• Title/Summary/Keyword: Mangrove forest

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Distribution of Phytoplankton and Bacteria in the Environmental Transitional Zone of Tropical Mangrove Area (열대 홍수림 주변 해역 환경 전이대의 식물플랑크톤 및 박테리아의 분포)

  • Choi, Dong Han;Noh, Jae Hoon;Ahn, Sung Min;Lee, Charity M.;Kim, Dongseon;Kim, Kyung-Tae;Kwon, Moon-Sang;Park, Heung-Sik
    • Ocean and Polar Research
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    • v.35 no.4
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    • pp.415-425
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    • 2013
  • In order to understand phytoplankton and bacterial distribution in tropical coral reef ecosystems in relation to the mangrove community, their biomass and activities were measured in the sea waters of the Chuuk and the Kosrae lagoons located in Micronesia. Chlorophyll a and bacterial abundance showed maximal values in the seawater near the mangrove forests, and then steeply decreased as the distance increased from the mangrove forests, indicating that environmental conditions for these microorganisms changed greatly in lagoon waters. Together with chlorophyll a, abundance of Synechococcus and phototrophic picoeukaryotes and a variety of indicator pigments for dinoflagellates, diatoms, green algae and cryptophytes also showed similar spatial distribution patterns, suggesting that phytoplankton assemblages respond to the environmental gradient by changing community compositions. In addition, primary production and bacterial production were also highest in the bay surrounded by mangrove forest and lowest outside of the lagoon. These results suggest that mangrove waters play an important role in energy production and nutrient cycling in tropical coasts, undoubtedly receiving large inputs of organic matter from shore vegetation such as mangroves. However, the steep decrease of biomass and production of phytoplankton and heterotrophic bacteria within a short distance from the bay to the level of oligotrophic waters indicates that the effect of mangrove waters does not extend far away.

Hypoglycemic Activities of a Mangrove Plant Rhizophora apiculata Blume

  • Sur, Tapas Kumar;Seal, Tapan;Pandit, Srikanta;Bhattacharyya, Dipankar
    • Natural Product Sciences
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    • v.10 no.1
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    • pp.11-15
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    • 2004
  • The leaves of Rhizophora apiculata, a plant belonging to the family Rhizophoraceae were collected from the mangrove forest of Sunderbans, West Bengal, India. Alcoholic extract of the leaves of this plant was prepared and hypoglycemic/anti-hyperglycemic activity was studied in fed rats, glucose loaded rats and streptozotocin induced diabetic rats. The results of this study reveal that this plant extract has potential hypoglycemic action.

Behaviour of Vegetation Health as a Response to Climate and Soil Dynamics between 2000 and 2015 in Different Ecological Zones of Rivers State, Nigeria

  • Eludoyin, Olatunde Sunday;Aladesoun, Olawale Oluwamuyiwa
    • Journal of Forest and Environmental Science
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    • v.37 no.4
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    • pp.280-291
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    • 2021
  • The study examined the influence of climate and soil dynamics on vegetation health across the ecological zones in Rivers State, Nigeria. MODIS imagery was used to assess the vegetation health through NDVI and point grid pattern of meteorological data for total precipitation (TP), air temperature (AT), soil moisture (SM) and soil temperature (ST) of 2000, 2003, 2006, 2009, 2012 and 2015 were used for the study. Descriptive and inferential statistics were used for data analysis. Findings showed that NDVI ranged between 0.420 and 0.612 in the freshwater swamp (FWS) while between 0.465 and 0.611 in the rainforest and the NDVI in the mangrove was generally low. The highest mean AT was experienced in the mangrove ecological zone and the least was experienced in the rainforest. The mean SM was generally highest in the rainforest with highest value in 2000 (774.44 m3/m3). The ST was highest in the mangrove and the least was experienced in the rainforest while the TP was highest in the mangrove. NDVI correlated significantly with SM (r=0.720; p<0.05) and ST (r= -0.493; p<0.05). NDVI, SM, TP and ST significantly varied among the ecological zones. Regression analysis showed that vegetation health was significantly related to the combination of soil temperature and soil moisture (R2=0.641; p=0.000). Thus, monitoring the factors that affect vegetation health in a changing climate and soil environments is highly required.

Preliminary evaluation of some medicinal plants of Sundarbans mangrove forest on central nervous system

  • Alamgir M;Alam SMS;Alaul M;Rashid M;Hasan M;Choudhuri MSK
    • Advances in Traditional Medicine
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    • v.6 no.3
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    • pp.215-220
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    • 2006
  • The Sundarbans mangrove forest has a rich biodiversity of flowering plants and many of these have been used in traditional medicine although the flora remains comparatively uninvestigated scientifically. Xylocarpus granatum, Xylocarpus moluccensis and Excoecaria agallocha methanolic extract showed a central nervous system depressant activity on the hole cross and open field test at 800 mg/kg dose level. The most significant depressant activity was observed in Xylocarpus granatum followed by Xylocarpus moluccensis and Excoecaria agallocha. There was no depressant activity observed in the models for Sarcolobus globosus. Further studies are required to confirm the activity and to explain the mechanism.

Biodiversity Conservation & World Natural Heritage in Bangladesh (방글라데시의 생물다양성 보전 및 세계자연유산)

  • Nayna, Omme Kulsum;Lee, Sang Don
    • Journal of Environmental Impact Assessment
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    • v.26 no.5
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    • pp.376-384
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    • 2017
  • Bangladesh is a South Asian country with subtropical monsoonal climate between the intersection of the Indo-Himalayan and Indo-Chinese sub-regions, is known as biodiversity hotspot of the Asian region. The country has different types of forest like deciduous forest, evergreen forest, mixed forest, haor (wetlands) and mangrove forest. The natural beauty of the country is increased with the presence of so many rivers, longest sea beach of the world, green plants, critical hilly regions and green agricultural forest widely spread here and there. Sundarbans is the world largest mangrove forest and world natural heritage site declared by UNESCO in 1999 situated in Bangladesh and India. About 62 percent of this mangrove forest is situated in Bangladesh and there are so many plants and animals are found in this forest. To meet the increasing demand of the large population most of the natural ecosystem is now altered, deforestation rate is increased, natural habitat of the species is disturbed. Due to the imbalance of the climate and natural system many of the rare species of the world found this region is now endangered and some of the species are extinct. Directly or indirectly they are benefited from natural resources. At present time community, based ecotourism is also an important source of income for rural poor peoples. To protect the natural resources the government is now developed so many conservation acts and policy as well NGOs are also doing work for the conservation of ecosystem and biodiversity. At present transboundary pollutants and so many natural disasters also destruct the natural resources of Bangladesh.

Selective Homologous Expression of Recombinant Manganese Peroxidase Isozyme of Salt-Tolerant White-Rot Fungus Phlebia sp. MG-60, and Its Salt-Tolerance and Thermostability

  • Kamei, Ichiro;Tomitaka, Nana;Motoda, Taichi;Yamasaki, Yumi
    • Journal of Microbiology and Biotechnology
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    • v.32 no.2
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    • pp.248-255
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    • 2022
  • Phlebia sp. MG-60 is the salt-tolerant, white-rot fungus which was isolated from a mangrove forest. This fungus expresses three kinds of manganese peroxidase (MGMnP) isozymes, MGMnP1, MGMnP2 and MGMnP3 in low nitrogen medium (LNM) or LNM containing NaCl. To date, there have been no reports on the biochemical salt-tolerance of these MnP isozymes due to the difficulty of purification. In present study, we established forced expression transformants of these three types of MnP isozymes. In addition, the fact that this fungus hardly produces native MnP in a high-nitrogen medium (HNM) was used to perform isozyme-selective expression and simple purification in HNM. The resulting MGMnPs showed high tolerance for NaCl compared with the MnP of Phanerochaete chrysosporium. It was worth noting that high concentration of NaCl (over 200 mM to 1200 mM) can enhance the activity of MGMnP1. Additionally, MGMnP1 showed relatively high thermo tolerance compared with other isozymes. MGMnPs may have evolved to adapt to chloride-rich environments, mangrove forest.

Effect of Chromium Stress on Antioxidative Enzymes and Malondialdehyde Content Activities in Leaves and Roots of Mangrove Seedlings Kandelia Candel (L.) Druce

  • Rahman, Mohammed Mahabubur;Rahman, Motiur M.;Islam, Kazi Shakila;Chongling, Yan
    • Journal of Forest and Environmental Science
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    • v.26 no.3
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    • pp.171-179
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    • 2010
  • Effect of chromium (Cr) stress on antioxidant enzyme activities and malondialdehyde (MDA) content were investigated in leaves and roots of mangrove (italic (L.) Druce) seedlings. Cr toxicity effects were also assessed on young seedlings. The seedlings were grown in green house condition for three months in nutrient solution with 0, 0.5, 1, 1.5, 2, 2.5, and 3 mg $L^{-1}$ $CrCl_3$. This study showed that Cr led to the change of antioxidant enzymes such as superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) and activities at different concentrations. The activity of antioxidant enzymes in leaves of K. candel seedlings indicates that enzymes engaged in antioxidant defense in certain level especially in low concentration of Cr treatments. The activities of SOD and POD were activated by Cr in the root level, while CAT activity was inhibited. CAT activity decreased in response to high concentrations of Cr. In the present study indicated that SOD in root was active in scavenging the superoxide produced by Cr. Both in roots and leaves, an increase in malondialdehyde (MDA) content was observed with increase in metal concentration and exposure periods. Our finding indicated that the high concentration of excessive Cr supply may interfere with several metabolic processes of seedlings, causing toxicity to plants as exhibited by chlorosis, necrosis, photosynthetic impairing and finally, plant death.

Studies on Xylan of Tropical Hardwood (I) Wood Analysis (열대산(熱帶産) 광엽수재(廣葉樹材)의 Xylan에 관(關)한 연구(硏究) (I) -목재분석(木材分析)-)

  • Lee, Jong Yoon
    • Journal of Korean Society of Forest Science
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    • v.35 no.1
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    • pp.19-23
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    • 1977
  • Tropical hard wood produces a number of extracts, especially hot-water extracts. The lignin content in the two kinds of bangkirai and red lauan belonging to genus Shorea, was as high as in temperate zone soft wood, mangrove wood of genus Rhizophara contained it on the same level as temperate zone hard wood and keruing of genus Dipterocarpus was in between the two kinds of bangkirau and red lauan, and keruing wood. The xylose content of saccharose composition in the tree of genus Shorea, was as low as in needle-leaved trees, mangrove wood contained it on the same level as broad-leaved trees and the xylose content in keruing wood was in between the above two kinds of wood. The total retrieving rate of alditol acetate acetificated with sulphuric acid and acetic anhydride, did not reach 100%, even if it was supplemented. There was no difficulty in analyzing alditol immediately after acetification but, when it was left for four or five days, the acetificated alditol acetate was dissolved. The pyridine alditol acetificated with pyridine and acetic anhydride, showed the same result.

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Prediction of Carbon Accumulation within Semi-Mangrove Ecosystems Using Remote Sensing and Artificial Intelligence Modeling in Jeju Island, South Korea (원격탐사와 인공지능 모델링을 활용한 제주도 지역의 준맹그로브 탄소 축적량 예측)

  • Cheolho Lee;Jongsung Lee;Chaebin Kim;Yeounsu Chu;Bora Lee
    • Ecology and Resilient Infrastructure
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    • v.10 no.4
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    • pp.161-170
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    • 2023
  • We attempted to estimate the carbon accumulation of Hibiscus hamabo and Paliurus ramosissimus, semimangroves native to Jeju Island, by remote sensing and to build an artificial intelligence model that predicts its spatial variation with climatic factors. The aboveground carbon accumulation of semi-mangroves was estimated from the aboveground biomass density (AGBD) provided by the Global Ecosystem Dynamics Investigation (GEDI) lidar upscaled using the normalized difference vegetation index (NDVI) extracted from Sentinel-2 images. In Jeju Island, carbon accumulation per unit area was 16.6 t C/ha for H. hamabo and 21.1 t C/ha for P. ramosissimus. Total carbon accumulation of semi-mangroves was estimated at 11.5 t C on the entire coast of Jeju Island. Random forest analysis was applied to predict carbon accumulation in semi-mangroves according to environmental factors. The deviation of aboveground biomass compared to the distribution area of semi-mangrove forests in Jeju Island was calculated to analyze spatial variation of biomass. The main environmental factors affecting this deviation were the precipitation of the wettest month, the maximum temperature of the warmest month, isothermality, and the mean temperature of the wettest quarter. The carbon accumulation of semi-mangroves predicted by random forest analysis in Jeju Island showed spatial variation in the range of 12.0 t C/ha - 27.6 t C/ha. The remote sensing estimation method and the artificial intelligence prediction method of carbon accumulation in this study can be used as basic data and techniques needed for the conservation and creation of mangroves as carbon sink on the Korean Peninsula.