Spatial heterogeneity in woody cover affects biodiversity and ecosystem function, and may be particularly influential in savanna ecosystems. Browsing and interactions with herbaceous plants can create and maintain heterogeneity in woody cover, but the relative importance of these drivers remains unclear, especially when considered across multiple edaphic contexts. In African savannas, abandoned...

The identification of a widespread contaminant of plant cell cultures is reported. Mycobacterium scr~luhtceum Prissick and Masson appears as yellow colonies on the medium and plant tissues of many ornamentals being propagated in vitro. It is a Gram positive and acid fast bacterium and requires a specifically formulated medium for growth in pure culture. Many laboratories have alluded to this co...

Wild herbivores and livestock share the majority of rangelands worldwide, yet few controlled experiments have addressed their individual, additive, and interactive impacts on ecosystem function. While ungulate herbivores generally reduce standing biomass, their effects on aboveground net primary production (ANPP) can vary by spatial and temporal context, intensity of herbivory, and herbivore id...

A study was carried out to investigate the utility of airborne hyperspectral and satellite L-band Synthetic Aperture Radar (SAR) data for estimating fractional coverages of herbaceous, coastal scrub, and bare ground cover types on the central California coast. Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) imagery collected in September of 2008 and Phased Array L-band SAR (PALSAR) (HH-...

We present an efficient method for monitoring woody (i.e., evergreen) and herbaceous (i.e., ephemeral) vegetation in Mediterranean forests at a sub pixel scale from Normalized Difference Vegetation Index (NDVI) time series derived from the Moderate Resolution Imaging Spectroradiometer (MODIS). The method is based on the distinct development periods of those vegetation components. In the dry sea...

Knowledge of the relationship between stocking rate or grazing intensity and plant production is fundamental to the sustainable management of rangelands. The general management paradigm is that plant production declines as stocking rate increases. Our objective was to determine the impact of stocking rate on herbaceous production of a sand sagebrush (Artemisia filifolia Torr.)grassland. Stockin...

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...

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...

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...

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...