نتایج جستجو برای: herbaceous distillates

تعداد نتایج: 4501  

2007
Barbara Allen-Diaz Randall D. Jackson

Livestock grazing effects on herbaceous vegetation diversity and ecosystem function are summarized from peer-reviewed literature. Ecosystem responses are linked to grazing management via residual dry matter (RDM), which is alternatively called litter or mulch. Residual dry matter is the dead herbaceous aboveground biomass remaining on a site at the time of autumn germination in annual grassland...

Journal: :محیط زیست طبیعی 0
مرضیه نوبخت دانش آموخته کارشناسی ارشد، دانشکده منابع طبیعی، دانشگاه گیلان، ایران حسن پوربابایی دانشیار دانشکده منابع طبیعی، دانشگاه گیلان، ایران مرضیه بیگم فقیر عضو هیأت علمی دانشکده علوم پایه، دانشگاه گیلان، ایران رویا عابدی دانش آموخته کارشناسی ارشد، دانشکده منابع طبیعی، دانشگاه گیلان، ایران

in order to investigate variations in plant diversity in dr. dorostkar's forest reservoir, located in gisoum talesh, 44 sampling plots were applied by the randomized-systematic method. the diameter of all tree species (dbh?5 cm) was measured in 400 m2 (20×20 m) square sampling plots. in addition, the number of individuals of shrubs and saplings (dbh?5 cm) were enumerated in circular 100 m2...

2016
Kendra L. Chritz Scott A. Blumenthal Thure E. Cerling Hans Klingel

Megaherbivores (>1000 kg) are critical for ecosystem health and function, but face population collapse and extinction globally. The future of these megaherbivore-impoverished ecosystems is difficult to predict, though many studies have demonstrated increasing representation of C3 woody plants. These studies rely on direct observational data, however, and tools for assessing decadal-scale change...

1998

0 We measured competition intensity "CI# between herbaceous vegetation and tree seedlings "Quercus macrocarpa and Q[ ellipsoidalis# along an experimental moistureÐ light gradient[ Contrasting theories were tested by comparing variation in competition intensity to changes in neighbour biomass and resource supply and demand[ 1 CI based on survival was inversely correlated with net soil water supp...

2006
M. Straatsma

Floodplain roughness parameterization is one of the key elements of hydrodynamic modeling of river flow, which is directly linked to safety level estimation of lowland fluvial areas. Necessary input parameters are median grain size for unvegetated areas, vegetation density for forest and vegetation height and density for herbaceous vegetation. This paper presents a method for spatially distribu...

2016
Edward K. Faison Stephen DeStefano David R. Foster Glenn Motzkin Joshua M. Rapp

Ungulates are leading drivers of plant communities worldwide, with impacts linked to animal density, disturbance and vegetation structure, and site productivity. Many ecosystems have more than one ungulate species; however, few studies have specifically examined the combined effects of two or more species on plant communities. We examined the extent to which two ungulate browsers (moose [Alces ...

2017
Stavros D Veresoglou Monika Wulf Matthias C Rillig

In late-successional environments, low in available nutrient such as the forest understory, herbaceous plant individuals depend strongly on their mycorrhizal associates for survival. We tested whether in temperate European forests arbuscular mycorrhizal (AM) woody plants might facilitate the establishment of AM herbaceous plants in agreement with the mycorrhizal mediation hypothesis. We used a ...

Journal: :Environmental management 2011
Kirk W Davies Jon D Bates Aleta M Nafus

Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis Beetle & Young) communities frequently are mowed in an attempt to increase perennial herbaceous vegetation. However, there is limited information as to whether expected benefits of mowing are realized when applied to Wyoming big sagebrush communities with intact understory vegetation. We compared vegetation and soil nutrient concentr...

Journal: :Journal of Insect Science 2003
David Lubertazzi Walter R. Tschinkel

Ant communities in longleaf pine habitats are poorly known and hence the naturally occurring ant assemblages of a large portion of southeastern North America are not well understood. This study examined the diverse ant community found in the longleaf pine flatwoods of north Florida and tested how ant diversity changes along a herbaceous ground cover gradient. Restoring the ground cover to its o...

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