Yowhan Son

Since the first attempts to increase forest growth using nitrogen (N) fixation, biological N fixation has been intensively studied. Numerous studies that focused on symbiotic N fixation and rates were well quantified. However, the rates and importance of non‐symbiotic N fixation in forest ecosystems remains incomplete. In this review, reports of non‐symbiotic N fixation from various studies throughout the world were examined and the ecological significance of non‐symbiotic N fixation in temperat

Microbial biomass and enzyme activity are essential for ecosystem function in managed forests; however, uncertainty remains because microbial biomass and enzymatic responses to thinning highly differ with case studies. This study addressed the drivers for the site-specific responses of microbial biomass and enzyme activity to thinning. Study sites included two oak and three larch forests; each had un-thinned control, intermediate thinning (15-23% basal area reduction), and heavy thinning treatme

Abstract The influences of thinning (50% of standing density) and liming (Ca+Mg, 2 Mg ha −1 ) on soil chemical properties were investigated for 2 years (2001, 2002) in 40‐year‐old pitch pine ( Pinus rigida Mill.) and 44‐year‐old Japanese larch ( Larix leptolepis Gord.) plantations established on similar soils. In general, soil properties varied significantly among plantations and treatments. For both plantations, thinning significantly increased soil organic C (SOC) concentrations whereas there

Abstract Soil carbon dioxide (CO2) evolution, litter decomposition, and nitrogen availability was measured four years after thinning in a 19-year-old Japanese larch (Larix leptolepis Gord.) plantation of central Korea. Four different thinning intensities [control (C), 10% (T10), 20% (T20), and 40% (T40)] were applied. There were significant differences in seasonal mean soil temperature, moisture, and CO2 evolution among the thinning intensities. Annual soil CO2 evolution (Mg CO2 ha−1) was 29.8 f

Biomass, production, and nutrient distribution of a pure Quercus variabilis Bl. stand (stand 1) and two mixed Q. variabilis – Q. mongolica Fisch. stands (stand 2 and 3) were investigated in central Korea. Stand 1 naturally occurred on a site with a southern aspect while stand 2 and stand 3 occurred on sites with a northern aspect. Total (overstory + understory vegetation) biomass (t ha ‐1 ) and annual production (t ha –1 year –1 ) were 137.8 and 11.1 for stand 1, 216.2 and 16.6 for stand 2, and

Understanding the complex diversity of species and their potential uses in traditional agroforestry systems is crucial for enhancing the productivity of tropical systems and ensuring the sustainability of the natural resource base. The aim of this study is the evaluation of the role of home gardens and parklands, which are prominent tropical agroforestry systems, in the conservation and management of biodiversity. Our study quantified and compared the diversity of woody and herbaceous perennial

We measured photosynthetically active radiation (PAR) beneath the forest canopy, understory species' richness and diversity, and biomass in a Larix leptolepis plantation in central Korea 4 years after thinning. Four different thinning intensities (control, 10%, 20%, and 40% stocking reduction) were applied in 1997. Mean annual intercepted PAR at 30 cm and 1 m above ground level was significantly different among the thinning intensities and strongly correlated with the number of stems remaining a

Soil respiration (RS, Soil CO2 efflux) is the second largest carbon (C) flux in global terrestrial ecosystems, and thus, plays an important role in global and regional C cycling; moreover, it acts as a feedback mechanism between C cycling and global climate change. RS is highly responsive to temperature and moisture, factors that are closely related to climate warming and changes in precipitation regimes. Here, we examined the direct and interactive effects of climate change drivers on RS of Pin

The effects of fertilization [control (C), 200 kg N ha −1 + 25 kg P ha −1 (LNP) and 400 kg N ha −1 + 50 kg P ha −1 (HNP)] on fine root dynamics were examined in a 40‐year‐old Larix leptolepis plantation in central Korea. The average fine root biomass during the growing season for C, LNP and HNP was 957, 934 and 814 kg ha −1 , respectively, whereas the fine root production for C, LNP and HNP was 2103, 2131 and 2066 kg ha −1 , respectively. Nitrogen and P inputs into the soil via fine root turnove