scholarly journals Study on Freshwater Macroinvertebrates of Some Tanzanian Rivers as a Basis for Developing Biomonitoring Index for Assessing Pollution in Tropical African Regions

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Julius D. Elias ◽  
Jasper N. Ijumba ◽  
Yunus D. Mgaya ◽  
Florence A. Mamboya
Keyword(s):  
Habitat Quality ◽  
Physicochemical Parameters ◽  
Ecological Status ◽  
Total Abundance ◽  
Freshwater Macroinvertebrates ◽  
Biological Index ◽  
Tropical Regions ◽  
Wide Range ◽  
Kilimanjaro Region

Macroinvertebrates and physicochemical parameters were assessed at 15 sites along five rivers in Kilimanjaro region, Tanzania, with the aim of understanding their ecological status and setting a base to the development of a biological index for tropical regions. Investigated rivers that occur within Pangani basin include Karanga, Rau, Lumbanga, Sere, and Umbwe. Sampling sites were categorized according to the level of water and habitat quality as follows: reference or least impacted (4 sites), moderately impacted (5 sites), and highly impacted (6 sites) sites. A total of 12,527 macroinvertebrates belonging to 13 orders and 48 families were recorded. The highest total abundance of 4,110 individuals per m2 was found in Karanga river, while Umbwe river had the lowest with 1,203 individuals per m2. Chironomidae was the most abundant family (2,588 individuals per m2) and the least were Hydridae and Thiaridae, each having 5 individuals per m2. High numbers of taxa were noted among the orders: Ephemeroptera (8), Odonata (8), Diptera (7), and Trichoptera (6). In conclusion, orders with greater diversity of macroinvertebrate families offer a wide range of tolerance to pollution and, thus can potentially be used to develop a biomonitoring index for evaluating pollution in tropical African rivers.

scholarly journals Water Quality as an Indicator of Stream Restoration Effects—A Case Study of the Kwacza River Restoration Project

Water ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 1249 ◽  
Author(s):  
Natalia Mrozińska ◽  
Katarzyna Glińska-Lewczuk ◽  
Paweł Burandt ◽  
Szymon Kobus ◽  
Wojciech Gotkiewicz ◽  
...  
Keyword(s):  
Water Quality ◽  
Cross Sections ◽  
Physicochemical Parameters ◽  
River Restoration ◽  
Ecological Status ◽  
Riparian Ecosystems ◽  
Left Tributary ◽  
Agricultural Areas ◽  
Natural Characteristics

River restoration projects rely on environmental engineering solutions to improve the health of riparian ecosystems and restore their natural characteristics. The Kwacza River, the left tributary of the Słupia River in northern Poland, and the recipient of nutrients from an agriculturally used catchment area, was restored in 2007. The ecological status of the river’s biotope was improved with the use of various hydraulic structures, including palisades, groynes and stone islands, by protecting the banks with trunks, exposing a fragment of the river channel, and building a by-pass near a defunct culvert. The effects of restoration treatments were evaluated by comparing the physicochemical parameters of river water along the 2.5 km restored section between the source and the mouth to the Słupia, before restoration and 6 years after hydrotechnical treatments. A total of 18 physicochemical parameters were analyzed at 10 cross-sections along the river. The greatest changes were observed in the concentrations of NO3−-N and NH4+-N, which decreased by 70% and 50%, respectively. Dissolved oxygen concentration increased by 65%. Chloride values increased by 44%, and chlorophyll-a concentration increased by 30% after the project. The cut-off channel (by-pass), semi-palisades, and single groynes were the treatments that contributed most to water quality improvement. The results of this study indicate that river restoration projects can substantially reduce nitrogen pollution, which is particularly important in agricultural areas. Such measures can effectively reinstate natural conditions in river ecosystems. Hydrochemical monitoring is required to control the parameters of restored rivers.

scholarly journals Improvement in physical river habitat quality in response to river restoration measures

Geografie ◽  
2016 ◽  
Vol 121 (1) ◽  
pp. 54-78
Author(s):  
Kateřina Kujanová ◽  
Milada Matoušková
Keyword(s):  
Habitat Quality ◽  
River Restoration ◽  
Field Survey ◽  
Reference Conditions ◽  
Ecological Status ◽  
River Habitat ◽  
Restoration Measures ◽  
Hydromorphological Quality

The main goal of this paper is to verify the hypothesis that application of appropriate restoration measures can lead to an improvement in river habitat quality and to achieve good hydromorphological conditions within the ecological status under the Water Framework Directive 2000/60/ES. The study includes an analysis of river network modifications founded on comparing historical and present-day maps, a determination of regional hydromorphological reference conditions based on a field survey and measurements, an assessment of hydromorphological quality of the studied water body and a proposal of appropriate restoration measures. The effects on improvement in hydromorphological status were predicted on the basis of a simulation of hydromorphological conditions after the application of proposed restoration measures. Overall, at least a good hydromorphological status would be achieved. The study proved that it is essential to carry out a hydromorphological survey including a determination of reference conditions as it provides some outputs necessary for a proposal and application of efficient restoration.

Pleospora herbarum. [Descriptions of Fungi and Bacteria].

1967 ◽  
Author(s):  
C. Booth
Keyword(s):  
Medicago Sativa ◽  
Geographical Distribution ◽  
Leaf Spot ◽  
Broad Bean ◽  
Net Blotch ◽  
Tropical Regions ◽  
Soil P ◽  
Wide Range ◽  
Ring Spot ◽  
Severe Leaf

Abstract A description is provided for Pleospora herbarum. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On a wide range of hosts including apple, ash, broad bean, clover, endive, gladiolus, gramineae, lettuce, lupin, muskmelon, onion, Onobrychis, Medicago sativa, mangold, tomato, Trifolium, Vicia (40: 230). DISEASES: Leaf spot of mangold, clover (Trifolium), lucerne (Medicago sativa), endive, lettuce, onion seedlings and gladiolus, net blotch of field and broad bean (Vicia), ring spot of sanfoin (Onobrychis) foot rot of tomato. Severe leaf spot on muskmelon may cause leaf fall and sun scald of fruit (37: 625). Lesions caused by other fungi may also be colonized as on lucerne (38: 11) or be associated with some other disease complex such as Pseudomonas savastanoi on ash (36: 144). GEOGRAPHICAL DISTRIBUTION: World-wide; very common in temperate and sub-tropical regions. TRANSMISSION: Generally air-borne as ascospores or conidia. These penetrate the leaf or petiole via stomata (37: 365). May also occur on seeds (38: 146) and in soil.

Pseudopestalotiopsis gilvanii sp. nov. and Neopestalotiopsis formicarum leaves spot pathogens from guarana plant: a new threat to global tropical hosts

Phytotaxa ◽  
2021 ◽  
Vol 489 (2) ◽  
pp. 121-139
Author(s):  
GILVANA F. GUALBERTO ◽  
ARICLÉIA DE M. CATARINO ◽  
THIAGO F. SOUSA ◽  
JEFERSON C. CRUZ ◽  
ROGÉRIO E. HANADA ◽  
...  
Keyword(s):  
Plant Pathogen ◽  
Elaeis Guineensis ◽  
Elongation Factor ◽  
Leaf Tissue ◽  
Euterpe Oleracea ◽  
Internal Transcribed Spacer Region ◽  
Tropical Regions ◽  
Tropical Plants ◽  
Wide Range ◽  
Genes Encoding

Pestalotioid species (Pestalotiopsis, Pseudopestalotiopsis and Neopestalotiopsis) cause extremely damaging diseases in a wide range of hosts across the word. Recently, pestalotioid strains isolated from damaged guarana leaf tissue were subject to morphological and molecular characterization. Six monosporic isolates were obtained and analysed based on the following conidial characters: length, width, septation, absence or presence of basal appendage, number and length of apical appendages. For phylogenetic inference, sequences of the Internal Transcribed Spacer region (ITS), partial sequences of the genes encoding the translation elongation factor 1-α (tef1-α) and β-tubulin (tub2) were used. Three out of six strains analysed were identified as Neopestalotiopsis formicarum, while the three other isolates are described here as a new species of Pseudopestalotiopsis, named Ps. gilvanii sp. nov.. The pathogenicity of N. formicarum and Ps. gilvanii were confirmed following Koch’s postulate. Besides guarana, the potential of N. formicaram and Ps. gilvanii to cause diseases in other economically important tropical plants were investigated. Ps. gilvanii was pathogenic to açaí palms (Euterpe oleracea, E. precatoria), and oil palm (Elaeis guineensis), but not to banana (Musa paradisiaca var. pacovan) and rubber trees (Hevea brasiliensis). N. formicarum was not pathogenic to rubber trees but was pathogenic to other species tested. To our knowledge this is the first report of N. formicarum as a plant pathogen in the guarana plant, and Ps. gilvanii as novel plant pathogen capable of causing disease in important plant crops from tropical regions.

scholarly journals Combined Effect of Light and Temperature on the Production of Saxitoxins in Cylindrospermopsis raciborskii Strains

Toxins ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 38 ◽  
Author(s):  
Marcella Mesquita ◽  
Miquel Lürling ◽  
Fabiane Dorr ◽  
Ernani Pinto ◽  
Marcelo Marinho
Keyword(s):  
Maximum Growth ◽  
Combined Effect ◽  
Cylindrospermopsis Raciborskii ◽  
Tropical Regions ◽  
Batch Cultures ◽  
Light Intensities ◽  
Cell Quota ◽  
Wide Range ◽  
Lower Light ◽  
Effect Of Light

Cylindrospermopsis raciborskii is a potentially toxic freshwater cyanobacterium that can tolerate a wide range of light and temperature. Due to climatic changes, the interaction between light and temperature is studied in aquatic systems, but no study has addressed the effect of both variables on the saxitoxins production. This study evaluated the combined effect of light and temperature on saxitoxins production and cellular quota in C. raciborskii. Experiments were performed with three C. raciborskii strains in batch cultures under six light intensities (10, 40, 60, 100, 150, and 500 μmol of photons m−2 s−1) and four temperatures (15, 20, 25, and 30 °C). The growth of C. raciborskii strains was limited at lower temperatures and the maximum growth rates were obtained under higher light combined with temperatures equal or above 20 °C, depending on the strain. In general, growth was highest at 30 °C at the lower light intensities and equally high at 25 °C and 30 °C under higher light. Highest saxitoxins concentration and cell-quota occurred at 25 °C under high light intensities, but were much lower at 30 °C. Hence, increased temperatures combined with sufficient light will lead to higher C. raciborskii biomass, but blooms could become less toxic in tropical regions.

On tropical mistletoes: tractable models for evolutionary ecology, ecosystem function, and phytochemistry

Botany ◽  
2017 ◽  
Vol 95 (3) ◽  
pp. 211-217 ◽  
Author(s):  
David M. Watson
Keyword(s):  
Seed Dispersal ◽  
Host Range ◽  
Plant Communities ◽  
Ecosystem Function ◽  
Evolutionary Ecology ◽  
Life Sciences ◽  
Evolutionary Trajectory ◽  
Tropical Regions ◽  
Wide Range

In 2001, I synthesised published information on mistletoe–animal interactions, demonstrating the pervasive influence these hemiparasites have on community composition and proposing that mistletoes represent keystone resources. Although the review was global in scope, I noted “Tropical regions, in particular, are underrepresented in the mistletoe literature, and it is unclear if mistletoe is as important in structuring these highly diverse ecosystems as in less diverse temperate areas”. Since then, research on tropical mistletoes has burgeoned, as a growing number of researchers use these forest and woodland hemiparasites to address a wide range of ecological and evolutionary questions. In this commentary, I highlight some recent findings, revisit and refine some emergent inferences, and suggest that tropical mistletoes offer many opportunities for further research, representing tractable models to address many unanswered questions in the life sciences. As well as reinforcing the role of mistletoes as facilitators for plant communities and keystone resources for animal assemblages, research on mistletoe pollination, seed dispersal, and host-range, challenge the established views about the ecological maintenance and evolutionary trajectory of specialization.

scholarly journals Development and characterisation of microsatellite markers for the fungus Lasiodiplodia theobromae

2008 ◽  
Vol 34 (1) ◽  
pp. 55-57 ◽  
Author(s):  
José Emilson Cardoso ◽  
Michael James Wilkinson
Keyword(s):  
Microsatellite Markers ◽  
Fungal Pathogen ◽  
Population Studies ◽  
Higher Plants ◽  
Epidemiologic Studies ◽  
Preliminary Evaluation ◽  
Lasiodiplodia Theobromae ◽  
Tropical Regions ◽  
Wide Range ◽  
Polymorphic Microsatellite

Lasiodiplodia theobromae is an important fungal pathogen of higher plants from tropical and sub-tropical regions. The fungus infects divergent hosts in a wide range of environmental conditions, suggesting that it is highly variable. The aim of this study was to develop new polymorphic microsatellite markers from a Brazilian isolate of L. theobromae that can be used in population studies of this and related fungi. The nine microsatellite markers developed included six that revealed allelic polymorphisms among nine isolates of the disease collected from infected plants in Brazil. Preliminary evaluation of the markers suggested substantial genetic variability among Brazilian L. theobromae populations. These markers have potential utility for evolutionary and epidemiologic studies of this fungus.

scholarly journals Modelling of ecological status of Polish lakes using deep learning techniques

2020 ◽  
Author(s):  
Daniel Gebler ◽  
Agnieszka Kolada ◽  
Agnieszka Pasztaleniec ◽  
Krzysztof Szoszkiewicz
Keyword(s):  
Deep Learning ◽  
Physicochemical Parameters ◽  
Practical Importance ◽  
Ecological Status ◽  
Aquatic Organisms ◽  
Model Quality ◽  
Stratified Lakes ◽  
Learning Techniques ◽  
Status Assessment ◽  
Input Variables

Abstract Since 2000, after the Water Framework Directive came into force, aquatic ecosystems’ bioassessment has acquired immense practical importance for water management. Currently, due to extensive scientific research and monitoring, we have gathered comprehensive hydrobiological databases. The amount of available data increases with each subsequent year of monitoring, and the efficient analysis of these data requires the use of proper mathematical tools. Our study challenges the comparison of the modelling potential between four indices for the ecological status assessment of lakes based on three groups of aquatic organisms, i.e. phytoplankton, phytobenthos and macrophytes. One of the deep learning techniques, artificial neural networks, has been used to predict values of four biological indices based on the limited set of the physicochemical parameters of water. All analyses were conducted separately for lakes with various stratification regimes as they function differently. The best modelling quality in terms of high values of coefficients of determination and low values of the normalised root mean square error was obtained for chlorophyll a followed by phytoplankton multimetric. A lower degree of fit was obtained in the networks for macrophyte index, and the poorest model quality was obtained for phytobenthos index. For all indices, modelling quality for non-stratified lakes was higher than this for stratified lakes, giving a higher percentage of variance explained by the networks and lower values of errors. Sensitivity analysis showed that among physicochemical parameters, water transparency (Secchi disk reading) exhibits the strongest relationship with the ecological status of lakes derived by phytoplankton and macrophytes. At the same time, all input variables indicated a negligible impact on phytobenthos index. In this way, different explanations of the relationship between biological and trophic variables were revealed.

scholarly journals Assessing the Benefits of Forested Riparian Zones: A Qualitative Index of Riparian Integrity Is Positively Associated with Ecological Status in European Streams

Water ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 1178 ◽  
Author(s):  
Francis J. Burdon ◽  
Ellinor Ramberg ◽  
Jasmina Sargac ◽  
Marie Anne Eurie Forio ◽  
Nancy de Saeyer ◽  
...  
Keyword(s):  
Human Impacts ◽  
Ecological Status ◽  
Riparian Buffers ◽  
Average Score ◽  
Land Use Impacts ◽  
Freshwater Biodiversity ◽  
Functional Relationships ◽  
Wide Range ◽  
Qualitative Index

Developing a general, predictive understanding of ecological systems requires knowing how much structural and functional relationships can cross scales and contexts. Here, we introduce the CROSSLINK project that investigates the role of forested riparian buffers in modified European landscapes by measuring a wide range of ecosystem attributes in stream-riparian networks. CROSSLINK involves replicated field measurements in four case-study basins with varying levels of human development: Norway (Oslo Fjord), Sweden (Lake Mälaren), Belgium (Zwalm River), and Romania (Argeş River). Nested within these case-study basins include multiple, independent stream-site pairs with a forested riparian buffer and unbuffered section located upstream, as well as headwater and downstream sites to show cumulative land-use impacts. CROSSLINK applies existing and bespoke methods to describe habitat conditions, biodiversity, and ecosystem functioning in aquatic and terrestrial habitats. Here, we summarize the approaches used, detail protocols in supplementary materials, and explain how data is applied in an optimization framework to better manage tradeoffs in multifunctional landscapes. We then present results demonstrating the range of riparian conditions present in our case-study basins and how these environmental states influence stream ecological integrity with the commonly used macroinvertebrate Average Score Per Taxon (ASPT) index. We demonstrate that a qualitative index of riparian integrity can be positively associated with stream ecological status. This introduction to the CROSSLINK project shows the potential for our replicated study with its panoply of ecosystem attributes to help guide management decisions regarding the use of forested riparian buffers in human-impacted landscapes. This knowledge is highly relevant in a time of rapid environmental change where freshwater biodiversity is increasingly under pressure from a range of human impacts that include habitat loss, pollution, and climate change.

scholarly journals Impact Assessment of Phosphogypsum Leachate on Groundwater of Sfax-Agareb (Southeast of Tunisia): Using Geochemical and Isotopic Investigation

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Samira Melki ◽  
Moncef Gueddari
Keyword(s):  
Physicochemical Parameters ◽  
Large Scale ◽  
Major Effect ◽  
Major Elements ◽  
Spatiotemporal Variation ◽  
Water Residence Time ◽  
Evaporation Process ◽  
Natural Conditions ◽  
Wide Range

The production of phosphoric acid by the Tunisian Chemical Group, in Sfax, Tunisia, led to the degradation of the groundwater quality of the Sfax-Agareb aquifer mainly by the phosphogypsum leachates infiltration. Spatiotemporal monitoring of the quality of groundwater was carried out by performing bimonthly sampling between October 2013 and October 2014. Samples culled in the current study were subject to physicochemical parameters measurements and analysis of the major elements, orthophosphates, fluorine, trace metals, and stable isotopes (18O, 2H). The obtained results show that the phosphogypsum leachates infiltration has a major effect on the downstream part of the aquifer, where the highest values of conductivity, SO42-, Ortho-P, and F-, and the lowest pH were recorded. In addition, these results indicated that phosphogypsum leachates contained much higher amount of Cr, Cd, Zn, Cu, Fe, and Al compared to the groundwater. Spatiotemporal variation of the conductivity and concentrations of major elements is linked to the phosphogypsum leachates infiltration as well as to a wide range of factors such as the natural conditions of feeding and the water residence time. Contents of O18 and 2H showed that the water of the Sfax-Agareb aquifer undergoes a large scale evaporation process originated from recent rainfall.

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