The Impact of Near Natural Forest Management on the Carbon Stock and Sequestration Potential of Pinus massoniana (Lamb.) and Cunninghamia lanceolata (Lamb.) Hook. Plantations

Angang Ming,Shirong Liu,Yi Tao,Liqun Lei,Ji Zeng,Dongjing Sun,Hua Li,Ning An,You Nong,Yujing Yang

doi:10.3390/f10080626

Abstract

Quantifying the impact of forest management on carbon (C) stock is important for evaluating and enhancing the ability of plantations to mitigate climate change. Near natural forest management (NNFM) through species enrichment planting in single species plantations, structural adjustment, and understory protection is widely used in plantation management. However, its long-term effect on forest ecosystem C stock remains unclear. We therefore selected two typical coniferous plantations in southwest China, Pinus massoniana (Lamb.) and Cunninghamia lanceolate (Lamb.) Hook., to explore the effects of long-term NNFM on ecosystem C storage. The C content and stock of different components in the pure plantations of P. massoniana (PCK) and C. lanceolata (CCK), and their corresponding near natural managed forests (PCN and CCN, respectively), were investigated during eight years of NNFM beginning in 2008. In 2016, there was no change in the vegetation C content, while soil C content in the 0–20 cm and 20–40 cm layers significantly increased, compared to the pure forests. In the P. massoniana and C. lanceolata plantations, NNFM increased the ecosystem C stock by 31.8% and 24.3%, respectively. Overall, the total C stock of soil and arborous layer accounted for 98.2%–99.4% of the whole ecosystem C stock. The increase in the biomass of the retained and underplanted trees led to a greater increase in the arborous C stock in the near natural forests than in the controls. The NNFM exhibited an increasingly positive correlation with the ecosystem C stock over time. Long-term NNFM enhances ecosystem C sequestration by increasing tree growth rate at individual and stand scales, as well as by likely changing the litter decomposition rate resulting from shifts in species composition and stand density. These results indicated that NNFM plays a positive role in achieving multi-objective silviculture and climate change mitigation.

Highlights

Climate change has become a major issue that has created global concern [1]
Over 70% of the subtropical plantations consist of pure stands of coniferous species, dominated by Pinus massoniana (Lamb.), Cunninghamia lanceolata (Lamb.) Hook, as well as short-rotation exotic species like Eucalyptus spp
After eight years of Near natural forest management (NNFM), no significant difference was detected in the C content of the organs of P. massoniana and C. lanceolata between the near natural and unimproved forests (p > 0.05, Table 3)

Summary

Introduction

Climate change has become a major issue that has created global concern [1]. It has been widely recognized that rational plantation management can mitigate climate change by enhancing its carbon (C) sequestration capacity [2]. Forests 2019, 10, 626 stock in different components of the forest ecosystem is critical for evaluating and enhancing the C sequestration potential of plantations. Over 70% of the subtropical plantations consist of pure stands of coniferous species, dominated by Pinus massoniana (Lamb.), Cunninghamia lanceolata (Lamb.) Hook, as well as short-rotation exotic species like Eucalyptus spp. Some pure coniferous plantations even potentially cause soil acidification [7]. Problems such as auto-toxicity, nutrient deficiency, and understory competition have been observed in areas reforested with several rotations of the same species [8,9]

Methods

Discussion

Conclusion