• Title/Summary/Keyword: Forest dynamics

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Mass Loss Rates and Nutrient Dynamics of Oak and Mixed-Hardwood Leaf Litters in a Gyebangsan (Mt,) Forest Ecosystem

  • Kim, Choonsig
    • The Korean Journal of Ecology
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    • v.26 no.6
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    • pp.335-340
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    • 2003
  • Patterns of mass loss and nutrient release from decomposing oak (Quercus mongolica) and mixed litters (Q. mongolica, Betula schmidtii, Acer pseudo-sieboldianum, Kalopanx pictus and Tilia amurensis) in a natural hardwood forest in Gyebangsan (Mt.) were examined using litterbags placed on the forest floor for 869 days. Mass loss rates from decomposing litter were consistently higher in mixed litter (59%) than in oak litter types (52%) during the study period. Nutrient concentrations such as nitrogen (N), phosphorus (P), potassium (K), and magnesium (Mg) from decomposing litter were also higher in mixed litter than in oak litter types. Nutrient concentrations (N, P, Ca, and Mg) increased compared with initial concentration of litter, while K concentrations dropped rapidly at the first 5 months and then stabilized. The results suggest that mas loss and nutrient release obtained from decomposing litter of single species in mixed hardwood forest ecosystem should be applied with caution because of the potential differences of mass loss and nutrient release between single litter and mixed litter types.

Analysis of Changes in Pine Forests According to Natural Forest Dynamics Using Time-series NFI Data (시계열 국가산림자원조사 자료 기반 자연적 임분동태 변화에 따른 소나무림의 감소 특성 평가)

  • Eun-Sook Kim;Jong Bin Jung;Sinyoung Park
    • Journal of Korean Society of Forest Science
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    • v.113 no.1
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    • pp.40-50
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    • 2024
  • Pine forests are continuously declining due to competition with broadleaf trees, such as oaks, as a consequence of changes in the natural dynamics of forest ecosystem. This natural decline creates a risk of losing the various benefits pine trees have provided to people in the past. Therefore, it is necessary to prepare future forest management directions by considering the state of pine tree decline in each region. The goal of this study is to understand the characteristics of pine forest changes according to forest dynamics and to predict future regional changes. For this purpose, we evaluated the trend of change in pine forests and extracted various variables(topography, forest stand type, disturbance, and climate) that affect the change, using time-series National Forest Inventory (NFI) data. Also, using selected key variables, a model was developed to predict future changes in pine forests. As a results, it showed that the importance of pine trees in forests across the country has decreased overall over the past 10 years. Also, 75% of the sample points representing pine trees remained unchanged, while the remaining 25% had changed to mixed forests. It was found that these changes mainly occurred in areas with good moisture conditions or disturbance factors inside and outside the forest. In the next 10 years, approximately 14.2% of current pine forests was predicted to convert to mixed forests due to changes in natural forest dynamics. Regionally, the rate of pine forest change was highest in Jeju(42.8%) and Gyeonggi(26.9%) and lowest in Gyeongbuk(8.8%) and Gangwon(13.8%). It was predicted that pine forests would be at a high risk of decline in western areas of the Korean Peninsula, including Gyeonggi, Chungcheong, and Jeonnam. This results can be used to make a management plan for pine forests throughout the country.

Classic Successional Theory and Stand Dynamics Studies on Fir Stand of Natural Forests in Naesorak Mt. - Focused on Patch Dynamics and Structure - (내설악 전나무 자연림 조사를 통한 고전천이론과 임분동태학에 관한 고찰 - Patch Dynamic과 임분 구조를 중점으로 -)

  • Youn, Young-Il
    • Korean Journal of Environmental Biology
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    • v.25 no.2
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    • pp.158-167
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    • 2007
  • A study conducted in NaeSorak Mt. from 1996 to 2006 shows some interesting results indicating general characteristics of natural forests, regeneration and structural patterns on fir stands. Those fir stands could have been confused as climax forests, which is a short-sighted from human-centered view on those stands. A classic theory of succession, which has been frequently applied to analyse the changes in forest ecosystem changes, failed to provide further understanding of fir stands. To comprehend the complicated and diverse process, a concept of ecosystem circulation need be introduced to the theory. This is a main idea of 'patch dynamics' theory developed from 'mosaic cycle' theory.

Invasion of Korean Pine Seedlings Originated from Neighbour Plantations into the Natural Mature Deciduous Broad-leaved Forest in Gwangneung, Korea (광릉 천연활엽수 성숙림에서 주변 인공림으로부터 잣나무 치수의 침입 정착)

  • Kang, Ho Sang;Lim, Jong-Hwan;Chun, Jung Hwa;Lee, Im Kyun;Kim, Young Kul;Lee, Jae Ho
    • Journal of Korean Society of Forest Science
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    • v.96 no.1
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    • pp.107-114
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    • 2007
  • Establishments of the seedlings inside the natural forest from adjacent artificial forests would be an important factor in forest stand dynamics. This study was conducted to see the invasion of Korean pine (Pinus koraiensis) seedlings which is not native in this region, into the natural deciduous broad-leaved forest in Gwangneung, Korea. There is no mother tree at the I ha study site while the number of naturally regenerated P. koraiensis seedlings was 345 trees and 56% of them were clumped with more than two seedlings at each point. Applying the image segmentation method to IKONOS satellite image of January, 2003, the distance from the center of 1 ha study site to the nearest mother tree and plantation of Korean pine were 200 m and 270 m, respectively. The average height and root-collar diameter of the seedlings were 34 em and 7 mm, respectively and the age of 207 seedlings (60%) were below 5 years old. Most abundant range of soil moisture gradient and LAl (leaf area index) were from 16 to 20% and those of LAI were from 3.1 to 3.5. To understand the dynamics and seed dispersal pattern of Korean pine in the Gwangneung natural deciduous broad-leaved forests, additional studies not only long-term monitoring of growth and mortality of naturally regenerated Korean pine seedlings but also application of stable isotope analysis and molecular genetic techniques was recommended.

Preliminary Study on Naturalness of Korean Fir (Abies holophylla) Stand in Mt. Sorak (설악산 전나무 고목림의 자연성 판단을 위한 기초연구)

  • 윤영일
    • Korean Journal of Environmental Biology
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    • v.20 no.4
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    • pp.287-293
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    • 2002
  • Natural forest stand plays a very important role to understand the forest ecosystem in Korea, in which there is no ancient forests aye left. Several old growth Korean fir stands were studied to determine their naturalness. Internationally accept-ed criteria for virgin or natural forests were used and the changes in several stages by stand dynamics were applied. Although the areas survey is limited in size, it was discovered that they clearly represent certain characteristics of naturalness. This study and collected data will hopefully be the starting point for the further studies for naturalness of forest in Korea in the future.

Estimation of Long-term Effects of Harvest Interval and Intensity, and Post-harvest Residue Management on the Soil Carbon Stock of Pinus densiflora Stands using KFSC Model (한국형 산림토양탄소모델(KFSC)을 이용한 수확 주기 및 강도와 수확 후 잔재물 처리방법에 따른 소나무림 토양탄소 저장량의 장기 변화 추정 연구)

  • Park, Chan-Woo;Yi, Koong;Lee, Jongyeol;Lee, Kyeong-Hak;Yi, Myong-Jong;Kim, Choonsig;Park, Gwan-Soo;Kim, Raehyun;Son, Yowhan
    • Journal of Korean Society of Forest Science
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    • v.102 no.1
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    • pp.82-89
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    • 2013
  • Harvest is one of the major disturbances affecting the soil carbon (C) dynamics in forests. However, researches on the long-term impact of periodic harvest on the soil C dynamics are limited since they requires rigorous control of various factors. Therefore, we adopted a modeling approach to determine the long-term impacts of harvest interval, harvest intensity and post-harvest residue management on soil C dynamics by using the Korean Forest Soil Carbon model (KFSC model). The simulation was conducted on Pinus densiflora S. et Z. stands in central Korea, and twelve harvest scenarios were tested by altering harvest intervals (50, 80, and 100-year interval), intensities (partial-cut harvest: 30% and clear-cut harvest: 100% of stand volume), and the residue managements after harvest (collection: 0% and retention: 100% of aboveground residue). We simulated the soil carbon stock for 400 years for each scenario. As a result, the soil C stocks in depth of 30 cm after 400 years range from 50.3 to 55.8 Mg C $ha^{-1}$, corresponding to 98.1 to 108.9% of the C stock at present. The soil C stock under the scenarios with residue retention was 2.5-11.0% higher than that under scenarios with residue collection. However, there was no significant impact of harvest interval and intensity on the soil C stock. The soil C dynamics depended on the dead organic matter dynamics derived from the amount of dead organic matter and growth pattern after harvest.

Effects of Geological Structure and Tree Density on the Forest Fire Patterns (지형구조와 나무밀도가 산불패턴에 미치는 영향)

  • Song, Hark-Soo;Kwon, Oh Sung;Lee, Sang-Hee
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.16 no.4
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    • pp.259-266
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    • 2014
  • Understanding the forest fire patterns is necessary to comprehend the stability of the forest ecosystems. Thus, researchers have suggested the simulation models to mimic the forest fire spread dynamics, which enables us to predict the forest damage in the scenarios that are difficult to be experimentally tested in laboratory scale. However, many of the models have the limitation that many of them did not consider the complicated environmental factors, such as fuel types, wind, and moisture. In this study, we suggested a simple model with the factors, especially, the geomorphological structure of the forest and two types of fuel. The two fuels correspond to susceptible tree and resistant tree with different probabilities of transferring fire. The trees were randomly distributed in simulation space at densities ranging from 0.5 (low) to 1.0 (high). The susceptible tree had higher value of the probability than the resistant tree. Based on the number of burnt trees, we then carried out the sensitivity analysis to quantify how the forest fire patterns are affected by the structure and tree density. We believe that our model can be a useful tool to explore forest fire spreading patterns.

The Distribution and Dynamics between Sexes, Conservation of Natural Populations of a Rare Woody Plant, Juniperus chinensis L. (희귀수종 향나무 자연집단의 분포와 성간 동태 및 보존)

  • Shin, Jae-Kwon;Chung, Jae-Min;Kim, Jin-Seok;Yoon, Chung-Won;Shin, Chang-Ho
    • Korean Journal of Plant Resources
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    • v.28 no.4
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    • pp.400-410
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    • 2015
  • Juniperus chinensis (Cupressaceae) is a valuable woody plant resource, but this rare plant is only distributed in restricted regions in Korea. In this study, we surveyed the geographic distribution regions, variation of sex ratio and the dynamics of natural populations of J. chinensis. in order to establish conservation strategies for the sustainable conservation of this important resource tree. The 17 natural populations of J. chinensis are restrictively distributed in the shore cliffs of (1) Ulleungdo island, (2) Gyeongju-si to Gangneung-si of the eastern coast, the riverside cliff along (3) Donggang-river of Jungsun-gun and Pyeongchang-gun and (4) branch of Nakdonggang-river in Uiseong-gun. The populations in Ulleungdo island showed continuous population distribution of over 200 individuals, but populations in other regions had discontinuous population distribution of under 200. The population of J. chinensis surveyed in Korea was estimated in ca. 3,200 individuals. The sex ratio (male/female) among populations of J. chinensis was diverse with variation from 0.46~1.67 range, but showed no significance. The sex ratio of the total individuals by species level was 0.74, and the percentage of female tree was significantly higher than the male. The results of dynamics analysis within population among regions showed that seedlings and saplings of J. chinensis in three regions surveyed were continuously regenerating. The distribution of DBH class showed a stable population structure of inverse J shape graph, but fragmentation and decrease in populations because of invading broad-leaved shrubs and trees from the surroundings were concerned. Further studies, and in situ and ex situ conservation strategies for the sustainable conservation on natural populations of this rare resources woody plant, J. chinensis in Korea are recommended.