نتایج جستجو برای: abundance of tolerant taxa eg chironomidae
تعداد نتایج: 21174288 فیلتر نتایج به سال:
Chemical recovery of acidified waters due to reductions in emissions has been reported from Europe and North America (1). The western Norwegian river Nausta is an example of a river where chemical recovery was observed during 1989–1998. Continuous monitoring of the zoobenthos using acidification indices indicated that biological recovery has followed chemical recovery (2). The Nausta was, there...
We assessed and compared abiotic preferences of aquatic macroinvertebrates in three river basins located in Ecuador, Ethiopia and Vietnam. Upon using logistic regression models we analyzed the relationship between the probability of occurrence of five macroinvertebrate families, ranging from pollution tolerant to pollution sensitive, (Chironomidae, Baetidae, Hydroptilidae, Libellulidae and Lept...
Tundra arthropods are of considerable ecological importance as a seasonal food source for many arctic-breeding birds. Dietary composition and preferences rarely known, complicating assessments interactions in changing environment. In our field study, we investigated the nestling diet snow buntings (Plectrophenax nivalis (L., 1758)) breeding Svalbard. We collected fecal samples from 8-day-old ne...
Eutrophication and climate warming are profoundly affecting fish in many freshwater lakes. Understanding the specific effects of these stressors is critical for development of effective adaptation and remediation strategies for conserving fish populations in a changing environment. Ecological niche models that incorporated the individual effects of nutrient concentration and climate were develo...
The zooplankton community and environmental conditions were monitored during Dec. 2012 PG-GOOS (Persian Gulf and Gulf of Oman Oceanographic Study) oceanographic cruise on board N/V Ja Nayband throughout the northwestern part of the Persian Gulf. Data of temperature, salinity, depth and pH as well as zooplankton community composition and abundance were collected from 17 stations. The zoopla...
Patterns of abundance and distribution of chironomid midges (Diptera, Chironomidae) in the middle Rio Doce basin were analysed. Human activities (mining, steel processing, and Eucalyptus spp. forestry) contribute to environmental degradation and low water quality in this watershed. Physical and chemical water traits (dissolved oxygen, pH, total alkalinity, electric conductivity, phosphorus and ...
phytoplankton communities play a significant role in the oceanic biological pump by forming the base of the trophic structure. increase in nutrients loading affects spatial and temporal distribution of phytoplankton. this study examined the phytoplankton community structure and ecological indices in relation to nutrients dynamics in both estuarine and oceanic areas of ramisi-vanga systems along...
1. Invasive species are present worldwide, yet predicting which invasive species will become problematic in which ecosystems remains an important ecological challenge. Floodplains are at particular risk for invasion, especially when subjected to anthropogenic disturbance. 2. We examined how components of flood regime, habitat quality and habitat configuration influenced the presence and abundan...
The index of biotic integrity (IBI) is a commonly used bioassessment tool that integrates abundance and richness measures to assess water quality. In developing IBIs that are both responsive to human disturbance and resistant to natural variability and sampling error, water managers must decide how to weigh information about rare and abundant taxa, which in turn requires an understanding of the...
Macroinvertebrate communities and environmental variables were assessed seasonally for 1 year in a temporary river in South Portugal receiving an effluent with high conductivity, pH, sulphates, nitrates and low oxygen content. The usefulness of the ordination method canonical correspondence analysis (CCA) and the classification method cluster analysis (UPGMA) were examined to evaluate the pertu...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید