Oriented Cultivation Technology And Sustainable Development Evaluation Of Quercus Variabilis High-forest On The South Slope Of Qinling Mountains

In order to explore the oriented cultivation technology of Quercus variabilishigh-forest, a comprehensive evaluation was taking on the sustainable development ofQ. variabilis high-forest under different thinning intensity, choosing the Q. variabilisnatural high-forest in Shangluo, south slope of Qinling Mountains as the object, whichwas under different thinning intensity of30%,20%and10%. Taking the un-thinnedforest as control, population fruiting, seed to seedling condition, growth conditions ofseedlings, stand structure and forest quality were analyzed under different thinningintensity through plot investigation before thinning and after five years of thinning.Fuzzy membership function was used to comprehensively evaluate the sustainabledevelopment of Q. variabilis high-forest. The main conclusions were as follows:(1) The fruiting of Q. variabilis had an obvious interval period of three years;The average fruiting number of individual plant would increase with the increasingintensity; The stand total fruiting number increased by8.4%when the thinningintensity reached30%, which compared with the control group; The spatialdistribution of the average single plant was the upper accounted for73.8%, and thelower had26.2%; the sunny side of canopy layer set relatively the most fruits of62.2%; The seed size、1000-seed mass and seed germination of the Q. variabilis werequite different under different thinning intensities, seed quality and heated indoorgermination rate performed the best when the thinning intensity reached30%.(2)The seeds amount in soil seed bank of10%,20%and30%thinning plots wererespectively increased2.0%,21.1%and34.8%after4years of thinning, and the1-year-old seedlings amount respectively increased28.5%、99.7%and122.2%in thenext year, compared with the control; the survival rates of seedlings in the10%,20%and30%thinning plots respectively increased by25.5%、235.7%and480.0%after5years of thinning; Thinning improved the light, temperature, soil moisture andnutrients in the forest, which promoted the height, new shoot growth and leaf areaindex of every-age seedlings, the three growth index increased with the increasing thinning intensity.(3) Thinning could promote increasing the DBH and crown of the trees layer andshrubs layer plants、the height of shrubs layer plants(especially light-loving plants),and the effect of promotion increased with the increasing thinning intensity, butthinning intensity could not promote the height of trees layer plants significantly; theincreasing thinning intensity was advantageous to the growth efficiency of individualvolume and per unit area of volume. The species diversity and soil fertility wereimproved after thinning, which showed the order of30%plots>20%plots>10%plots> control plots.(4) To comprehensively evaluate the sustainable development degree of Q.variabilis natural high-forest in Shangluo, south slope of the Qinling Mountains, fourcategories of11factors on constructive species population update, volume, speciesdiversity and soil fertility were used by comprehensive evaluation model of fuzzymembership function. The results were as follows: thinning intensity of30%>20%>control>10%.Thinning intensity of30%was more suitable for the orientedcultivation in Q. variabilis forest on the Qinling Mountains.