• Journal of Ecology and Environment
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• v.44 no.2
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• pp.90-97
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• 2020

Background: Natural forests are generally considered to be less prone to biological invasions than other modified ecosystems, particularly when canopy cover is high. Few decades of management of degraded forests by local communities in Nepal has increased canopy cover and altered disturbance regimes. These changes might have reduced the abundance of invasive alien plant species (IAPS) in forests. To understand the status of IAPS in such forests, we studied two community managed Shorea robusta forests (Sundari and Dhusheri) of Nawalpur district in central Nepal. In these two forests, vegetation sampling was done using circular plots 10 m radius at forest edge, gaps, and within canopy. Variation of IAPS richness and cover across these microhabitats were compared, and their variation with tree canopy cover and basal area analyzed. Result: Altogether 14 IAPS were recorded in the study forests; among them Chromolaena odorata, Ageratum houstonianum, and Lantana camara had the highest frequency. Mikania micrantha was at the early stage of colonization in Sundari Community Forest (CF) but absent in Dhuseri CF. Both IAPS cover and richness was higher at forest edge and gap than in canopy plots and both these attributes declined with increasing canopy cover and tree basal area. Conclusion: The results indicate that increase in canopy cover and closure of forest gaps through participatory management of degraded forests can prevent plant invasions and suppress the growth of previously established IAPS in Shorea robusta forests of Nepal. This is the unacknowledged benefit of participatory forest management in Nepal.

• Ocean and Polar Research
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• v.41 no.3
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• pp.159-168
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• 2019

Understanding the interaction between climate and the water cycle is critical especially in a drought sensitive region such as California. This study explored hydrologic changes in central and southern California in relation to the glacial-interglacial climate cycles over the last 30 thousand years. To do this, we reconstructed paleovegetation using plant wax carbon isotopic compositions (${\delta}^{13}C$) preserved in marine sediment cores retrieved from the central California continental shelf (ODP Site 1018) and Santa Barbara Basin (ODP Site 893A). The results were then compared to the existing sea surface temperature (SST) and pollen records from the same cores to understand terrestrial hydrology in relation to oceanographic processes. The Last Glacial was generally dry both in central and southern California, indicated by grassland expansion, confirming the previously suggested notion that the westerly storm track that supplies the majority of the precipitation in California may not have moved southward during the glacial period. Southern California was drier than central California during the Last Glacial Maximum (LGM). This drying trend may have been associated with the weakening of the California Current and northerly winds leading to the early increase in SST in southern California and decline in both offshore and coastal upwelling. The climate was wetter during the Holocene in both regions compared to the glacial period and forest coverage increased accordingly. We attribute this wetter condition to the precipitation contribution increase from the tropics. Overall, we found a clear synchronicity between the terrestrial and marine environment which showed that the terrestrial vegetation composition in California is greatly affected by not only the global climate states but also regional oceanographic and atmospheric conditions that regulate the timing and amount of precipitation over California.

• Journal of Ecology and Environment
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• v.38 no.4
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• pp.461-476
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• 2015

Global warming has accelerated glacial retreat in the high Arctic. The exposed glacier foreland is an ideal place to study chronosequential changes in ecosystems. Although vegetation succession in the glacier forelands has been studied intensively, little is known about the microbial community structure in these environments. Therefore, this study focused on how glacial retreat influences the bacterial community structure and its relationship with soil properties. This study was conducted in the foreland of the Midtre Lovénbreen glacier in Svalbard (78.9°N). Seven soil samples of different ages were collected and analyzed for moisture content, pH, soil organic carbon and total nitrogen contents, and soil organic matter fractionation. In addition, the structure of the bacterial community was determined via pyrosequencing analysis of 16S rRNA genes. The physical and chemical properties of soil varied significantly along the distance from the glacier; with increasing distance, more amounts of clay and soil organic carbon contents were observed. In addition, Cyanobacteria, Firmicutes, and Actinobacteria were dominant in soil samples taken close to the glacier, whereas Acidobacteria were abundant further away from the glacier. Diversity indices indicated that the bacterial community changed from homogeneous to heterogeneous structure along the glacier chronosequence/distance from the glacier. Although the bacterial community structure differed on basis of the presence or absence of plants, the soil properties varied depending on soil age. These findings suggest that bacterial succession occurs over time in glacier forelands but on a timescale that is different from that of soil development.

• Journal of Environmental Impact Assessment
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• v.4 no.1
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• pp.37-46
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• 1995

This study was carried out to find the problems of assessment on terrestrial ecosystem part in environmental impact analysis(EIA) and to suggest the proper amelioration measures by analyzing 19 environmental impact statements(EIS) published during the period from 1991 to 1994. The results obtained from this study were as follows. Field survey for the investigation of fauna and flora in project areas should be conducted at least 3 times a year and name of investigator should be written on the EIS clearly. Increase or decrease in degree of green naturality and productivity cannot be an absolute criteria for expressing the amount of changes in ecosystem. Evaluation for the ecosystems and their composition in project area is more important than presenting merely the increase or decrease in degree of green naturality and productivity. Alleviation measures in 19 EISs analyzed in this study were summarized into 6 types: They are establishment of landscape plan, transplanting of useful trees preservation of big tree and protected species, restoration and preservation of existent vegetation, establishment of soil conservation measures and diminution of the impact on animal. However, they were somewhat insufficient because they wouldn't suggest the alleviation measures in detail. The more positive counter-proposals are needed to decrease the impact of the project on terrestrial ecosystem.

• Journal of The Korean Society of Grassland and Forage Science
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• v.10 no.3
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• pp.152-157
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• 1990

To find out the effect of different patterns of nitrogen and potassium distribution on dry matter yield and botanical composition of temperate pastures, a field experiment was conducted with 6 treatments replicated 3 times in a randomized complete block design. It was lasted from September, 1986 to October, 1989 at the Livestock Experiment Station in Suweon. The results obtained are summarized as follows: 1. In early spring, winter hardiness, growth vigour, cold damage and coverage of grasses with 30% dressing of the total amount of N and K20 fertilizer in spring and at the 4th cutting time respectively were better than those of the other treatments. 2. Average dry matter yield for 3 years with heavy dressing in spring and at the 1st cutting time(l1, 187 kg DM/ha) was much more increased by 9% than that of the equally fertilized treatment(l0,24lkg DM/ha). 3. Changes in the botanical composition showed, in general, the same tendency for all treatments except equal N and K20 distribution. However, grassland vegetation with heavy dressing in spring and at the 1st cutting time was changed into relatively good botanical composition with 76.7% grasses, 22.3% legumes and 1.0% herbs at the end of the experiment. 4. By DM yield and botanical composition treatment 3(40-30-15-0-1570) seemed to be an optimal nitrogen and potassium distribution pattern in a temperate pasture.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.24 no.2
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• pp.1-17
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• 2021

As population concentration, high-rise, and high-density progresses amid rapid industrialization and urbanization in Korea, green areas in the city have decreased significantly and the natural environment has deteriorated day by day due to various development projects. In order to cope with these social changes, many studies related to park and green areas have been conducted, but in the case of Gwangju-si, only studies on green areas such as vegetation structures, street facilities, and recreation forests have been conducted on park green areas. The situation is not losing. Therefore, in this study, a survey was conducted on Gwangju citizens to understand the usage behavior and satisfaction of park green areas, and to provide basic data for future park development and reorganization. As a result, first, to induce a variety of static and dynamic activities in order to increase the park satisfaction of Gwangju citizens, it is possible to create a park that has not been formed as soon as possible, and by planning programs with various themes. Second, it is necessary to expand green space services in marginalized areas by creating water streams, flower pots, and rooftop greening around the lives of Gwangju citizens, and create park green spaces with themes using cultural and historical resources for each administrative district. Third, in order to solve the dry landscape in some urban areas, it is necessary to establish a three-dimensional landscape plan by creating a variety of green areas such as potted plants, green areas, and street trees, and by giving functions of park green areas such as expanding leisure and convenience facilities.

• Atmosphere
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• v.33 no.1
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• pp.61-72
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• 2023

Accurate estimation of forest carbon stocks is important in establishing greenhouse gas reduction plans. In this study, we estimate the spatial distribution of forest carbon stocks using machine learning techniques based on high-resolution remote sensing data and detailed field survey data. The high-resolution remote sensing data used in this study are Landsat indices (EVI, NDVI, NDII) for monitoring vegetation vitality and Shuttle Radar Topography Mission (SRTM) data for describing topography. We also used the forest growing stock data from the National Forest Inventory (NFI) for estimating forest biomass. Based on these data, we built a model based on machine learning methods and optimized for Korean forest types to calculate the forest carbon stocks per grid unit. With the newly developed estimation model, we created forest carbon stocks maps and estimated the forest carbon stocks in South Korea. As a result, forest carbon stock in South Korea was estimated to be 432,214,520 tC in 2020. Furthermore, we estimated the loss of forest carbon stocks due to the Donghae-Uljin forest fire in 2022 using the forest carbon stock map in this study. The surrounding forest destroyed around the fire area was estimated to be about 24,835 ha and the loss of forest carbon stocks was estimated to be 1,396,457 tC. Our model serves as a tool to estimate spatially distributed local forest carbon stocks and facilitates accounting of real-time changes in the carbon balance as well as managing the LULUCF part of greenhouse gas inventories.

• The Korean Journal of Ecology
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• v.17 no.3
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• pp.311-318
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• 1994

We examined spatial and temporal patterns of root decomposition for three and half years, from October 1986 to April 1990, in semi-arid Chihuahuan Desert. Decomposition of roots occurred in a two-phased pattern: an early period of rapid mass loss followed by a period of slower loss. The rate of root decomposition had a high negative correlation with the initial lignin concentration in roots (r=-0.84, p<0.05). Annual mass loss rate of Baileya multiradiata, a herbaceous annual, was the highest with the value of 0.60, while that of Panicum obtusum. a perennial grass which was restricted to playa, was the lowest with 0.13. The mass loss rate of roots in the playa was the lowest among the vegetation zones along the transect. After 42 months elapsed, fluffgrass roots in playa lost 40% of the initial mass, while in other sites it lost on average 55% of the initial mass. In all roots except for desert marigold, there was an initial release of nitrogen early in decomposition followed by net nitrogen immobilization. Nitrogen concentration of the desert marigold roots showed linear increase from the beginning. Lignin concentration of perennial grass roots were higher than those of herbaceous annual and woody perennial root.

• Journal of Ecology and Environment
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• v.30 no.1
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• pp.101-105
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• 2007

Lammas growth, a rare phenomenon for Korean red pine (Pinus densiflora), occurred in 2006. Lammas shoots showed higher frequency and longer length in Seoul's hotter urban center than in urban boundary or suburban forest sites. Frequency and length showed a close correlation with urbanization density and vegetation cover expressed in NDVI. Air temperature in the late summer of 2006 was more than $1^{\circ}C$ higher than an average year. Of the predominant environmental signals that modulate bud flush, only temperature changed significantly during the year. Differences in temperature between the urban centers, urban boundaries and suburban forests correlated with varying land-use density. The rise in temperature likely spurred lammas growth of the Korean red pine. Symptoms of climate change are being detected throughout the world, and its consequences will be clearer in the future. Considerate interest in the responses of ecological systems to the variable changes is required to prepare for unforeseeable crises. Monitoring of diverse ecological phenomena at Long Term Ecological Research sites could offer harbingers of change.

• Journal of Plant Biology
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• v.11 no.4
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• pp.9-20
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• 1968

In general there are few cases which were caused by lightening and no fire was observed to have been caused but by artificial or accidental fires during preliminary survey. And then the most scales of burning in Korea are like the fig. 2. Temperature 5 cm apart from flame at the burning site were known to range from 165$^{\circ}$to 20$0^{\circ}C$ in surface fire on Myozangdong, pine-quercus dominant community and from 120$^{\circ}$ to 145$^{\circ}C$ in surface fire of Wolwoonni, Mischanthus dominant area and from 120$^{\circ}$ to 14$0^{\circ}C$ in ground fire of Wangzinkun, Mischanthus dominant, respectively. Through the preliminary survey, fire indicater plants in Korea were confirmed as Mischanthus coreensis Hack and Carex alterifolia Franch. The plants of highest frequency appeared in the burnt sites were known to as Potentilla cryptotaeniae Max, Mischanthus coreensis Hack, Carex alterifolia Franch and Artemisia brachyphylla Kitamura. Lespedezas were proved as one of the fire tolerant and Pinus densiflora was found out as the lowest intolerant plant to fire. The acidity of burnt soil was decreased according to the considerable amount of ash left on the ground. The acidity of surface soil was more decreased than the below 10cm of soil. The chemical composition(NO3, P, K, Mg, Total-N and Organic-C) of burnt soil was more increased than those of the unburnt sites. And the population changes of soil microflora seemed to have a certain tendency. The population of soil microflora was increased a little according to climatic conditions. Also there was an initial decrease in the population of microflora followed immediately by a significant increase.