نتایج جستجو برای: annual forbs

تعداد نتایج: 110865  

2008
Lance T. Vermeire Rodney K. Heitschmidt Marshall R. Haferkamp

Grazing systems may alter botanical composition and productivity of grasslands through differential use in time, space, or intensity. Seven simulated grazing treatments were applied six years in eastern Montana, USA to determine effects on plant community composition and standing crop. Treatments were moderate stocking (28.8 AUD ha 1 year ) of cattle using 3-pasture summer rotation, season-long...

2009
Robin G. Marushia Edith B. Allen

Exotic annual grasses are a major challenge to successful restoration in temperate and Mediterranean climates. Experiments to restore abandoned agricultural fields from exotic grassland to coastal sage scrub habitat were conducted over two years in southern California, U.S.A. Grass control methods were tested in 5 m2 plots using soil and vegetation treatments seeded with a mix of natives. The t...

2005
J. A. Ellis A. D. Walter J. F. Tooker M. D. Ginzel P. F. Reagel E. S. Lacey A. B. Bennett E. M. Grossman L. M. Hanks

We conducted Weld experiments to test the hypothesis that regulation of herbivorous pests in urban landscapes can be enhanced with forbs that provide Xoral resources for adult natural enemies. The herbivore was bagworm, Thyridopteryx ephemeraeformis (Haworth) (Lepidoptera: Psychidae), which is attacked by a guild of hymenopterous parasitoids. We established host shrubs in common garden planting...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2010
Timothy D Meehan Allen H Hurlbert Claudio Gratton

Mandates for biofuel and renewable electricity are creating incentives for biomass production in agricultural landscapes of the Upper Midwest. Different bioenergy crops are expected to vary in their effects on biodiversity and ecosystem services. Here, we use data from the North American Breeding Bird Survey to forecast the impact of potential bioenergy crops on avian species richness and the n...

Journal: :Environmental pollution 2002
J D Reeder G E Schuman

We evaluated the effects of livestock grazing on C content of the plant-soil system (to 60 cm) of two semi-arid grasslands: a mixed-grass prairie (grazed 12 years), and a short-grass steppe (grazed 56 years). Grazing treatments included season-long grazing at heavy and light stocking rates, and non-grazed exclosures. Significantly higher soil C (0-30cm) was measured in grazed pastures compared ...

2011
Steven S. Seefeldt Jeffery S. Conn

Orange hawkweed is a perennial European plant that has colonized roadsides and grasslands in south-central and southeast Alaska. This plant is forming near-monotypic stands, reducing plant diversity, and decreasing pasture productivity. A replicated greenhouse study was conducted in 2006 and repeated in 2007 to determine the efficacy of six herbicides (aminopyralid, clopyralid, picloram, piclor...

2012
S. M. Kulpa E. A. Leger E. K. Espeland E. M. Goergen

As wildland fire frequency increases around the globe, a better understanding of the patterns of plant community recovery in burned landscapes is needed to improve rehabilitation efforts. We measured establishment of seeded species, colonization of Bromus tectorum and other nonnative annual plants, and recovery of nonseeded native species in topographically distinct areas within five fires that...

2013
Guofang Liu Xiufang Xie Duo Ye Xuehua Ye Indree Tuvshintogtokh Bayart Mandakh Zhenying Huang Ming Dong

BACKGROUND The Mongolian steppe is one of the most important grasslands in the world but suffers from aridization and damage from anthropogenic activities. Understanding structure and function of this community is important for the ecological conservation, but has seldom been investigated. METHODOLOGY/PRINCIPAL FINDINGS In this study, a total of 324 quadrats located on the three main types of...

Journal: :مرتع و آبخیزداری 0
رضا سیاه منصور دانشجوی دکتری علوم مرتع، دانشگاه آزاد اسلامی، واحد علوم و تحقیقات تهران حسین ارزانی استاد دانشکدة منابع طبیعی دانشگاه تهران محمد جعفری استاد دانشکدة منابع طبیعی دانشگاه تهران سید اکبر جوادی استادیار دانشکدة کشاورزی و منابع طبیعی، دانشگاه آزاد اسلامی، واحد علوم و تحقیقات تهران علی طویلی دانشیار دانشکدة منابع طبیعی دانشگاه تهران

fire consider as a factor and basic management in rangeland in order to reform of composition and biological diversity that use in rangeland ecosystems. this project was established to deal with the effect of fire in the research center for rangeland. zagheh locale where is in 35 km of north eastern of khoramabad with 1960 meters above sea level. the average comparison and analysis show that he...

2007
Wilfred O. Odadi Truman P. Young J. B. Okeyo-Owuor

The impacts of wild herbivores on cattle diet selection were investigated in an East African rangeland during August 2001 and February 2002. The study compared cattle diets in plots exclusively accessible to cattle (C) and those accessible to megaherbivores (elephants and giraffes), non-megaherbivore wild herbivores . 15 kg (zebras, hartebeests, Grant’s gazelles, oryx, elands, and buffaloes) an...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید