نتایج جستجو برای: shrubs

تعداد نتایج: 3863  

2002
Jorge Castro Regino Zamora José A. Hódar José M. Gómez

Common techniques currently used for afforestation in the Mediterranean basin consider the pre-existing vegetation (mainly shrubs) as a source of competition for trees, and consequently it is generally eliminated before planting. Nevertheless, it has been demonstrated that woody plants can facilitate the establishment of understory seedlings in environments that, like the Mediterranean area, ar...

2014
Rebecca E. Hewitt Teresa N. Hollingsworth Stuart Chapin D. Lee

Climate-induced changes in the tundra fire regime are expected to alter shrub abundance and distribution across the Arctic. However, little is known about how fire may indirectly impact shrub performance by altering mycorrhizal symbionts. resprouting Betula nana shrubs across a fire-severity gradient after the largest tundra fire recorded in the Alaskan Arctic resolution. Variation in fungal co...

Journal: :مرتع و آبخیزداری 0
طاهره صادقی شاهرخت کارشناس ارشد مرتع داری، دانشگاه فردوسی مشهد محمد جنگجو دانشیار گروه مرتع و آبخیزداری دانشکده منابع طبیعی و محیط زیست، دانشگاه فردوسی مشهد منصور مصداقی استاد مدعو، دانشکده منابع طبیعی و محیط زیست دانشگاه فردوسی مشهد

rangeland shrubs may provide mechanical facilitation on their understory plants, by protecting themagainst the livestock grazing. however, such a facilitation effect may vary depending on the rangelandutilization rate. in a field research, mechanical facilitation of rangeland shrubs was compared in ahighly grazed, a moderately grazed and an enclosure site; in an arid rangeland, kakhak, gonabad,...

2009

Question: Does the proximity of shrubs affect seasonal water stress of young Austrocedrus chilensis trees (a native conifer of the Austral Temperate Forest of South America) in xeric sites? Location: A. chilensis xeric forest in northwest Patagonia, Argentina. Methods: We examined the dependence of predawn twig water potential on tree development (seedling to adult) and proximity to nurse shrub...

2016
Francisco Sánchez-Piñero Fernando Urbano-Tenorio

The distribution and behavior of foraging animals usually imply a balance between resource availability and predation risk. In some predators such as scorpions, cannibalism constitutes an important mortality factor determining their ecology and behavior. Climbing on vegetation by scorpions has been related both to prey availability and to predation (cannibalism) risk. We tested different hypoth...

2008
Rosemary L. Pendleton Burton K. Pendleton Karen R. Wetherill Terry Griswold

USDA Forest Service Proceedings RMRS-P-52. 2008 In: Kitchen, Stanley G.; Pendleton, Rosemary L.; Monaco, Thomas A.; Vernon, Jason, comps. 2008. Proceedings—Shrublands under fire: disturbance and recovery in a changing world; 2006 June 6–8; Cedar City, UT. Proc. RMRS-P-52. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. Rosemary L. Pendleton and...

2008
C. Armas O. E. Sala

The plant community in the Patagonian steppe is arranged in two structural patch types: scattered grasses and shrubs, which are often surrounded by a ring of grasses. Previous studies suggested that this pattern results from a cyclical succession driven by plant interactions. Although there is a good understanding of the factors affecting the formation of the grass rings encircling the shrubs, ...

2005
Jose Gómez Regino Zamora Janis Boettinger

Question: Is the facilitative effect of nurse shrubs on early recruitment of trees mediated by a ‘canopy effect’ (microclimate amelioration and protection from herbivores), a ‘soil effect’ (modification of soil properties), or both? Location: Two successional montane shrublands at the Sierra Nevada Protected Area, SE Spain. Method: Seedlings of Quercus and Pinus species were planted in four exp...

2016
Sarah J. Thompson Colleen M. Handel Rachel M. Richardson Lance B. McNew

Climate change is facilitating rapid changes in the composition and distribution of vegetation at northern latitudes, raising questions about the responses of wildlife that rely on arctic ecosystems. One widely observed change occurring in arctic tundra ecosystems is an increasing dominance of deciduous shrub vegetation. Our goals were to examine the tolerance of arctic-nesting bird species to ...

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