Windstorm disturbance effects on mountain stream ecosystems and the Plecoptera assemblages

Biologia ◽  
2015 ◽  
Vol 70 (9) ◽  
pp. 1215-1227 ◽  
Author(s):  
Iľja Krno ◽  
Tomáš Lánczos ◽  
Ferdinand Šporka
Keyword(s):  
Organic Matter ◽  
Water Temperature ◽  
Species Abundance ◽  
River Basins ◽  
Mountain Stream ◽  
Functional Feeding Groups ◽  
Channel Stability ◽  
Forested Areas ◽  
Disturbed Forest ◽  
Annual Water

Abstract Within the investigated river basins the deforestation ranged from 0-45.5%, dependent on the amount of windstorm damage. Our water temperature readings revealed that the canopy elimination above the streams in the areas damaged by the windstorm caused increase in daily and annual water temperature and also wider daily water temperature range, than those in the undisturbed reference stream, which caused the decline of cold stenotherm species abundance. The stream basins deforestation was collinear with FPOM and UFPOM concentrations, water temperature gradient and nitrate concentrations. Statistical analysis showed that size of stream, conductivity, catchment area and discharge were negatively correlated with the stonefly mesotherm ratio and nitrate contents. Higher average concentrations of nutrients (like NO−3) in samples from some streams are a consequence of their mobilization from disturbed forest soils due to the windstorm. Most streams located in the deforested area were found by us in a higher trophic status, especially due the particulate organic matter (POM) content and biofilms amount, what caused increase in some functional feeding groups occurrence (collectorgatherers, scrapers and mainly predators). Stream degradation positively correlated with the percentage of deforested area, ratio of eurytherm taxa, transported organic matter, dissolved organic matter, and biofilms occurrence. The conductivity values measured in water samples were collinear with alkalinity and pH values and increased with watersheds areal extent. We established environmental variables influenced by the windstorm event along the catchment degradation gradient using measurable characteristics of stonefly assemblages and metrics. The proportion of the Leuctridae family and the Nemoura genus expressed as the LN index (1) shows a negative correlation with part undisturbed forested areas and channel stability, and positive correlation with stream erosion (expressed as the TAM quantity) in river basins. Proportion of shredders among the investigated streams was significantly higher in deforested streams, and shows lower stability of stonefly community in these habitats, where significantly fluctuate channel stability, water temperature and discharge of these streams.

scholarly journals Effects of Physicochemical Variables of Superficial Waters on the Abundance of the North African Freshwater Crab Potamon algeriense (Bott, 1967)

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Soufiane Fadlaoui ◽  
Ouahid El Asri ◽  
Mustapha Bouterfas ◽  
Mohammed Melhaoui
Keyword(s):  
Organic Matter ◽  
Dissolved Oxygen ◽  
Water Temperature ◽  
Suspended Matter ◽  
Mountain Stream ◽  
Freshwater Crab ◽  
Physicochemical Variables ◽  
The North ◽  
Global Quality ◽  
Nitrite Nitrate

The large number of pollutants discharged into the aquatic environment may influence the physicochemical and biological qualities of the aquatic ecosystem. This study discloses the global quality of the surface waters and the effect of physicochemical variables on the abundance of the African freshwater crab Potamon algeriense inhabiting Zegzel watercourse, a mountain stream in the northeast of Morocco. Physicochemical variables including streamflow, water temperature, pH, dissolved oxygen, suspended matter, chloride, calcium, magnesium, ammonia, nitrite, nitrate, orthophosphate, and organic matter were evaluated monthly for one year (October 2017–September 2018). The evaluation of the physicochemical quality showed that the waters of all the stations studied are between the excellent and good quality classes concerning all the physicochemical variables and highlights also two variations with a tendency towards degradation, one spatial from upstream to downstream and the other seasonal from the wet to the dry period. The abundance of crabs was recorded to exhibit a positive correlation with dissolved oxygen, calcium (N = 44) (p < 0.01), and magnesium. However, a negative correlation has been noticed for streamflow (N = 1) (p < 0.01), water temperature, pH, suspended matter, chloride, ammonia, nitrite, nitrate, orthophosphate, and organic matter. The results obtained reveal that besides the biotic variables, the distribution of P. algeriense also depends on these specific environmental variables.

Abundance- and biomass-based metrics of functional composition of macroinvertebrate as surrogates of ecosystem attributes in Afrotropical streams

2021 ◽  
Author(s):  
Augustine Sitati ◽  
Frank Onderi Masese ◽  
Mourine J. Yegon ◽  
Alfred Otieno ◽  
Simon Agembe
Keyword(s):  
Organic Matter ◽  
Particulate Organic Matter ◽  
Functional Feeding Groups ◽  
Taxon Richness ◽  
Channel Stability ◽  
Ecosystem Integrity ◽  
Western Kenya ◽  
Fine Particulate Organic Matter ◽  
Fine Particulate ◽  
The Tropics

The composition of macroinvertebrate functional feeding groups (FFGs) has been used as surrogates of ecosystem attributes in aquatic ecosystems but studies that utilize such knowledge are still limited in the tropics. This study investigated the suitability of abundance- vs. biomass-based metrics of macroinvertebrate FFGs as surrogates of ecosystems attributes of the Sosiani-Kipkaren River in western Kenya. Macroinvertebrates were sampled in wet and dry seasons, classified into five FFGs and used to derive five metrics that are surrogates of ecosystem attributes; 1) a balance between autotrophy and heterotrophy, 2) linkage between riparian inputs of coarse particulate organic matter (CPOM) and fine particulate organic matter (FPOM), 3) top-down predator control, 4) geomorphic channel stability, and 5) relative dominance of fine particulate organic matter (FPOM) in transport compared to FPOM deposited in the sediments. Taxon richness, abundance and biomass of shredders were higher in forested sites, scrapers were numerically dominant in mid-order streams, whereas collectors dominated agricultural and urban sites. Abundance-based metrics were better predictors of ecosystem attributes and displayed a greater response to changes in stream size than biomass-based metrics. Moreover, there was incongruence between abundance- and biomass-based indicators for P/R and CPOM/ FPOM. Catchment land use did not influence metric performance, suggesting that reach scale influences played a predominant role in structuring communities and determining ecosystem functioning. Although the use of FFGs as indicators of ecosystem integrity and functioning in this river show promise, the lack of agreement between abundance- and biomass-based measures suggests that more studies are needed to refine the metrics used.

scholarly journals Diversity and Species Composition of Subaerial Algal Communities in Forested Areas of Meghalaya, India

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Diana Kharkongor ◽  
Papiya Ramanujam
Keyword(s):  
Relative Humidity ◽  
Species Composition ◽  
Algal Species ◽  
Sacred Grove ◽  
Algal Communities ◽  
Tree Barks ◽  
Significant Difference ◽  
Forested Areas ◽  
Mixed Plantation ◽  
Disturbed Forest

The study deals with a comparative study on diversity and species composition of subaerial algal communities from tree barks of closed undisturbed sacred grove, mixed plantation, and open disturbed forest. A total of 85 taxa had been recorded, 30 cyanobacteria and 55 algal species belonging to six classes of algae. Sacred grove harboured the highest subaerial algal diversity compared to those of plantation and open disturbed forest. There was a strong significant difference in species composition among the three different sampling areas. High number of diatoms with 14 species was recorded in sacred grove. Cyanobacteria with 22 species were the frequent group in disturbed forest whereas Trentepohliales dominated in plantation. Canonical correspondence analysis confirmed that high photon irradiance favored the growth of cyanobacteria in disturbed forest. The abundance of Trentepohliales members correlated to high rainfall and photon irradiance. High diversity and presence of many diatom species in undisturbed Mawphlang sacred grove were associated with low photon irradiance and high relative humidity and could also be due to a presence of suitable substrata formed by the growth of mosses. Sunlight, relative humidity, and rainfall were the important factors which played a major role in determining the diversity and distribution of subaerial algal communities.

Effet de certains paramètres physico-chimiques sur les relations prédateurs–proies dans les populations de copépodes cyclopoïdes des mares temporaires d'eau douce

1986 ◽  
Vol 64 (1) ◽  
pp. 8-11
Author(s):  
Louise Vallières ◽  
Antoine Aubin
Keyword(s):  
Organic Matter ◽  
Body Size ◽  
Dissolved Oxygen ◽  
Water Temperature ◽  
Feeding Ecology ◽  
Mineral Content ◽  
Abiotic Factors ◽  
Size Class ◽  
Regression Analyses ◽  
Physical And Chemical

Copepod populations of three temporary freshwater pools (Alnus unit, Carex unit, and Molinia unit) were studied using a standard approach (species versus abiotic factors) and a holistic one (body size and feeding ecology). Multiple regression analyses of data indicate that the physical and chemical features of water (temperature, pH, dissolved oxygen, mineral content, and depth) explain 62 to 98% of the variability of carnivorous copepods, while the abundance of their prey accounts for much less. No size class of prey seems to be preferred. The abundance of decaying organic matter, typical of such pools, would result in an overabundance of prey. Predators would then be under the control of nonalimentary factors.

Macroinvertebrate Communities and Environment in a Southern African Mountain Stream

1988 ◽  
Vol 45 (12) ◽  
pp. 2168-2181 ◽  
Author(s):  
J. M. King ◽  
J. A. Day ◽  
P. R. Hurly ◽  
M-P. Henshall-Howard ◽  
B. R. Davies
Keyword(s):  
Community Structure ◽  
Environmental Variables ◽  
Mediterranean Ecosystems ◽  
Mountain Stream ◽  
Functional Feeding Groups ◽  
Stepwise Discriminant Analysis ◽  
Macroinvertebrate Communities ◽  
Strong Correlations ◽  
Stream Community ◽  
Community Changes

In a study of a second-order southern African stream, complementary classification and multidimensional scaling (MDS) techniques revealed longitudinal changes in macroinvertebrate community structure, but no temporal changes. Stepwise discriminant analysis and multiple linear regression were used to identify environmental variables correlated with the community changes but produced conflicting results depending on the information used, possibly because of strong correlations between some of the variables. The MDS plot of biotic samples illustrated that potassium levels correlated most strongly with community distribution. Because of the large number of variables now shown worldwide to correlate with faunal distributions, we suggest ways to choose the variables to suit the kind of study to be undertaken. Attempts to assign the invertebrates to functional feeding groups (FFGs) were unsatisfactory as the relevant categories are poorly defined and often inadequate for classifying the fauna. We suggest that until these categories are more clearly defined, and more uniformly applied, concepts relating to FFGs cannot be tested satisfactorily. The stream community in Langrivier is more similar to communities found in two other mediterranean ecosystems than to those in other southern African rivers, probably because of the greater predictability of flow in the former.

Changes in discharge affect more surface than subsurface breakdown of organic matter in a mountain stream

2016 ◽  
Vol 67 (12) ◽  
pp. 1826 ◽  
Author(s):  
Libe Solagaistua ◽  
Maite Arroita ◽  
Ibon Aristi ◽  
Aitor Larrañaga ◽  
Arturo Elosegi
Keyword(s):  
Organic Matter ◽  
Water Depth ◽  
Alnus Glutinosa ◽  
Mountain Stream ◽  
Litter Breakdown ◽  
Lotic Ecosystems ◽  
Leaf Litter Breakdown ◽  
Discharge Fluctuations ◽  
Breakdown Rates ◽  
Dry Out

Discharge fluctuations modify water depth and velocity in streams and this can affect leaf litter breakdown, which is an important ecosystem function. Both during droughts, when parts of the surface dry out, and during floods, which scour the benthic surface, macroinvertebrates can seek refuge in the subsurface. Therefore, as an important part of them depend on organic matter, the effects of discharge fluctuations on leaf breakdown might be greater on the surface than in the subsurface of lotic ecosystems. To test this hypothesis, we measured microbial and total breakdown rates of alder (Alnus glutinosa (L.) Gaertner) both on the surface and in the subsurface in two areas of a stream, namely, the permanently wet channel and the parafluvial areas. Reduced discharge dried out only the surface of the parafluvial areas, and thus, breakdown rates were reduced only in this habitat. In contrast, breakdown rates were similar in both habitats of the permanently wet channel, but also in the subsurface of the parafluvial area. The subsurface can mitigate the effects of discharge alterations on the breakdown of organic matter in streams, which might be critical for the productivity of these ecosystems under increased drought frequencies.

COMPARATIVE ASSESSMENT OF THE INTRA-ANNUAL WATER RUNOFF DISTRIBUTION OF THE RIVERS THE ROS AND UBORT

2020 ◽  
pp. 72-80
Author(s):  
O. A. Chunarov
Keyword(s):  
Initial Data ◽  
Water Content ◽  
River Water ◽  
Water Consumption ◽  
River Runoff ◽  
River Basins ◽  
Comparative Assessment ◽  
Water Runoff ◽  
Annual Water ◽  
Annual Distribution

The article examines the intra-annual distribution of water runoff of the Ros and Ubort rivers, as well as its comparative assessment. The rivers Ros and Ubort were chosen for further research, because according to geographical conditions, river basins belong to natural and regulated water bodies. The rivers Ros and Ubort are characterized by summer-autumn and winter lows, which are disturbed by separate rises in water levels during rains or melting snow. The formation of the main part of river runoff is due to spring flooding. The initial data for studying the intra-annual distribution of runoff were the data of average annual water flow in the confluence of the rivers Ros and Ubort, namely: the river Ros – Korsun-Shevchenkivsky and the river Ubort – Perga for the entire period of hydrological observations. The initial data are the average annual water consumption of the closing sections of the Ros and Ubort rivers for the entire observation period. To confirm (or refute) the changes in the water content of the studied rivers, the homogeneity of some of their runoff characteristics was analyzed by different methods. Statistical methods for estimating the homogeneity of hydrological series are used for quantities that are random and internally independent. The homogeneity of the series of average annual water consumption over a multi-year period is estimated according to the current hydrological posts of the basins of the rivers Ros and Ubort. The analysis of previous publications on the intra-annual distribution of river water runoff for the territory of the studied river basins, the influence of climatic factors on the change of river runoff, as well as summarizes the results of these studies. The intra-annual distribution of river water runoff for years of different water content and separate phases for the basins of both studied rivers is calculated by the season composition method. The comparative characteristics of the obtained results are carried out and the common hydrological characteristics and significant differences in the studied river basins are revealed.

Geographic distribution of the short-tailed river stingray (Potamotrygon brachyura): assessing habitat loss and fishing as threats to the world’s largest obligate freshwater elasmobranch

2016 ◽  
Vol 67 (10) ◽  
pp. 1463 ◽  
Author(s):  
Luis O. Lucifora ◽  
Santiago A. Barbini ◽  
Sabina Llamazares Vegh ◽  
Pablo A. Scarabotti ◽  
Facundo Vargas ◽  
...  
Keyword(s):  
Water Temperature ◽  
Geographic Distribution ◽  
River Basins ◽  
Paraná River ◽  
Habitat Modification ◽  
Rio De La Plata ◽  
Fishing Pressure ◽  
Río De La Plata ◽  
La Plata ◽  
Parana River

Freshwater elasmobranchs are threatened but little is known about them. Potamotrygon brachyura is the world’s largest obligate freshwater elasmobranch. This makes it popular among fishermen and suggests a susceptibility to anthropogenic threats. We collected records of P. brachyura (n=70) from media, fishermen and scientific sampling, to estimate its global geographic distribution (using both generalised additive and MaxLike models). Then, we estimated the species’ exposure to habitat modification and fishing pressure, by applying multinomial ordinal models with threat levels as response and the presence or absence of P. brachyura as an independent variable. Distance to coast, depth, water temperature range, salinity range and mean water temperature were the main determinants of the distribution in the Río de la Plata. This resulted in a narrow coastal distribution. In the Uruguay and Paraná River basins, the probability of occurrence was positively associated with flow accumulation, percentage of open water and submerged vegetation, and lowland ecoregions, and negatively to wetness index and altitude. This limited the distribution to large lowland rivers. Approximately 41% of the range of P. brachyura in the Río de la Plata was subject to high habitat modification. In the Uruguay and Paraná River basins, this percentage reached 7%; however, the overlap with high fishing pressure was 59%. For conservation purposes, P. brachyura may function as an umbrella species.

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