scholarly journals Structure of aquatic macroinvertebrate communities in streams of a sub-basin in the Pampa Biome, Southern Brazil

2021 ◽  
Vol 16 (2) ◽  
pp. 249-271
Author(s):  
Sirlei Maria Hentges ◽  
Tieli Cláudia Menzel ◽  
Cristiane Maria Loebens ◽  
Samuel Elias Siveris ◽  
David Augusto Reynalte-Tataje ◽  
...  
Keyword(s):  
Correspondence Analysis ◽  
Canonical Correspondence Analysis ◽  
Riparian Forest ◽  
Trophic Group ◽  
Temporal Variations ◽  
Macroinvertebrate Community ◽  
Taxon Richness ◽  
Macroinvertebrate Communities ◽  
Aquatic Macroinvertebrate ◽  
Environmental Integrity

The Piratinim River is located in the northwest of Rio Grande do Sul, and represents an important effluent from the Uruguay River, with streams located far from urbanized areas, in conditions similar to those of environmental integrity, but under the influence of agricultural activities. In this study, we aim at investigating the structure of the aquatic macroinvertebrate community in streams of the Piratinim river basin by observing both spatial and local scales. The sampling was carried out in six streams distributed in three regions (upper, middle and lower) of the basin, thus exploring its upstream, intermediate and downstream stretches, during spring and autumn. Macroinvertebrates were collected using aquatic dipnets and were identified at the family level; trophic-functional categories were established according to the classification adapted to the state of Paraná. The spatial and temporal variations of the groups and of the biotic attributes (density, richness, diversity and equitability) were subjected to Kruskal-Wallis non-parametric tests and a posteriori Dunn’s tests. The abiotic variables were obtained to verify possible influence on the composition of the macroinvertebrate community, evaluated through a Canonical Correspondence Analysis. We sampled 11,564 macroinvertebrate individuals from 72 taxa, and found a predominance of the collector-filter trophic group. Abundance and richness were different between streams; the highest densities were found in the streams located in the upper region of the watershed (Chuní and Itú). The highest taxon richness was found in the lower region of the watershed (Guaracapa stream), and the lowest richness was found in the two streams for the intermediate region (Santana and Ximbocu). Diversity and equitability did not vary; temporal variations were not found. Canonical correspondence analysis explained 31.7% of the data variability. The main environmental variables that influenced macroinvertebrates distribution were temperature, electrical conductivity, dissolved oxygen, altitude and extension of the riparian forest. Seasonality and the longitudinal gradient along the basin represented determining factors for the structure and distribution of the macroinvertebrate community in the tributary streams of the Piratinim River.

scholarly journals The Relationship Between Reparian Vegetation and the Trophic Structure of Aquatic Macroinvertebrate Communities Within the Greater Yellowstone Area

1997 ◽  
Vol 21 ◽  
pp. 99-118
Author(s):  
Peter Meier ◽  
David Travers
Keyword(s):  
Group Analysis ◽  
Trophic Group ◽  
The Other ◽  
Macroinvertebrate Communities ◽  
Insect Community ◽  
Aquatic Macroinvertebrate ◽  
Greater Yellowstone Area ◽  
Greater Yellowstone ◽  
And Function ◽  
Aquatic Macroinvertebrate Communities

This study investigated the effects of reduced vegetation cover on stream ecosystems within the Greater Yellowstone Area. The emphasis of the research concerned whether these effects express themselves within the aquatic macroinvertebrate community. Three general vegetation categories, each comprising three to four streams, were used to distinguish gradations of riparian vegetation: dense cover (control), moderate cover, and low cover. Within each site, five aquatic macroinvertebrate samples were collected from riffle areas with a Hess sampler. The organisms were identified to the lowest practicable taxonomic level and assigned to trophic groups on the basis of gut content analysis. Riparian and in-stream variables also were measured. Statistical analyses were performed to elicit significant differences in riparian, stream, and insect community indices among the streams and to relate the structure (i.e., density, diversity, trophic organization) of the insect assemblage to the riparian and stream variables. The analysis of the data yielded no statistically significant differences among the vegetation categories with respect to embeddedness, bank overhang, and several physicochemical indices of water quality. Similarly, macroinvertebrate densities, biomass, and species richness did not differ among the categories. The trophic group analysis, however, revealed that the abundance and biomass indices of the scraper community were significantly greater within the low cover sites than within the other streams. Conversely, the indices of the shredder community were significantly higher within the control streams than within the other sites. It is proposed that a shift from allochthonous to autochthonous food resources, corresponding to the different vegetation gradients, accounted for these observations. Of critical importance is the fact that the nominally shredder genera were not excluded from or even reduced in abundance within the low cover streams, but rather seemed to have adapted to the decline in allochthonous matter by shifting their mode of food acquisition from shredding to gathering. The implications of such trophic generalism for understanding the structure and function of aquatic macroinvertebrate communities are discussed.

scholarly journals Aphid Gall Interactions with Forest Tree Genotypes Influence Leaf Litter Decomposition in Streams

Forests ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 182
Author(s):  
Carri J. LeRoy ◽  
Dylan Fischer ◽  
Jennifer A. Schweitzer ◽  
Joseph K. Bailey
Keyword(s):  
Leaf Litter ◽  
Litter Decomposition ◽  
Riparian Forest ◽  
Leaf Tissue ◽  
Forest Tree ◽  
Macroinvertebrate Community ◽  
Leaf Litter Decomposition ◽  
Decomposition Rates ◽  
Aquatic Macroinvertebrate ◽  
Forest Stream

Genetic variation within a dominant riparian forest tree affects susceptibility to a leaf-galling aphid (Pemphigus betae), which induces phytochemical and structural changes in leaf tissue. Research Highlights: We show here that these changes to tree leaf tissue alter adjacent in-stream leaf litter decomposition rates and the aquatic macroinvertebrate community associated with litter in the stream for some Populus genotypes. Background and Objectives: Naturally occurring hybrid cottonwoods (Populus fremontii × Populus angustifolia) are differentially susceptible to aphid attack and vary in induced phytochemistry following attack. When leaves are galled by aphids, foliar tissue is altered structurally (through the formation of pea-sized gall structures) and phytochemically (through an increase in foliar condensed tannin concentrations). Materials and Methods: To examine the effect of aphid-galled leaves on forest stream processes, we collected both galled and un-galled leaves from five clones of three hybrid cottonwood genotypes in an experimental forest. We measured in-stream litter decomposition rates, aquatic fungal biomass and aquatic macroinvertebrate community composition. Results: Decomposition rates differed among genotypes and the galled litter treatments, with a 27% acceleration of decomposition rate for the galled litter of one genotype compared to its own un-galled litter and no differences between galled and un-galled litters for the other two genotypes. Genotype by foliar gall status interactions also occurred for measures of phytochemistry, indicating a prevalence of complex interactions. Similarly, we found variable responses in the macroinvertebrate community, where one genotype demonstrated community differences between galled and un-galled litter. Conclusions: These data suggest that plant genetics and terrestrial forest herbivory may be important in linking aquatic and terrestrial forest processes and suggest that examination of decomposition at finer scales (e.g., within species, hybrids and individuals) reveals important ecosystem patterns.

scholarly journals Monitoring of Neotropical Streams Using Macroinvertebrate Communities: Evidence from Honduras

Environments ◽  
2021 ◽  
Vol 8 (4) ◽  
pp. 27
Author(s):  
Stefano Fenoglio ◽  
Alberto Doretto
Keyword(s):  
Water Quality ◽  
Working Party ◽  
Biological Indicators ◽  
Environmental Conservation ◽  
Taxon Richness ◽  
Macroinvertebrate Communities ◽  
Class A ◽  
Neotropical Streams ◽  
Local Contribution ◽  
Level Identification

Assessing the water quality by using biological indicators is a reliable and economically feasible way to promote environmental conservation in developing tropical countries. Here, we report one of the few examples of river biomonitoring in Honduras. In June 2005, benthic macroinvertebrates were collected from six sites in the Río Cangrejal basin. An adapted version of the Biological Monitoring Working Party index (BMWP) was used to assess the water quality because it is simple, consolidated, relatively easy to use, and needs a family-level identification. Moreover, two other community metrics were calculated, namely the total taxon richness and local contribution to beta diversity (LCBD). Differences in the biomonitoring and diversity metrics among sites and their correlations were statistically tested. Thirty-nine macroinvertebrate taxa were collected and, despite significant differences in the BMWP score, all sampling sites were classified in the high environmental quality class. A very strong and positive correlation between the BMPW and taxon richness was found, while LCBD did not vary significantly and did not correlate with the other metrics. Our results suggest that taxon richness could be used as a surrogate indicator to assess the water quality when consolidate biomonitoring methods are not available.

Environmental factors including management practices as correlates of weed community composition in spring seeded crops

1992 ◽  
Vol 70 (10) ◽  
pp. 1931-1939 ◽  
Author(s):  
M. R. T. Dale ◽  
A. G. Thomas ◽  
E. A. John
Keyword(s):  
Community Composition ◽  
Correspondence Analysis ◽  
Canonical Correspondence Analysis ◽  
Environmental Variables ◽  
Management Practices ◽  
Geographic Region ◽  
Climatic Conditions ◽  
Weed Species ◽  
Weed Communities ◽  
Seed Crops

The relationship between the weed communities and environmental variables such as soil, crop, and management was investigated in two provinces of Canada. The frequencies of weed species were recorded in cereal and oilseed fields in Saskatchewan (2244 fields over 4 years) and Manitoba (864 fields over 3 years), Canada. Information on some of the physical characteristics of the fields and on the management practices imposed on them was also collected, in part by questionnaire. The two kinds of data were ordinated together using canonical correspondence analysis to assess the relationships between the species and the environmental variables. In the Saskatchewan data, there was a clear and consistent separation of the species into groups along an axis correlated with soil zone and the associated climatic gradient. In the Manitoba data, the same groups of species did not separate as clearly or as consistently, although geographic region was a major determinant of the weed communities. The greater variability may be due to the fact that the gradient of soil types is much more restricted in Manitoba and not as closely correlated with climatic conditions. In both provinces, culture practices were less important as correlates of the weed community composition than soil type or, to a certain extent, the previous crop. Key words: canonical correspondence analysis, cereal crops, oil seed crops.

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