scholarly journals The Mangrove Periwinkle Littoraria angulifera (Mollusca: Littorinidae) in the Urabá Gulf (Colombian Caribbean): Finding Ways in an Urbanizing Coast?

2021 ◽  
Vol 8 ◽  
Author(s):  
Jhostin Ramos ◽  
Marco Boto ◽  
Juan Felipe Blanco-Libreros ◽  
José M. Riascos
Keyword(s):  
Urban Areas ◽  
Size Structure ◽  
Woody Debris ◽  
Land Use Changes ◽  
Estuarine System ◽  
Mangrove Forests ◽  
Demographic Traits ◽  
Tropical Estuarine ◽  
Anthropogenic Substrates ◽  
Different Populations

Periwinkles (Littorinidae: genus Littoraria) are one of the very few molluscan clades showing an adaptive radiation closely associated to the mangrove habitat. However, pervasive land use changes associated to urbanization is prompting mangrove loss or degradation, with unknown consequences for mangrove-associated fauna. In the southern Colombian Caribbean, mangrove ecosystems have been encroached by human settlements and different populations of Littoraria angulifera (Lamarck, 1822) now inhabit anthropogenic intertidal substrates in urban areas, but the demographic traits of populations thriving in these novel environments are unknown. We studied the relative abundance and size structure of L. angulifera in remnant mangrove patches, woody debris and anthropogenic substrates (boulder seawalls and built structures) in 13 locations throughout the Urabá Gulf, a human-transformed tropical estuarine system. The abundance of L. angulifera was up to two orders of magnitude higher in anthropogenic than in quasi-natural or natural substrates. Snails also displayed a significant preference for wave protected positions in boulder seawalls and built structures exposed to heavy wave action, which was not previously reported in mangrove forests. Moreover, snail populations in anthropogenic substrate were consistently dominated by individuals of small sizes in comparison with mangroves or driftwood. We argue that the anthropogenic disturbances caused by the expansion of Turbo city during nearly one century in a coast formerly dominated by mangrove forests are providing novel and expanding habitats, whose quality might be good enough as to support high-density populations of L. angulifera. However, we hypothesize that shifted thermal regimes in hard and novel wave-exposed urban seascapes might also be prompting behavioral adjustments and the selection of smaller size ranges than those observed in mangrove forests.

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 Estimating surface runoff and groundwater recharge in an urban catchment using a water balance approach

2021 ◽  
Vol 29 (7) ◽  
pp. 2411-2428
Author(s):  
Robin K. Weatherl ◽  
Maria J. Henao Salgado ◽  
Maximilian Ramgraber ◽  
Christian Moeck ◽  
Mario Schirmer
Keyword(s):  
Soil Moisture ◽  
Water Balance ◽  
Groundwater Recharge ◽  
Surface Runoff ◽  
Urban Areas ◽  
Water Cycle ◽  
Land Use Changes ◽  
Curve Number ◽  
Hydrograph Separation ◽  
Balance Approach

AbstractLand-use changes often have significant impact on the water cycle, including changing groundwater/surface-water interactions, modifying groundwater recharge zones, and increasing risk of contamination. Surface runoff in particular is significantly impacted by land cover. As surface runoff can act as a carrier for contaminants found at the surface, it is important to characterize runoff dynamics in anthropogenic environments. In this study, the relationship between surface runoff and groundwater recharge in urban areas is explored using a top-down water balance approach. Two empirical models were used to estimate runoff: (1) an updated, advanced method based on curve number, followed by (2) bivariate hydrograph separation. Modifications were added to each method in an attempt to better capture continuous soil-moisture processes and explicitly account for runoff from impervious surfaces. Differences between the resulting runoff estimates shed light on the complexity of the rainfall–runoff relationship, and highlight the importance of understanding soil-moisture dynamics and their control on hydro(geo)logical responses. These results were then used as input in a water balance to calculate groundwater recharge. Two approaches were used to assess the accuracy of these groundwater balance estimates: (1) comparison to calculations of groundwater recharge using the calibrated conceptual HBV Light model, and (2) comparison to groundwater recharge estimates from physically similar catchments in Switzerland that are found in the literature. In all cases, recharge is estimated at approximately 40–45% of annual precipitation. These conditions were found to closely echo those results from Swiss catchments of similar characteristics.

scholarly journals Implications of an extensive salt water barrage on the distribution of black clam in a tropical estuarine system, Southwest coast of India

Oceanologia ◽  
2021 ◽  
Author(s):  
Arunpandi Nagarathinam ◽  
Jyothibabu Retnamma ◽  
Jagadeesan Loganathan ◽  
Parthasarathi Singaram ◽  
Savitha Mohanan ◽  
...  
Keyword(s):  
Salt Water ◽  
Estuarine System ◽  
Southwest Coast Of India ◽  
Southwest Coast ◽  
Tropical Estuarine

Phytoplankton cell size in an urban tropical estuarine system in Northeast Brazil

2021 ◽  
Vol 43 ◽  
pp. 101659
Author(s):  
Nayana Buarque A. Silva ◽  
Manuel Flores-Montes ◽  
Marcella Guennes ◽  
Gislayne Borges ◽  
Carlos Noriega ◽  
...  
Keyword(s):  
Cell Size ◽  
Estuarine System ◽  
Northeast Brazil ◽  
Tropical Estuarine ◽  
Phytoplankton Cell

Nitrogen fixation and carbon uptake in a tropical estuarine system of Goa, western India

2019 ◽  
Vol 144 ◽  
pp. 16-21
Author(s):  
Ayaz Ahmed ◽  
Hema Naik ◽  
Sarvesh S. Adel ◽  
Pratirupa Bardhan ◽  
Mangesh Gauns ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Carbon Uptake ◽  
Western India ◽  
Estuarine System ◽  
Tropical Estuarine

scholarly journals The Evolution of the Urban Spatial Pattern in the Yangtze River Economic Belt: Based on Multi-Source Remote Sensing Data

2018 ◽  
Vol 10 (8) ◽  
pp. 2733 ◽  
Author(s):  
Yang Li ◽  
Hua Shao ◽  
Nan Jiang ◽  
Ge Shi ◽  
Xin Cheng
Keyword(s):  
Size Distribution ◽  
Urban Areas ◽  
Yangtze River ◽  
Size Structure ◽  
Urban Land ◽  
Urban Agglomeration ◽  
Spatial Distance ◽  
The Yangtze River ◽  
Urban Agglomerations ◽  
Urban Size

The development of the Yangtze River Economic Belt (YREB) is an important national regional development strategy and a strategic engineering development system. In this study, the evolution of urban spatial patterns in the YREB from 1990 to 2010 was mapped using the nighttime stable light (NSL) data, multi-temporal urban land products, and multiple sources of geographic data by using the rank-size distribution and the Gini coefficient method. Through statistical results, we found that urban land takes on the feature of “high in the east and low in the west”. The study area included cities of different development stages and sizes. The nighttime light increased in most cities from 1992 to 2010, and the rate assumed an obvious growth tendency in the three urban agglomerations in the YREB. The results revealed that the urban size distribution of the YREB is relatively dispersed, the speed of urban development is unequal, and the trend of urban size structure shows a decentralized distribution pattern that has continuously strengthened from 1990 to 2010. Affected by factors such as geographical conditions, spatial distance, and development stage, the lower reaches of the Yangtze River have developed rapidly, the upper and middle reaches have developed large cities, and a contiguous development trend is not obvious. The evolution of urban agglomerations in the region presents a variety of spatial development characteristics. Jiangsu, Zhejiang, and Shanghai have entered a phase of urban continuation, forming a more mature interregional urban agglomeration, while the YREB inland urban agglomerations are in suburbanization and multi-centered urban areas. At this stage, the conditions for the formation of transregional urban agglomerations do not yet exist, and there are many uncertainties in the boundary and spatial structure of each urban agglomeration.

scholarly journals Relationships between landslides and land use changes in the Sanbagawa and Mikabu Belts, Shikoku, Japan

2019 ◽  
Vol 1 ◽  
pp. 1-1
Author(s):  
Roxanne Lai ◽  
Takashi Oguchi
Keyword(s):  
Land Use ◽  
Spatial Data ◽  
Landslide Susceptibility ◽  
Urban Areas ◽  
Land Use Changes ◽  
Land Abandonment ◽  
Crystalline Schist ◽  
Agricultural Abandonment ◽  
Landslide Kinematics

<p><strong>Abstract.</strong> Changing land use is an increasingly important issue as human habits, behaviors, and needs change. There has been an increase in land and agricultural abandonment in some places of the world. In Japan, movement of the population from rural to urban areas have resulted in much land and agricultural abandonment. In 2016, a land ministry survey showed that 4.1 million hectares of land in Japan had unclear ownership, with farmland making up 16.9% of the total. As vegetation cover changes after land abandonment, this temporal and spatial effect may have important effects on geomorphic processes such as landslide susceptibility and landslide kinematics.</p><p>Here we track long-term land use changes over vegetated landslide areas of the Sanbagawa and Mikabu Belts of Shikoku Island, Japan. The Sanbagawa and Mikabu Belts are metamorphic belts that run across Southwest Japan, and are home to numerous large crystalline schist landslides, including the widely-studied slow but continuously moving Zentoku landslide. Villages and communities have been built on these landslide areas due to historical and cultural factors, as well as the fertility of the soil. Consequently, given the changing land uses including land abandonment in these landslide areas over time, we use long-term high-resolution land cover vegetation datasets to examine first the long-term land use changes, and then use statistical methods to explore their relationships with landslide susceptibility and kinematics. Mapping of spatial data and their analysis using GIS constitute a core part of the research. The results suggest interconnections between land use changes and land movement.</p>

scholarly journals The Influence of Meteorological Parameters and Traffic Flows on the Concentration of Ozone (O3) in Urban Areas in Brcko

2016 ◽  
Vol 1 (1) ◽  
Author(s):  
Radoslav Kojić ◽  
Matija Antić
Keyword(s):  
Wind Speed ◽  
Correlation Coefficient ◽  
Urban Areas ◽  
Meteorological Parameters ◽  
Size Structure ◽  
Ground Level ◽  
Motor Vehicles ◽  
Traffic Flows ◽  
Minimum Concentration ◽  
Ground Level Ozone

Meteorological parameters and traffic flows have a direct impact on air quality in large urban areas, and hence on the quality of life in them. A large number of done surveys confirmed the great dependence of the concentration of ground-level ozone (O3) upon meteorological parameters and the size, structure and imbalances of traffic flows. As part of the research conducted in the period from November 5th to December 8th 2014 in Brcko in Muderis Ibrahimbegic St concentrations of ground-level ozone (O3) were measured, meteorological parameters (temperature, humidity, wind speed and intensity of solar radiation) and characteristics of traffic flow of road motor vehicles. The maximum concentrations of ground-level ozone (O3) in the measurement period was 106.54μg/m³, while the minimum concentration was 4.794μg/m³. By analyzing the results of measurements the high coefficient of correlation between wind speed, air temperature and humidity was established. The correlation coefficient between the traffic flows on the one hand and the concentration of ground-level ozone (O3), on the other hand is very low and does not exceed the value of 0.301. A negative correlation coefficient between traffic flows and concentrations of ground-level ozone (O3) is also observed in the certain time of the day.

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