The Experts below are selected from a list of 12543 Experts worldwide ranked by ideXlab platform
Keith W. Wesley) - One of the best experts on this subject based on the ideXlab platform.
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RITF Report 45: 1997 Summary of range Brush Control research: Demonstration trials in New Mexico
New Mexico State University Library;, 2014Co-Authors: Keith W. Wesley)Abstract:Introduction; Silky Crazyweed (White Point Locoweed) Control; Saltcedar Control; Snakeweed Control; Yucca Control; Other species; 1997 Tests not yet evaluated;Range Improvement Task Force report containing summaries of research data collected from range Brush Control demonstration trials in New Mexico in 1997
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RITF Report 46: 1998 Summary of range Brush Control research: Demonstration trials in New Mexico
New Mexico State University Library, 2014Co-Authors: Keith W. Wesley)Abstract:Introduction; Saltcedar Control; Locoweed and Snakeweed Control; Yucca Control; Other Species; 1998 Tests - Not yet evaluated;Range Improvement Task Force report containing summaries of research data collected from range Brush Control demonstration trials in New Mexico in 1998
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RITF Report 48: 1999 Summary of range Brush Control research: Demonstration trials in New Mexico
New Mexico State University Library, 2014Co-Authors: Keith W. Wesley)Abstract:Introduction; African Rue Control; Leafy Spurge Control; Locoweed and Snakeweed Control; Saltcedar Control; Yucca Control; Other species; 1999 Tests - Not yet evaluated;Range Improvement Task Force report containing summaries of research data collected from range Brush Control demonstration trials in New Mexico in 1999
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RITF Report 59: 2004 Summary of range Brush Control research: Demonstration trials in New Mexico
New Mexico State University Library, 2013Co-Authors: Keith W. Wesley)Abstract:Introduction; African rue Control; Locoweed and Snakeweed Control; Saltcedar; Russian Olive; Juniper Control; Yucca;Range Improvement Task Force report containing summaries of research data collected from range Brush Control demonstration trials in New Mexico in 2004
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RITF Report 55: 2002 Summary of range Brush Control research: Demonstration trials in New Mexico
New Mexico State University Library;, 2013Co-Authors: Keith W. Wesley)Abstract:Introduction; African Rue Control; Locoweed and Snakeweed Control; Russian Olive Control; Juniper Control; Saltcedar Control; Other species;Range Improvement Task Force report containing summaries of research data collected from range Brush Control demonstration trials in New Mexico in 2002
Michael R Saunders - One of the best experts on this subject based on the ideXlab platform.
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patterns of growth compensation in eastern white pine pinus strobus l the influence of herbivory intensity and competitive environments
Oecologia, 2001Co-Authors: Klaus J Puettmann, Michael R SaundersAbstract:To investigate complex growth compensation patterns, white pine (Pinus strobus L.) seedlings were clipped to simulate different herbivory levels. Seedlings were growing with different understory competition levels (created through monthly weeding vs no Brush Control) under a range of overstory canopy closures. Compensation patterns varied for the different growth and size measures. After one growing season, seedlings did not fully compensate for lost biomass regardless of the competitive environments of the seedlings. Although relative height growth was stimulated by light intensity clipping (20–40% of last-year shoots removed), relative diameter growth, total biomass, and biomass growth of seedlings declined sharply with increasing clipping intensity. Likewise, all growth parameters declined with increasing interspecific competition. Results showed that seedlings in highly competitive environments showed smaller growth loss due to clipping than those in competition-free environments, presumably because seedlings experiencing high interspecific competition devoted more energy to maintaining apical dominance and a balanced shoot-root ratio. While competition from canopy trees altered compensatory patterns, competition from understory vegetation only altered the magnitude, but not the patterns, of compensatory growth. We suggest that compensatory growth follows a complex pattern that will vary with the parameters measured, competitive conditions, and clipping intensities. Our results support the assertion that overcompensation may be an adaptation to competitive ability, rather than a response to herbivory itself.
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effects of overstory and understory competition and simulated herbivory on growth and survival of white pine seedlings
Canadian Journal of Forest Research, 1999Co-Authors: Michael R Saunders, Klaus J PuettmannAbstract:The interactive impact of overstory canopy closure, understory Brush Control, and simulated white-tailed deer (Odocoileus virginianus Zimmermann) herbivory (i.e., clipping) on growth and survival of underplanted white pine (Pinus strobus L.) seedlings was examined. Clipping was conducted in April 1996 and 1997 at three intensities (Control, 0% previous year's growth removed; lightly clipped, terminal and 50% previous year's growth removed, and heavily clipped: 100% of previous-year's growth removed) and three frequencies (never clipped, clipped once, clipped 2 years in a row). Decreasing overstory canopy closure and Brush competition generally increased growth of seedlings under all clipping regimes, with heavily clipped seedlings showing the least benefit of reduced competition. Although first-year height growth was stimulated after light-intensity clipping, this effect did not persist the following year, and these trees still were significantly shorter than Controls at the end of the experiment. Diameter growth was reduced at any clipping intensity or frequency, and remained below Controls throughout the experiment. Seedling mortality was higher without Brush Control and after clipping. Results suggest that increased overstory and understory competition reduced seedling growth and survival. In regards to clipping, initial height growth stimulation may result from (i) resource reallocation away from diameter and root growth and (or) (ii) hormonal redistributions from loss of apical Control in the seedling. Since both high competition levels and increased herbivory reduced seedling vigor, we suggest that understory Brush Control and deer protection (e.g., budcapping) go hand in hand to regenerate white pine.
Klaus J Puettmann - One of the best experts on this subject based on the ideXlab platform.
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patterns of growth compensation in eastern white pine pinus strobus l the influence of herbivory intensity and competitive environments
Oecologia, 2001Co-Authors: Klaus J Puettmann, Michael R SaundersAbstract:To investigate complex growth compensation patterns, white pine (Pinus strobus L.) seedlings were clipped to simulate different herbivory levels. Seedlings were growing with different understory competition levels (created through monthly weeding vs no Brush Control) under a range of overstory canopy closures. Compensation patterns varied for the different growth and size measures. After one growing season, seedlings did not fully compensate for lost biomass regardless of the competitive environments of the seedlings. Although relative height growth was stimulated by light intensity clipping (20–40% of last-year shoots removed), relative diameter growth, total biomass, and biomass growth of seedlings declined sharply with increasing clipping intensity. Likewise, all growth parameters declined with increasing interspecific competition. Results showed that seedlings in highly competitive environments showed smaller growth loss due to clipping than those in competition-free environments, presumably because seedlings experiencing high interspecific competition devoted more energy to maintaining apical dominance and a balanced shoot-root ratio. While competition from canopy trees altered compensatory patterns, competition from understory vegetation only altered the magnitude, but not the patterns, of compensatory growth. We suggest that compensatory growth follows a complex pattern that will vary with the parameters measured, competitive conditions, and clipping intensities. Our results support the assertion that overcompensation may be an adaptation to competitive ability, rather than a response to herbivory itself.
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effects of overstory and understory competition and simulated herbivory on growth and survival of white pine seedlings
Canadian Journal of Forest Research, 1999Co-Authors: Michael R Saunders, Klaus J PuettmannAbstract:The interactive impact of overstory canopy closure, understory Brush Control, and simulated white-tailed deer (Odocoileus virginianus Zimmermann) herbivory (i.e., clipping) on growth and survival of underplanted white pine (Pinus strobus L.) seedlings was examined. Clipping was conducted in April 1996 and 1997 at three intensities (Control, 0% previous year's growth removed; lightly clipped, terminal and 50% previous year's growth removed, and heavily clipped: 100% of previous-year's growth removed) and three frequencies (never clipped, clipped once, clipped 2 years in a row). Decreasing overstory canopy closure and Brush competition generally increased growth of seedlings under all clipping regimes, with heavily clipped seedlings showing the least benefit of reduced competition. Although first-year height growth was stimulated after light-intensity clipping, this effect did not persist the following year, and these trees still were significantly shorter than Controls at the end of the experiment. Diameter growth was reduced at any clipping intensity or frequency, and remained below Controls throughout the experiment. Seedling mortality was higher without Brush Control and after clipping. Results suggest that increased overstory and understory competition reduced seedling growth and survival. In regards to clipping, initial height growth stimulation may result from (i) resource reallocation away from diameter and root growth and (or) (ii) hormonal redistributions from loss of apical Control in the seedling. Since both high competition levels and increased herbivory reduced seedling vigor, we suggest that understory Brush Control and deer protection (e.g., budcapping) go hand in hand to regenerate white pine.
Chong Wang - One of the best experts on this subject based on the ideXlab platform.
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analysis of rotary Brush Control characteristics for a road sweeping robot vehicle
International Conference on Mechatronics and Control, 2014Co-Authors: Chong Wang, Graham A ParkerAbstract:This paper discusses some aspects of Brush Control techniques for a concept of a novel semi-autonomous road sweeper. One of the main difficulties of developing such a robot sweeping vehicle is that the general characteristics of the sweeping Brushes are not well known. This study employs a FE model that calculates the Brush deformation to assist the Controller design. Using the FE model some useful Brush characteristics, such as the stiffness and the deformation geometry can be obtained. The analysis suggests that Brush characteristics may vary significantly at different operating points and introduce considerable challenges to the servo Control strategies. The FE modeling results may be utilized to predict these characteristics and to develop a more adaptive Brush servo Controller. A simulation of such a predictive Brush Controller is then introduced for road sweeping automation.
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Brush Modelling and Control Techniques for Automatic Debris Removal During Road Sweeping.
2005Co-Authors: Chong WangAbstract:This study explores enhanced Brush modelling and Control techniques with respect to facilitating the development of a new generation road-sweeping vehicle. Achieving automatic road sweeping was difficult in the past, partly because Brush characteristics were not fully understood thus it was not known how to properly use a Brush to sweep debris more efficiently. A number of results to overcome such a constraint are presented in this work. In the first part of this thesis, a Finite Element (FE) model for analysing Brush characteristics is presented. The FE model calculates three-dimensional Brush tine deformation to give a general prediction of Brush mechanical characteristics, such as force-deformation relationship, Brush shape, rotational torque, etc. This model is an extension work of a previous mathematical model developed by Peel (2002), with the advantages that it provides better accuracy and that it can be used to analyse different Brush types. The modelling results can also be utilized for a wide range of Brush design applications. Secondly, road sweeping effectiveness has been assessed using both theoretical and experimental methods. In order to deduce the fundamental debris removal mechanisms, a FE model has been developed to analyse the interaction between Brush tines and debris. By implementing sweeping tests on different classes of debris, optimized criteria for configuring Brushing force, tilt angle and rotational speed have been suggested. These criteria can be used to design a predictive Brush Control system. This study finally addresses several considerations for designing an automatic Brush Control system. It is shown that the performance of such a system not only depends on the optimized Brush configuration criteria, but also depends on reliable servo Controllers, which should be able to deal with Brush nonlinear characteristics. It is highlighted that the FE modelling results should be utilized to predict the Brush stiffness, so that an auto-tuning PD Controller can be developed to improve the Control performance.
James D Haywood - One of the best experts on this subject based on the ideXlab platform.
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eight years of seasonal burning and herbicidal Brush Control influence sapling longleaf pine growth understory vegetation and the outcome of an ensuing wildfire
Forest Ecology and Management, 2009Co-Authors: James D HaywoodAbstract:Abstract To study how fire or herbicide use influences longleaf pine ( Pinus palustris Mill.) overstory and understory vegetation, five treatments were initiated in a 5–6-year-old longleaf pine stand: check, biennial arborescent plant Control by directed herbicide application, and biennial burning in March, May, or July. The herbicide or prescribed fire treatments were applied in 1999, 2001, 2003, and 2005. All prescribed fires were intense and averaged 700 kJ/s/m of fire front across all 12 burns. Using pretreatment variables as covariates, longleaf pine survival and volume per hectare were significantly less on the three prescribed fire treatments than on checks. Least-square means in 2006 for survival were 70, 65, 64, 58, and 56% and volume per hectare was 129, 125, 65, 84, and 80 m 3 /ha on the check, herbicide, March-, May-, and July-burn treatments, respectively. A wildfire in March 2007 disproportionately killed pine trees on the study plots. In October 2007, pine volume per hectare was 85, 111, 68, 98, and 93 m 3 /ha and survival was 32, 41, 53, 57, and 55% on the check, herbicide, March-, May-, and July-burn treatments, respectively, after dropping trees that died through January 2009 from the database. Understory plant cover was also affected by treatment and the ensuing wildfire. In September 2006, herbaceous plant cover averaged 4% on the two unburned treatments and 42% on the three prescribed fire treatments. Seven months after the wildfire, herbaceous plant cover averaged 42% on the two previously unburned treatments and 50% on the three prescribed fire treatments. Before the wildfire, understory tree cover was significantly greater on checks (15%) than on the other four treatments (1.3%), but understory tree cover was similar across all five treatments 7 months after the wildfire averaging 1.1%. The greater apparent intensity of the wildfire on the previously unburned treatments most likely resulted from a greater accumulation of fuels on the check and herbicide plots that also collectively had a higher caloric content than fuels on the biennially prescribed burned plots. These results showed the destructive force of wildfire to overstory trees in unburned longleaf pine stands while also demonstrating the rejuvenating effects of wildfire within herbaceous plant communities. They caution for careful reintroduction of prescribed fire even if fire was excluded for less than a decade.
