The effects of species-composition-oriented silviculture on timber value and carbon - a stand-level case study in subtropical China

Species selection and composition in afforestation affect forest characteristics, which, in turn, affect the quality and quantity of ecosystem services a forest provides to society. Trade-offs and synergies among the various forest goods and services are key issues in multipurpose forest management. In this study, we propose a stand-level integrated analysis framework applying the dynamic forest simulator PICUS v1.5 and techno-economic analysis to assess the effects of a range of species-composition-oriented silvicultural options on timber value and carbon sequestration in subtropical China. The aim is to inform stakeholders on the costs and benefits of the stand-level options. Taking Pinus massoniana and Castanopsis hystrix to represent dominant native conifers and broadleaves, respectively, in subtropical China, five typical silvicultural options were studied: P. massoniana monoculture with normal and high density (stems ha(-1)); C. hystrix pure stands; and even-aged and uneven-aged mixtures of both species. Results indicate that the uneven-aged mixture performed better in carbon sequestration than the other four options. The even-aged mixture showed better combined benefits of timber production and carbon sequestration and additional advantages in balancing long- and short-term benefits over 50 years. Furthermore, the even-aged mixture had the strongest adaptability to market fluctuations. The uneven-aged mixture performed best economically among the five options in scenarios of future higher timber prices. The results will inform stakeholders about the performance of stand-level silvicultural options with respect to revenues and environmental benefits to society.

Automated summary

Species selection and composition in afforestation have significant effects on forest characteristics and ecosystem services. In this study, an integrated analysis framework was used to assess the effects of silvicultural options on timber value and carbon sequestration in subtropical China. The uneven-aged mixture showed better carbon sequestration, while the even-aged mixture had better combined benefits of timber production and carbon sequestration over 50 years. The results provide valuable information for stakeholders to make informed decisions regarding stand-level silvicultural options.