• Title/Summary/Keyword: Wetland ecosystems

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A Prediction and Distribution of Wetland Based on an E-GIS (E-GIS 기반의 습지분포 및 규모예측)

  • Jang, Yong Gu;Kim, Sang Seok
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.26 no.6D
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    • pp.1011-1017
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    • 2006
  • It is so sensitive that the wetland ecosystem very weak in artificial interference and environment change. wetlands are a transitional zone between aquatic and terrestrial ecosystems. This natural property is important to people and life. It is necessary to preservation and protection of the wetland with a countermeasure. we really need to Environment-GIS (E-GIS) and digital map which is included correct position, attribute data and range of the wetland. In this study, we take priority of making a database of wetland management. Moreover, we standardize a digital map production of wetland in our research and we improve accuracy of control survey using GPS surveying. The main purpose of this study is to suggest a pre-estimated wetland that have not yet been discovered. by analysing terrain, geological feature, a geographical distribution of plants and animals using GIS.

A review of factors that regulate extracellular enzyme activity in wetland soils (습지 토양 내 체외효소 활성도를 조절하는 인자에 대한 고찰)

  • Kim, Haryun
    • Korean Journal of Microbiology
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    • v.51 no.2
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    • pp.97-107
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    • 2015
  • Wetlands constitute a transitional zone between terrestrial and aquatic ecosystems and have unique characteristics such as frequent inundation, inflow of nutrients from terrestrial ecosystems, presence of plants adapted to grow in water, and soil that is occasionally oxygen deficient due to saturation. These characteristics and the presence of vegetation determine physical and chemical properties that affect decomposition rates of organic matter (OM). Decomposition of OM is associated with activities of various extracellular enzymes (EE) produced by bacteria and fungi. Extracellular enzymes convert macromolecules to simple compounds such as labile organic carbon (C), nitrogen (N), phosphorus (P), and sulfur (S) that can be easily taken up by microbes and plants. Therefore, the enzymatic approach is helpful to understand the decomposition rates of OM and nutrient cycling in wetland soils. This paper reviews the physical and biogeochemical factors that regulate extracellular enzyme activities (EEa) in wetland soils, including those of ${\beta}$-glucosidase, ${\beta}$-N-acetylglucosaminidase, phosphatase, arylsulfatase, and phenol oxidase that decompose organic matter and release C, N, P, and S nutrients for microbial and plant growths. Effects of pH, water table, and particle size of OM on EEa were not significantly different among sites, whereas the influence of temperature on EEa varied depending on microbial acclimation to extreme temperatures. Addition of C, N, or P affected EEa differently depending on the nutrient state, C:N ratio, limiting factors, and types of enzymes of wetland soils. Substrate quality influenced EEa more significantly than did other factors. Also, drainage of wetland and increased temperature due to global climate change can stimulate phenol oxidase activity, and anthropogenic N deposition can enhance the hydrolytic EEa; these effects increase OM decomposition rates and emissions of $CO_2$ and $CH_4$ from wetland systems. The researches on the relationship between microbial structures and EE functions, and environmental factors controlling EEa can be helpful to manipulate wetland ecosystems for treating pollutants and to monitor wetland ecosystem services.

Application of Multispectral Remotely Sensed Imagery for the Characterization of Complex Coastal Wetland Ecosystems of southern India: A Special Emphasis on Comparing Soft and Hard Classification Methods

  • Shanmugam, Palanisamy;Ahn, Yu-Hwan;Sanjeevi , Shanmugam
    • Korean Journal of Remote Sensing
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    • v.21 no.3
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    • pp.189-211
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    • 2005
  • This paper makes an effort to compare the recently evolved soft classification method based on Linear Spectral Mixture Modeling (LSMM) with the traditional hard classification methods based on Iterative Self-Organizing Data Analysis (ISODATA) and Maximum Likelihood Classification (MLC) algorithms in order to achieve appropriate results for mapping, monitoring and preserving valuable coastal wetland ecosystems of southern India using Indian Remote Sensing Satellite (IRS) 1C/1D LISS-III and Landsat-5 Thematic Mapper image data. ISODATA and MLC methods were attempted on these satellite image data to produce maps of 5, 10, 15 and 20 wetland classes for each of three contrast coastal wetland sites, Pitchavaram, Vedaranniyam and Rameswaram. The accuracy of the derived classes was assessed with the simplest descriptive statistic technique called overall accuracy and a discrete multivariate technique called KAPPA accuracy. ISODATA classification resulted in maps with poor accuracy compared to MLC classification that produced maps with improved accuracy. However, there was a systematic decrease in overall accuracy and KAPPA accuracy, when more number of classes was derived from IRS-1C/1D and Landsat-5 TM imagery by ISODATA and MLC. There were two principal factors for the decreased classification accuracy, namely spectral overlapping/confusion and inadequate spatial resolution of the sensors. Compared to the former, the limited instantaneous field of view (IFOV) of these sensors caused occurrence of number of mixture pixels (mixels) in the image and its effect on the classification process was a major problem to deriving accurate wetland cover types, in spite of the increasing spatial resolution of new generation Earth Observation Sensors (EOS). In order to improve the classification accuracy, a soft classification method based on Linear Spectral Mixture Modeling (LSMM) was described to calculate the spectral mixture and classify IRS-1C/1D LISS-III and Landsat-5 TM Imagery. This method considered number of reflectance end-members that form the scene spectra, followed by the determination of their nature and finally the decomposition of the spectra into their endmembers. To evaluate the LSMM areal estimates, resulted fractional end-members were compared with normalized difference vegetation index (NDVI), ground truth data, as well as those estimates derived from the traditional hard classifier (MLC). The findings revealed that NDVI values and vegetation fractions were positively correlated ($r^2$= 0.96, 0.95 and 0.92 for Rameswaram, Vedaranniyam and Pitchavaram respectively) and NDVI and soil fraction values were negatively correlated ($r^2$ =0.53, 0.39 and 0.13), indicating the reliability of the sub-pixel classification. Comparing with ground truth data, the precision of LSMM for deriving moisture fraction was 92% and 96% for soil fraction. The LSMM in general would seem well suited to locating small wetland habitats which occurred as sub-pixel inclusions, and to representing continuous gradations between different habitat types.

A Review on Monitoring the Everglades Wetlands in the Southern Florida Using Space-based Synthetic Aperture Radar (SAR) Observations

  • Hong, Sang-Hoon;Wdowinski, Shimon
    • Korean Journal of Remote Sensing
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    • v.33 no.4
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    • pp.377-390
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    • 2017
  • Space-based Synthetic Aperture Radar (SAR) observations have been widely and successfully applied to acquire invaluable temporal and spatial information on wetlands, which are unique environments and regarded as important ecosystems. One of the best studied wetland area is Everglades, which is located in southern Florida, USA. As a World Heritage Site, the Everglades is the largest natural and subtropical wilderness in the United States. The Everglades wetlands have been threatened by anthropogenic activities such as urban expansion and agricultural development, as well as by natural processes, as sea level changes due to climate change. In order to conserve this unique wetland environment, various restoration plans have been implemented. In this review paper, we summarize the main studies using space-based SAR observations for monitoring the Everglades. The paper is composed of the following two sections: (1) review of backscattered amplitude analysis and observations, and (2) review of interferometric SAR (InSAR) analysis and applications. This study also provides an overview of a wetland InSAR technique and space-based SAR sensors. The goal of this review paper is to provide a comprehensive summary of space-based SAR monitoring of wetlands, using the Everglades wetlands as a case study.

Consideration on Application of Zooplankton Index for Wetland Ecosystem Evaluation (습지생태계 평가를 위한 동물플랑크톤 지수 적용 방안 고찰)

  • Hyun-Woo Kim
    • Korean Journal of Ecology and Environment
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    • v.57 no.1
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    • pp.51-59
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    • 2024
  • This note summarizes the application of zooplankton indices for water quality management and estimation based on main research topics of articles focusing on wetland ecosystems, topics that are remained poorly investigated in S. Korea. The aquatic ecosystem-based consists of indices that respond to different target environmental factors, including environmental disturbance. Among the major indicator species and biota, we reviewed that management strategy for the wetland environment has to be focused more on small-sizes, in terms of zooplankton ecology and indices. The ecology of zooplankton communities in freshwater ecosystem has been the focus of an increasing number of studies since 2019, and considerable progress has been made in understanding the major mechanisms involved in regulating their abundance, diversity and spatio-temporal patterns. Even though studies on the freshwater ecosystem in Korea have a long history, a few of studies on zooplankton biota were conducted at wetlands. We suggested the candidate zooplankton indices proposed by the U.S. EPA and EU to suit Korean conditions. In the step of selecting metrics, the best available metrics are species-related variables, such as composition and abundance, as well as richness and diversity. Overall, in spite of several limitations, the development of a plankton-based multivariate assessment method in Korea wetlands is possible using mostly field research data. Later, it could be improved based on qualitative metrics on zooplankton, and with the emergence of further survey data. The present information can be used as basic information for researchers who are dealing with aquatic environments and its interaction with organisms.

Herbivory effects and growth rate of invasive species, Pomacea canaliculata on different macrophytes species

  • Ismail, Hasnun Nita;Anuar, Wan Nurul Hidayah Wan;Noor, Noormawaty Mohammad
    • Fisheries and Aquatic Sciences
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    • v.24 no.12
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    • pp.415-427
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    • 2021
  • Wetland ecosystems act as natural freshwater purification systems, but their rich biodiversity is being threatened with the introduction of the non-native freshwater snail, Pomacea canaliculata. This study was conducted to measure the herbivory effects and growth rate of P. canaliculata on common macrophytes: Ipomoea aquatica, Ipomoea batatas, Pandanus amaryllifolius and Cucurma longa. In separate experiments, the macrophyte species were served as the snails' food as individual species and simultaneously. In the individual treatment, the growth pattern and rate were based on the snails' weight (mg/snail/day; n = 9) while the individual feeding consumption (mg/snail/day) was calculated from the leftover food. In the simultaneous treatment, the herbivory effects were evaluated as the feeding preference (%) from observations every two hours, while the total feeding consumption (mg) was calculated based on the food remaining after a 12-hour experiment (3 replicates: total n = 27). The results indicated that the growth pattern was significant for snails grazing on I. aquatica but not when other macrophyte species were eaten. The individual feeding consumption was higher when using I. aquatica than P. amaryllifolius but the growth rate for snails grazing on I. aquatica and P. amaryllifolius did not differ significantly. Meanwhile, the consumption of C. longa deterred the snails' growth rate. Although the snails consumed all the macrophytes in the individual experiment, when given the species simultaneously, the feeding preference and total feeding consumption were directed significantly more toward I. aquatica than P. amaryfollius and C. longa. We conclude that P. canaliculata is a generalist feeder given a limited choice of food but tends to show a strong feeding preference after being introduced to more food choices. These findings indicate that the introduction of P. canaliculata into wetland ecosystems may increase the herbivory effects on macrophytes, making these ecosystems vulnerable to the impact of eutrophication and biodiversity reduction.

Classification of Unit Ecosystems in Damyang Riverine Wetland (담양 하천습지 내 단위 생태계의 분류)

  • Son, Myoung Won;Chang, Mun Gi;Yoon, Kwang Sung;Choi, Tae Bong
    • Journal of the Korean association of regional geographers
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    • v.19 no.1
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    • pp.1-13
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    • 2013
  • Damyang Wetland Reserve with $980,575m^2$ area is located in Damyang-gun, Jeonlanam-do and Buk-gu, Gwangju Metropolitan City. The purpose of this paper is to divide Damyang riverine wetland into several geomorphic units, to analyze their sediments, and to categorize small ecosystem units composing riverine wetland. Riverine wetlands are classified into three types such as riverbed-, floodplain-, and abandoned-channel-wetland, and Damyang riverine wetland belongs to riverbed-wetland type. In this paper to categorize small geomorphic units of riverine wetland, we divide small geomorphic units from aircraft images analysis, and modify and supplement them following field survey results. Damyang Wetland Reserve is categorized into 22 ecosystem units. That physical and chemical properties of their sediments are different spatially, implicate that inorganic environment of Damyang riverine wetland ecosystem is very extensive. On the basis of the results of this study, policymakers will be able to design a strategy which manage Damyang Riverine Wetland Reserve more effectively, and for them interdisciplinary researches on relationships between various fluvial landforms and various lifeforms inhabiting them in Damyang Riverine Wetland Reserve are required.

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Vascular Plants of Hwapocheon Wetland Protected area in Gimhae (김해 화포천 습지보호지역의 관속식물상)

  • Yun-do, Hwang;Sang-jun, Han
    • Journal of Wetlands Research
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    • v.26 no.1
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    • pp.92-113
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    • 2024
  • The Purpose of this study were to present the basic data for conservation and management of wetland ecosystem by surveying the characteristics of vascular plants distributed in Hwapocheon wetland protected area. The results are as follows. The numbers of vascular plants were summrized as 339 taxa including 81 familices, 221 genera, 315 species, 9 subspecies and 12 varieties and 2 forms. The rare plants were 7 taxa including Aristolochia contorta, Hydrocharis dubia and so on. The floristic target species were 32 taxa including 17 taxa of grade I, 7 taxa of grade II, 4 taxa of grade III, 2 taxa of grade IV and 2 taxa of grade V. The invasive alien plants were 66 Rumex crispus, Oenothera biennis, Veronica arvensis and so on. The ecosystem disturbing species were 11 taxa including Humulus scandens, Ambrosia artemisiifolia, Ambrosia trifida, Lactuca seriola, Symphyotrichum pilosum and so on. The hydrophytes were 29 taxa including 16 taxa of emergent plants, 3 taxa of submerged plants, 4 taxon of free-floating plant 6 taxa of floation-leaved plants.

Monitoring Vegetation Structure Changes in Urban Wetlands (도시 내 습지의 식생구조 변화 모니터링)

  • Kim, Na-Yeong;Nam, Jong-Min;Lee, Gyeong-Yeon;Lee, Kun-Ho;Song, Young-Keun
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.26 no.6
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    • pp.135-154
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    • 2023
  • Urban wetlands provide various ecosystem services and are subject to restoration and creation projects due to their increased value in the context of climate change. However, the vegetation structure of wetlands is sensitive to environmental changes, including artificial disturbances, and requires continuous maintenance. In this study, we conducted a vegetation survey of three wetlands created as part of a project to restore urban degraded natural ecosystems and monitored the quantitative changes in wetland vegetation structure using an unmanned aerial vehicle. The vegetation survey revealed 73 species in Incheon Yeonhui wetland, and the change in vegetation composition based on wetland occurrence frequency was 11.5% on average compared to the 2018 vegetation survey results. The vegetation survey identified 44 species in Busan Igidae wetland, and the proportion of species classified as obligate upland plants was the highest at 48.8% among all plants, while the proportion of naturalized plants accounted for 15.9% of all plants. The open water surface area decreased from 10% in May 2019 to 6.7% in May 2020. Iksan Sorasan wetland was surveyed and 44 species were confirmed, and it was found that the proportion of facultative wetland plant decreased compared to the 2018 vegetation survey results, and the open water surface area increased from 0.4% in May 2019 to 4.1% in May 2020. The results of this study showed that wetlands with low artificial management intensity exhibited a tendency for stabilization of vegetation structure, with a decrease in the proportion of plants with high wetland occurrence frequency and a relatively small number of new species. Wetlands with high artificial management intensity required specific management, as they had a large change in vegetation structure and a partially high possibility of new invasion. We reaffirmed the importance of continuous monitoring of vegetation communities and infrastructure for wetlands considering the function and use of urban wetlands, and restoration stages. These research results suggest the need to establish a sustainable wetland maintenance system through the establishment of long-term maintenance goals and monitoring methods that consider the environmental conditions and vegetation composition of wetlands.