نتایج جستجو برای: ecological species groups

تعداد نتایج: 1311827  

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه شیراز 1381

‏‎the community dynamics of aquatic coleoptera(insecta)in one of the spring-stream habitats of bammo national park in fars province called cheshmeh-ye-ghanbari is studied as a pilot project and model for acquaintance with and furthering the biodiversity studies on fauna of iran. sixteen species-populations out of nineteen of this community were already identified for their taxonomy and for thei...

2016
Evgeny A Kurashov Elena V Fedorova Julia V Krylova Galina G Mitrukova

The paper focuses on the assessment of the spectrum of biological activities (antineoplastic, anti-inflammatory, antifungal, and antibacterial) with PASS (Prediction of Activity Spectra for Substances) for the major components of three macrophytes widespread in the Holarctic species of freshwater, emergent macrophyte with floating leaves, Nuphar lutea (L.) Sm., and two species of submergent mac...

1996
Peter M. Todd

What engenders biodiversity? Natural selection certainly adapts species to their ecological niches, but does it really create all of the new niches and new species to ll them? Consider: the most successful, complex, and numerous species on earth are composed of sexually-reproducing animals and owering plants. Both groups typically undergo a form of sexual selection through mate choice: animals ...

2004
Thomas Koellner Anna M. Hersperger Thomas Wohlgemuth

In national conservation plans, it is necessary to comparatively assess species pools of different regions and monitor their changes over time. Two specific problems arise: i) species diversity must be standardized per area, because regions differ in size, and ii) the diversity measure should take into account how common or rare the species are on the regional scale. We used the rarefaction met...

Journal: :Molecular phylogenetics and evolution 2007
Ben D Marks Jason D Weckstein Robert G Moyle

The bee-eaters (family Meropidae) comprise a group of brightly colored, but morphologically homogeneous, birds with a wide variety of life history characteristics. A phylogeny of bee-eaters was reconstructed using nuclear and mitochondrial DNA sequence data from 23 of the 25 named bee-eater species. Analysis of the combined data set provided a well-supported phylogenetic hypothesis for the fami...

Journal: :Molecular ecology 2005
Jennifer L Trusty Richard G Olmstead Arnoldo Santos-Guerra Susana Sá-Fontinha Javier Francisco-Ortega

Abstract A molecular phylogenetic study of Bystropogon L'Her. (Lamiaceae) is presented. We performed a cladistic analysis of nucleotide sequences of the internal transcribed spacers (ITS), of the nuclear ribosomal DNA, and of the trnL gene and trnL-trnF intergenic spacer of the chloroplast DNA. Bystropogon odoratissimus is the only species endemic to the Canary Islands that occurs in the three ...

2013
Kristy J Kroeker Rebecca L Kordas Ryan Crim Iris E Hendriks Laura Ramajo Gerald S Singh Carlos M Duarte Jean-Pierre Gattuso

Ocean acidification represents a threat to marine species worldwide, and forecasting the ecological impacts of acidification is a high priority for science, management, and policy. As research on the topic expands at an exponential rate, a comprehensive understanding of the variability in organisms' responses and corresponding levels of certainty is necessary to forecast the ecological effects....

Journal: :Molecular ecology 2006
A W Spaulding K E Mock M A Schroeder K I Warheit

Both current and historical patterns of variation are relevant to understanding and managing ecological diversity. Recently derived species present a challenge to the reconstruction of historical patterns because neutral molecular data for these taxa are more likely to exhibit effects of recent and ongoing demographic processes. We studied geographical patterns of neutral molecular variation in...

Variation along the successional stage of a plant community is not limited to plant composition and diversity but also related to nutrient resources and plant species abundance distribution. Therefore, the use of models that consider the distribution of ecological niches in addition to the relative frequency of species in the distribution of species is also important. The object of current stud...

ژورنال: آبزیان زینتی 2020
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Following the report of suckermouth catfish (Hypostomus plecostomus) from Anzali Wetland, the present study was conducted to review the biological and ecological characteristics of this species and its effects on aquatic ecosystems. A literature review revealed that the suckermouth catfish is native to South America and one of the most popular species in the ornamental fish industry. This speci...

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