Soung-Ryoul Ryu

Erratum to: Effects of forest fires on forest ecosystems in eastern coastal areas of Korea and an overview of restoration projects

Recent large fires have highlighted the importance of understanding post-fire processes in forest ecosystems, in order to implement ecologically sound post-fire forest restoration practices. Restoration principles should be based on a thorough understanding and appropriate integration of the ecological, social, and economic factors associated with forest ecosystems. In Korea, forest fires mainly affect pine forests, which provide habitats for pine mushrooms, a major source of income for local residents. Curculionid beetles can easily attack fire-damaged trees because of the trees’ weakened defense mechanisms. On the other hand, fire accelerates the decomposition of organic matter and nutrient release, thereby improving forest productivity. Natural restoration after large fires depends on regeneration (e.g., from seeds and sprouts) of the remaining trees that have sustained less damage, until secondary forests are established. However, severely burned areas may require rapid artificial regeneration depending on the specific climatic (e.g., summer rainy season), geographic (e.g., shallow surface soil and land erosion), and economic (e.g., local mushroom harvesting) objectives. A restoration plan should include constructing fuel breaks to reduce the fire risk if the area is replanted mainly with pine species.

Changes in soil properties of Abies holophylla and Quercus-dominated stands 4 years after trenching

Abstract Few studies tried to isolate the influence of plant roots on the soil characteristics including soil carbon (C) and nitrogen (N) storage. We evaluated the impact of root trenching on soil characteristics of coniferous (Abies holophylla) and deciduous (Quercus spp.) stands 4 years after trenching. Trenching treatment significantly increased the soil water content and nitrate concentration in both stand types. Soil pH, cation exchange capacity, soil C and N pools and isotopic compositions of C and N were significantly different between two stands, but trenching was not found to have significant impact on these soil properties. Our results indicated that root trenching in coniferous and broad-leaved deciduous forests of temperate region could significantly alter soil moisture regime and inorganic N levels, but not C and N stabilization in soils.

Fire Spread Regulated by Weather, Landscape Structure, and Management in Wisconsin Oak- Dominated Forests and New Jersey Pinelands

This study is to predict fire spread behavior and burned area across two fire-prone landscapes with contrasting vegetation (Oak-dominated ecosystem in WI vs. pine-dominated ecosystem in NJ), fuel-type composition, and land-use history regulated by the effects of weather, landscape structure and land management by combining simulations from three models (FARSITE, HARVEST, AND FRAGSTATS) under different scenarios. The results demonstrate:\1- substantial differences in fire-spread patterns between the two landscapes were observed when holding weather conditions constant and excluding roads, indicating that landscape fragmentation is a main controlling factor on fire spread at the landscape level; ➁ roads functioning as barriers could significantly reduce the burned area from fire spread; and ➂ Harvesting effects showed different trends, depending on landscape fuel type composition and weather conditions. At 4% harvesting intensity, both clustered and dispersed methods showed no significant impact (a=0.01) on reducing the mean burned area across the more fragmented WI landscape, but showed significant effects on fire spread in the less fragmented NJ landscape in summer when weather was hot and dry.

Simulating Fire Spread with Landscape Level Edge Fuel Scenarios

Area-of-edge influence (AEI) is sometimes the dominant element of many forested landscapes. Patch vegetation dynamics can create a different fuel loading at the edge relative to the interior. We used the computer simulation model FARSITE to examine a fuel edge structural feature with scenarios from three levels of edge fuel loading to determine what impacts fuels in AEI have on fire spread by ranking all of the landscape scenarios. The mean burned area (ha) was significantly different among the landscapes after seven days. Fire spread increased by 38% with a high fuel loading assigned to the designated edge structure; while it decreased by 20% with medium edge fuel loading and 44% with low edge fuel loading. The landscape without edge structure (i.e., control) produced burned areas between the medium and the high edge fuel loading scenarios. The daily rate of fire spread was also significantly affected by edge fuel loading. We encourage model users to include edge fuel in FARSITE fuel maps of highly fragmented forests. This study suggests that with on the ground fuel treatments, AEI can be manipulated to change the spread potential of large fires.

Oak sprout dynamics after a 1996 stand-replacing fire in Korea

Sprouting is an effective means to re-establish a forest after forest fires. However, these sprouts are vulnerable to fungi-related infection (e.g., discoloration, heart rot, and decay) through wounds on primary stumps or root systems to produce low-quality timber. A stand-replacing fire consumed 3762 ha of pine-dominated forests in Goseong-gun, Gangwon-do in 3 days in 1996 and a low-intensity fire swept the area again in 2000. We established five 9 × 9 m2 plots in the area designated for natural regeneration, where oak species (i.e., Quercus dentata Thunb., Q. mongolica Fisch. ex Ledeb, Q. serrata Thunb. ex. Murray, Q. variabilis Blume) replaced Japanese red pine (Pinus densiflora Siebold & Zucc.) forests. All the measurements were carried out in April 2010. The objectives of the study were to evaluate the natural regeneration patterns of oak species and to assess the factors associated with oak sprout discoloration. Sprout production was the highest in the third growing season from each fire in 1996 and 2000, implying that oak species might focus more on root development for the first few years and move onto sprout production. A t-test was employed to evaluate the difference between normal and discolored sprouts. There were significant differences in height, DBH, and age between normal and discolored sprouts (P < 0.05), except for those of Q. dentata. Additionally, correlation analysis was conducted between sprout discoloration occurrences and sequentially shifted annual sprout production to assess the time-lagged relationship. Discoloration occurrences showed the highest correlation coefficient with annual sprout production at a 2-year advance (r = 0.36, 0.82, 0.62, and 0.80 for Q. dentata, Q. mongolica, Q. serrata, and Q. variabilis, respectively), indicating that discoloration tended to occur within 2 years after the sprout production. Approximately 50% of sprouts were discolored showing that discoloration is a common phenomenon in oak sprouts after fire and oak sprouts would likely produce less desirable timbers. The results suggest that fire-induced oak forests should be managed for small timber forests with short rotation.