| Cornus controversa Hemsl.is not only a greening tree species in China,but also a kind of good timber tree species.In order to grasped the growth characteristics of Cornus controversa Hemsl.plantation and improved the soil fertility of Xiangxi Karst Area,this paper mainly studied the growth rules,the biomass,the productivity of Cornus controversa Hemsl.plantation and studied the soil physical and chemical properties of Xiangxi Karst Area.The results were as the followings:?1?The Xiangxi Karst Area Cornus controversa Hemsl.diameter at breast height?DBH?of sunny slope,semi-shady slope and shady slope were 18.4cm?20.8cm and 17.6cm respectively.The total diameter growth curve of DBH was S shape.In 0-5u,DBH grew slowly.In 5-15th,DBH grew fast.The Cornus controversa Hemsl.tree height of sunny slope,semi-shady slope and shady slope were 11.60m,13.40m and 11.00m respectively.In 0-15th,tree height grew fast.After 15th,tree height increased slowly.The Cornus controversa Hemsl.volume of sunny slope,semi-shady slope and shady slope were 0.1428m,0.1853m3 and 0.1326m3 respectively.The fast growing period of volume began at the 10 year and ended in 30 year.The current annual increment curve and the annual increment curve of shady slope nearly intersected in 36 year.It means the quantitative mature age of shady slope Cornus controversa Hemsl.plantation was nearly 36.The current annual increment curve and the annual increment curve of sunny slope and semi-shady slope didn't intersected in 36 year.?2?The average biomass per plant of sunny slope,semi-shady slope and shady slope Cornus controversa Hemsl.plantation were 141.51kg,166.68kg and 123.62kg respectively.The above ground biomass of three slope were 120.82kg,142.12kg and 106.62kg,accounting for 85.33%,85.23%and 86.26%of individual total biomass respectively.The under ground biomass of three slope were 20.70kg,24.56kg and 16.99kg,accounting for 14.67%,14.77%and 13.74%of individual total biomass respectively.Except the leaves and bark,the biomass of semi-shady slope was the highest among three slope.?3?The average biomass per area of sunny slope,semi-shady slope and shady slope Cornus controversa Hemsl.plantation were 217.32t·hm-2,246.92t·hm-2 and 185.00t·hm-2 respectively.The biomass of tree layer of sunny slope,semi-shady slope and shady slope accounted for 92.88%,94.78%and 93.32%of total biomass respectively.The biomass in different layer ranged from large to small was tree layer,litter layer,shrub layer and herb layer.The biomass per area of semi-shady slope was the highest among three slope.The productivity of sunny slope,semi-shady slope and shady slope Cornus controversa Hemsl.plantation were19.68t·hm-2·a-1,21.14t·hm-2.a-1 and 18.48t·hm-2·a-1.The productivity of semi-shady slope was highest while shady slope was lowest.?4?The BNR of sunny slope,semi-shady slope and shady slope Cornus controversa Hemsl.plantation were 1.44,1.47 and 1.28;BNI were 0.20,0.22 and 0.21;FC were 0.09,0.10 and 0.10;STR were 0.73,0.71 and 0.70;CRR were 5.86,6.28 and 6.28 respectively.The biomass distribution of three slopes were reasonable.?5?Cornus controversa Hemsl.plantation could decrease soil bulk density and pH of Karst Area,and increase soil moisture content,soil porosity,soil C,soil N,soil P and soil K.In a word,Cornus controversa Hemsl.plantation could improve the ability of water conservation and soil fertility. |
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