient pear trees and culture of pear orchards, ancient pear orchards and water wheel of Lanzhou.4. Systematic conservation and regeneration techniques of the ancient and famous trees were put forward.The main conservation techniques include: (1)Implicating fence; (2)Humidity control and irrigation; (3)Adding nutrients and adequate fertilization; (4)Improving ground environment and cultivation; (5)Coving soil surface with tree leaves and litters; (6)Insect disease prevention and cure; (7) pruning and tidying branches.The main regeneration techniques include: (1)improving soil quality;(2)reasonable water supply; (3)securing with bracket or rope; (4)antisepsis and cavity repair; (5)fixing lightning rod; (6)other regeneration techniques;5. The current situation and existing problems of the ancient and famous trees were also mentioned in this study, some corresponding protective measures were advanced as following: (1)strengthening leadership, assigning responsibilities and increasing investment. (2)reinforcing the study on rejuvenation technologies. (3)Identifying and protecting ancient woods protection areas. (4)utilizing the value of the ancient and famous trees and strengthening their subsequent resource protection.