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Full-Text Articles in Life Sciences
Rapid Response Of A Grassland Ecosystem To An Experimental Manipulation Of A Keystone Rodent And Domestic Livestock, Ed Frederickson
Rapid Response Of A Grassland Ecosystem To An Experimental Manipulation Of A Keystone Rodent And Domestic Livestock, Ed Frederickson
Ed L. Frederickson
Megaherbivores and small burrowing mammals commonly coexist and play important functional roles in grassland ecosystems worldwide. The interactive effects of these two functional groups of herbivores in shaping the structure and function of grassland ecosystems are poorly understood. In North America's central grasslands, domestic cattle (Bos taurus) have supplanted bison (Bison bison), and now coexist with prairie dogs (Cynomys spp.), a keystone burrowing rodent. Understanding the ecological relationships between cattle and prairie dogs and their independent and interactive effects is essential to understanding the ecology and important conservation issues affecting North American grassland ecosystems. To address these needs, we established …
Mesquite: A Long View, Ed Frederickson, Curtis Monger, Eduardo Guevara, Dan Fredrickson
Mesquite: A Long View, Ed Frederickson, Curtis Monger, Eduardo Guevara, Dan Fredrickson
Ed L. Frederickson
Mesquite (Prosopis glandulosa) is among the most successful plants in Northern México and America"s arid Southwest. Mesquite optimizes pollinator services and reproductive effort, resulting in seeds that persist in herbivore digestive tracts and soil seed banks for extended periods. An extensive root system fully occupies the soil profile long distances from its base, allowing it to harvest water and nutrients with extraordinary efficiency. Root nodules harbor nitrogen-fixing bacteria allowing mesquite to overcome usual nitrogen limitations. Mesquite survival is determined early, but once established, it is long-lived, often benefiting from hardships killing most plants. So with mesquite"s superior adaptations and competitive …
In Search Of "Organ Iii" Strata-A Sedimentary Record Of The Medieval Warm Period (Ca. Ad 900 To 1300), Ed Frederickson, Curtis Monger, Katie Laney
In Search Of "Organ Iii" Strata-A Sedimentary Record Of The Medieval Warm Period (Ca. Ad 900 To 1300), Ed Frederickson, Curtis Monger, Katie Laney
Ed L. Frederickson
The period AD 900 to 1300, internationally referred to as the Medieval Warm Period, is a critical time for the archaeological record of the Southwestern USA. During the Medieval Warm Period both alluvial and eolian sedimentation increased, but not to the magnitude of the middle Holocene (the Altithermal) or since Historical erosion began in the middle 1850s (the end of the Little Ice Age). Locally, the term "Organ III" has been given to the Medieval Warm Period allostratigraphic unit. It is a subtle unit stratigraphically between Altithermal sediments (Organ I) and Historical sediments. Diagnostic features for identifying these three units …
Composition Of Ceanothus Gregii Oil As Determined By Steam Distillation And Solid-Phase Microextraction, Ed Frederickson, R. Estell, M. Lucero
Composition Of Ceanothus Gregii Oil As Determined By Steam Distillation And Solid-Phase Microextraction, Ed Frederickson, R. Estell, M. Lucero
Ed L. Frederickson
Ceanothus gregii Gray was collected from the Jornada Experimental Range in south central New Mexico. Current year’s growth was collected from ten plants found within an approximate 50 m radius of the GPS coordinates N32°40.605’ and W106°33.486’at an altitude of 1,741 m during July 2001. Composite samples of the plants were steam distilled in triplicate, and the composite oil was analyzed using both GC-FID and GC/MS. The volatile composition of the same plants was also examined using solid-phase microextraction (SPME) with a 100?m polydimethylsiloxane fiber. Mass spectra and retention indices were used to identify 41 previously described compounds. Methyl salicylate …