Effect of Thinning on Partitioning of Aboveground Biomass in Naturally Regenerated Shortleaf Pine

Abstract

The study focused on shortleaf pine in southeast Oklahoma with possible application to shortleaf pine in other regions of southern United States and to other southern pines. Tree biomass equations were fitted for the shortleaf pine by nonlinear regression techniques. The biomass equations were used to estimate tree and tree component biomass for trees in three different thinning treatment levels. Tree and tree component biomass in the different thinning treatment levels were then compared using ANOVA techniques. Thinning naturally regenerated shortleaf pine stands at the age of 30 to 37 years did not affect proportion of biomass partitioned to stem or foliage. Thinning, however, increased partitioning of biomass to branches and decreased partitioning to bole bark. These results indicate that thinning 1) does not alter the relationship between total aboveground growth and bole wood production, 2) increases branch production, an important consideration in whole-tree harvesting systems, carbon sequestration, and wood quality issues, and 3) does not alter the proportion of aboveground growth partitioned to leaf biomass, an important consideration for stand photosynthetic surface and fine fuels input.