Studies On Davidia Involucrata Baill And Cultivating Techniques In The Qian-Jia-Ping Forest Areas

Davidia involucrata Baill originates from anciency,belongs to relict of paleotropy flora in Tertiary period.It was listed as protected plant of the first class in China.It is a living fossil to study ancient biology and its anagenesis.In order to research the distribution of D. involucrata Baill and effectively protect Chinese dove tree.This paper indicates the scarcity of the studies at Davidia involucrata Baill in the past,and does a expectation of studies in the future basing on classification,morphology,biology,ecology,anatomized structure etc. Moreover,the distributing characteristics,techniques of the seedling and forestation in mountanious region,and the growth characteristics on young trees of dove trees were studied. The research results as follows:1.Qian-jia-ping is the north boundary of Davidia involucrate distribution.Three locations of Sichahe,Qinglongping and Songya where D.involucrate is distributed have significant differences,especially in light,soil and the quantity of associated plants.The three locations,however,have share a general feature that single distribution take a majority and cluster distribution take up less.D.involucrata prefers shade and cool conditions;it also growth in brown soil with shallow layer,acid,mixed with small stones.Geologically,it is mostly distributed in two side of steepgullu.2.The seedling breeding experiment of D.involucrata was conducted with different seed treatment methods and varied substrates in the mountainous area.It was indicated by the results that:Low temperature stratification with river sand in the open air could promote seedling sprout rate by 17.1%compared to the method of burying the seeds in cattle manure. The seedling sprout rate by sowing in the autumn was 14.6%higher than sowing in the spring. Humus substrate could increase the height growth and basal diameter growth by 59.3%and 41.6%respectively than those of regular sand substrate.The best seedlings of D.involucrata were bred at elevation range between 1250 m and 1500 m.Adventitious roots could take place in cuttings prepared from spring shoots with secondary sprouts,while there were no adventitious roots taking place from cuttings made of the autumn shoots.3.The young dove tree development characteristics were expatiated,and forestation techniques were summarized basing on the observed results of experimentation.It was indicated that young tree of D.involucrata Baill rapid develop in the first ten days of June and cease development form August to September.It is good to survive for plantatation in Leeward plot and with a sunny exposure.Yet,it is not good for plantation in Downfold.4.The pests damaging seedlings of dove tree were investigated in Qian-jia-ping forest farm.The results show that there were 24 kinds of pests damage seedlings of dove tree. Damping-off and larva of chafer were the most serious pests to harm D.involucrata seedlings.