Research On Recession Provention Technology Of Ancient Cryptomeria Fortunei In Tianmu Mountain

Cryptomeria fortunei is one of the unique and precious kinds of trees in TianMu Mountain NatureReserve，which is known as “famous for its great canopy in the world”. But now there has been a seriousrecession that happened on Cryptomeria fortunei in recent years. This article intends to make a research on the4factors that affect the health of Cryptomeria fortunei, namely altitude,age,acid rain and tumor disease, andshowing recession causes so as to find better solutions to cure the recession of Cryptomeria fortunei by meansof outdoor experiment and data measuring and analysis.The results are as follows:(1) As the altitudes increases, the health of samples on higher altitude is worse than the one on the loweraltitude, but the photosynthetic capacity is not getting worse apparently.On the same altitude, themiddle-aged period samples both in ChanYuan Temple and KaiShan Old Palace are the best in healthand photosynthetic capacity.The second and third place are the samples at growing period and childperiod.The samples at old period is the worst in health and photosynthetic capacity..(2) Tumor disease and acid rain are the main causes that lead the recession of Cryptomeria fortunei inTianMu Mountain Nature Reserve through the analysis of physiological parameters of samples affectedby tumor disease and the change of pH on different altitudes in recent3years.(3) Comparing with the ways to preventing, The Quicklime-pouring and the Tumor-removing methods canimprove the environment adaptation and prevent the sample from affecting tumor disease, but do littleto strengthen the photosynthetic capacity. The nutrient transfusion method can do well in controllingspread of tumor disease and promote the health of samples. The5kinds of chemicals chosen inChemical preventing methods are all effective for curing tumor disease and improve the health ofsamples and the result shows that the Sulphur can improve the photosynthetic ability of samples,DaoBingNing can increase the relative chlorophyll content of samples, Chlorothalonil and Carbendazolcan improve the environment adaptation of samples.