Quantifying Impacts of National-Scale Afforestation on Carbon Budgets in South Korea from 1961 to 2014

Abstract

Forests play an important role in regulating the carbon (C) cycle. The main objective of this study was to quantify the effects of South Korean national reforestation programs on carbon budgets. We estimated the changes in C stocks and annual C sequestration in the years 1961–2014 using Korea-specific models, a forest cover map (FCM), national forest inventory (NFI) data, and climate data. Furthermore, we examined the differences in C budgets between Cool forests (forests at elevations above 700 m) and forests in lower-altitude areas. Simulations including the effects of climate conditions on forest dynamics showed that the C stocks of the total forest area increased from 6.65 Tg C in 1961 to 476.21 Tg C in 2014. The model developed here showed a high degree of spatiotemporal reliability. The mean C stocks of the Cool forests and other forests increased from 4.03 and 0.43 Mg C ha−1, respectively, to 102.43 and 73.76 Mg C ha−1 at a rate of 1.82 and 1.36 Mg C ha−1 yr−1 during the same period. These results imply that, although the total Cool forest area of South Korea occupied only about 12.3% (772,788 ha) of the total forest area, the Cool forests play important roles in C balances and forest ecosystems in South Korea. Annual C sequestration totals are projected to decrease at a low rate in the near future because the overall growth rate of a mature forest decreases as the stand ages. Our results quantified forest C dynamics in South Korean forests before and after national reforestation programs. Furthermore, our results can help in development of regional and national forest management strategies to allow for sustainable development of society and to cope with climate change in South Korea.

Species- and elevation-dependent productivity changes in East Asian temperate forests

“…The results confirmed the general pattern of sigmoidal age-growth relation that is the width of tree rings decreases with age due to the increase in stem area as trees age (e.g. Kim et al 2019), and yet, the rate of change varies across both tree species and forest types. We found negligible differences between the annual growth rates of PD and LK in LLFs and PD and LK in HMFs (figures 3(a), (c)), while PK, QV, and QM have distinct growth discrepancies between the two elevation classes (figures 3(e), (g), (i)).…”

“…In this study, the area for each tree species was categorized as lowland forest (LLF) or high mountain forest (HMF). HMFs were classified as forests at elevations above 700 m based on the definition of Cool forest (Kim et al 2019). When this definition is applied, the total HMF in South Korea is an estimated 821 634 ha based on high spatial resolution (10 m×10 m) digital elevation model data and the forest map data (table 1).…”

“…Forests play an important role in the preservation of a sustainable society, ecosystems, and the environment; this is especially the case considering the risk posed to the environment by global warming (Rudel et al 2005, Lindner et al 2010, Kim et al 2019. More specifically, forests provide a number of ecosystem services including timber production, carbon sequestration, recreation, preservation of biodiversity, water management, and non-wood forest products.…”

“…Besides, mountain ecosystems have many endemic species due to their isolation compared to lowland vegetation communities that can occupy climatic niches spread over wider latitudinal belts. These forest systems are particularly susceptible to climate change (Dale et al 2001, Pearson and Dawson 2003, Kim et al 2019 and may become more vulnerable in the future because of extensive drought and higher temperatures as a consequence of global change (van Mantgem et al 2009, Anderegg et al 2012, Seidl et al 2014, McIntyre et al 2015, Khabarov et al 2016. However, as little is known about the long-term dynamics of productivity and adaptation and the mitigation potential of these forest systems in the Eastern Asian region, reliable information on productivity is required for sustainable forest management.…”

“…In addition, shifting tree species suitability and increased damage from insects have been observed in Korean forests (Kim et al 2017b). The velocity and impact of climate change appears to be site, environment, and tree species-specific (Kim et al 2019). Therefore, it is important to continue to monitor changes in forests in response to climate change (Kraxner et al 2017, Reyer et al 2017.…”