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Full-Text Articles in Life Sciences
Modelling Emergent Patterns Of Dynamic Desert Ecosystems, J. Stewart, A. J. Parson, J. Wainwright, G. S. Okin, B. T. Bestelmeyer, E. L. Frederickson, W. H. Schlesinger
Modelling Emergent Patterns Of Dynamic Desert Ecosystems, J. Stewart, A. J. Parson, J. Wainwright, G. S. Okin, B. T. Bestelmeyer, E. L. Frederickson, W. H. Schlesinger
Ed L. Frederickson
In many desert ecosystems vegetation is both patchy and dynamic: vegetated areas are interspersed with patches of bare ground, and both the positioning and the species composition of the vegetated areas exhibit change through time. These characteristics lead to the emergence of multi-scale patterns in vegetation that arise from complex relationships between plants, soils and transport processes. Previous attempts to probe the causes of spatial complexity and predict responses of desert ecosystems tend to be limited in their focus: models of dynamics have been developed with no consideration of the inherent patchiness in the vegetation, or else models have been …
An Assessment Of Behavioural Syndromes In Rangeland-Raised Beef Cattle, Robert Wesley, Andrés Cibils, J. Mulliniks, Emily Pollak, Mark Petersen, Ed Frederickson
An Assessment Of Behavioural Syndromes In Rangeland-Raised Beef Cattle, Robert Wesley, Andrés Cibils, J. Mulliniks, Emily Pollak, Mark Petersen, Ed Frederickson
Ed L. Frederickson
Individuals in most animal groups exhibit consistent behavioural differences across situations or over time known as behavioural syndromes. We conducted a study with a herd of young rangeland-raised cows to determine whether animals exhibited consistent differences in foraging behaviours across contexts (confinement vs. rangeland pasture) and could be clustered into behavioural type groups on the basis of a suite of correlated behaviours. We also investigated whether cows with different behavioural types performed differently in this environment. Supplement consumption rate (SCR) in confinement was used to select two groups of cows (fast eaters vs. slow eaters). This classification was validated by …
Characterising The Spatial And Temporal Activities Of Free-Ranging Cows From Gps Data, Dean Anderson, Craig Winters, Rick Estell, Ed Frederickson, Marek Doniec, Carrick Detweller, Daniela Rus, Darren James, Barbara Nolen
Characterising The Spatial And Temporal Activities Of Free-Ranging Cows From Gps Data, Dean Anderson, Craig Winters, Rick Estell, Ed Frederickson, Marek Doniec, Carrick Detweller, Daniela Rus, Darren James, Barbara Nolen
Ed L. Frederickson
Electronic tracking provides a unique way to document behaviour by cows on a continuous basis. Over 2 years 17 beef cows with calves were fitted with global positioning system (GPS) devices programmed to record uncorrected GPS locations at 1-s intervals in a semi-desert rangeland. Each cow was periodically observed during daylight hours and foraging, walking and stationary (standing/lying) activity times were recorded across days and individual cows to calculate a mean travel rate for each activity. Data without observers present were collected immediately preceding and following the abrupt weaning of calves at between 223 and 234 days of age to …
Managing Livestock Using Animal Behavior: Mixed Species Stocking And Flerds, D. M. Anderson, E. L. Frederickson, R. E. Estell
Managing Livestock Using Animal Behavior: Mixed Species Stocking And Flerds, D. M. Anderson, E. L. Frederickson, R. E. Estell
Ed L. Frederickson
Mixed-species stocking can foster sound landscape management while offering economic and ecological advantages compared with mono-species stocking. Producers contemplating a mixed-species enterprise should reflect on several considerations before implementing this animal management strategy. Factors applicable to a particular producer's landscape must be considered together with goals and economic constraints before implementing mixed-species stocking. A major consideration when using mixed-species stocking is how to deal with predation losses, especially among small ruminants. An approach being adopted in some commercial operations capitalizes on using innate animal behaviors to form cohesive groups of two or more livestock species that consistently remain together under …
Distribution Of Antiherbivory Compounds In Flourensia Cernua, Ed Frederickson, Richard Estell, James Darren, Dean Anderson
Distribution Of Antiherbivory Compounds In Flourensia Cernua, Ed Frederickson, Richard Estell, James Darren, Dean Anderson
Ed L. Frederickson
Flourensia cernua is serving as a shrub model to study the influence of terpenes on intake by livestock at this location. Two studies (n=20 plants per study) were conducted to examine within plant distribution of volatile compounds to improve sampling protocol. Leaves from 3 positions (outer canopy, subcanopy, and basal) were collected from 4 quadrants (based on ordinal direction) in Exp. 1. Leaves were removed from 2 leaders of current year's growth for each position in each quadrant. In Exp. 2, 10 leaders of current year's growth were collected from the outer canopy in each quadrant and 3 leaf age …
Foraging Behavior Of Heritage Versus Recently Introduced Herbivores On Desert Landscapes Of The American Southwest, Ed Frederickson, H. Peinetti, Debra Peters, Andres Cibils, J. Roacho-Estrada, Andrea Laliberte
Foraging Behavior Of Heritage Versus Recently Introduced Herbivores On Desert Landscapes Of The American Southwest, Ed Frederickson, H. Peinetti, Debra Peters, Andres Cibils, J. Roacho-Estrada, Andrea Laliberte
Ed L. Frederickson
Since the 1800s managed grasslands and shrublands of the arid American Southwest have been grazed predominantly by cattle originally bred for temperate climates in northern Europe. A heritage breed, the criollo cattle, has survived in northern Mexico for more than 400 years under desert-like conditions of low and variable rainfall, hot temperatures in the growing season, and both spatially and temporally scarce levels of primary production. We tested the hypothesis that the heritage breed has a broader spatial foraging distribution under harsh environmental conditions, and that its distribution is driven by environmental variables which differ from those that control the …
Characterizing Foraging Patterns Among Cattle And Bonded And Non-Bonded Small Ruminants Using Spatial Point Process Techniques, Ed Frederickson, Dean Anderson, Leigh Murray, Peixn Sun, Richard Estell
Characterizing Foraging Patterns Among Cattle And Bonded And Non-Bonded Small Ruminants Using Spatial Point Process Techniques, Ed Frederickson, Dean Anderson, Leigh Murray, Peixn Sun, Richard Estell
Ed L. Frederickson
Two mixed-species livestock groups were monitored while foraging on 410 ha of brush-infested Southern New Mexico rangeland during July and August 1988. The groups consisted of crossbred Bos taurus and Bos indicus beef cattle with white-faced sheep (Ovis aries) and mohair goats (Capra hircus). The bonded group consisted of small ruminants that had their behaviours modified through socialization with cattle to form a flerd in which small ruminants consistently remained near cattle. Small ruminants in the non-bonded group had not been socialized with cattle. A subset of animal location data measured during the morning over five days for both the …
Dust Emissions From Undisturbed And Disturbed, Crusted Playa Surfaces: Cattle Trampling Effects, Ed Frederickson, Teddy Zobeck, Robert Van Pelt, Matthew Baddock
Dust Emissions From Undisturbed And Disturbed, Crusted Playa Surfaces: Cattle Trampling Effects, Ed Frederickson, Teddy Zobeck, Robert Van Pelt, Matthew Baddock
Ed L. Frederickson
Dry playa lake beds can be significant sources of fine dust emission. This study used a portable field wind tunnel to quantify the PM10 emissions from a bare, fine-textured playa surface located in the far northern Chihuahua Desert. The natural, undisturbed crust and its subjection to two levels of animal disturbance (one and ten cow passes) were tested. The wind tunnel generated dust emissions under controlled conditions for firstly an initial blow-off of the surface, followed by two longer runs with sand added to the flow as an abrader material. Dust was measured using a GRIMM particle monitor. For the …
Differentiating Among Plant Spectra By Combining Ph Dependent Photoluminescence Spectroscopy With Multi-Way Principal Component Analysis (Mpca), Ed Frederickson, Dean Anderson, T. Danielson, S. Obeidet, G. Rayson, R. Estell, B. Bai
Differentiating Among Plant Spectra By Combining Ph Dependent Photoluminescence Spectroscopy With Multi-Way Principal Component Analysis (Mpca), Ed Frederickson, Dean Anderson, T. Danielson, S. Obeidet, G. Rayson, R. Estell, B. Bai
Ed L. Frederickson
Photoluminescence spectroscopic probes offer the potential for differentiation among plant species in real-time. Spectral emission signatures (excitation at 365 nm) from three different pH (2.2, 7.5 and 12.5) phosphate buffered saline (PBS) extracts from two grasses, Sporobolus flexuosus (Thurb. ex Vasey) Rydb., [mesa dropseed], and Pleuraphis mutica Buckley [tobosa], two forbs, Dimorphocarpa wislizenii (Engelm.) Rollins [spectacle pod], and Sphaeralcea incana Torrey [pale globemallow], and leaves and twigs from two shrubs Flourensia cernua DC. [tarbush], and Atriplex canescens (Pursh) Nutt., [fourwing saltbush] were examined. Since pH has been shown to be pivotal in affecting extraction effi- ciency of other plant compounds …
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 …
Dust Emissions From Undisturbed And Disturbed, Crusted Playa Surfaces: Cattle Trampling Effect, Ed Frederickson, Teddy Zobeck, Matthew Baddock, Robert Van Pelt
Dust Emissions From Undisturbed And Disturbed, Crusted Playa Surfaces: Cattle Trampling Effect, Ed Frederickson, Teddy Zobeck, Matthew Baddock, Robert Van Pelt
Ed L. Frederickson
Dry playa lake beds can be a significant source of fine dust emissions during high wind events in arid and semiarid landscapes. The physical and chemical properties of the playa surface control the amount and properties of the dust emitted. In this study, we use a field wind tunnel to quantify the dust emissions from a bare, fine-textured playa surface located in the Chihuahua Desert at the Jornada Experimental Range, near Las Cruces, New Mexico, USA. We tested natural, undisturbed crusted surfaces and surfaces that had been subjected to two levels of domestic animal disturbance. The animal disturbance was provided …
Grassland In The Borderlands: Understanding Coupled Natural Human Systems And Transboundary Conservation, Ed Frederickson, G. Ceballos, R. List, A. Davidson, Sierra Corona, L. Martinez, J.E. Herrick, J. Pacheco
Grassland In The Borderlands: Understanding Coupled Natural Human Systems And Transboundary Conservation, Ed Frederickson, G. Ceballos, R. List, A. Davidson, Sierra Corona, L. Martinez, J.E. Herrick, J. Pacheco
Ed L. Frederickson
As conservationists well know, political borders rarely coincide with natural ecological boundaries. International borders such as that between the United States and Mexico traverse numerous ecosystems and watersheds. Many species of animals, birds, and insects regularly migrate between habitats across international borders. Conservation of Shared Environments collects works that take on the environmental issues along the U.S.-Mexico border. Covering topics as diverse as wildlife preservation, grassland ecology, water rights, indigenous peoples, and the ecological consequences of border security, the contributors to this volume offer not only scientific analysis but also insight on how to bridge the gaps between scientists, policy …
Effects Of Cis-Ss-Ocimene, Cis-Sabinene Hydrate, And Monoterpene And Sesquiterpene Mixtures On Alfalfa Pellet Intake By Lambs, Ed Frederickson, R. Estell, Dean Anderson
Effects Of Cis-Ss-Ocimene, Cis-Sabinene Hydrate, And Monoterpene And Sesquiterpene Mixtures On Alfalfa Pellet Intake By Lambs, Ed Frederickson, R. Estell, Dean Anderson
Ed L. Frederickson
Interpretive Summary: The conversion of grasslands to shrublands in the western United States and in arid regions throughout the world is a serious concern to livestock producers and ecologists. This process of desertification not only reduces available forage for livestock and wildlife, but also leads to increased soil erosion and reduced biodiversity. These shrubs often contain chemicals that make them unpalatable to browsing animals. We have been conducting a long-term study on the impact of volatile plant chemicals such as terpenes on shrub consumption by livestock. Our previous work showed that for a common shrub in the northern Chihuahuan Desert …
Effects Of Eugenol, Α-Terpineol, Terpin-4-Ol, And Methyl Eugenol On Consumption Of Alfalfa Pellets By Sheep, Ed Frederickson
Effects Of Eugenol, Α-Terpineol, Terpin-4-Ol, And Methyl Eugenol On Consumption Of Alfalfa Pellets By Sheep, Ed Frederickson
Ed L. Frederickson
Many secondary compounds are typically present in unpalatable shrubs on arid and semi-arid rangelands. However, the relationship between intake by livestock and concentration of individual chemicals has been examined for very few of these compounds. Four experiments were conducted to examine effects of individual volatile compounds on intake of alfalfa pellets by lambs. Forty-five lambs (9 lambs/treatment) were individually fed alfalfa pellets with eugenol, α-terpineol, terpin-4-ol, or methyl eugenol applied at one of five concentrations. Treatments were multiples (0, 0.5, 1, 2, and 10×) of the concentration (×) of each compound on the leaf surface of Flourensia cernua. Treatment solutions …