The voluntary carbon market allows participants to go beyond regulatory carbon offsetting. Recent developments have improved the transparency and credibility of voluntary carbon trading, and forest carbon credit transactions constitute more than half of trade volume. Its workings, however, have not been sufficiently explored in the literature. This study analyses the characteristics of forest carbon credit transactions in the voluntary carbon market using frequency analysis and logistic regression analysis. The results reveal that the co-benefits of forest carbon projects are an important factor influencing carbon credit transactions. From the higher transaction ratio of credits from CCB Standards-labelled projects and projects using co-benefit-oriented standards, it can be inferred that credits with potential for co-benefits (e.g. fostered corporate social responsibility, social cohesion of local communities and voluntary leadership, and positive environmental impacts) are preferred to those focusing exclusively on emission reduction in the voluntary carbon market. The findings of this study suggest that developing co-benefits is important for strengthening the market competitiveness of forest carbon credits in the voluntary carbon market. Additionally, unlike the compliance carbon market, in the voluntary carbon market stringent carbon standards do not always guarantee credit transaction performance. POLICY RELEVANCE After UNFCCC COP-21, the global society agreed to acknowledge various forms of international carbon crediting mechanisms, and noted the significance of greenhouse gas emissions reduction for sustainable development and environmental integrity through the Paris Agreement. Moreover, the agreement encouraged both REDD+ activities in developing countries and supports from developed countries. Additionally, co-benefits of forest carbon projects are important for credit transaction in the global voluntary carbon market. Under the new climate regime, co-benefits of forest carbon projects are expected to gain attention in the carbon market. To promote the social, economic, and environmental co-benefits of forest carbon projects, the introduction of an objective co-benefit assessment and certification system should be reviewed at the national level.

With the institutionalization of reducing emissions from deforestation and forest degradation, and the role of conservation, sustainable management of forests, and enhancement of forest carbon stocks in developing countries (REDD+), the global REDD+ financial network has been formed to support the implementation of REDD+ in developing countries. Although the rapid expansion of the network made it decentralized, it is still a highly centralized network in terms of the distribution of financial resources, revolving around only a few major actors. While the source of financing was diversified due to an increase in influential donors, the majority of financing still came from a few constant major donors, and a few constant major developing countries received most of the financial support. Although increases in donor numbers and the amount of finance received can provide more chances to support developing countries, it may cause inefficiency due to overlaps and duplications. Also, over-centralization of financial resources can be ineffective in terms of achieving maximum greenhouse gas (GHG) reduction, and can broaden gaps between developing countries’ ability to cope with climate change and deforestation. Lack of coordination among donors and the differing capacity of developing countries may have caused centralization of financial resources in the global REDD+ financial network. To minimize this problem, a comprehensive monitoring system and platforms for information sharing are needed.

A cooperative approach for REDD+ between developing and developed countries can be a sound means to achieve national and global mitigation targets. To accomplish the Nationally Determined Contribution (NDC) of countries and the global 2 °C climate target more effectively, it is necessary to explore the coordination options, based on the understanding of bilateral REDD+ cooperation. This study explains the current status of bilateral REDD+ cooperation and investigates determinants affecting REDD+ recipient decisions of donor countries, by analyzing bilateral REDD+ arrangements, which has been promoted for 10 years under the the Kyoto Protocol regime from 2006 until 2015. The results show that Norway and Japan supported more than half of the total financial pledges for bilateral REDD+ projects for 10 years. Out of 87 REDD+ recipients, four countries—Brazil, India, Indonesia, and China—accounted for more than half of the 10-year financial pledges. Approximately 78% of total financing was found to be concentrated in the top 10 recipients. The aid darlings and orphans problem, the concentration of bilateral supports in a few developing countries and the exclusion of several developing countries from the recipient selection process, which has been discussed in ODA researches, was also observed. Applying a shared frailty model, recipient need, recipient merit, and donor interest was found to be the main determinants of donors’ REDD+ recipient decision. Donor interest and recipient merit were found to have more significant effects on the decision than recipient need. A balanced two-track approach is further required, in which, along with the bilateral REDD+ cooperation in the REDD+ darling countries, international organizations and multilateral funds for REDD+ need to increase financial accessibility, including the result-based compensation system for the REDD+ orphan countries.

Temperate forest ecosystems in Korea are currently undergoing a successional transition from Pinus densiflora Siebold & Zucc. (evergreen conifer) communities to Quercus mongolica Fisch. ex Ledeb. (deciduous broadleaf) communities. This study aimed to assess interspecific differences in ecological responses to climate change [Representative Concentration Pathway (RCP) 4.5] by evaluating changes in ecological niche characteristics and species distribution. Controlled-environment experiments, principal component analysis (PCA), and MaxEnt species distribution modeling were employed to quantify and predict ecological shifts in the two dominant species under climate change scenarios. Both species exhibited increases in niche breadth and interspecific overlap under climate change conditions. However, Q. mongolica showed a more pronounced increase in niche breadth compared to P. densiflora, indicating greater ecological flexibility and adaptive potential to warming conditions. According to the MaxEnt model projections, climate change is expected to result in an approximate 30% reduction in suitable habitat for P. densiflora in lowland areas. In contrast, Q. mongolica is projected to expand its suitable habitat by over 80%, notably in both low-elevation (below 800 m) and high-elevation (above 1400 m) zones, without being restricted to any specific altitudinal range. Our findings suggest that climate change may increase ecological similarity between P. densiflora and Q. mongolica, thereby raising the potential for interspecific competition. This convergence in niche traits could contribute to an accelerated successional transition, although actual competitive interactions in natural ecosystems require further empirical validation. Consequently, Korean forests are likely to transform into predominantly deciduous forest ecosystems under future climate conditions.

Managed plantation forests are important for timber production and carbon sequestration, but their biodiversity value compared with unmanaged secondary forests remains debated. We compared vascular plant diversity between a managed Japanese larch (Larix kaempferi) planted forest (MPF) and a nearby unmanaged secondary Mongolian oak (Quercus mongolica) forest (USF) in the Garisan Leading Forest Management Complex, Hongcheon-gun, Republic of Korea, where stand age and site conditions were broadly comparable. Using Modified-Whittaker plots across 1–1,000 m² at five sites per forest type, we analyzed pooled species richness of total vascular plants, spring-active herbs, native species, and alien species, and estimated species accumulation using species–area slopes. We also examined taxonomic structure with hierarchical diversity partitioning and dominance patterns using rank–abundance curves. Total species richness was significantly higher in the MPF across all plot sizes, and species accumulated more rapidly with area than in the USF (b = 14.14 vs. 4.48). Spring-active herbs and native species were also richer in the MPF, with steeper species–area slopes. Alien species occurred slightly more often in the MPF but remained scarce in both forest types. The MPF had significantly higher within-family genus diversity, whereas within-genus species diversity did not differ. These results suggest that early understory control, periodic thinning, microsite heterogeneity, and the spring light window under deciduous larch can promote understory plant diversity in mid-aged managed plantations.