نتایج جستجو برای: pollen and nectar resources

تعداد نتایج: 16848597  

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تبریز 1389

in reality, most structures involved in geotechnical engineering are three dimensional in nature, and although in many, plane strain or axisymmetric approximations are reasonable, there are some, for which 3-d treatment is required. the quantity of data, and the size of the various vectors and matrices involved in such analysis, increase dramatically. this has sever implications for computer r...

Journal: :Reviews of environmental contamination and toxicology 2014
G Christopher Cutler John Purdy John P Giesy Keith R Solomon

CPY is an organophosphorus insecticide that is widely used in North American agriculture. It is non-systemic, comes in several sprayable and granular formulations,and is used on a number of high-acreage crops on which pollinators can forage,including tree fruits, alfalfa, corn, sunflower, and almonds. Bees (Apoidea) are the most important pollinators of agricultural crops in North America and w...

Journal: :Biology letters 2017
Ya-Ru Zhu Min Yang Jana C Vamosi W Scott Armbruster Tao Wan Yan-Bing Gong

Floral nectar usually functions as a pollinator reward, yet it may also attract herbivores. However, the effects of herbivore consumption of nectar or nectaries on pollination have rarely been tested. We investigated Iris bulleyana, an alpine plant that has showy tepals and abundant nectar, in the Hengduan Mountains of SW China. In this region, flowers are visited mainly by pollen-collecting po...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه شهید چمران اهواز - دانشکده مهندسی علوم آب 1393

drought is transient phenomenon , slow , repetitive and integral part of the climate of each region. drought begins with a substantial reduction in precipitation over the long-term average rainfall and over time, reduced soil moisture and surface and ground water resources will continue to decrease. this phenomenon is the most important in bakhtegan basin because of its importance in strategic ...

2015
Marc Badger Victor Manuel Ortega-Jimenez Lisa von Rabenau Ashley Smiley Robert Dudley Alexei Gruverman

Electrostatic phenomena are known to enhance both wind- and insect-mediated pollination, but have not yet been described for nectar-feeding vertebrates. Here we demonstrate that wild Anna's Hummingbirds (Calypte anna) can carry positive charges up to 800 pC while in flight (mean ± s.d.: 66 ± 129 pC). Triboelectric charging obtained by rubbing an isolated hummingbird wing against various plant s...

2015
Xiaobao Deng Dharmalingam Mohandass Masatoshi Katabuchi Alice C. Hughes David W. Roubik Jeff Ollerton

Nectar-robbing has the potential to strongly affect male and female reproductive fitness of plants. One example of nectar theft is that shown by striped-squirrels (Tamiops swinhoei) on a number of ginger species, including Alpinia roxburghii and A. kwangsiensis (Zingiberaceae). In this study, we used a fluorescent dye as a pollen analogue, and measured fruit and seed output, to test the effect ...

2017
E C Palmer-Young B M Sadd L S Adler

Repeated exposure to inhibitory compounds can drive the evolution of resistance, which weakens chemical defence against antagonists. Floral phytochemicals in nectar and pollen have antimicrobial properties that can ameliorate infection in pollinators, but evolved resistance among parasites could diminish the medicinal efficacy of phytochemicals. However, multicompound blends, which occur in nec...

2016
Jenny A. Hazlehurst Boris Tinoco Santiago Cárdenas Jordan Karubian

Geographic variation in pollination ecology is poorly documented, if at all, in many plant-pollinator systems. Great insights could be gained into the abiotic and biotic factors which impact the evolution of floral properties and their potential to lead to speciation by doing so, as both can vary naturally over the geographic range of a plant species. We characterized the pollination ecology of...

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