Implications of seasonal variation for biomonitoring with predictive models in the Fraser River catchment, British Columbia

2001 ◽  
Vol 58 (7) ◽  
pp. 1411-1417 ◽  
Author(s):  
Pamela F Reece ◽  
Trefor B Reynoldson ◽  
John S Richardson ◽  
David M Rosenberg
Keyword(s):  
Seasonal Variation ◽  
Test Site ◽  
Benthic Invertebrate ◽  
Large River ◽  
Reference Condition ◽  
Taxonomic Resolution ◽  
Reference Database ◽  
Fraser River ◽  
River Catchment ◽  
Invertebrate Assemblage

Reference-condition models for the Fraser River catchment were developed using samples collected during the autumn of 1994, 1995, and 1996. The goal of this study was to examine applicability to the reference-condition models of samples collected in other seasons and the effect of taxonomic resolution (genus and family) on model sensitivity to seasonal variation in the benthic invertebrate assemblage. Samples from eight streams representing interior, coastal, and large-river habitats were collected in spring, summer, autumn, and winter of 1995 and in spring of 1996. The benthic invertebrate assemblage changed seasonally such that the models could not be used for seasons other than autumn. The models were equally sensitive to seasonal variation when genus-level or family-level data were used. We recommend that test samples (i.e., samples collected from disturbed sites and meant for comparison with the reference database) be collected either during the autumn or over multiple sampling dates to reduce the possibility that seasonal shifts or stochastic events will lead to erroneous conclusions about the state of a test site.

Dispersal traits as benthic invertebrate assemblage drivers in a neotropical large river

2020 ◽  
Vol 193 (3) ◽  
pp. 275-283
Author(s):  
Miguel Saigo ◽  
Mercedes Marchese ◽  
Luciana Montalto
Keyword(s):  
Spatial Structure ◽  
Environmental Conditions ◽  
Distribution Patterns ◽  
Benthic Invertebrate ◽  
Large River ◽  
Species Dispersal ◽  
Dispersal Traits ◽  
Metacommunity Dynamics ◽  
Invertebrate Assemblage

Metacommunity theory is a mechanistic framework that explains the interdependence of local factors and regional processes as community drivers. Recent evidence suggests that dispersal mode is a key trait that potentially affects metacommunity dynamics. We analyzed the distribution patterns of benthic macroinvertebrates with different dispersal modes in the Middle Paraná, a neotropical large river. We assessed the relative importance of local environmental conditions and regional spatial structure as assemblage drivers. Aquatic and aerial dispersers presented Clementsian and Gleasonian structures, respectively. For both groups, local environmental conditions influenced community assembly, and spatial structure (overland distances) also affected the distribution of aerial dispersers. Our study highlights that the role of spatial structure as a driver of benthic metacommunities depends on species' dispersal modes. Aerial dispersers responded to regional spatial variables and it is likely that these organisms are also influenced by mass effects. Our results are consistent with current ideas of metacommunity dynamics in large rivers, where dispersal is not considered to limit the distribution of benthic organisms.

Comparison of models predicting invertebrate assemblages for biomonitoring in the Fraser River catchment, British Columbia

2001 ◽  
Vol 58 (7) ◽  
pp. 1395-1410 ◽  
Author(s):  
T B Reynoldson ◽  
D M Rosenberg ◽  
V H Resh
Keyword(s):  
British Columbia ◽  
Predictive Model ◽  
Function Analysis ◽  
Reference Condition ◽  
Fraser River ◽  
Reference Sites ◽  
River Catchment ◽  
The Family ◽  
Level Model ◽  
Invertebrate Assemblages

A multivariate, predictive model based on the reference-condition approach is described for the Fraser River catchment in British Columbia. Benthic invertebrate assemblages and environmental descriptors were measured at more than 200 sites from 1994 to 1996, including 219 reference sites. Reference sites were classified into groups representing similar invertebrate assemblages. Five such classifications were produced, using three taxonomic levels (family, genus, and species) and species and family multimetrics. For each of the classifications, discriminant function analysis was used, with environmental descriptors, to develop a predictive model for the reference sites. These models predicted from 43.8% (species) to 61.6% (family) of the reference sites to the correct benthic group. Each model was used to assess deviation from reference condition for 21 test sites exposed to either agriculture, logging, or mining. The models were examined with regard to their sensitivity, robustness, usability, temporal variability, predictive performance, and model certainty. The family and family-metric models were ranked best, followed by the species-metric, genus, and species models. The family-level model is recommended for assessment purposes; its overall performance was slightly superior to the family-metric model and it avoids an extra step in calculation of the metrics. However, the species-level model is recommended for conservation or biodiversity issues.

scholarly journals Improved freshwater macroinvertebrate detection from environmental DNA through minimized nontarget amplification

2021 ◽  
Vol 4 ◽  
Author(s):  
Mandy Sander ◽  
Arne Beermann ◽  
Dominik Buchner ◽  
Vasco Elbrecht ◽  
Peter Haase ◽  
...  
Keyword(s):  
Benthic Invertebrates ◽  
Environmental Dna ◽  
Benthic Invertebrate ◽  
Coi Gene ◽  
Taxonomic Resolution ◽  
Universal Primers ◽  
Reference Database ◽  
Mountain Range ◽  
Degenerate Primers ◽  
Universal Primer

Environmental DNA (eDNA) metabarcoding is a new, promising, and non-invasive method to detect biodiversity in aquatic environments. So far, it has mainly been used to screen for fish and amphibian diversity and rarely to detect macroinvertebrates. Typically, DNA metabarcoding relies on PCR amplification of a fragment of the mitochondrial cytochrome c oxidase I (COI) gene with degenerate primers. In comparison to other genes like 16S, COI has a greater taxonomic resolution and availability of an extensive reference database. Benthic stream invertebrates are of critical importance for regulatory biomonitoring, but when using universal primers on eDNA isolated from water, the number of reads and OTUs is “watered down”. This means the target taxa, macroinvertebrates, are underrepresented in comparison to other nontarget taxa, e. g. algae, bacteria, and fungi. The aim of the project was to design an insect-specific primer, which minimizes nontarget amplification. Therefore, data from a time series of 15 months at the Kinzig (Hesse), a silica-rich low-mountain-range stream, which is part of the Rhine‑Main‑Observatory (LTER site) was generated using the universal primers BF2/BR2. With this data we identified the most abundant nontarget taxa and designed a new reverse primer (EPTDr2n) with 3’ ‐ specificity toward benthic invertebrate taxa. Primer specificity was validated in silico together with universal forward primer fwhF2 using available data from GenBank and BOLD. 20 eDNA samples from the Kinzig River and its tributaries were then used to test the new primer in situ together with primer fwhF2. The new primer combination showed a much higher amplification of benthic invertebrates, insects in particular, than two other universal primer pairs for both, number of target reads (fwhF2/EPTDr2n: 99.6% versus BF2/BR2: 25.89% and fwhF2/fwhR2n: 39.04%; Fig. 1) and number of target species (fwhF2/EPTDr2n: 305 versus BF2/BR2: 113 and fwhF2/fwhR2n: 185). Additionally, the number of benthic invertebrate species exceeded even the number of 153 species identified by expert taxonomists at nearby sites across two decades of sampling. While several taxa reported, like a few trichopteran genera, flatworms, and some crustaceans, were not found, the primer shows greatly improved results for eDNA metabarcoding of benthic invertebrates(Leese et al. 2021).

scholarly journals River-Induced Anomalies in Seasonal Variation of Traffic-Emitted CO Distribution over the City of Krasnoyarsk

Atmosphere ◽  
2019 ◽  
Vol 10 (7) ◽  
pp. 407 ◽  
Author(s):  
Michael Hrebtov ◽  
Kemal Hanjalić
Keyword(s):  
Seasonal Variation ◽  
Road Traffic ◽  
Thermal Inertia ◽  
Pollutant Dispersion ◽  
Ambient Air ◽  
Large River ◽  
Navier Stokes ◽  
Thermal Buoyancy ◽  
Diurnal Cycles ◽  
The City

Seasonal variation of air quality in a city with a large river was investigated by means of numerical simulations of air movement and pollutant dispersion over inversion-capped diurnal cycles using a Reynolds-averaged Navier–Stokes (RANS) approach with algebraic turbulent flux model. The study accounts for the effects of urban heat island (UHI), terrain orography and high thermal inertia of the river body. The case mimics the real environment of the Krasnoyarsk region with the river Yenisei (Russia). Two scenarios were considered typical of the winter and summer seasons. The study is focused on the dynamics of dispersion of CO emanating mainly from road traffic, which remains fairly uniform throughout the year. The simulation starts from a mild low-altitude inversion with penetrative convection gradually developing over the daytime and attenuating during the night. The main difference between the two cases is in the temperature of the river surface relative to the ambient air. In winter, the non-freezing river acts as a source of positive thermal buoyancy, while in summer the cool river at the daytime acts in the opposite way, as a heat sink. The effect of the river-induced air circulation appears significant enough to account for the observed winter accumulation of the pollutant in the city center.

scholarly journals Tributaries as richness source for Oligochaeta assemblage (Annelida) of Neotropical dammed river

2014 ◽  
Vol 74 (4) ◽  
pp. 861-869 ◽  
Author(s):  
FH Ragonha ◽  
DK Petsch ◽  
GHZ Alves ◽  
HS Santana ◽  
TS Michelan ◽  
...  
Keyword(s):  
Abundant Species ◽  
Benthic Invertebrate ◽  
Main Channel ◽  
Paraná River ◽  
Good Tool ◽  
Parana River ◽  
Main River ◽  
The Difference ◽  
Invertebrate Assemblage ◽  
Dammed River

Tributaries may serve as richness source for the river main channel and the zoobenthos community is a good tool to verify this kind of pattern. In this study, we aimed to characterize the benthic invertebrate assemblage in three tributaries associated to the Paraná River main channel, focusing in Oligochaeta community. We hypothesized that (i) in tributaries, Oligochaeta are richer than the main river (Paraná River) and (ii) dammed tributary (Paranapanema River) is poorly diverse than the others. Samples were conducted in Paranapanema, Baía and Ivinhema tributaries using a modified Petersen grab along three transects (samples conducted inside the tributary, in the mouth of each tributary and inside Paraná River). To analyze (i) the difference between the richness and density among the tributaries and the Paraná River and (ii) effect of each tributary transect on the Oligochaeta richness we used a nonparametric Kruskal-Wallis test. Changes in environmental variables and in richness and composition of Oligochaeta were summarized by Canonic Correspondence Analysis. It was registered 21 different benthic invertebrates taxa, being Oligochaeta assemblage with the highest density. Within Oligochaeta, Narapa bonettoi was the most abundant species, followed by Haplotaxis aedochaeta and Paranadrilus descolei. In our results we refused both hypotheses, because we did not found significant differences for richness and density between the tributaries and the main river, and also no difference between the three transects of each tributary were found. However, the tributaries less influenced by damming, especially the Baía recorded high richness. This corroborates their importance to diversity in the floodplain and the species of Oligochaeta reflect the peculiar characteristics of habitats within each tributaries.

scholarly journals Geographic distribution pattern of low and high nucleic acid content bacteria on a river-catchment scale

2017 ◽  
Vol 68 (9) ◽  
pp. 1618 ◽  
Author(s):  
Jie Liu ◽  
Dan Ma ◽  
Lili Ma ◽  
Yuhao Song ◽  
Guanghai Gao ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Acid Content ◽  
Large River ◽  
Nucleic Acid Content ◽  
Catchment Scale ◽  
Songhua River ◽  
River Catchment ◽  
Wide Range ◽  
Biogeographical Pattern ◽  
The Songhua River

Bacteria with low nucleic acid content (LNA) and high nucleic acid content (HNA) are widely distributed in aquatic environments. Most of the current understanding of these two subgroups is derived from studies in marine environments. In comparison, information on the spatial distribution of these two subgroups in freshwater environments is very limited. The present study analysed the biogeographical pattern of those two groups on a large-river scale (i.e. the Songhua River catchment, >1000km). The results showed that the concentrations of LNA and HNA bacteria were distributed over a wide range from 5.45×104 to 4.43×106cellsmL–1, and from 1.35×105 to 4.37×106cellsmL–1 respectively. The two groups have almost equal proportions in the Songhua River, with the average contribution of LNA bacteria reaching 47.0%. In comparison, the abundance of LNA bacteria in the mainstream was significantly higher than in the tributaries. The cytometric expressions (green fluorescence and side scatter) within LNA and HNA were strongly covaried, which implies that these two subgroups are intrinsically linked. Multivariate redundancy analysis indicated that both the abundance and cytometric characteristics of co-occurring LNA and HNA bacteria were regulated differently in the Songhua River. This suggests that LNA and HNA bacteria play different ecological roles in river ecosystems.

Gully erosion susceptibility modelling for avoided degradation planning

2020 ◽  
Author(s):  
Jay Le Roux ◽  
Bennie Van der Waal
Keyword(s):  
Sediment Yield ◽  
Soil Loss ◽  
Large River ◽  
River Network ◽  
Gully Erosion ◽  
Yield Potential ◽  
Strategic Information ◽  
Large Reservoir ◽  
River Catchment ◽  
Dispersive Soils

<p>Gully erosion can reach alarming dimensions and contribute significantly to soil loss and sediment yield in a catchment.  Since restoration resources are usually limited, strategic information on sensitive and erosion susceptible areas are needed to avoid future degradation.  Although the mapping of areas susceptible to gully formation is not a new concept, this study has potential in the Mzimvubu River Catchment, the only large river network in South Africa without a large reservoir.  The Tsitsa tributary’s catchment, where two large reservoirs are planned, consists of large areas of highly erodible soils with widespread gully erosion evident.  It is important to prevent further gully erosion in the catchment due to the presence of duplex and dispersive soils. Therefore, this study modelled areas that are susceptible to gully development in the Tsitsa River Catchment, as well as estimated the sediment yield potential from the susceptible areas if gully development occurs.  This was achieved by mapping gully-free areas in a GIS that have the same DEM-derived topographical variables, soil associations and land cover than gullied areas, followed by scenario analysis of the potential sediment yield.  More than 30 000 ha (7%) of the catchment is intrinsically susceptible to further gully development, consisting of drainage paths with a large contributing area and erodible duplex soils.  If not protected, these susceptible areas could contribute an additional 300 million m<sup>3</sup> of sediment to the river network, reducing the volumes of both reservoirs by more than 50%. </p>

scholarly journals Evolution of soil and plant parameters on the agricultural Gebesee test site: a database for the set-up and validation of EO-LDAS and other satellite-aided retrieval models

2017 ◽  
Author(s):  
Sina C. Truckenbrodt ◽  
Christiane C. Schmullius
Keyword(s):  
Reference Data ◽  
Spatial Scales ◽  
Test Site ◽  
Earth Observation ◽  
Reference Database ◽  
Observation Data ◽  
Monitoring Methods ◽  
Retrieval Models ◽  
In Situ Data

Abstract. Ground reference data are a prerequisite for the calibration, update and validation of retrieval models facilitating the monitoring of land parameters based on Earth Observation data. Here, we describe the acquisition of a comprehensive ground reference database which was elaborated to test and validate the recently developed Earth Observation Land Data Assimilation System (EO-LDAS). In situ data was collected for seven crop types (winter barley, winter wheat, spring wheat, durum, winter rape, potato and sugar beet) cultivated on the agricultural Gebesee test site, central Germany, in 2013 and 2014. The database contains information on hyperspectral surface reflectance, the evolution of biophysical and biochemical plant parameters, phenology, surface conditions, atmospheric states, and a set of ground control points. Ground reference data was gathered with an approximately weekly resolution and on different spatial scales to investigate variations within and between acreages. In situ data collected less than 1 day apart from satellite acquisitions (RapidEye, SPOT5, Landsat-7 and -8) with a cloud coverage ≤ 25 % is available for 10 and 16 days in 2013 and 2014, respectively. The measurements show that the investigated growing seasons were characterized by distinct meteorological conditions causing interannual variations in the parameter evolution. In the article, the experimental design of the field campaigns, and methods employed in the determination of all parameters are described in detail. Insights into the database are provided and potential fields of application are discussed. We hope these data will contribute to a further development of crop monitoring methods based on remote sensing techniques. The database is freely available at PANGAEA (doi:10.1594/PANGAEA.874251).

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