scholarly journals Environmental Gradient Favours Functionally Diverse Macrobenthic Community in a Placer Rich Tropical Bay

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
S. K. Sivadas ◽  
B. S. Ingole ◽  
C. E. G. Fernandes
Keyword(s):  
Functional Diversity ◽  
Environmental Variables ◽  
Environmental Gradient ◽  
Geographic Location ◽  
Environmental Parameters ◽  
Coastal Habitat ◽  
Diversity Pattern ◽  
Deposit Feeders ◽  
Biodiversity Pattern ◽  
Tropical Bay

The present paper examines the functional diversity-environment relation in a placer rich tropical bay. Understanding the environmental variables that determine the biodiversity pattern will help in the effective conservation plans of coastal habitat. However, few studies have been carried out on the biodiversity-environment relation from the diverse tropical coastal ecosystem. The geographic location of Kalbadevi Bay along the west coast of India provides an opportunity to study the functional diversity pattern of macrofauna along an environmental gradient. Additionally, the area is also a potential placer mining site. Seasonal sampling was carried out for macrofauna and environmental variables. Macrofaunal functional diversity showed significant temporal variation related to the environmental parameters. The most important environmental variables were organic matter and sediment texture. Filter feeders dominated during postmonsoon which is a period when the water column is enriched with sinking detritus. The deposit feeders which rapidly ingest the settled detritus and also transport it to deeper sediment for the subsurface deposit feeders dominated during premonsoon. Abundance of carnivores was high during premonsoon, a response to increase in food in terms of deposit feeders. The result thus indicates that the temporal environmental variation influenced the macrofaunal functional diversity pattern in the Kalbadevi Bay.

scholarly journals A Monitoring System for Online Fault Detection and Classification in Photovoltaic Plants

Sensors ◽  
2020 ◽  
Vol 20 (17) ◽  
pp. 4688 ◽  
Author(s):  
André Eugênio Lazzaretti ◽  
Clayton Hilgemberg da Costa ◽  
Marcelo Paludetto Rodrigues ◽  
Guilherme Dan Yamada ◽  
Gilberto Lexinoski ◽  
...  
Keyword(s):  
Fault Detection ◽  
Monitoring System ◽  
Environmental Variables ◽  
Energy Use ◽  
Short Circuit ◽  
Environmental Parameters ◽  
Open Circuit ◽  
Ann Model ◽  
Pv System ◽  
Fault Detection And Classification

Photovoltaic (PV) energy use has been increasing recently, mainly due to new policies all over the world to reduce the application of fossil fuels. PV system efficiency is highly dependent on environmental variables, besides being affected by several kinds of faults, which can lead to a severe energy loss throughout the operation of the system. In this sense, we present a Monitoring System (MS) to measure the electrical and environmental variables to produce instantaneous and historical data, allowing to estimate parameters that ar related to the plant efficiency. Additionally, using the same MS, we propose a recursive linear model to detect faults in the system, while using irradiance and temperature on the PV panel as input signals and power as output. The accuracy of the fault detection for a 5 kW power plant used in the test is 93.09%, considering 16 days and around 143 hours of faults in different conditions. Once a fault is detected by this model, a machine-learning-based method classifies each fault in the following cases: short-circuit, open-circuit, partial shadowing, and degradation. Using the same days and faults applied in the detection module, the accuracy of the classification stage is 95.44% for an Artificial Neural Network (ANN) model. By combining detection and classification, the overall accuracy is 92.64%. Such a result represents an original contribution of this work, since other related works do not present the integration of a fault detection and classification approach with an embedded PV plant monitoring system, allowing for the online identification and classification of different PV faults, besides real-time and historical monitoring of electrical and environmental parameters of the plant.

Combining management based indices with environmental parameters to explain regional variation in soil carbon under dryland cropping in South Australia

Soil Research ◽  
2013 ◽  
Vol 51 (8) ◽  
pp. 738 ◽  
Author(s):  
Lynne M. Macdonald ◽  
Tim Herrmann ◽  
Jeffrey A. Baldock
Keyword(s):  
Environmental Variables ◽  
Explanatory Power ◽  
Regional Scale ◽  
South Australia ◽  
Vapour Pressure Deficit ◽  
Environmental Parameters ◽  
Decomposition Processes ◽  
Historical Management ◽  
Broad Scale

Identifying drivers of variation in soil organic carbon (OC) at a regional scale is often hampered by a lack of historical management information. Focusing on red-brown-earth soils (Chromosol) under dryland agriculture in the Mid-North and Eyre Peninsula of South Australia, our aims were 2-fold: (i) to provide a baseline of soil OC stocks (0.3 m) and OC fractions (mid-infrared predictions of particulate, humus, and resistant OC in 0.1 m samples) in cropping and crop-pasture systems; and (ii) to evaluate whether the inclusion of management-based indices could assist in explaining regional-level variation in OC stocks and fractions. Soil OC stocks in both regions varied ~20 Mg ha–1, with higher OC stocks in the Mid-North (38 Mg ha–1) than the Eyre Peninsula (29.1 Mg ha–1). The humus OC fraction was the dominant fraction, while the particulate OC was the most variable. Environmental variables only partially explained soil OC variability, with vapour pressure deficit (VPD) offering the greatest potential and likely acting as an integrator of temperature and moisture on plant growth and decomposition processes. Differences between broad-scale cropping and crop–pasture systems were limited. In the Mid-North, variability in soil OC stocks and fractions was high, and could not be explained by environmental or management variables. Higher soil OC concentrations (0.1 m) in the Eyre Peninsula cropping than crop–pasture soils were largely accounted for in the particulate OC fraction and are therefore unlikely to represent a long-term stable OC pool. Use of the management data in index format added some explanatory power to the variability in OC stocks over the main environmental variables (VPD, slope) within the Eyre Peninsula cropping soils only. In the wider context, the management data were useful in interpreting differences between regional findings and highlighted difficulties in using uninformed, broad-scale management categories.

scholarly journals Structural variability and composition of fish communities in the northern continental shelf of the Bay of Bengal, Bangladesh

2019 ◽  
Vol 66 (4) ◽  
Author(s):  
Mamun Abdullah Al ◽  
Aysha Akhtar ◽  
Abu Hena Mustafa Kamal ◽  
Muhammed Farruq Rahman ◽  
Md. Shafiqul Islam ◽  
...  
Keyword(s):  
Continental Shelf ◽  
Bay Of Bengal ◽  
Suspended Solids ◽  
Fish Communities ◽  
Environmental Parameters ◽  
Total Dissolved Solids ◽  
Compositional Variation ◽  
Coastal Habitat ◽  
Structural Variability ◽  
Nitrite Nitrogen

The structural variability and composition of fish communities in the northern continental shelf of the Bay of Bengal, Bangladesh were assessed from monsoon 2014 to pre-monsoon 2015. A total of 73 species belonging to 43 orders, comprising 61 species of finfishes and 12 species of shellfishes were identified from estuarine set bag net (ESBN) fisheries. Of these, sixty species were commonly found throughout the study period and while nine species were dominant with higher contribution to the total communities. Community parameters and abundance were higher in monsoon and lower in winter. Multivariate analysis revealed a clear structural and compositional variation in fish communities. Furthermore, RELATE (coefficient of correlation between the fisheries communities and environmental parameters) and BIOENV/BEST (Biotaenvironment best matching) analyses showed that these variations were driven by both single (transparency) and multistressors [transparency in combination with associated factors such as salinity, total dissolved solids (TDS), total suspended solids (TSS), phosphate-phosphorus (PO4-P) and nitrite-nitrogen (NO2-N)]. Community parameters showed significant positive correlation with transparency, salinity and PO4-P which indicated that structure of fish communities is shaped by ecological conditions in this coastal habitat.

scholarly journals Cladocera distribution along an environmental gradient on the Cerrado-Amazon ecotone: a preliminary study

2019 ◽  
Vol 31 ◽  
Author(s):  
Leandro Schlemmer Brasil ◽  
Ana Luiza-Andrade ◽  
Tiago Borges Kisaka ◽  
Paulo Ilha ◽  
Francisco Diogo Rocha Sousa
Keyword(s):  
Land Use ◽  
Species Distribution ◽  
Environmental Variables ◽  
Redundancy Analysis ◽  
Environmental Gradient ◽  
Canopy Cover ◽  
Knowledge Gap ◽  
Stream Communities ◽  
Preliminary Study

Abstract: Aim Our objective in this study is to understand Cladocera species distribution along an environmental gradient in forest and cropland landscapes in the southern Amazon. Methods We collected Cladocera communities and environmental variables from five streams and verified their associations with a Redundancy Analysis. Results Acroperus tupinamba, Alonella dadayi e Kisakiellus aweti were mostly associated to sites with higher canopy cover. Anthalona neotropica, Anthalona verrucose and Flavalona iheringula occurred exclusively in site with more thalweg depth. Conclusions If these results are confirmed Cladocera stream communities are affected by changes in land use. Further studies in this line are extremely necessary to reduce this knowledge gap.

Spatial and seasonal variations of subtidal free-living nematode assemblages in the northern Beibu Gulf, South China Sea

2011 ◽  
Vol 92 (2) ◽  
pp. 255-264 ◽  
Author(s):  
S.J. Fu ◽  
L.Z. Cai ◽  
J. Yang ◽  
X.P. Zhou ◽  
X. Peng ◽  
...  
Keyword(s):  
Organic Matter ◽  
South China Sea ◽  
Water Depth ◽  
Environmental Variables ◽  
Beibu Gulf ◽  
Free Living ◽  
Deposit Feeders ◽  
Free Living Nematode ◽  
Offshore Station ◽  
The Mean

This study determined the spatial and seasonal density, number of genera, genera composition, maturity index and trophic structure of free-living nematode assemblages in the subtidal waters of the northern Beibu Gulf, South China Sea, and explored whether these five biotic characteristics were related to various environmental variables. Based on the data derived from samples collected seasonally at nine stations, the mean densities of nematodes decreased from alongshore to offshore station in the northern Beibu Gulf. However, the number of nematode genera increased from alongshore to offshore station. Non-parametric multidimensional scaling analysis showed no clear seasonal changes for nematode assemblages in most sampling stations. Higher densities of the generaElzaliaandTricomawere found in offshore sampling stations, and a higher density of the genusCheironchuswas found in alongshore sampling stations. The mean percentage of each feeding type compared to the total numbers was highest in epigrowth feeders (2A), second highest in non-selective deposit feeders (1B), third highest in predators (2B), and lowest in selective deposit feeders (1A). There were significant negative correlations between nematode density and water depth and temperature; significant positive correlations between the number of nematode genera and water depth and salinity; and significant negative correlation between the maturity index of the nematode assemblage and organic matter. BIOENV analysis indicated that water depth, salinity, pH, median sediment particle size and organic matter were the most correlated combination of environmental variables affecting the nematode assemblages.

The PCA index for measuring functional diversity and its application to Juglans mandshurica communities in the Beijing mountains, China

2017 ◽  
Vol 10 (07) ◽  
pp. 1750097
Author(s):  
Naiqi Song ◽  
Jin-Tun Zhang ◽  
Fenggu Zhao
Keyword(s):  
Functional Diversity ◽  
Plant Communities ◽  
Environmental Variables ◽  
Principal Component ◽  
Functional Trait ◽  
Effective Index ◽  
Key Factors ◽  
Juglans Mandshurica ◽  
Factors Affecting ◽  
Functional Studies

Methods for measuring functional diversity are essential for functional studies of plant communities. A useful method, the PCA index, based on principal component analysis ordination of functional trait data was introduced and applied to functional diversity analysis of Juglans mandshurica communities in the Beijing Mountains. Thirty-five [Formula: see text] quadrats were established in Juglans mandshurica communities. Species composition, functional traits and environmental factors were measured and recorded. The four common indices, FAD, MFAD, FDp and FDc, were used and compared with the PCA index in the analysis. The results showed that the PCA index was successful in quantifying functional diversity and describing its relationships with environmental variables; therefore, it was an effective index in functional diversity analyses. Functional diversity in Juglans mandshuricacommunities varied widely. Elevation and aspect were the key factors affecting functional diversity in communities. Functional diversity increased with elevation increases and with the change in aspect from North to South. Functional diversity was significantly correlated with species richness and heterogeneity.

scholarly journals The correspondence between environmental similarity and geographical sympatry in Uromastyx species

2020 ◽  
Vol 41 (2) ◽  
pp. 245-251
Author(s):  
Marwa Kechnebbou ◽  
Jorge M. Lobo ◽  
Mohsen Chammem
Keyword(s):  
Related Species ◽  
Environmental Variables ◽  
Potential Distribution ◽  
Environmental Gradient ◽  
Climatic Variables ◽  
Geographical Isolation ◽  
Speciation Process ◽  
Environmental Similarity ◽  
Eleven Species

Abstract Estimating the realized and potential distribution of species has become a very active field of research with capacity to propose likely speciation mechanisms. Here, environmental variables and point locality data derived from several sources were used to examine the concordance between geographical distributions and environmental niches derived from occurrences for eleven species of the genus Uromastyx (Reptilia, Agamidae). Our results indicate that the degree of geographical overlap is definitively and statistically lower than the degree of environmental similarity. This reinforces the hypothesis that speciation process within the genus Uromastyx will be mainly based on geographical isolation. However, the environmental divergence among some groups of species cannot be excluded; high environmental distances can be obtained for some related species and the environmental gradient represented by two unique climatic variables allows discriminating some species among which an ecological or environmental segregation would be a plausible explanation.

Sign in / Sign up

Export Citation Format

Share Document