نتایج جستجو برای: plants cover composition
تعداد نتایج: 551987 فیلتر نتایج به سال:
BACKGROUND The noctuid Helicoverpa armigera is one of the key cotton pests in the Old World. One possible pest regulation method may be the management of host crop in the landscapes. For polyphagous pests such as H. armigera, crop diversity and rotations can offer sequential and alternate resources that may enhance abundance. We explore the impact of landscape composition and host crop diversit...
BACKGROUND AND AIMS Adventitious sprouting from the hypocotyle and roots in monocarpic herbs has been confirmed in previous experimental studies as a means to avoid bud limitation after severe injury in annual and biennial plants. Data regarding the role of adventitious sprouting in natural populations, however, were lacking. The aim of the present study was to assess whether adventitious sprou...
Soil conditions and microclimate are important determinants of the fine-scale distribution of plant species in the Arctic, creating locally heterogeneous vegetation. We hypothesize that root-associated fungal (RAF) communities respond to the same fine-scale environmental gradients as the aboveground vegetation, creating a coherent pattern between aboveground vegetation and RAF. We explored how ...
The abundance of plants with extrafloral nectaries was determined for a series of temperate habitats in Nebraska. Mean cover of plants with extrafloral nectaries was 1.3% in riparian forest understory, 1.8% in virgin deciduous forest understory, 0.0% in tall-grass prairie, and 8.3% in sandhill prairie. Sandhills prairie contained distinct communities with different mean cover of plants with ext...
in the absence of herbicides, cover crops play an important role for weed management in organic than in conventional farming. therefore, in order to evaluate the effects of cover crop management and plant density of buckwheat (fagopyrum esculentum) as cover crop on weed suppression, a field experiment was conducted at the research farm of university of zanjan, during the growing season of 2011....
Golan Bel and Yosef Ashkenazy Department of Environmental Physics, Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus 84990, Israel (Dated: May 11, 2014) Abstract Psammophilous plants are special plants that flourish in sand moving environments. There are two main mechanisms by which the wind affects these plants: (i) sand drift exposes roots and cov...
Grazing effect on vegetation cover and soil factors in natural environments is inevitable. The present study was conducted to investigate the effect of grazing on soil factors and distribution of plant species in grazed and non-grazed areas in rangelands of western parts of Hoz-e-Soltan Lake, Qom. Systematic-randomized sampling method was used alongside of 4 transects. Adjacent to the transects...
Increased livestock densities near artificial watering sites create disturbance gradients called piospheres. We studied responses of alien and native annual plants and native perennial plants within 9 piospheres in the Mojave Desert of North America. Absolute and proportional cover of alien annual plants increased with proximity to watering sites, whereas cover and species richness of native an...
For studying vegetation cover in Choghakhor wetland located in Chaharmahal-o-Bakhtiari province (W Iran), some zones of vegetation life forms were determined and also digitized in order to produce the primary map of plant cover by using LISS-IV sensor of IRS satellite with the spatial resolution of 5.8 m. As aquatic plants in Choghakhor wetland were fully grown, homogeneity or heterogeneity of ...
Plant community assembly can be influenced by many environmental factors. In seasonal wetlands, most studies focus on the considerable variation that occurs from hydro-regime (patterns of inundation and desiccation). Other factors their interactions also influence plants but are seldom studied, including nutrient thatch levels. Furthermore, responses aquatic terrestrial functional groups provid...
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