Study On Bungeana Breeding Bases And Evaluation Of The Effectiveness Of The Lei Temple Forest Farm In Hancheng City

Pinus bungeana Zucc.et Endi.,one of endemic species in China,is a kind of precious evergreen trees in our country.It is dark green,tall and straight,which is a good tree for urban greening in the northern China.P.bungeana germplasm resources are abundant in Shaanxi province,and mainly distribute in Leisizhuang state-owned forest farm in Hancheng City.The farm is the largest well-saved P.bungeana forest area.Till now,there are young and middle age trees about 22.7km2,which are growing into fruits stage gradually.Building a P. bungeana breeding base can relief the intense situation of P.bungeana seedling supplication, impulse the healthy development of regional seedling industry and promote the rapid development of regional countryside virescence,and it has a practical significance in adjusting the industrial structure of forest region and promoting the formation of a scientific, normative and regional tree breeding and production system.This thesis made a comprehensive research and analysis on the resources of/! bungeana in timberland of Leisizhuang forest farm by field reconnaissance and sub-compartment investigation.According to the results,we provided tentative plans for constructing excellent P. bungeana species breeding base,made an evaluation of the industry basis construction plan and the expected benefit.The results are showed as follows:1.The resource areas of P.bungeana in timberland of Leisizhuang Forest Farm has been divided into three configuration modes,including seed collecting forest area,seed collecting forest area for follow-up development and optimal growth distribution area that will hopefully become seed collecting forest.2.By proposing a suggestion of establishing the fine variety base and analyzing the area coverage,plan of construction and distribution,the main technical measure and the feasibility of construction,we built an overall framework for the construction of fine variety base,which provided a scientific reference for the specific implementation in the next stage.3.Made benefit analysis on the construction of fine variety base and the preliminary study drawn a conclusion that:the seeds in the base can yield the elite seeds of 24,580 kg per year in the initial production period,and 46,087.5 kg per year during the abundant period;the number of annual nursery stock can reach 1.5 million per year,and 2,000 for 10-year nursery stock after 10 years.