Variation In Phytolith-occluded Organic Carbon Sequestration Potential Of Twenty Provenances Of Masson Pine(Pinus Massoniana Lamb.)

Phytolith-occluded organic carbon(PhytOC)plays a unique role in reducing atmospheric CO2 content and mitigating the greenhouse effect.Masson pine(Pinusmassoniana Lamb.)was a kind of forest type with wide distribution area,and it is also the most widely used pioneer tree species in China’s pine family and the Masson pine ecosystem has considerable PhytOC storage.We collected the samples of leaves and trunk from twenty provenances of Masson pine which come from 20 areas in 11 provinces in Caishan Forest Farm,Chunan,Zhejiang Province.Then the contents of total OC,phytoliths,PhytOC,PhytOC in dry matter as well as bionass of Masson pine were analyzed.Based on the above results,these twenty provenances of Masson pine were clustered by using the mean values of total organic carbon content,PhytOC content and other parameters.Therefore,in this study our objectives were to find out if there were Masson pine provenances with significantly higher PhytOC sequestration potential than others,and to provide the basis for carbon sequestration of phytoliths in Masson pine ecosystem in China.The primary results of this study were summarized as follows:1.Comparative study on PhytOC sequestration potential in leaves of Masson pine(Pinusmassoniana Lamb.)from different provenances.(1)The OC in phytoliths in Masson pine leaves collected from 20 different provenances were 132.8～233.8 g·kg-1,the leaf biomass and PhytOC stock of Masson pine leaves collected from 20 different provenances were 7.53～18.90 kg·plant-1 and 1.67～9.22 g·plant-1,respectively;(2)The PhytOC in dry matter and PhytOC produce flux of Masson pine leaves collected from 20 different provenances were 0.165～0.520 g·kg-1 and 2.88～15.50 g-e-CO2·plant-1·a-1,respectively;(3)According to the results of cluster analysis,20 provenances of Masson pine can be divided into three categories.There were significant differences in total OC,the content of phytoliths,PhytOC,and PhytOC in dry matter in leaves of Masson pine from different provenances(P<0.05).2.Comparative study on PhytOC sequestration potential in trunk of Masson pine from different provenances.(1)The PhytOC and PhytOC in dry matter in the trunks of Masson pine were 126.8～210.2 g·kg-1,and 0.049～0.128 g·kg-1,the trunk biomass and PhytOC stock in the trunks of Masson pine were 76.48～295.39 kg·plant-1 and 4.83～31.58 g·plan-1,respectively;(2)According to the results of cluster analysis,20 provenances of Masson pine can be divided into four categories,there were significant differences in the content of phytoliths,PhytOC,and PhytOC in dry matter in trunks of Masson pine from different provenances(P<0.05).3.The sum of PhytOC stock of standard plant leaves and standard plant trunk of Masson pine from different provenances were 6.55～34.77 g·plant-1,in which the highest and lowest were obtained from Guangxi Cenxi 115(34.77 g·plant-1)and Hunan Anhua 72(6.55 kg-plant-1),Assuming the highest PhytOC of 34.77 g·planr-1,and the estimated stand density is 1 306 plant-1·hm-2,the total leaves and trunk PhytOC stock of Masson pine stand in China stand(1.20×10-7 hm2)is estimated to be5.4×105 t C.