نتایج جستجو برای: Bromus tomentollus
تعداد نتایج: 1398 فیلتر نتایج به سال:
اکولوژِیستها و مدیران محیط زیست به طور فزایندهای مدلهای پیشبینی را به عنوان وسیلهای برای بررسی الگوهای پراکنش گونهای تأکید میکنند. هدف تحقیق حاضر بررسی کارآمدی مدل خطی تعمیم یافته (GLM) و مدل جمعی تعمیم یافته (GAM) در تعیین روابط بین پوشش گیاهی و عوامل محیطی در مراتع خطه ریز است. شاخصهای محیطی مطالعه شده شامل خصوصیات خاک (15 مورد)، عوامل توپوگرافی (3 مورد) و عوامل اقلیمی (3 مورد) بودند. ...
Bromus sect. Triniusa is revised in Khorassan based on the new taxonomic concepts of Bromus danthoniae complex group and a remarkable herbarium material collected from Khorassan (Kopetdagh, northeastern Iran), as the main center of its diversity. Bromus turcomanicus, a narrow endemic species in central Kopetdagh hitherto known only from the type locality in southern Turkmenistan, is newly recor...
Chromosome morphometry and nuclear DNA content are useful data for cytotaxonomy and to understand the evolutionary history of different taxa. For the genus Bromus Linnaeus, 1753, distinct ploidy levels have been reported, occurring from diploid to duodecaploid species. The geographic distribution of Bromus species has been correlated with chromosome number and ploidy level. In this study, the a...
A prominent goal of invasive plant management is to prevent or reduce the spread of invasive species into uninvaded landscapes and regions. Monitoring and control efforts often rely on scientific knowledge of suitable habitat for the invasive species. However, rising temperatures and altered precipitation projected with climate change are likely to shift the geographic range of that suitable ha...
به منظور بررسی تنوع ژنتیکی موجود در گونه بروموس تومنتولوس ، 12 ژنوتیپ از گونه فوق که در بانک ژن گیاهان مرتعی نگهداری می شوند و از نقاط مختلف کشور جمع آوری شده اند از لحاظ 11 صفت مورفولوژیکی مورد مطالعه قرار خواهد گرفتند. تحقیق فوق در قالب طرح پایه بلوکهای کامل تصادفی و در سه تکرار انجام شد. با توجه به تجزیه واریانس داده های حاصل در قالب طرح فوق الذکر، اختلاف معنی داری بین توده ها مشاهده گردید ک...
Abiotic factors have a strong infl uence on where annual Bromus species are found. At the large regional scale, temperature and precipitation extremes determine the boundaries of Bromus occurrence. At the more local scale, soil characteristics and climate infl uence distribution, cover, and performance. In hot, dry, summerrainfall-dominated deserts (Sonoran, Chihuahuan), little or no Bromus is ...
Abundance of invasive plants is often attributed to their ability ot outcompete native species. We compared resource acquisition and allocation of the invasive annual grass Bromus madritensis subsp. rubens with that of two native Mojave Desert annuals, Vulpia octoflora and Descurainia pinnata, in a glasshouse experiment. Each species was grown in monoculture at two densities and two levels of N...
UNLABELLED PREMISE OF THE STUDY Phenolic compounds exuded by roots have been implicated in allelopathic interactions among plants. Root enzymes that destroy phenolics may protect plants against allelopathic inhibition and thus may aid in invasiveness. Phenolic-degrading enzymes are chiefly found in aboveground plant parts, but have also been previously reported in root tissues where the enzy...
A former lectotype for Bromus cincinnatus Ten. (Poaceae) has been superseded, as it is in serious conflict with the protologue. Another element of protologue designated effective lectotype. The new identified coespecific intermedius Guss., a Mediterranean species L. subg. Bromus. combination Helictochloa panormitana (Lojac.) Romero Zarco proposed originally described Avena australis Parl., nom....
Exotic invasive species can directly and indirectly influence natural ecological communities. Cheatgrass (Bromus tectorum) is non-native to the western United States and has invaded large areas of the Great Basin. Changes to the structure and composition of plant communities invaded by cheatgrass likely have effects at higher trophic levels. As a keystone guild in North American deserts, graniv...
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