Recession Reason Analysis And Rejuvenation Research Of Ancient Cryptomeria Fortunei In Tianmu Mountain

Tianmu Mountain is a National Nature Reserve in ZheJiang, it has a special forest landscape because of the rare huge Cryptomeria fortunei forest. However, in recent years, these ancient Cryptomeria fortunei are declining at an alarming rate. These ancient Cryptomeria fortunei recession will not only damage the natural landscape of Tianmu Mountain, but also damage the local biodiversity, more serious, these ancient Cryptomeria fortunei as rare Cryptomeria fortunei group, their historical significance and scientific value is immeasurable. Firstly, surveyed the growth conditions of the Tianmu Mountain ancient Cryptomeria fortunei, pests and diseases, environmental pollution, site conditions, then analysed Tianmu Mountain ancient Cryptomeria fortunei recession reasons, finally, tried to make the rejuvenation agent that appropriate to Tianmu Mountain ancient Cryptomeria fortunei.According to wild investigation, interview of natives and review of history, we found out the recession situation of the Tianmu Mountain ancient Cryptomeria fortunei. Cryptomeria fortunei which growing strong was only0.6%whereas that growing poor or death accounted for36.3%of the total number in the survey. In accordance with the actual situation of Tianmu Mountain, we think that the main reasons are that pests and diseases, environmental pollution, site conditions impact, Cryptomeria fortunei intraspecific and interspecific competition, microwave radiation and so on. The main pest and disease are the gall disease of Cryptomeria fortunei、 Dendrolimus houi Lajonquiere、Chinolyda flagellicornis and Homona issikii Yasuda。Acid rain and microwave radiation all played an important role in the recession of Cryptomeria fortunei. Soil compacti on and interspecific and outspecific competition all caused the recession.Furthermore, we tried to make the rejuvenation agent that appropriate to Tianmu Mountain ancient Cryptomeria fortunei, after field trials have shown that:the rejuvenation agent administered recession Cryptomeria fortunei, the shoots an average increase of3.3cm after22days, and failed to make a deal with the recession Cryptomeria fortunei, the shoots average increased by only2.4cm. Rejuvenation agent has a certain role in promoting the growth of Cryptomeria.Finally, authors according to their own long-term work and practical experience, put forward some recommendations to protect the Tianmu Mountain ancient Cryptomeria fortunei.