نتایج جستجو برای: grassland

تعداد نتایج: 10371  

2016
James C. Han Stephen L. Young

Invasive and native plant species compete for resources in similar pools, with disturbances often favoring the invader. Yet, increased climate variability may be shifting the competitive edge back toward the natives. We conducted field studies in perennial grasslands to determine the effects of clipping and drought on resource aVailability (light and moisture) and subsequent establishment of Ca...

2016
Anna Ma Nianpeng He Guirui Yu Ding Wen Shunlei Peng

The accurate estimate of grassland carbon (C) is affected by many factors at the large scale. Here, we used six methods (three spatial interpolation methods and three grassland classification methods) to estimate C storage of Chinese grasslands based on published data from 2004 to 2014, and assessed the uncertainty resulting from different integrative methods. The uncertainty (coefficient of va...

2006
Achilleas Psomas Niklaus E. Zimmermann Mathias Kneubühler Tobias Kellenberger Klaus Itten

Dry grasslands in Switzerland are species-rich habitats resulting from a traditional agricultural land use. Almost 40% of plant and in some cases over 50% of the animal species present on dry grasslands are included in the red lists, and are classified as endangered or threatened. Furthermore, it is estimated that about 90% of dry grassland in Switzerland have been transformed to other land cov...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2013
Keith L Kline Nagendra Singh Virginia H Dale

The conclusions of a recent study by Wright and Wimberly (1) suggesting that corn/ soy cultivation in the Western Corn Belt (WCB) “threatens grasslands” are questionable because of the methods and data used. The study (1) compared National Agricultural Statistics Service (NASS) Cropland Data Layer (CDL) for 2006 with CDL for 2011 (2) and found 530,000 ha of net “grassland conversion” to corn/so...

2017
Yingxin Gu Stephen P. Boyte Bruce K. Wylie Larry L. Tieszen

This study dynamically monitors ecosystem performance (EP) to identify grasslands potentially suitable for cellulosic feedstock crops (e.g., switchgrass) within the Greater Platte River Basin (GPRB). We computed grassland site potential and EP anomalies using 9-year (2000–2008) time series of 250 m expedited moderate resolution imaging spectroradiometer Normalized Difference Vegetation Index da...

2000
Zerihun Woldu Mohammed Saleem

The species composition of grazing lands can be influenced by livestock and grazing pressure. A study on manure seed bank was conducted in Ghinchi highland Research Site in Ethiopia between 1995 and 1997. The data on species composition and life-form of the plants germinating in pots receiving air dried manure were compared with species composition of experimental plots in natural grassland sub...

2016
Athole H. Marshall Rosemary P. Collins Mike W. Humphreys John Scullion

Grasslands cover a significant proportion of the agricultural land within the UK and across the EU, providing a relatively cheap source of feed for ruminants and supporting the production of meat, wool and milk from grazing animals. Delivering efficient animal production from grassland systems has traditionally been the primary focus of grassland-based research. But there is increasing recognit...

Journal: :Proceedings. Biological sciences 2006
Philip D McLoughlin Mark S Boyce Tim Coulson Tim Clutton-Brock

Individuals are predicted to maximize lifetime reproductive success (LRS) through selective use of resources; however, a wide range of ecological and social processes may prevent individuals from always using the highest-quality resources available. Resource selection functions (RSFs) estimate the relative amount of time an individual spends using a resource as a function of the proportional av...

Journal: :Remote Sensing 2017
Mbulisi Sibanda Onisimo Mutanga Mathieu Rouget Lalit Kumar

The ability of texture models and red-edge to facilitate the detection of subtle structural vegetation traits could aid in discriminating and mapping grass quantity, a challenge that has been longstanding in the management of grasslands in southern Africa. Subsequently, this work sought to explore the robustness of integrating texture metrics and red-edge in predicting the above-ground biomass ...

2001
ANNE FERNALD CROSS WILLIAM H. SCHLESINGER

This study examined the concentration of organic and inorganic phosphorus in surface soils of a Bouteloua gracilis-Bouteloua eriopoda grassland, and a Larrea tridentata shrubland, in the northern Chihuahuan Desert, New Mexico, USA. In this desert where the grassland vegetation has a uniform spatial distribution and individual shrubs have a patchy spatial distribution across the landscape, veget...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید