Growth Pattern,Blossoms And Solid Characteristic Of Corylus Chinensis Plantation

Corylus Chinensis,for producing wood and nuts,is an unique and fine tree species in China.Aimed to get the information about the plantation growth and development pattern,and their relationship with afforestation sites index,which could be the basis of afforestation techniques for Corylus chinensis plantation,research on plantation growth regularity,flowering and fruiting development laws,along with the techniques of afforestation were conducted in this paper.The main results were showed as followings:(1)Average increment of DBH increased persistently,and the current annual increment increased rapidly from 5 to 7 years after planting,the increment peak was at 7 years old plantation,then the DBH increment slowed down,which closed to average growth amount.Compared with DBH growth,the height grew slowly at the first 3 years,and growth peak was at 6 years old plantation,then slow down.There were growth peaks at 4a,6a and 9a of the current annual increment.12 years after planted,the plantation growth rapidly,then grew slowly.Within the 12 year,there were 5times intersect between the average growth and current annual growth.For wood volume,both the current annual and average increment increased slowly,however the difference between them was enlarged year by year.Averagely,increment of diameter at breast height(DBH)of 14 years old Corylus chinensis in the middle-age plantation was 1.03cm/a,and height increment was 0.9m/a,the Breast-height form-factor was 0.44～0.49.(2)In the mixed community of Corylus chinensis totally 98.6%of roots by weight,88.9%roots whose diameter were smaller than 0.1 cm distributed within 40 cm from the surface of the soil.The fertility factors that controlled the young plantation growth were soil organic matter,available nitrogen,phosphorus,and available phosphorus and potassium controlled the growth of middle-age plantation.(3)Corylus chinensis in the area of Northwest of Hunan,the initial fruiting was 11 years after planting.The flowering time was from end of January to middle of March.Buds started germinating in the middle of March,and young fruits exhibited at the end of April,the nuts matured in October,leaf started falling in the last 10 days of Novenber.the fruit-setting rate of female inflorescence was 89.2%.And average number of fruits bract per fructescence was 6.4.The ratio of kernel production was 17.3%.Thousand nut weight was 1835 g,and thousand kernel weight was 352.9g.There were great different among different plants in thousand nuts weight,thousand kernel weight,the number of fruit bract per fructescence and morphological traits of the fruit.Variable coefficient of fruit morphological traits orderly as:the number of furit bract per fructescence>length of bract>diameter of bract>thickness of nutshell>kernel width>kernel thickness>transverse diameter of nut>index of fruit shape>longitudinal diameter of nut.(4)There were great different in growth pattern,nut quality,when plants grown at different type of site conditions.For increment of individual stand timber volume,it orderly ranged as plants grown mountain yellow soil>mountain yellow brown soil>lime soil.In middle-age plantation,average DBH related with stand density negatively,such as 2433 plant/hm2 of stand density would control the DBH growth of 14 years old plant.(5)The key techniques for establishing timber plantation,for producing nuts and for setting up dual-purpose of timber and nut plantation of Corylus chinesis were developed respectively.For timber it could be afforested at low and middle.mountain area with shale soil,or sand soil,but lime soil.The top soil was more than 40 cm.Planting density was 2000～2500 plant/hm2 with spacing between rows 2m×2.5m～2m×2m.The plantation could be mixed with Cunninghamia lanceolata,Castanea mollissima,Carpinus turczaninowii,Cinnamomum eassia,Sorbus folgneri,Lithocarpus harlandii and Linder a communis;For nuts,it’s better to setup plantation at 400 m～800m low mountain area with shale soil or lime soil.The stand density was 600～900 plant/hm2,with the 4m×4m～4m×2.5m spacing between rows.And plant having trunk with sparse canopy shape would be the high yield tree;For setting up dual-purpose of timber and nut plantation:the stand density was 1200～1665plant/hm2,with the 4m×2m～2m×3m spacing between rows.10%substratum arbor could be mixed,or planted pure Corylus chinensis within a small area,so as to cultivate large diameter timber.