Your search for keyword(s) "simulation model" resulted in 7 record(s).

Title: Wildfire effects and post-fire responses of an invasive mesquite population: The interactive importance of grazing and non-native herbaceous species invasion: Journal: Journal of Biogeography; Authors: J. A. Kupfer, and J. D. Miller; Date: 2005; Summary: Prescribed fire has been considered to control velvet mesquite (Prosopis velutina) invasion in southwest rangelands, however, the success of fire for controlling mesquite plants may be related to grassland species composition and grazing factors that influence fire characteristics. In this study, authors determined that the heat, intensity, and scorching of a fire are reduced by grazing, possibly because of reduced fuel loads, and increased when invasive lovegrass (Eragrostis sp.) species are dominant compared to native grasses. More large trees were ...; Agrovoc Control Words: Riparian zones, Rangelands, Wildlife; View more details about this article

Title: Landslide erosion risk to New Zealand pastoral steeplands productivity: Journal: Land Degradation & Development; Authors: P. G. Luckman, R. D. Gibson, and R. C. Derose; Date: 1999; Summary: A simple model was developed to evaluate the impacts of long-term soil erosion on pasture productivity caused by storm-induced landslides steep (>25°) hill slopes. The study area is located on the North Island of New Zealand (38° 24\' S; 175° 43\' E) where the risk of landslides can increase following initial forest or scrub clearance, ultimately leading to a decrease in pasture productivity caused by increased soil erosion. The basic modeling unit of measurement used was the terrain mapping unit (TMU) which is described as a relatively homogenous parcel of land cover ...; Agrovoc Control Words: Pasture management, Landslides, Erosion; View more details about this article

Title: Physiological responses of plant populations to herbivory and their consequences for ecosystem nutrient flow: Journal: The American Naturalist; Authors: E. A. Holland, W. J. Parton, J. K. Detling, and D. L. Coppock; Date: 1992; Summary: Holland et al. showed how physiological responses to herbivory provide feedbacks to nutrient availability by controlling carbon and nitrogen supply to soil heterographs. The analysis focused on three physiological differences between two populations that vary in grazing tolerance: changes in net primary production in response to defoliation, changes in carbon allocation in response to defoliation, and changes in nitrogen allocation in response to defoliation. Holland et al. used meteorological driving variables from, and parameterized the CENTURY model, a nutrient-cycling simulation model, f ...; Agrovoc Control Words: Riparian zones, Rangelands, Wildlife; View more details about this article

Title: A gap dynamics simulation model of succession in a semiarid grassland: Journal: Ecological Modelling; Authors: D. P. Coffin, and W. K. Lauenroth; Date: 1990; Summary: In this Colorado study, authors applied a gap dynamics conceptualization of succession to a semiarid grassland, by focusing on gaps produced in the belowground resource space by death of an individual of the dominant species, the perennial grass, blue grama (Bouteloua gracilis). Average time required for B. gracilis to dominate biomass on a simulated plot was 20 years, a more rapid recovery time than has been reported from other studies of large-scale disturbances. A second set of simulations incorporating effects of seed availability resulted in an average recovery time of 65 years. Aboveg ...; Agrovoc Control Words: Riparian zones, Rangelands, Wildlife; View more details about this article

Title: Disturbances and gap dynamics in a semiarid grassland: A landscape-level approach: Journal: Landscape Ecology; Authors: D. P. Coffin, and W. K. Lauenroth; Date: 1989; Summary: Coffin and Lauenroth evaluated the effects of spatially-explicit processes on the recovery of Bouteloua gracilis after disturbances using a modification of a gap dynamics simulation model, developed for a semiarid grassland in northcentral Colorado. Of particular interest was the recovery of the dominant plant species, the perennial grass, blue grama (B. gracilis) after disturbances. Coffin and Lauenroth focused on scale-dependent processes, such as seed dispersal, that are important to the recruitment of individuals of B. gracilis. Landscapes composed of independent plots recovered more ra ...; Agrovoc Control Words: Riparian zones, Rangelands, Wildlife; View more details about this article

Title: The effects of disturbance size and frequency on a shortgrass plant community: Journal: Ecology; Authors: D. P. Coffin, and W. K. Lauenroth; Date: 1988; Summary: From field data collected in Colorado, Coffin and Lauenroth modeled the effects of three types of small patch-producing disturbances on a short-grass community, dominated by blue grama (Bouteloua gracilis). Disturbance included cattle fecal pats, western harvester ant mounds (Pogonomyex occidentalis), and small animal burrows. Ant mounds and animal burrows were significantly larger than blue grama plants, whereas fecal pats were comparable in size to blue grama plants. Frequency of disturbance occurrence was a good predictor of the amount of basal cover and the number of plants killed each ...; Agrovoc Control Words: Riparian zones, Rangelands, Wildlife; View more details about this article

Title: Simulation and management implications of feral horse grazing on Cumberland Island, Georgia: Journal: Journal of Range Management; Authors: M. G. Turner; Date: 1988; Summary: Data from field studies was used in a simulation model to determine the number of feral horses (Equus caballus) that can graze Spartina alterniflora in the salt marshes of Cumberland Island without causing damage to this plant community. The model indicated that damage to the salt marsh occurred when biomass of S. alterniflora was reduced below a threshold of 2700 hg/ha (dry weight). Biomass of S. alterniflora produced above this threshold would be able to sustain between 49 and 73 horses when horses consumed ...; Agrovoc Control Words: Riparian zones, Rangelands, Wildlife; View more details about this article