Biomass and growth analysis of different provenances of Pinus densata seedling in P. yunnanensis habitat site

The superior provenance of four-year-old Pinus densata was selected by the determination of biomass and growth characteristics at seedling stage. Different biomass models for components were constructed and then the optimum estimating models were selected based on the fitting analysis. The results showed that there were extremely significant difference among different provenances of P. densata for all growth and biomass characteristics except the primary lateral root number and lateral branch number. Aboveground biomass was the main part of the seedling biomass，accounting for about 75.60%，and aboveground biomass and total biomass was in the order： provenance Palung Zangbo > Baoxing > Niyang valley > Kangding > Chayu > Yarlung Zangbo > Lixian > Maerkang. There were different biomass distributions in various organs. The moisture content of all components were extremely significanly different among provenances of P. densata except the moisture content of branch. The correlation was more close between the ground line diameter and all components biomasses than the correlation with seedling height’s. The optimal model was the power function biomass model，in which the independent variables were the ground line diameter（ D），the ground line diameter and seedling height（ D2H） of all components biomass. Comprehensive comparison showed that Palung Zangbo provenance had higher seedling quality than others，which accumulated more dry matter to adapt to the environment of testing location，and had the great ability in carbon storage and carbon sequestration capacity.