Production, tree size inequality and growth dominance in loblolly pine plantations under different silvicultural management regimes.

• Growth dominance increased from negative to positive with age in loblolly pine plantations. • More intensive silviculture decreased tree size inequality but increased growth dominance. • Higher planting densities increased both tree size inequality and growth dominance. • Row thinning treatments decreased both tree size inequality and growth dominance. • Stand biomass growth was negatively related to tree size inequality. • Stand biomass growth was positively related to growth dominance. Understanding stand structure and growth relationships and how they are influenced by silvicultural treatments can help us optimize forest management regimes. With two large long-term silvicultural research experiments in loblolly pine plantations, we examined the effects of planting density, silvicultural intensity (sustained competition control and repeated fertilization), and thinning treatments on temporal patterns of stand biomass, biomass growth, tree size inequality, growth dominance, and on stand growth-structure relationships. Results showed that more intensive silvicultural treatments decreased tree size inequality but increased growth dominance, while higher planting densities increased both tree size inequality and growth dominance in unthinned plots. Growth dominance increased from negative to positive with age. For a given silviculture and planting density, tree size inequality became stable after 15 years while growth dominance continued to change over time. Thinning treatments decreased both tree size inequality and growth dominance, and there were no effects of silviculture and planting density in thinned stands. Stand biomass growth was negatively related to tree size inequality and positively related to growth dominance, after accounting for the effects of silvicultural treatment and planting density. [ABSTRACT FROM AUTHOR]