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Black mangrove (Avicennia germinans) reproduces by producing propagules through the process of cryptovivipary, which requires a significant energy investment.
We conducted a series of field and greenhouse studies to track propagule production in years of high and low disturbances
(i.e., hurricanes), the effects of time and salinity on propagule dispersal potential, and the relationship between hydrology
and propagule establishment elevations. Trees tended to produce greater numbers of propagules in years after hurricanes, and
individual trees alternated the amount of energy they invested in reproduction in consecutive years. In the greenhouse, propagule
buoyancy was affected by salinity with propagules in 36 remaining buoyant for over 110 days and establishment success decreasing
with dispersal period length. Finally, a field survey across five sites in southeastern Louisiana revealed that the 2009 cohort
of propagules established at significantly lower elevations than mature trees occurred. These findings elucidate some salient
features of black mangrove reproductive biology in the northern portion of its North American distribution. 相似文献
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Bourgeois B.S. Martinez A.B. Alleman P.J. Cheramie J.J. Gravley J.M. 《Oceanic Engineering, IEEE Journal of》1999,24(4):414-423
This paper describes the Autonomous Bathymetry Survey System (AutoSurvey), a system that provides automation of swath sonar bathymetric surveys. This system enables faster surveying of an area through environmentally adaptive techniques while ensuring adequate coverage and data quality. AutoSurvey assesses data quality and coverage in real time and generates next-trackline waypoints based on actual system performance. The need for real-time performance assessment is discussed. A primary factor considered is the effect of the environment on swath bathymetry system performance, which is difficult to predict a priori. The system's features, design, and implementation are discussed in this paper. Simulation and sea trial results are presented, as well as an analysis of the system's ability to reduce survey time 相似文献
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N. Fagel L.Y. Alleman L. Granina F. Hatert E. Thamo-Bozso R. Cloots L. Andr 《Global and Planetary Change》2005,46(1-4):315
In an effort to better understand vivianite formation processes, four Lake Baikal sediment cores spanning two to four interglacial stages in the northern, central and southern basins and under various biogeochemical environments are scrutinized. The vivianite-rich layers were detected by anomalous P-enrichments in bulk geochemistry and visually by observations on X-radiographs. The millimetric concretions of vivianite were isolated by sieving and analysed by X-ray diffraction, scanning electron microscope (SEM), microprobe, infrared spectroscopy, inductively coupled plasma atomic emission spectrometry and mass spectrometry (ICP-AES, ICP-MS). All the vivianites display similar morphological, mineralogical and geochemical signature, suggesting a common diagenetic origin. Their geochemical signature is sensitive to secondary alteration where vivianite concretions are gradually transformed from the rim to the center into an amorphous santabarbaraite phase with a decreasing Mn content. We analysed the spatial and temporal distribution of the concretions in order to determine the primary parameters controlling the vivianite formation, e.g., lithology, sedimentation rates, and porewater chemistry. We conclude that vivianite formation in Lake Baikal is mainly controlled by porewater chemistry and sedimentation rates, and it is not a proxy for lacustrine paleoproductivity. Vivianite accumulation is not restricted to areas of slow sedimentation rates (e.g., Academician and Continent ridges). At the site of relatively fast sedimentation rate, i.e., the Posolsky Bank near the Selenga Delta, vivianite production may be more or less related to the Selenga River inputs. It could be also indirectly related to the past intensive methane escapes from the sediments. While reflecting an early diagenetic signal, the source of P and Fe porewater for vivianites genesis is still unclear. 相似文献
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Hoang Tung Do Huyen Alleman James Cetin Bora Dayioglu Asli Y. 《Acta Geotechnica》2023,18(2):1073-1092
Acta Geotechnica - This paper addresses a soil bio-stabilization technique using bacterial enzyme-induced calcium carbonate precipitation (BEICP) as an alternative to previous conventional methods... 相似文献
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