Tracing carbon transfer and assimilation by invertebrates and fish across a tropical mangrove ecosystem using stable isotopes          下载免费PDF全文

Nguyen Tai Tue  Tran Dang Quy  Mai Trong Nhuan  Luu Viet Dung  Nguyen Dinh Thai 《Marine Ecology》2017,38(5)

Mangroves are highly productive ecosystems that exhibit a diverse range of habitats, including tidal creeks and flats, forest gaps and interior forest with varying understory light intensity, tidal dynamics, geomorphological settings, and overall biological production. Within mangrove ecosystems, invertebrates and fish feed on heterogeneous food sources, the occurrence of which is unevenly distributed across the system. This provides a basis for testing models of carbon transfer across mangrove ecosystems. We hypothesized that the carbon transfer and assimilation by fish and invertebrates will vary across the different mangrove habitats and that such variations can be predicted by their stable isotope compositions. We analysed δ¹³C and δ¹⁵N signatures of consumers and their potential organic carbon sources across a tropical mangrove ecosystem in Vietnam. The δ¹³C values of crabs and snails significantly decreased from the tidal flat to interior forest, indicating that variations in carbon transfer and assimilation occurred at small scales <30 m. Reduced variation in δ¹³C of suspension‐feeding bivalves suggested that tidal water was a vector for large‐scale transport of carbon across the mangrove ecosystem. An analysis of co‐variance using habitat as a fixed factor and feeding habit and movement capacity of consumers as co‐variates indicated that habitat and feeding types were major features that affected the δ¹³C values of invertebrates and fish. The findings demonstrate that carbon transfer and assimilation across mangrove ecosystems occur as a diverse combination of small (<30 m) and large (>30 m) scale processes.  相似文献   

GIS在移动蜂窝网络中的应用研究     

陈晓勇  吴华玲  Tran Minh Tri 《测绘科学》2012,37(2):133-137

GIS在移动蜂窝网络规划中有重要应用,本文旨在研究以最低的投资和维护费用,确定GIS最佳解决方案用以改善蜂窝网络的传播质量。本文利用GIS能将蜂窝网络数据库中空间与非空间数据相结合的优势,提供必要的参数,更准确地预测蜂窝网络的覆盖范围。本文研究对象为越南胡志明市的部分区域,实验成功开发出预测移动蜂窝网络覆盖范围的基础地理信息系统模型,实现了预测信号强度的可视化,分析了场强覆盖范围,并显示了研究区域中每个小区站的可能切换区域。实验结果表明,GIS模型在移动通信尤其对小区站覆盖范围预测是非常有用的。  相似文献   

Bioaccumulation of Heavy Metals in Soft Tissues of Bivalve Mollusks from Natural Lakes in Eastern Sikhote Alin (Russia) and the Mekong Delta (Vietnam)     

Bogatov  V. V.  Prozorova  L. A.  Chernova  E. N.  Lysenko  E. V.  Ngo  Q.  Tran  T.  Hoang  S. 《Doklady Earth Sciences》2019,484(1):76-78

Doklady Earth Sciences - The concentrations of seven heavy metals (HMs) in tissues of bivalve mollusks of the families Unionidae (genera Ensidens, Scabies, Kunashiria) and Cyrenidae (genus...  相似文献   

Matched field processing of deep-water ambient noise     

Sotirin  B.J. Tran  J.-M.Q.D. Hodgkiss  W.S.  Jr. 《Oceanic Engineering, IEEE Journal of》1990,15(4):316-323

Matched-field ambiguity surfaces produced by deep-water ambient-noise data are discussed and quantified in terms of power levels and correlation values. Two processors were implemented (Bartlett and minimum variance) using data at 35 and 95 Hz with similar but distinct vertical angular distributions. In general, the ambiguity surfaces have both diffuse and discrete components. The diffuse distribution extends across the sound channel with correlation values increasing with distance. The discrete sources have higher correlation values and are distributed in a convergence-zone sidelobe structure. Local wind conditions appear to affect the received power but not the correlation values or the processor output power  相似文献   

Simulated annealing technique in discrete fracture network inversion: optimizing the optimization     

Nam H. Tran 《Computational Geosciences》2007,11(3):249-260

Simulated annealing (SA) has the capacity to handle complex problem of fracture heterogeneity. However, its applications to characterization and modeling of an actual discrete fracture network are limited. Borrowing the context of geothermal reservoirs (where extensive discrete fractures exist), this paper attempts to solve several key practical issues that persist in current models: objective function’s (OF’s) formulation, modification scheme, and stop criteria. The improvements are examined in a case study on an actual fracture outcrop, where results are compared with a current and advanced SA work.  相似文献   

Rainfall-induced catastrophic landslide in Quang Tri Province: the deadliest single landslide event in Vietnam in 2020     

Van Tien  Pham  Luong  Le Hong  Duc  Do Minh  Trinh  Phan Trong  Quynh  Dinh Thi  Lan  Nguyen Chau  Thuy  Dang Thi  Phi  Nguyen Quoc  Cuong  Tran Quoc  Dang  Khang  Loi  Doan Huy 《Landslides》2021,18(6):2323-2327

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Using Geomorphological Indicators to Predict Earthquake Magnitude (MOb‒Max): A Case Study from Cao Bang Province and Adjasent Areas (Vietnam)     

Trong  C. D.  Hoang  N.  Bach  M. X.  Luc  N. M.  Dung  L. V.  Trieu  C. D.  Syrbu  N. S.  Hai  D. Th.  Tuan  Th. A.  Toan  N. Q.  Thanh  D. V. 《Geotectonics》2022,56(3):321-338

Geotectonics - This paper presents analysis of geomorphological indices for predicting the maximum observed earthquake (MOb?Max) in research region, conducted in three steps: (i)...  相似文献   

Description of a complex,rainfall-induced landslide within a multi-stage three-dimensional model     

Tran  T. V.  Alvioli  M.  Hoang  V. H. 《Natural Hazards》2022,110(3):1953-1968

Natural Hazards - The mechanical processes involved in movements of earth or rock masses under the effect of gravity—a landslide—may include several phases where the failure of one...  相似文献   

Performances of Different Machine Learning Algorithms for Predicting Saltwater Intrusion in the Vietnamese Mekong Delta Using Limited Input Data: A Study from Ham Luong River     

Tran  T. T.  Pham  N. H.  Pham  Q. B.  Pham  T. L.  Ngo  X. Q.  Nguyen  D. L.  Nguyen  P. N.  Veettil  B. K. 《Water Resources》2022,49(3):391-401

Water Resources - Accurate forecasting of salinity intrusion has a vital role in water resource management to mitigate and prevent its adverse effects. However, monitoring of salinity presents...  相似文献   

A Closed-Form Solution for Tunnels with Arbitrary Cross Section Excavated in Elastic Anisotropic Ground   总被引：1，自引：1，他引：0  

Huy Tran Manh  Jean Sulem  Didier Subrin 《Rock Mechanics and Rock Engineering》2015,48(1):277-288

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