Knowledge about carbon and nutrient fluxes by litterfall is important for understanding nutrient cycling in geologically unique ecosystems. However, the determination of forest litterfall production patterns is difficult due to many biophysical factors influencing the process. In this study, we (1) quantified the litterfall production and carbon and nutrient fluxes in warm-temperate evergreen forest stands in Jeju Gotjawal and (2) compared these values to those of a typical cool-temperate deciduous forest stand by forest types and climate differences. Litterfall from evergreen broadleaved forests at Cheongsu (CS) and Seonheul (SH_b), a mixed forest at Seonheul (SH_m) in Jeju Gotjawal, and a deciduous broadleaved forest at Chungnam National University Forest (CNU) was collected for a full two years using litter traps. Samples were sorted into leaves, twigs, barks, seeds, and unidentified materials, and then weighed and measured for C, N, P, K, Ca, and Mg fluxes by litterfall. Results showed that the mean annual litterfall (846.3 g m⁻², average of CS, SH_b, and SH_m) at Jeju Gotjawal was similar to that of CNU (885.5 g m⁻²), but varied by site in Jeju Gotjawal: CS (933.1 g m⁻²) was significantly higher than the average of SH_b and SH_m (802.9 g m⁻²). Seasonal patterns of litterfall production differed by forest types; evergreen broadleaved forests showed a bimodal peak in fall and spring while deciduous broadleaved forests showed a unimodal peak in fall. Jeju Gotjawal had significantly higher total macronutrient concentrations and contents (except for K) than CNU and they also varied by site in Jeju Gotjawal: CS had higher N, P, Ca, and Mg contents than SH_b and SH_m. We conclude that litterfall production and nutrient fluxes differed by forest stand as influenced by forest types and climate. Further, our findings are important for understanding carbon and nutrient dynamics in the geologically unique ecosystem of Jeju Gotjawal and other areas with similar characteristics.

Urban green spaces (UGSs) are critical in providing essential ecosystem services (ESs) that enhance the quality of life of urban communities. This study investigated the synergies and trade-offs between structural characteristics of urban trees and their ecosystem services and their implications for urban park management within Yurim Park, Daejeon, South Korea, using the i-Tree Eco tool. The study specifically focused on regulating and supporting services, assessing diversity, air pollution removal, carbon sequestration, and avoiding runoff. A systematic review of urban park management practices complemented the empirical analysis to provide comprehensive management recommendations. The findings of a total of 305 trees from 23 species were assessed, revealing moderate species diversity and significant variations in structural attributes, such as diameter at breast height (DBH), leaf area index (LAI), and crown width (CW). These attributes were found to be strongly correlated with ES outcomes, indicating that healthier and larger trees with extensive canopies are more effective in providing benefits such as pollution removal, runoff reduction, and carbon sequestration. However, the study also identified trade-offs, particularly regarding volatile organic compound (VOC) emissions, which can contribute to ground-level ozone formation despite the trees’ pollution removal capabilities, sensitivity to water stress, requirements for shade and cooling effects, and impacts on water yield. The results highlight the importance of strategic management practices to balance these trade-offs, such as selecting low-emitting species and employing incremental pruning to enhance pollutant removal while minimizing VOC emissions. Additionally, the findings underscore the significance of tree placement and landscape patterns in optimizing year-round benefits, particularly in reducing urban heat island effects and enhancing energy efficiency in adjacent buildings. The study concludes that while urban parks like Yurim Park offer substantial ecological and environmental benefits, continuous monitoring and adaptive management are essential to maximize synergies and mitigate trade-offs. The insights provided on species selection, tree placement, and landscape design offer valuable guidance for urban planners and landscape architects aiming at enhancing the effectiveness of urban parks as nature-based solutions for sustainable urban development.

In this study, the interacting effects of shade and planting methods on the growth and competitive ability of two understory plants Heracleum moellendorffii Hance and Adenophora divaricata Franch. & Sav. were investigated under different soil moisture and nutrient conditions. One-year-old seedlings were subjected to different light levels (0%, 35%, and 55% shade) and planting methods (monoculture and mixed) under contrasting soil moisture (1.2 L/m² and 2.3 L/m² of water) and soil nutrient conditions (unfertilized and fertilized). Here, shading significantly improved the height growth of H. moellendorffii (10–20 cm increase) in unfertilized and fertilized plots and at high soil moisture conditions. Contrarily, A. divaricata seedlings planted singly at full sunlight yielded a higher aboveground biomass growth (8–17 g plant⁻¹), compared with those shaded and intercropped seedlings (0.9–3.9 g plant⁻¹). The increased competitiveness of H. moellendorffii suppressed the growth of A. divaricata across different light conditions when planted together. The amount of light, soil moisture, and nutrients and their interactions significantly affected the growth of the seedlings, resulting in asymmetric interspecific competition between the two species. Results provide us with a better understanding of the environmental factors affecting plant growth for forest farming in the understory.

Biochars are used to improve soil quality and crop productivity as well as to increase carbon sequestration in soil. However, it is important to identify the characteristics of biochar prior to its application because of the positive and negative effects on soil and crop productivity. The purpose of this study was to investigate the effects of charcoals on the growth and seedling quality of Quercus serrata and Prunus sargentii in a containerized seedling production system. Two of the charcoals used in our research were from oak tree; one produced at 1200 °C and the other at 700 ∼ 800 °C, and a bamboo charcoal produced at about 800 °C. Three charcoals were mixed with artificial soil (peat moss, perlite, and vermiculite with a ratio of 1:1:1 (v/v/v)), and applied commercial fertilizer at two concentrations; 0.5 and 1.0 g L⁻¹. Growth parameters, such as height, root collar diameter, and dry weight, were decreased in charcoal treatments compared to control. However, charcoal treatments significantly increased the quality index of seedlings by 8.3% in Q. serrata and by 19.9% in P. sargentii. Our results suggested that charcoal can be applied to improve seedling quality in the containerized Q. serrata and P. sargentii seedling production system.

Urbanization and associated forest conversions have given rise to a continuum of native (forest fragments) and modified (artificial grasslands and perennial ecosystems) land-use types. However, little is known about how these shifts affect soil and fine-root compartments that are critical to a functioning carbon and nutrient circulation system. In this study, soil physicochemical properties, fine-root mass, and vertical distribution patterns were investigated in four representative urban land-use types: grassland (ZJ), perennial agroecosystem (MP), broadleaf deciduous forest patch (QA), and coniferous evergreen forest patch (PD). We quantified the fine-root mass in the upper 30 cm vertical profile (0–30 cm) and at every 5 cm depth across three diameter classes (<2 mm, 2–5 mm, and <5 mm). Soil physicochemical properties, except for phosphorus, nitrogen, ammonium nitrogen, and sodium cations, varied significantly across land-use types. The total root biomass ( PD (487.2 g m⁻²) > ZJ (440.1 g m⁻²) > MP (98.3 g m⁻²). The fine-root mass of ZJ and MP was correlated with soil nutrients, which was attributed to intensive management operations, while the fine-root mass of QA and PD had a significant relationship with soil organic matter due to the high inputs from forest litter. Very fine roots (<2 mm) presented a distinct decremental pattern with depth for all land-use types, except for MP. Very fine roots populated the topmost 5 cm layer in ZJ, QA, and PD at 52.1%, 49.4%, and 39.4%, respectively. Maintaining a woody fine-root system benefits urban landscapes by promoting soil stabilization, improving ground infiltration rates, and increasing carbon sequestration capacity. Our findings underscore the importance of profiling fine-root mass when assessing urban expansion effects on terrestrial ecosystems.