scholarly journals Combined effects of water chemistry, canopy cover, and stream size on benthic macroinvertebrates along a Central Appalachian stream continuum

2002 ◽  
Author(s):  
Jesse Adam Bopp
Keyword(s):  
Water Chemistry ◽  
Benthic Macroinvertebrates ◽  
Canopy Cover ◽  
Combined Effects ◽  
Stream Size

scholarly journals Broad-scale spatial patterns of canopy cover and pond morphology affect the structure of a Neotropical amphibian metacommunity

2013 ◽  
Author(s):  
Diogo B. Provete ◽  
Thiago Gonçalves-Souza ◽  
Michel Garey ◽  
Itamar A. Martins ◽  
Denise Rossa-Feres
Keyword(s):  
Species Composition ◽  
Water Chemistry ◽  
Spatial Patterns ◽  
Site Selection ◽  
Spatial Scales ◽  
Canopy Cover ◽  
Breeding Site ◽  
Larval Anurans ◽  
Metacommunity Structure ◽  
Broad Scale

Spatial and environmental processes influence species composition at distinct scales. Previous studies suggested that the landscape-scale distribution of larval anurans is influenced by environmental gradients related to adult breeding site selection, such as pond canopy cover, but not water chemistry. However, the combined effects of spatial, pond morphology, and water chemistry variables on metacommunity structure of larval anurans have not been analyzed. We used a partial redundancy analysis with variation partitioning to analyze the relative influence of pond morphology (e.g., depth, area, and aquatic vegetation), water chemistry, and spatial variables on a tadpole metacommunity from southeastern Brazil. We predict that the metacommunity will be spatially structured at broad spatial scales, while environmental variables, mainly related to adult habitat selection, would play a larger role at fine spatial scales. We found that broad-scale spatial patterns of pond canopy cover and pond morphology strongly influenced metacommunity structure. Additionally, species composition was spatially autocorrelated at short distances. We suggest that the reproductive behavior of adult anurans is driving tadpole metacommunity dynamics, since pond morphology, but not water chemistry affects breeding site selection by adults. Our results contribute to the understanding of amphibian species diversity in tropical environments.

scholarly journals Establishing baseline biological conditions and monitoring metrics for stream benthic macroinvertebrates and fish in an area of potential shale gas development

2019 ◽  
Vol 76 (9) ◽  
pp. 1480-1494 ◽  
Author(s):  
Jennifer Lento ◽  
Michelle A. Gray ◽  
Allison J. Ferguson ◽  
R. Allen Curry
Keyword(s):  
Water Chemistry ◽  
Benthic Macroinvertebrates ◽  
Shale Gas ◽  
Environmental Gradients ◽  
Early Carboniferous ◽  
Gas Production ◽  
Reference Sites ◽  
Age Classes ◽  
Geological Age ◽  
Dependent Variables

Potential for shale gas production is linked to regional geology, which influences water chemistry of freshwater systems. However, there has been little work to establish baseline ecological conditions of rivers within areas of shale gas development. In this study, water chemistry and monitoring metrics for fish and benthic macroinvertebrates were compared among varying-sized streams in New Brunswick, Canada, with different underlying geology. Water chemistry and biotic community structure differed strongly among geological age classes. Early Carboniferous stations, with highest potential for shale gas production, had the highest ions, invertebrate abundances, and richness of invertebrates and fish, with strongest differences between Early Carboniferous and Older Classes of bedrock. A reference condition model indicated numerous sites deviated from normal, but this was not specific to geological classes and reflected the lack of model reference site coverage. These results highlight the importance of selecting appropriate reference sites for bioassessment in areas of resource development to ensure that response to perturbation is differentiated from natural variability along environmental gradients in geology and resource-dependent variables that potentially influence aquatic ecosystem composition.

scholarly journals Scenario Studies on Effects of Soil Infiltration Rates, Land Slope, and Furrow Irrigation Characteristics on Furrow Irrigation-Induced Erosion

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Jibrin M. Dibal ◽  
A. A. Ramalan ◽  
O. J. Mudiare ◽  
H. E. Igbadun
Keyword(s):  
Soil Erosion ◽  
Soil Water ◽  
Furrow Irrigation ◽  
Interactive Effects ◽  
Combined Effects ◽  
Soil Infiltration ◽  
Infiltration Rates ◽  
Interaction Dynamics ◽  
Slope Steepness ◽  
Stream Size

Furrow irrigation proceeds under several soil-water-furrow hydraulics interaction dynamics. The soil erosion consequences from such interactions in furrow irrigation in Samaru had remained uncertain. A furrow irrigation-induced erosion (FIIE) model was used to simulate the potential severity of soil erosion in irrigated furrows due to interactive effects of infiltration rates, land slope, and some furrow irrigation characteristics under different scenarios. The furrow irrigation characteristics considered were furrow lengths, widths, and stream sizes. The model itself was developed using the dimensional analysis approach. The scenarios studied were the interactive effects of furrow lengths, furrow widths, and slopes steepness; infiltration rates and furrow lengths; and stream sizes, furrow lengths, and slopes steepness on potential furrow irrigation-induced erosion, respectively. The severity of FIIE was found to relate somewhat linearly with slope and stream size, and inversely with furrow lengths and furrow width. The worst soil erosion (378.05 t/ha/yr) was found as a result of the interactive effects of 0.65 m furrow width, 50 m furrow length, and 0.25% slope steepness; and the least soil erosion (0.013 t/ha/yr) was induced by the combined effects of 0.5 l/s, 200 m furrow length, and 0.05% slope steepness. Evidently considering longer furrows in furrow irrigation designs would be a better alternative of averting excessive FIIE.

Benthic Macroinvertebrates Composition and Distribution at Sungai Dawai and Sungai Dekong in Lojing Highland, Gua Musang, Kelantan

2014 ◽  
Vol 68 (3) ◽  
Author(s):  
Sharifah Aisyah Syed Omar ◽  
Aweng Eh Rak ◽  
Ahmad Fadli Ahmad Sanusi ◽  
Azrinaaini Md Yusoff
Keyword(s):  
Benthic Macroinvertebrates ◽  
Canopy Cover ◽  
Benthic Macroinvertebrate ◽  
Agricultural Activities ◽  
River Health ◽  
Water Condition ◽  
Health Quality ◽  
Preliminary Study

A preliminary study of benthic macroinvertebrate at two rivers in Lojing Highlands, Kelantan was conducted in January 2014 to study and describe the composition and distribution at upland area. Benthic macroinvertebrate samples were collected by using Surber net (0.3m X 0.3m) at six sites around Sungai Dawai and three sites at lower part of Sungai Dekong. A total of 182 individuals of phyla arthropoda with six orders namely Ephemeroptera, Plecoptera, Trichoptera, Ordonata, Coleoptera and Hemiptera were found at Sungai Dawai. For station 4 which was located at Sungai Dawai, 14 families of benthic macroinvertebrate was found such as Scirtidae, Elmidae, Heptageniidae, Perlidae, Chironomidae, Simuliidae, Baetidae, Tipulidae, Emphididae, Ptilodactylidae, Psephenidae, Aphelocheiridae, Gomphidae and Aeshnidae. Reduction in richness, diversity and evenness was observed from Sungai Dawai to Sungai Dekong due to the changes of water condition and their habitat, such as canopy cover by logging and agricultural activities. The change distribution of benthic macroinvertebrates was useful to detect the impacted sites and the river health quality consequence.

scholarly journals Mangrove forest structure and composition along urban gradients in Puerto Rico

2018 ◽  
Author(s):  
Benjamin Branoff ◽  
Sebastian Martinuzzi
Keyword(s):  
Puerto Rico ◽  
Surface Water ◽  
Water Chemistry ◽  
Forest Structure ◽  
Vegetation Cover ◽  
Mangrove Forest ◽  
Canopy Cover ◽  
Basal Area ◽  
Surface Water Chemistry ◽  
Nitrogen Concentrations

Urban forests are repeatedly characterized as distinct in composition and structure in comparison with their non-urban counterparts. This holds true for mangroves, although previous studies lack quantified representations of urbanness as well as any inclusion of hydrology or water chemistry, which are important influences on mangrove forest structure, composition, and function. This study uses LiDAR and ground-based measurements of mangroves within well quantified urban gradients in Puerto Rico to test for the relative importance of urbanization alongside flooding metrics and surface water chemistry in explaining observed patterns of forest structure and composition. In simple regression, urban metrics were the most powerful predictors of forest composition but not structure. Results show higher tree diversity but lower mangrove diversity in the most urban forests. Structural measurements, however, were best explained by flooding, surface water chemistry, and non-urban land cover metrics. Nitrogen concentrations best explained stem density and tree size, while flooding metrics best explained stand biomass and basal area, and surrounding vegetation cover best explained canopy cover and height metrics. In multiple regression, land cover and surface water chemistry were more important than flooding, with population density again being the most important variable in explaining mangrove forest diversity. Results show that urbanization is an important influence on mangrove composition and basal area, leading to higher tree diversity and lower basal area, consistent with patterns in terrestrial forests. But urban mangrove forests are also lower in mangrove diversity and tend to have representation only by Laguncularia racemosa. Nitrogen concentrations and surrounding vegetation cover, both of which are indirectly influenced by urbanization, were positively related to tree size and canopy cover and height, respectively. These tests suggest urbanization is an important influence on mangrove forest structure and composition, but that flooding and water chemistry must also be considered when managing these forests.

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