• The Korean Journal of Quaternary Research
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• v.14 no.1
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• pp.33-48
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• 2000

Vegetation disturbance history of the Korean Peninsula from the Palaeolithic Age to the Koryo Dynasty (1392) has reconstructed by the use of various data sources. Active vegetation disturbance, which has begun during the Neolithic Age, seems to be more widespread on lowland and coastal areas in the early stages, but later expanded into inland areas. The ploughing of a field and the selective cutting of certain trees, such as oak trees, nettle trees and pine trees are noticeable, and eventually caused deforestation during the Bronze Age. The use of iron tools of the Iron Age has enabled the forest clearing to develope the dry fields. During the Three Kingdoms period (BC 57∼AD 918) extensive deforestation has maintained for the development of cultivated fields, as well as other activities, such as timber, lumbering, production of iron farm implement, ploughing by cattle. The encouragement of disafforestation on mountain slope and creation of terraced field during the Koryo Dynasty (918∼1392) has caused the deforestation over the country, along with the consumption of large amount of wood and timber for fire-wood, ship-building, mining, xylography and so on.

• Korean Journal of Environment and Ecology
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• v.23 no.6
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• pp.569-576
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• 2009

Sediment and nutrient loading caused by the removal of forest cover and alteration of agricultural lands in catchments have led to the deterioration in Lake Shirarutoro. To examine the effects of deforestation and agricultural activities on water quality, I examined changes in total nitrogen (TN) and total phosphorus (TP) of lake water induced by land use change, and compared them with the various research data produced over the years. Our investigation showed that the level of TN and TP in the lake water decreased when forest cover increased but increased when farmland area increased. The concentration of TN and TP was high in Lake Shirarutoro despite that its catchment was surrounded by large forests and small farmlands. This result indicates that land uses near Lake Shirarutoro have affected the quality of the lake water. I have examined the changes of sediment yield in the lake's catchment over the last approximately 300 years. Eleven core samples were obtained from the lake sediment and analyzed to establish a chronology after using two tephra layers (Ko-c2 in 1694 and Ta-a in 1739) and a $^{137}Cs$ peak (in 1963). The average sediment yield under the natural condition during the first two periods was 8.4 tons/$km^2$/year in 1694~1739 and 8.9 tons/$km^2$/year in 1739~1963 respectively. The conversion of the Shirarutoro catchment into agricultural lands and deforestation intensified, leading to an increased sediment yield of 21.1 tons/$km^2$/year during 1963~2007.

• Journal of the Korean Geographical Society
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• v.50 no.3
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• pp.277-287
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• 2015

This paper addresses limitations of land-change modeling application in the context of REDD (Reducing Emissions from Deforestation and forest Degradation). REDD is an international conservation policy that aims to protect forests via carbon credit generation and trading. In REDD, carbon credits are generated only if there is measurable quantied carbon sequestration activities that are additional to business-as-usual (BAU). A "reference level" is defined as simulated baseline carbon emissions for the future under a BAU scenario, and predictive land-change modeling plays an important role in constructing reference levels. It is tested in this research how predictive accuracies of two land-change models, namely Geographic Emission Benchmark (GEB) and GEOMOD, vary with respect to different spatial scales: Xishuangbanna prefecture and Yunnan province. The accuracies are measured by Figure of Merit. In this Chinese case study, it turns out that GEB's better performance is mainly due to quantity (e.g., how many hectares of forest will be converted to agricultural land?) rather than spatial allocation (e.g., where will the conversion happen?). As both quantity and allocation are crucial in REDD reference level setting it appears to be fundamental to systematically analyze accuracies of quantity and allocation independently in pursuit of accurate reference levels.

• Korean Journal of Environment and Ecology
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• v.29 no.5
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• pp.785-790
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• 2015

As an alternative to large-scale clear cutting silviculture, strip clear cutting (SC) is being considered as a system compatible with ecological conservation and forest regeneration. In South Korea, application and effectiveness of SCC in varying forest types were rarely found. In this study, under the subject of strip clear cutting lands of pinus densiflora forest at Samcheok, Gangwon-do Province, the developmental aspect of low vegetation prior to and after deforestation and the correlation between environmental factor and pine regeneration were analyzed. The cover rate of understory vegetation was appeared to be increased after deforestation and rapidly increased two years after deforestation, and it was evaluated to be affected by vigorous tree species and photophilic species. From the perspective of relative importance value, Quercus mongolica, Artemisia keiskeana, and Rubus crataegifolius that influence the cover rate showed the inclination of continuous growth. The diversity of species showed increment inclination as well due to introduction and settlement of early transient species. As a result of analyzing the correlation between vegetation and environmental factor and generation of pine tree size, the soil exposure rate, intensity of light, and canopy openness showed positive relationship, and the understory vegetation cover and woody debris cover rate showed negative relationship.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.10 no.4
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• pp.41-53
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• 2007

The Baekdudaegan Mountain Range is a backbone of the Korean Peninsula which carries special spiritual and sentimental signatures for Koreans as well as significant ecological values for diverse organisms. However, in spite of importance of this region, the forests of Baekdudaegan have been damaged in a variety of human activities by being used as highland vegetable grower, lumber region, grass land, and bare land, and are still undergoing destruction. The existing researches had determined the details of the damage through on-site and recent observations. Such methods cannot provide quantitative and integrated analysis therefore could not be utilized as objective data for the ecological conservation of Baekdudaegan forests. The goal of this study is to quantitatively analyze the forest damage in the Baekdudaegan preservation region through land cover categorization and change detection techniques by using satellite images, which are 1980s, and 1990s Landsat TM, and 2000s Landsat ETM+. The analysis was executed by detecting land cover changed areas from forest to others and analyzing changed areas' spatial patterns. Through the change detection analysis based on land cover classification, we found out that the deforested areas were approximately three times larger after the 1990s than from the 1980s to the 1990s. These areas were related to various topographical and spatial elements, altitude, slope, the distance form road, and water system, etc. This study has the significance as quantitative and integrated analysis about the Baekdudaegan preservation region since 1980s. These results could actually be utilized as basic data for forest conservation policies and the management of the Baekdudaegan preservation region.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.18 no.6
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• pp.73-83
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• 2015

The objective of this study is to establish implications for forest restoration planning in North Korea by analyzing spatio-temporal forest changes and detecting bio-physical factors driving forest degraded. We measured the relationship and spatial distribution between shifting cultivation and sparse forest. We also analyzed between degraded forest land and ecological variables by binary logistic regression to find biophysical drivers of forest degradation and deforestation in North Korea. Between the sparse forest and the shifting cultivation, a positive relationship is found (r=0.91) and scattered discontinuously throughout the country (Moran's I = -1, Z score = -13.46 (p=0.000)). The sparse forest showed a negative relationship with the warmest month(bio 9), the coldest month(bio10), and the minimum of soil water contents (swc_min), while the shifting cultivation had a negative relationship with the warmest month(bio 9) and the minimum of soil water contents(swc_min). However, the most critical drivers convert forests into sloping farmland were the three months rainfall in summer(bio8) and the yearly mean of soil water contents. Such results reflect the growth period of crops which overlaps with the rainy season in North Korea and the recent land reclamation of uplands where the soil water contents are maintained with a dense forest. When South Korea aids forest restoration projects in North Korea, in consideration of food shortage due to North Korea's cropland deficiency, terrace farmlands where soil water contents can be maintained should be excluded from the priority restoration area. In addition, an evaluation method for selecting a potential restoration area must be modified and applied based on multiple criteria including altitude and socio-economic factors in the respective regions.

• Journal of Environmental Impact Assessment
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• v.22 no.5
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• pp.439-454
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• 2013

UN-REDD (United Nations programme on Reducing Emissions from Deforestation and forest Degradation) is currently being emerged as one of important mechanism to reduce carbon dioxide in relation to the deforestation. Although administrative boundary has already gained world-wide recognition as a typical method of monitoring unit in the process of GHG (Greenhouse Gas) reduction project, this approach did not provide a realistic evidence in the carbon sequestering monitoring in terms of UN-REDD; the meaningful comparison of land use patterns among watershed boundaries, interpretation for distribution trends of carbon density, calculation of opportunity cost, leakage management, etc. This research proposes a comparative evaluation framework in a more objective and quantitative way for carbon sequestering monitoring between administrative and watershed boundary approaches. Mt. Geumgang of North Korea was selected as a survey objective and an exhaustive and realistic comparison of carbon sequestration between the two approaches was conducted, based on change detection using TM satellite images. It was possible for drainage boundary approach to identify more detailed area-wide patterns of carbon distribution than traditional administrative one, such as estimations of state and trends, including historical trends, of land use / land cover and carbon density in the Mt. Geumgang. The distinctive changing trends in terms of carbon sequestration were specifically identified over the watershed boundary from 4.0% to 34.8% while less than 1% difference was observed in the administrative boundaries, which were resulting in almost 21-22%. It is anticipated that this research output could be used as a valuable reference to support more scientific and objective decision-making in introducing watershed boundary as carbon sequestering monitoring unit.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.149-149
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• 2019

Gross Primary production (GPP) and evapotranspiration (ET) are the two critical components of carbon and water cycle respectively, linking the terrestrial surface and ecosystem with the atmosphere. The ratio between GPP to ET is called ecosystem water use efficiency (EWUE) and its quantification at the forest site helps to understand the impact of climate change due to large scale anthropogenic activities such as deforestation and irrigation. This study was conducted at the FLUXNET forest site CN-Qia (2003-2005) using Community land model (CLM 5.0). We simulated carbon and water fluxes including GPP, ecosystem respiration (ER), and ET using climatic variables as forcing dataset for 30 years (1981-2010). Model results were validated with the FLUXNET tower observations. The correlation showed better performance with values of 0.65, 0.77, and 0.63 for GPP, ER, and ET, respectively. The model underestimated the results with minimum bias of -0.04, -1.67, and -0.40 for GPP, ER, and ET, respectively. Effect of climate 'CLIM' and '$CO_2$' were analyzed based on EWUE and its trend was evaluated in the study period. The positive trend of EWUE was observed in the whole period from 1981-2010, and the trend showed further increase when simulated with rising $CO_2$. The time period were divided into two parts, from 1981-2000 and from 2001 to 2010, to identify the warming effect on EWUE. The first period showed the similar increasing trend of EWUE, but the second period showed slightly decreasing trend. This might be associated with the increase in ET in the wet temperate forest site due to increase in climate warming. Water use efficiency defined by transpiration (TR) (TWUE), and inherent-TR based WUE (IT-WUE) were also discussed. This research provides the evidence to climate warming and emphasized the importance of long term planning for management of water resources and evaporative demand in irrigation, deforestation and other anthropogenic activities.

• Korean Journal of Agricultural Science
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• v.46 no.1
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• pp.205-217
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• 2019

The aim of this study was to identify land resources because food production and supply in North Korea have been at risk due to variations in its seasonal climate. More than three-fifths of the soils are locally derived from the weathering of granitic rocks or various kinds of schists developed from crystalline rocks. Well-developed reddish brown soils derived from limestone are found in the North Hwanghae province and in the southern part of the South Pyeongan province. Additionally, a narrow strip of similarly fertile land runs through the eastern seaboard of the Hamgyong and Kangwon Provinces. The loss of clay particles and organic matter are major causes of degradation in the soil physical and chemical properties in North Korea. 75% of the areas converted from forests became croplands, and 69% of the land converted to croplands came from forests. The net forest loss was quite small from the 1990s to the 2000s. However, deforestation in areas with a slightly lower elevation and gentler slope between 1997 and 2014 led to severe soil erosion resulting in a drastic change in the physical and chemical properties of the soil which influenced cropland stability and productivity. Therefore, the drastic changes in land cover as well as in the physical and chemical properties of the soil caused by various geographical features have seriously influenced the productivity of crops in North Korea.

• Journal of Ecology and Environment
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• v.42 no.4
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• pp.163-173
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• 2018

Background: Deforestation and degradation are currently affecting the ecosystem services of forests. Among the ecosystem services affected by deforestation and degradation are the amount of soil organic carbon (SOC) and total nitrogen (TN) stored in forest soils which have greater impacts in global climate change. This study aimed at examining the amount of SOC and TN in the forest fragments which were separated from the continuous tracts of forests of Jibat and Chillimo through fragmentation processes over four decades. Methods: We have sampled soils from 15 forest fragments of Chillimo and Jibat in the central highlands of Ethiopia. The soil samples obtained in two separate soil depths (0-30 and 30-60 cm) were bulked, dried, and sieved for analysis. Results: Our results have shown that the two sites (Jibat and Chillimo forest fragments) differed in their SOC and TN contents. While the values for Jibat were found to be 29.89 Mg/ha of SOC and 2.84 Mg/ha for TN, it was 14. 06 Mg/ha of SOC and 1.40 Mg/ha for TN for Chillimo. When all forest fragment soil samples were bulked together, Jibat site had twice the value of SOC and TN than Chillimo. When disaggregated on the basis of each fragments, there existed differences in SOC (1.86 Mg/ha and 42.15 Mg/ha) and TN (0.24 Mg/ha and 4.23 Mg/ha) values. Among the forest fragments, fragment four ($F_4$) had the highest Relative Soil Improvement Index (RSII) value of 3826.82% and fragment fifteen ($F_{15}$) had the lowest RSII value (726.87%) which indicated that the former had a better quality of soil properties than the latter. Conclusion: SOC and TN differed across sampled fragments and sites. Variations in soil properties are the reflections of inherent soil parent material, aboveground vegetation, human interferences, and other physical factors. Such differences could be very important for identifying intervention measures for restoration and enhancing ecosystem services of those fragments.