scholarly journals Variación anatómica de la madera de Avicennia germinans en la Laguna de la Mancha, Veracruz, México

2019 ◽  
Vol 85 ◽  
pp. 7
Author(s):  
Laura Yáñez Espinosa ◽  
Guillermo Angeles ◽  
Jorge López Portillo ◽  
Saamantha Barrales
Keyword(s):  
Mechanical Stability ◽  
Salinity Gradient ◽  
Avicennia Germinans ◽  
Mangrove Species ◽  
Low Salinity ◽  
La Mancha ◽  
Effi Ciency ◽  
Character Variation ◽  
Anatomical Characters ◽  
Tolerance To Salinity

<em>Avicennia germinans</em> is a mangrove species with a high tolerance to salinity, but only has shown tendencies towards increase size in wood character at low salinity sites. In La Mancha lagoon, Veracruz, A. germinans is distributed in a wide salinity gradient, making interesting to analyze their anatomical character variation with respect to salinity. The results suggest that differences among sites for a) vessel tangential wall thickness, b) vessel frequency, and c) fi ber tangential lumen diameter, could be attributed to an environmental effect. Increase in these three anatomical characters associated with high salinity and increased fl ooding exposure implies a trade-off between hydraulic effi ciency and mechanical stability of wood. This suggests that global warming would affect <em>A. germinans</em> when sea level raise increase salinity, affecting hydraulic conductivity, reducing growth in height and leaf area.

scholarly journals Forest Structure and Projections of Avicennia germinans (L.) L. at Three Levels of Perturbation in a Southwestern Gulf of Mexico Mangrove

Forests ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 989
Author(s):  
Basáñez-Muñoz Agustín de Jesús ◽  
Jordán-Garza Adán Guillermo ◽  
Serrano Arturo
Keyword(s):  
Size Structure ◽  
Transition Probabilities ◽  
High Sensitivity ◽  
Avicennia Germinans ◽  
Mangrove Forests ◽  
Mangrove Species ◽  
Adult Trees ◽  
Mangrove Dynamics ◽  
Projection Matrices ◽  
Partial Tree

Mangrove forests have declined worldwide and understanding the key drivers of regeneration at different perturbation levels can help manage and preserve these critical ecosystems. For example, the Ramsar site # 1602, located at the Tampamachoco lagoon, Veracruz, México, consists of a dense forest of medium-sized trees composed of three mangrove species. Due to several human activities, including the construction of a power plant around the 1990s, an area of approximately 2.3 km2 has suffered differential levels of perturbation: complete mortality, partial tree loss (divided into two sections: main and isolated patch), and apparently undisturbed sites. The number and size of trees, from seedlings to adults, were measured using transects and quadrats. With a matrix of the abundance of trees by size categories and species, an ordination (nMDS) showed three distinct groups corresponding to the degree of perturbation. Projection matrices based on the size structure of Avicennia germinans showed transition probabilities that varied according to perturbation levels. Lambda showed growing populations except on the zone that showed partial tree loss; a relatively high abundance of seedlings is not enough to ensure stable mangrove dynamics or start regeneration; and the survival of young trees and adult trees showed high sensitivity.

scholarly journals Nonionic Surfactant to Enhance the Performances of Alkaline–Surfactant–Polymer Flooding with a Low Salinity Constraint

2020 ◽  
Vol 10 (11) ◽  
pp. 3752 ◽  
Author(s):  
Shabrina Sri Riswati ◽  
Wisup Bae ◽  
Changhyup Park ◽  
Asep K. Permadi ◽  
Adi Novriansyah
Keyword(s):  
Nonionic Surfactant ◽  
Oil Recovery ◽  
Anionic Surfactant ◽  
Pore Volume ◽  
Salinity Gradient ◽  
Reference Case ◽  
Low Salinity ◽  
Asp Flooding ◽  
Optimum Salinity ◽  
Alkaline Surfactant Polymer

This paper presents a nonionic surfactant in the anionic surfactant pair (ternary mixture) that influences the hydrophobicity of the alkaline–surfactant–polymer (ASP) slug within low-salinity formation water, an environment that constrains optimal designs of the salinity gradient and phase types. The hydrophobicity effectively reduced the optimum salinity, but achieving as much by mixing various surfactants has been challenging. We conducted a phase behavior test and a coreflooding test, and the results prove the effectiveness of the nonionic surfactant in enlarging the chemical applicability by making ASP flooding more hydrophobic. The proposed ASP mixture consisted of 0.2 wt% sodium carbonate, 0.25 wt% anionic surfactant pair, and 0.2 wt% nonionic surfactant, and 0.15 wt% hydrolyzed polyacrylamide. The nonionic surfactant decreased the optimum salinity to 1.1 wt% NaCl compared to the 1.7 wt% NaCl of the reference case with heavy alcohol present instead of the nonionic surfactant. The coreflooding test confirmed the field applicability of the nonionic surfactant by recovering more oil, with the proposed scheme producing up to 74% of residual oil after extensive waterflooding compared to 51% of cumulative oil recovery with the reference case. The nonionic surfactant led to a Winsor type III microemulsion with a 0.85 pore volume while the reference case had a 0.50 pore volume. The nonionic surfactant made ASP flooding more hydrophobic, maintained a separate phase of the surfactant between the oil and aqueous phases to achieve ultra-low interfacial tension, and recovered the oil effectively.

scholarly journals Large seasonal and spatial variation in nano- and microphytoplankton diversity along a Baltic Sea—North Sea salinity gradient

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Malin Olofsson ◽  
James G. Hagan ◽  
Bengt Karlson ◽  
Lars Gamfeldt
Keyword(s):  
Community Structure ◽  
Temporal Variation ◽  
High Salinity ◽  
Salinity Gradient ◽  
Seasonal Succession ◽  
Phytoplankton Diversity ◽  
Cell Abundance ◽  
Low Salinity ◽  
Spatio Temporal ◽  
The Impact

Abstract Aquatic phytoplankton experience large fluctuations in environmental conditions during seasonal succession and across salinity gradients, but the impact of this variation on their diversity is poorly understood. We examined spatio-temporal variation in nano- and microphytoplankton (> 2 µm) community structure using almost two decades of light-microscope based monitoring data. The dataset encompasses 19 stations that span a salinity gradient from 2.8 to 35 along the Swedish coastline. Spatially, both regional and local phytoplankton diversity increased with broad-scale salinity variation. Diatoms dominated at high salinity and the proportion of cyanobacteria increased with decreasing salinity. Temporally, cell abundance peaked in winter-spring at high salinity but in summer at low salinity. This was likely due to large filamentous cyanobacteria blooms that occur in summer in low salinity areas, but which are absent in higher salinities. In contrast, phytoplankton local diversity peaked in spring at low salinity but in fall and winter at high salinity. Whilst differences in seasonal variation in cell abundance were reasonably well-explained by variation in salinity and nutrient availability, variation in local-scale phytoplankton diversity was poorly predicted by environmental variables. Overall, we provide insights into the causes of spatio-temporal variation in coastal phytoplankton community structure while also identifying knowledge gaps.

scholarly journals Post-Glacial Expansion and Population Genetic Divergence of Mangrove Species Avicennia germinans (L.) Stearn and Rhizophora mangle L. along the Mexican Coast

PLoS ONE ◽  
2014 ◽  
Vol 9 (4) ◽  
pp. e93358 ◽  
Author(s):  
Eduardo Sandoval-Castro ◽  
Richard S. Dodd ◽  
Rafael Riosmena-Rodríguez ◽  
Luis Manuel Enríquez-Paredes ◽  
Cristian Tovilla-Hernández ◽  
...  
Keyword(s):  
Genetic Divergence ◽  
Population Genetic ◽  
Rhizophora Mangle ◽  
Avicennia Germinans ◽  
Mangrove Species ◽  
Glacial Expansion

Physiological energetics of the estuarine crab Hemigrapsus crenulatus (Crustacea: Decapoda: Varunidae): responses to different salinity levels

2010 ◽  
Vol 90 (2) ◽  
pp. 267-273 ◽  
Author(s):  
Mauricio Urbina ◽  
Kurt Paschke ◽  
Paulina Gebauer ◽  
Oscar R. Chaparro
Keyword(s):  
Salinity Gradient ◽  
Ingestion Rate ◽  
Assimilation Efficiency ◽  
Decapod Crustacean ◽  
Growth Potential ◽  
Low Salinity ◽  
Physiological Processes ◽  
Salinity Levels ◽  
Nitrogen Ratio ◽  
Physiological Energetics

Hemigrapsus crenulatus is an abundant and frequent decapod crustacean inhabiting estuarine environments, where it must tolerate large shifts in salinity. The present study evaluates the effect of salinity (5, 13, 21 and 30 psu) on the adult physiological processes related to the energy balance. The growth potential (SFG) and the respired oxygen:excreted nitrogen ratio were used as indices of stress. Ingestion, excretion and respiration rates showed a significant dependence on salinity, being higher at low salinities. The assimilation efficiency remained constant along the studied salinity gradient. The assimilation and ingestion rates were inversely related with the salinity. Given this scenario, the growth potential remained constant within the studied salinity gradient, as did the oxygen:nitrogen ratio. The results suggest that the increased energy losses at low salinity due to respiration and excretion are compensated by an increment in the ingestion rate, contributing to the success of H. crenulatus in dynamic habitats such as estuaries.

Salinity tolerances of three succulent halophytes (Tecticornia spp.) differentially distributed along a salinity gradient

2016 ◽  
Vol 43 (8) ◽  
pp. 739 ◽  
Author(s):  
Louis Moir-Barnetson ◽  
Erik J. Veneklaas ◽  
Timothy D. Colmer
Keyword(s):  
Growth Rates ◽  
Shoot Growth ◽  
High Salinity ◽  
Salt Lake ◽  
Salinity Gradient ◽  
Saline Soils ◽  
Low Salinity ◽  
Substrate Limitation ◽  
Extreme Salinity ◽  
Osmotic Potentials

We evaluated tolerances to salinity (10–2000 mM NaCl) in three halophytic succulent Tecticornia species that are differentially distributed along a salinity gradient at an ephemeral salt lake. The three species showed similar relative shoot and root growth rates at 10–1200 mM NaCl; at 2000 mM NaCl, T. indica subsp. bidens (Nees) K.A.Sheph and P.G.Wilson died, but T. medusa (K.A.Sheph and S.J.van Leeuwen) and T. auriculata (P.G.Wilson) K.A.Sheph and P.G.Wilson survived but showed highly diminished growth rates and were at incipient water stress. The mechanisms of salinity tolerance did not differ among the three species and involved the osmotic adjustment of succulent shoot tissues by the accumulation of Na+, Cl– and the compatible solute glycinebetaine, and the maintenance of high net K+ to Na+ selectivity to the shoot. Growth at extreme salinity was presumably limited by the capacity for vacuolar Na+ and Cl– uptake to provide sufficiently low tissue osmotic potentials for turgor-driven growth. Tissue sugar concentrations were not reduced at high salinity, suggesting that declines in growth would not have been caused by inadequate photosynthesis and substrate limitation compared with plants at low salinity. Equable salt tolerance among the three species up to 1200 mM NaCl means that other factors are likely to contribute to species composition at sites with salinities below this level. The lower NaCl tolerance threshold for survival in T. indica suggests that this species would be competitively inferior to T. medusa and T. auriculata in extremely saline soils.

scholarly journals Insignificant enhancement of export flux in the highly productive Subtropical Front, east of New Zealand: a high resolution study of particle export fluxes based on <sup>234</sup>Th:<sup>238</sup>U disequilibria

2011 ◽  
Vol 8 (5) ◽  
pp. 9535-9576
Author(s):  
K. Zhou ◽  
S. D. Nodder ◽  
M. Dai ◽  
J. A. Hall
Keyword(s):  
New Zealand ◽  
Salinity Gradient ◽  
Salinity Range ◽  
Water Type ◽  
Export Flux ◽  
Low Salinity ◽  
Iron Fertilization ◽  
Natural Iron ◽  
Poc Export ◽  
Particle Export

Abstract. We evaluated the downward Particulate Organic Carbon (POC) export fluxes in the Subtropical Frontal zone (STF) of the Southern Ocean. The site is characterized by enhanced primary productivity which has been suggested to be stimulated through so-called natural iron fertilization processes at its northern boundary where iron-depleted subantarctic water (SAW) mixes with oligotrophic, iron-replete subtropical water (STW). We adopted the small-volume 234Th method to achieve highest spatial sampling resolution as possible based on a cruise to the STF to the east New Zealand in austral late autumn-early winter, May–June 2008. The inventories of fluorescence, particulate 234Th and POC observed in the upper 100 m were all elevated in the mid-salinity part of the water type (34.5<S<34.8), compared with low (S<34.5) and high (S>34.8) salinity waters. However, Steady-State 234Th fluxes were similar cross all of the salinity gradient being 1484 in the mid-salinity, and 1761 and 1304 dpm m−2 d−1 in the high and low salinity zones respectively. Bottle POC/Th ratios at the depth of 100 m were used to convert the Th fluxes into POC export flux. The POC flux was again not enhanced in the mid-salinity range where the primary production was highest, being 7.4 mmol C m−2 d−1 as compared to 9.9 mmol C m−2 d−1 in high salinity waters, and 5.9 mmol C m−2 d−1 in low salinity waters. This study implied that natural iron fertilization does not necessarily lead to the enhancement of POC export in STF regions.

scholarly journals Geographic and environmental contributions to genomic divergence in mangrove forests

2020 ◽  
Author(s):  
Michele Fernandes da Silva ◽  
Mariana Vargas Cruz ◽  
João de Deus Vidal Júnior ◽  
Maria Imaculada Zucchi ◽  
Gustavo Maruyama Mori ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Avicennia Germinans ◽  
Global Changes ◽  
Mangrove Forests ◽  
Tidal Variation ◽  
Mangrove Species ◽  
Coastal Species ◽  
Precipitation Regimes ◽  
Isolation By Environment ◽  
Mangrove Trees

ABSTRACTAssessing the relative importance of geographic and environmental factors to the spatial distribution of genetic variation may provide relevant information about the processes that maintain genetic variation in natural populations. With a globally wide but very restricted habitat distribution, mangrove trees are an interesting model for studies aiming to understand the contributions of these factors. Mangroves occur along the continent-ocean interface of tropical and subtropical latitudes, regions considered inhospitable to many other plant types. Here, we used landscape genomics approaches to investigate the relative contributions of geographic and environmental variables to the genetic variation of two black mangrove species, Avicennia schaueriana and Avicennia germinans, along the South American coast. Using single nucleotide polymorphisms, our results revealed an important role of ocean currents in the gene flow of A. schaueriana and isolation by environment as the pattern that best explains the genetic differentiation of A. germinans. Additionally, for both species, we observed significant correlations between genetic variation with evidence of selection and precipitation regimes, tidal variation, solar radiation and temperature patterns. These discoveries expand our knowledge about the evolution of mangrove trees and provide important information to predict future responses of coastal species to the expected global changes for this century.

scholarly journals Status and perspectives of mangrove management in Côte d'Ivoire

2021 ◽  
Vol 9 (2) ◽  
pp. 045-050
Author(s):  
Egnankou Wadja Mathieu ◽  
Gnagbo Anthelme
Keyword(s):  
Cote D'ivoire ◽  
Côte D’Ivoire ◽  
Avicennia Germinans ◽  
Mangrove Species ◽  
Entropy Model ◽  
Cote D’Ivoire ◽  
Intertidal Zones ◽  
Conocarpus Erectus ◽  
Côte D'ivoire ◽  
Mode Of Operation

Mangroves are ecosystems characteristic of intertidal zones in tropical and subtropical regions. Rhizophora racemosa, Avicennia germinans and Conocarpus erectus are characteristic mangrove species found in Côte d'Ivoire. These mangroves could disappear without being fully studied due to the strong anthropic pressure. This study therefore proposes to establish a detailed cartography of the mangroves reported in Côte d'Ivoire and to model their potential distribution. Mangroves cover approximately 57.92 km², ie a linear coverage of 20.11% of the 540.14 km of coastline. The extent of these mangroves also decreased by 4.91 km² between 1996 and 2016. The maximum entropy model presents low-altitude coastal areas with high rainfall as well as average sunshine as favorable to mangroves. The particular ecological characteristic of mangroves as well as their particular mode of operation deserve to be taken into account in studies of flora in Côte d'Ivoire. It is therefore opportune to consider larger studies focusing specifically on the mangroves present in Ivory.

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