Pine production comparison : production potential of Loblolly pine (Pinus taeda) and Slash pine (Pinus elliottii) in the southeastern USA in relation to initial density and forest management
Sammanfattning: The southeastern (SE) United States (US) produces more industrial timber than any other region in the world. Pine plantations in the southern US have increased from 1.8 million acres (728,400 ha) in the beginning of the 1950’s to 32 million acres (13 million ha) in the beginning of the 21st century, and cover 17 % of the forest land. Both the increase in area and productivity over time is remarkable. The increase in productivity is due, in part, to more intensive silviculture methods. Both loblolly and slash pine are being managed intensively in plantations today. In Sweden, another country with large industrial pine timber production, the productivity also has increased over the past 100 years, mainly due to more efficient forest management. Research about productivity in SE US pine plantations has since 1975 been done by the Plantation Management Research Cooperative (PMRC) at the University of Georgia. One of their culture/density studies evaluates how management intensity and planting density affect growth and yield of loblolly and slash pine. Evaluation was done using ANOVA analysis in R, and the results from the analysis were compared with trends from scots pine trials in Sweden through a literature study. Additionally, this study also evaluated whether or not these forest management practices are sustainable for production. The results showed that loblolly pine performs better than slash pine across a range of different management intensities and planting densities. It also showed that the intensive treatment, and the 300 and 1500 trees per acre (TPA) planting densities (741 and 3,705 trees per hectare) had largest impact in terms of productivity of different stand-level measures in pine plantations. More intensive treatments could be applied in Sweden if the regulations would allow it, and those treatments would be sustainable from the perspective of reduction in greenhouse gas emissions, sources to bioenergy and biofuels, and for the economy.
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