Seasonal Change of Sediment Microbial Communities and Methane Emission in Young and Old Mangrove Forests in Xuan Thuy National Park

( Cuong Tu Ho ),( Unno Tatsuya ),( Son Giang Nguyen ),( Thi-hanh Nguyen ),( Son Truong Dinh ),( Son Tho Le ),( Thi-minh-hanh Pham ) 한국미생물생명공학회 2024 Journal of microbiology and biotechnology Vol.34 No.3

Microbial communities in mangrove forests have recently been intensively investigated to explain the ecosystem function of mangroves. In this study, the soil microbial communities under young (< 11 years-old) and old ( >17 years-old) mangroves have been studied during dry and wet seasons. In addition, biogeochemical properties of sediments and methane emission from the two different mangrove ages were measured. The results showed that young and old mangrove soil microbial communities were significantly different on both seasons. Seasons seem to affect microbial communities more than the mangrove age does. Proteobacteria and Chloroflexi were two top abundant phyla showing >15%. Physio-chemical properties of sediment samples showed no significant difference between mangrove ages, seasons, nor depth levels, except for TOC showing significant difference between the two seasons. The methane emission rates from the mangroves varied depending on seasons and ages of the mangrove. However, this did not show significant correlation with the microbial community shifts, suggesting that abundance of methanogens was not the driving factor for mangrove soil microbial communities.

Mapping the Mangrove Forest Restoration Potential and Conservation Gaps in China Based on Random Forest Model

Zhonghua Yu,Wei Li,Shaowei Zhang,Buqing Zhong,Jun Wang,이시영,최재혁,Shulin Deng 인간식물환경학회 2022 인간식물환경학회지 Vol.25 No.4

Background and objective: The area of mangroves is gradually decreasing globally, and mangroves are already one of the most threatened ecosystems. Despite net growth in the mangrove areas in China, the restoration potential of mangroves is still insufficient. This study proposed the Random forest model as an excellent data mining method to map the restoration potential based on the predicted probability of mangrove habitat suitability. Methods: We demonstrated the vital environmental variables influencing habitat suitability. The de-cisive advantages of RFM were parsimonious (variables selection), cost-effective (us-ing existing open-source data), accurate (training AUC was 0.89, testing AUC was 0.91), highly efficient (fast-training speed); and its results had high explanatory power. Here, we first mapped the conservation gaps using the RFM. Results: The results showed that temperature was the most important environmental factor influencing the habitat suit-ability of mangroves. The northern limit of suitable areas was around 24°44' N. The theoretical suitable habitat area for mangrove was 196,566.6 ha (the highly suitable area was 32,551.4 ha, the medium suitable area was 164,015.2 ha). The potential area for mangrove restoration was 176,264 ha (Guangdong with 104215.4 ha, Guangxi with 65957.5 ha). Conclusion: We proposed 24 sites with conservation gaps for mangrove forests restoration and nine potential sites as examples for the further restoration plan. We took one example site with high restoration potential for further explanation: how the key environmental factors influence the habitat suitability and how to use the infor-mation to guide the restoration strategies. RFM can be used as a data mining algo-rithm for the utmost use of the presence-only ecological data, objectively evaluating the suitability of species distribution, and providing scientifically technical data for species restoration planning.

열대 홍수림 주변 해역 환경 전이대의 식물플랑크톤 및 박테리아의 분포

최동한,노재훈,안성민,이미진,김동선,김경태,권문상,박흥식 한국해양과학기술원 2013 Ocean and Polar Research Vol.35 No.4

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.

Microbial Community Response to a Simulated Hydrocarbon Spill in Mangrove Sediments

Rodrigo Gouvêa Taketani,Natália Oliveira Franco,Alexandre Soares Rosado,Jan Dirk van Elsas 한국미생물학회 2010 The journal of microbiology Vol.48 No.1

In this study, we examined the hypothesis that the microbial communities in mangrove sediments with different chemical and historical characteristics respond differently to the disturbance of a hydrocarbon spill. Two different mangrove sediments were sampled, one close to an oil refinery that had suffered a recent oil spill and another that had not been in contact with oil. Based on the sampled sediment, two sets of mesocosms were built, and oil was added to one of them. They were subjected to mimicked mangrove conditions and monitored for 75 days. Archaeal and bacterial communities were evaluated through PCRDGGE. Both communities showed the emergence of small numbers of novel bands in response to oil pollution. 16S rRNA gene clone libraries were constructed from both mesocosms before the addition of oil and at day 75 after oil addition. LIBSHUFF analysis showed that both mangrove-based mesocosms contained similar communities at the start of the experiment and that they were different from the initial one, as well as from each other, after 75 days. These results hint at a role of environmental history that is not obvious from community diversity indicators, but is apparent from the response to the applied stress.

적도태평양 마이크로네이사 축주 퇴적물 내 중금속 연구

나공태(Kongtae Ra),김은수(Eun-Soo Kim),김경태(Kyung-Tae Kim),김종근(Joung-Keun Kim),이정무(Jung-Moo Lee),노재훈(Jae-Hoon Noh),박흥식(Heung-Sik Park),권문상(Moon-Sang Kwon) 한국해양환경·에너지학회 2012 한국해양환경공학회 학술대회논문집 Vol.2012 No.11

본 연구에서는 적도태평양 마이크로네시아 축주 연안에서 채취한 표층수 및 퇴적물 내 미량금속의 지화학적 특성 및 오염도에 대한 조사를 실시하였다. 연안에서 가까우며 홍수림이 잘 발달된 지역에서는 상대적으로 높은 중금속 농도가 검출되었으며 외해역으로 갈수록 감소하고 있었다. 연안에서 가까운 해역에서의 높은 중금속 농도는 화학적 풍화작용을 통한 토양기원 및 홍수림에 기인한 유기물 함량이 높기 때문이며 외해역에서 낮은 중금속 농도는 산호 부스러기 및 석회조류 등과 같은 탄산염 성분이 대부분을 차지하기 때문으로 사료된다. 홍수림이 인접한 지역에서 Cr, Ni, Cu, Zn 등이 약간 오염된 것으로 나타났으며 평균적으로 하위생물 10%에 위해영향을 줄 수 있는 ERL 기준을 초과한 것으로 나타났다. We studied the heavy metal concentration in surface seawater and surface sediments of Chuuk, the federate state of Micronesia(FSM) to identify the geochemical characteristics and pollution assessment. Relatively higher concentrations of heavy metals in seawater and sediments were observed in the nearby Mangrove forest which was developed in coastal area. This is due to the chemical weathering processes and the higher organic matter contents from Mangrove. Where as metal concentrations were decreased to the open ocean because the sediments mainly consisted of coral debris and inorganic calcium carbonate originated from Halimeda. Sediments around mangrove were contaminated for Cr, Ni, Cu, Zn according to pollution assessments using geo-accumulation index. Mean concentrations of those metals were exceeded the ERL levels by NOAA.

Saroclazines A–C, thio-diketopiperazines from mangrove-derived fungi Sarocladium kiliense HDN11-84

Feng Li,Wenqiang Guo,Li Wu,Tian-jiao Zhu,Qian Qun Gu,De-Hai Li,Qian Che 대한약학회 2018 Archives of Pharmacal Research Vol.41 No.1

Three new diketopiperazine derivatives (DKPs), saroclazines A–C (1–3) along with three known DKPs (4– 6) were isolated from mangrove-derived fungi Sarocladium kiliense HDN11-84. Saroclazines A–B (1 and 2) possessed a free amide structure, which was first found in sulfurcontaining aromatic DKPs. Their structures were elucidated by NMR, HRESIMS and X-ray. The cytotoxic activity of new compounds (1–3) was tested against HeLa cell lines, among which compound 2 showed an IC50 value of 4.2 lM.

Seedling Morphology of Three Mangrove Species and Its Taxonomic Implications

Das, Sauren 한국식물학회 2001 Journal of Plant Biology Vol.44 No.2

Seedling establishment is an important part of the life cycle of mangroves. Very early in the juvenile stage, they face adverse situations such as a variable and unstable substrate as well as a high-saline environment Therefore, the propagules should have some ability to float in saline water. Seedlings differ morphologically from the adult plants. Here, I examined the seedling growth stages in three species of mangrove: Aegialitis rotundifolia Roxb., Aegiceras corniculatum (L) Blanco, and Avicennia marina (Forsk.) Vierh. that grow in the Sundarbans swamps of West Bengal. In all cases, fruits were the propagating units; seeds were inseparable from those fruits. Germination was rapid and required no dormancy period. The hypocotyl pierced the seed coat rather than emerging from the pericarp-a variation on the traditional viviparous type of germination. Seedlings then became exposed prior to abscission from parent plants. Based on germination patterns and differences in seedling morphology observed here, these species should be classified in a more relevant taxonomic group than was done previously.

Metabolites from the Mangrove-derived Fungus Xylaria cubensis PSU-MA34

Saranyoo Klaiklay,Vatcharin Rukachaisirikul,Yaowapa Sukpondma,Souwalak Phongpaichit,Jirayu Buatong,Boonsom Bussaban 대한약학회 2012 Archives of Pharmacal Research Vol.35 No.7

Two new succinic acid derivatives, xylacinic acids A (1) and B (2), along with seven known compounds, including one succinic acid derivative (3), three mellein derivatives (4-6), cytochalasin D (7), 2-chloro-5-methoxy-3-methylcyclohexa-2,5-diene-1,4-dione (8) and isosclerone (9), were isolated from the mangrove-derived fungus Xylaria cubensis PSU-MA34. Their structures were established by spectroscopic evidence. They were evaluated for cytotoxicity against KB cells and antibacterial activity against Staphylococcus aureus ATCC 25923 and methicillin-resistant S. aureus.

마리즈 콩데Maryse Condé의 『맹그로브 숲 가로지르기Traversée de la mangrove』에 나타난 프랑스어권 카리브해 문화의 불투명성과 ‘관계-정체성’

이가야(LEE Ka-Ya) 프랑스문화예술학회 2015 프랑스문화예술연구 Vol.52 No.-

마이크로네시아 웨노섬의 맹그로브 숲에 서식하는 고둥류 및 집게의 영양원에 대한 이해

고아라,김민섭,주세종 한국해양과학기술원 2013 Ocean and Polar Research Vol.35 No.4

Carbon cycling and productivity within Weno Island of Micronesia enclosed by the coral reef may be likely self-maintained and insignificantly affected by the open ocean. Therefore, it is important to understand the role of the mangrove known as providing the organic matter and habitats for many organisms in this enclosed area. In order to trace the nutritional source of fauna (mostly invertebrates) in the mangrove forest of Weno island, we analyzed the fatty acid (FA) and carbon and nitrogen stable isotopes of potential nutritional sources (mangrove leaf & pneumatophore, seagrass leaf & root, surface sediment, and particulate organic matter (POM) in water) and consumers (4 gastropods and anomura). The mangrove and seagrass contained the abundance of 18:2ω6, and 18:3ω3, whereas FAs associated with phytoplankton and bacteria were accounted for a high proportion in the surface sediment and POM. FA composition of consumers was found to be similar to those of the surface sediment, mangrove, and seagrass. These were also confirmed through the mixing model of stable isotope for contribution of nutritional sources to consumers. Overall results with the feeding types of investigated mangrove fauna indicate that investigated mangrove fauna obtained their nutrition from the various sources, i.e. the mangrove for Littorina cf. scabra, the microalgae for Strombus sp., and omnivorous Pagurus sp. and Terebralia cf. palustris. However, it is obvious that the nutrition of most species living in the mangrove ecosystem is highly dependent on the mangrove, either directly or indirectly. More detail food-web structure and function of the mangrove ecosystem would be established with the analysis of additional fauna and flora.