Study On Plant Diversity And Carbon Stocks Of Camellia Oleifera Plantation In Guangxi

Biodiversity and carbon sink function are closely related to the survival and development of human beings.China is ranking first in the world as a large reserves of artificial forest.In recent years,integrative management of artificial forest has brought economic benefits,but also enlarged the degree of interference to the ecosystem,resulting in low productivity,poor stability and other problems.The ecological benefits of artificial forest have been paid more attention.Camellia oleifera is a traditional and characteristic economic forest tree species in Guangxi Province.The area of Camellia oleifera cultivation is increasing with the development of its economic application.From the scale of forest community,Camellia oleifera plantation ecosystem will be an important part of forest ecosystem in Guangxi.In order to understand the ecological value of Camellia oleifera plantation ecosystem,the understory biodiversity and background information of Carbon stocks is very important.In this study,the community diversity and Carbon stocks of Camellia oleifera plantations in Guangxi were investigated by field investigation and model simulation from an ecosystem perspective.Through the investigation and analysis of plant diversity and Carbon stocks capacity of 7 distribution areas,3 forest age levels and 5 management measures of Guangxi Camellia oleifera plantations,the effects of regional distribution,forest age levels and management measures on community diversity and Carbon stocks of Guangxi Camellia oleifera plantations were studied.According to the diversity index and the statistical data of Guangxi Camellia oleifera plantation in 2015,the functional value and Carbon stocks conditions are estimated.The results are as follows:1.Plant flora composition and diversity of Guangxi Camellia oleifera plantationsIn the area of Guangxi Camellia oleifera plantations,there are distributiing a total of 100 families,268 genera,414 species.Among them,there are fern plants of 15 families,22 genera and 31 species,gymnosperms plants of 2 families,2 genera and 2 species,and angiosperms plants of 83 families,244 genera and 381 species.The fern plants regional differentiation index of family and genus were 1.47 and 1.41,respectively,and the genera and species were small.The distribution area type of fern family includes 4 types,and the distribution area type of genus includes 6 species.The differentiation intensity coefficient of seed plant family is 2.91,which belongs to middle small family and small family.The differentiation intensity coefficient of genus is 1.57,and there are more oligospecies and single genus,which contains only 1 species of genus as many as 172,accounting for 69.92%of the total number of seed plants in the whole region.The distribution area type of seed plant family includes 10 distribution types,and the distribution area type of genus includes 13 distribution classes.In this area seed plants,also include the Chinese endemic distribution type,which contains 4 genera.In general,the distribution area of vegetation under the plantation of Camellia oleifera in Guangxi is tropical.2.Diversity characteristics of vegetation under plantation of Guangxi Camellia oleiferaThe variation of shrub family number,genus number and species number in different regions of Camellia oleifera forest is related to the heterogeneity of habitat in each region.The similarity of species among different regions was low.The dominant species of shrub layer and herbaceous layer were basically cross-species.Only the Margalef index of shrub layer was significantly different,and the Margalef index,Simpson index,Shannon-wiener index of herbaceous layer plants were different.The families,genera and species number of shrubs layer increased with the increasing forest age.The dominant species of shrub layer and herbaceous layer were basically common species;the change of Camellia oleiferae forest diversity index of different forest age was not consistent with the two sites,but the difference of Margalef index and Shannon-Wiener index of CX Camellia forest and SJ Camellia forest was significant.The families,genera and species number of Camellia oleiferae vegetation families with extensive management and tending measures of different management measures were higher than those of Camellia oleiferae forest with grafting for crown exchange and reforestation.3.Biomass of Camellia oleifera Plantation in Guangxi and Its Distribution CharacteristicsIn general,the biomass of each organ(regardless of fruit)was divided into branches>roots>leaves>flower buds,and the proportion of biomass of branches and roots was more than 50%.The total biomass of Camellia oleifera forest in different regions is higher than that of Camellia oleifera forest in high latitude.The biomass range is 5.705-74.413t.hm-2 of Camellia oleifera ecosystem.4.Carbon stocks of Camellia oleifera Plantation in Guangxi and Its Distribution CharacteristicsOn the whole,the Carbon stocks capacity in trunk and limb is the highest,and the Carbon stocks capacity of flower bud is the lowest.Soil layer Carbon stocks is the highest,followed by trees.In different regions,the total Carbon stocks of low latitude Camellia oleifera forest is higher than that of high latitude Camellia oleifera forest.The variation of the total Carbon stocks of Camellia oleifera forest in different forest ages is different,but the carbon stocks in tree layer increases with the increase of forest age.The variation of total Carbon stocks of Camellia oleifera forest with different management measures is related to the management measures adopted.Factors affecting Carbon stocks in Camellia oleifera plantations:each factor has different effects on Carbon stocks in arbor layer and Carbon stocks in soil layer.The physical properties of soil(porosity,water holding capacity)are negatively correlated with Carbon stocks in arbor layer and positively correlated with Carbon stocks in soil layer.ground diameter,crown width,forest age,leaf biomass,branch biomass,total biomass,latitude and arbor layer Carbon stocks were positively correlated and negatively correlated with soil Carbon stocks.5.Relationship between Carbon stocks and Community Diversity Characteristics of Camellia oleifera Plantation in GuangxiThe shrub layer Margalef index,Simpson index,Shannon-wiener index and species number were positively correlated with the Carbon stocks capacity of the arbor layer.The herbaceous layer Margalef index,Simpson index,Shannon-wiener index,and pielou index were negatively correlated with the Carbon stocks capacity of the soil layer.The effect of Carbon stocks and diversity index regression in arbor layer is remarkable.The fitting equation list is as follow:Y1=-2.739+13.056x1+96.204 x2-46.154x3.6.Carbon stocks estimation of Guangxi Camellia oleifera plantationsTotal Carbon stocks range of Camellia oleifera ecosystem is 55.62-157.28 t.hm-2.Based on the statistics data of 2015,the Carbon stocks estimation of Guangxi Camellia oleifera plantations are:young forest 7.69Tg,middle age forest 30.11Tg,adult forest 37.59Tg.