نتایج جستجو برای: pollinators

تعداد نتایج: 3395  

Journal: :Journal of theoretical biology 2017
Mohsen B Mesgaran Juliette Bouhours Mark A Lewis Roger D Cousens

Empirical evidence suggests that co-flowering species can facilitate each other through shared pollinators. However, the extent to which one co-flowering species can relieve pollination limitation of another while simultaneously competing for abiotic resource has rarely been examined. Using a deterministic model we explored the demographic outcome for one ("focal") species of its co-occurrence ...

Journal: :علوم و فنون زنبور عسل 0

abstract this chapter describes how the climate change is potentially the mostsevere threat to pollinator biodiversity. mounting evidence demonstrates that therehave already been biotic responses to the relatively small climate changes that haveoccurred this century. pollinators such as birds, bees, butterflies, moths, flies, wasps,beetles bats and even mosquitoes are essential for food product...

2011
Sean A. Rands Heather M. Whitney

The areas of wild land around the edges of agricultural fields are a vital resource for many species. These include insect pollinators, to whom field margins provide both nest sites and important resources (especially when adjacent crops are not in flower). Nesting pollinators travel relatively short distances from the nest to forage: most species of bee are known to travel less than two kilome...

2006

The aim of the present study was to investigate the effects of bee pollination of buckwheat crops on the seed productivity and plant development. Six plots each 4 m2 in size were arranged in a buckwheat field. Four plots in the field were isolated by a net. Nucs with bees were placed in two of the plots (one per plot). Plant productivity, height of plants and number of branches per marked plant...

Journal: :Journal of Plant Sciences 2011

Journal: :چغندرقند 0
حسنعلی شهبازی مربی پژوهشی مرکز تحقیقات کشاورزی و منابع طبیعی خراسان رضوی سید یعقوب صادقیان مطهر استاد مؤسسه تحقیقات ثبت و گواهی بذر و نهال

in order to transfer rhizomania resistance genes to improved sugar beet lines, crosses were made between 11 commercial resistant varieties and two improved inbred o-type lines of sugar beet (231 and 261) at agricultural research center of khorasan razavi   and jam sugar factory in 2007. o-types carried self fertile (sf) genes and contained male sterile (ms) genotypes. commercial varieties were ...

2001
THEODORE H. FLEMING CATHERINE T. SAHLEY J. NATHANIEL HOLLAND JOHN D. NASON J. L. HAMRICK

We studied variation in flowering phenology, fruit and seed set, and the abundance of the pollinators of four species of night-blooming Sonoran Desert columnar cacti for up to eight years at one site in Mexico and one year at one site in Arizona. We determined how spatiotemporal variation in plant–pollinator interactions affects the evolution of generalized pollination systems. We conducted pol...

2011
Rachael Winfree Ignasi Bartomeus Daniel P. Cariveau

Animals pollinate 87% of the world’s flowering plant species. Therefore, how pollinators respond to human-induced land-use change has important implications for plants and the species that depend on them. Here, we synthesize the published literature on how land-use change affects the main groups of pollinators: bees, butterflies, flies, birds, and bats. Responses to land-use change are predomin...

2017
Agnieszka Rewicz Radomir Jaskuła Tomasz Rewicz Grzegorz Tończyk

BACKGROUND Epipactis helleborine is an Eurasian orchid species which prefers woodland environments but it may also spontaneously and successfully colonise human-made artificial and disturbed habitats such as roadsides, town parks and gardens. It is suggested that orchids colonising anthropogenic habitats are characterised by a specific set of features (e.g., large plant size, fast flower produc...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید