نتایج جستجو برای: range forage
تعداد نتایج: 678674 فیلتر نتایج به سال:
California sea lions increased from approximately 50 000 to 340 000 animals in the last 40 years, and their pups are starving and stranding on beaches in southern California, raising questions about the adequacy of their food supply. We investigated whether the declining sea lion pup weight at San Miguel rookery was associated with changes in abundance and quality of sardine, anchovy, rockfish ...
in this study 18 forage corn (zea mays l.) hybrid varieties were evaluated based on rcbd with four replications in khorasan razavi agricultural and natural resources research centre, iran, on 2008-2009. result of analysis of variance showed that there was significantly difference between hybrids in forage yield, ear weight and ear to biomass ratio. results of hybrids mean comparison with duncan...
We assessed national scale changes in the forage plants of bumblebees in Britain, as a means of providing quantitative evidence for the likely principal cause of declines in bumblebee species. We quantified the relative value of native and long-established plant species as forage (nectar and pollen) resources for bumblebees by collating visitation data from 14 field sites across Britain. Twenti...
For determination of grazing capacity, information of forage quality is essential which is influenced by various factors. The main objective of this research was investigation on effects of species, phenological stages, and life form on values of forage quality indices of six range species. Species were two grasses (Bromus tomentellus and Dactylis glomerata), two forbs (Ferula ovina and Coronil...
1. Foraging range is a key aspect of the ecology of 'central place foragers'. Estimating how far bees fly under different circumstances is essential for predicting colony success, and for estimating bee-mediated gene flow between plant populations. It is likely to be strongly influenced by forage distribution, something that is hard to quantify in all but the simplest landscapes; and theories o...
Recent research in range ecology has emphasized the importance of forage quality as a key indicator of rangeland condition. However, we lack tools to evaluate forage quality at scales appropriate for management. Using canopy reflectance data to measure forage quality has been conducted at both laboratory and field levels separately, but little work has been conducted to evaluate these methods s...
In many studies, topographic factors have been considered as an important factor in establishing the vegetation in different ecosystems. So, it affects vegetation composition and diversity by influencing soil moisture, fertility and soil depth. The aim of this research was to investigate the effects of slope, elevation and geographical aspects on species growth, forage production and vegetation...
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