2,746 research outputs found
Run numbering system for use with data recorders
Run numbering identification system provides a permanent identification on the recorder traces of data runs. It automatically enters, by pulse coding, the number of the current data run on the recorder trace. The system uses a keyboard, registers, converters, amplifiers, and a pulse generator
Making color infrared film a more effective high altitude sensor
Infrared color film for remote sensors at high altitude
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Temporal Variation In The Carrying Capacity Of A Perennial Grass Population
Density dependence and, therefore, K (carrying capacity, equilibrium population size) are central to understanding and predicting changes in population size (N). Although resource levels certainly fluctuate, K has almost always been treated as constant in both theoretical and empirical studies. We quantified temporal variation in K by fitting extensions of standard population dynamic models to 16 annual censuses of a population of the perennial bunch-grass Bouteloua rigidiseta. Variable-K models provided substantially better fits to the data than did models that varied the potential rate of population increase. The distribution of estimated values of K was skewed, with a long right tail (i.e., a few >jackpot> years). The population did not track K closely. Relatively slow responses to changes in K combined with large, rapid changes in K sometimes caused N to be far from K. In 13%-20% of annual intervals, K was so much larger than N that the population's dynamics were best described by geometric growth and the population was, in effect, unregulated. Explicitly incorporating temporal variation in K substantially improved the realism of models with little increase in model complexity and provided novel information about this population's dynamics. Similar methods would be applicable to many other data sets.Integrative Biolog
A system of regional agricultural land use mapping tested against small scale Apollo 9 color infrared photography of the Imperial Valley (California)
System of regional agricultural land use mapping tested against Apollo 9 color infrared photography of Imperial Valley, Calif
Iowa Master Conservationist Program
A county-level Master Conservationist Program educated many Iowans about conservation and sustainability in exchange for the participants volunteering both time and expertise to their communities
Attitudes and behaviors of Iowa farmers toward wildlife
This research examines the attitudes and behaviors of Iowa farmers toward wildlife. Based on a 1991 statewide mailed survey of 822 farmers, it divides Iowa farmers into wildlife-oriented and non-wildlife-oriented groups for sampling and analysis. It identifies demographic and personal factors that are correlated with a wildlife orientation. Wildlife-oriented farmers in Iowa tend to be farmers with smaller acreages overall, with smaller gross farm incomes, with fewer acres devoted to row-crops, and with more diverse landscapes that more often include trees, streams, Conservation Reserve Program acres or other non-agricultural land than farmers who are not wildlife-oriented. Wildlife-oriented farmers also engage in more wildlife-related activities, seek wildlife information from locally-available sources, and are significantly more likely to seek assistance of conservation professionals than are their non-wildlife-oriented counterparts. Wildlife-oriented farmers also hold opinions and have attitudes that accord more value to wildlife for aesthetic and recreational purposes. Regression analysis reveals the association of these variables with management practices the farmers use on their land;Since both wildlife-oriented and non-wildlife-oriented farmer groups had substantial portions (65% and 44%, respectively) of hunters, another analysis was conducted, dividing farmers by whether or not they hunted;Farmer-hunters farm smaller acreages, engage more in other wildlife-associated activities, and are more likely to have hunted as children than non-hunting farmers. Their hunting activity is correlated with practices on their farms that are specifically favorable to wildlife. Farmer-hunters accord significantly higher value to wildlife for both aesthetic and recreational purposes. Non-hunting farmers are more likely than farmer-hunters to favor lease-hunting, though farmer-hunters are evenly split on the issue. Regression analyses reveals that hunting, some attitudinal variables, youth activity variables, and contact with conservation professionals are significantly related to farmers\u27 attitudes toward hunting and to the wildlife habitat practices they put on their land;The implications of these findings for wildlife management are discussed
Rotationally Grazed Pastures as Bird Habitat
Little is known about the use of rotationally grazed pastures by wild bird species, particularly in Midwestern landscapes. What is known is that continuously grazed pastures tend to have low bird production and use due to the lack of sufficient vegetative structure and to trampling of ground nests by cattle. Long-term rotational grazing (where livestock are shifted between several pastures every few days or weeks, as opposed to intensive rotational grazing where they are shifted every day) has the potential to produce high-quality cattle grazing and grasslands for wildlife. Early in the grazing season, farmers could use cool-season grass and forb (CSG) pastures for rotational grazing, leaving warm-season grass and forb (WSG) pastures to produce wildlife, especially birds. At the end of June or early July, cattle could be shifted to the WSG pastures for rotational grazing. Not only does this allow the WSG to grow to excellent grazing height, it also allows ground-nesting birds to potentially complete a nesting cycle. Further, as CSG are left to grow (although slowly) until fall, late-nesting birds and re-nesters may utilize the CSG, as well. Depending on the length of time between rotations, early nesters may also use the CSG early in the nesting season
Comparison of Soil Phosphorus Concentration in Farm Restored and Reference Wetlands in Lake County, IL
The soil in the Midwest is fertile for agriculture use and therefore a lot of the wetlands have been turned into farmland. Wetlands can act as a sink for excess nutrients such as phosphorus. In part due to their value for nutrient storage, restoration of wetlands has become more frequent, including restoration of wetlands on former farmland. I am interested in phosphorus and the potential of wetlands to either store or release phosphorus. I compared differences in soil reactive phosphorus of restored and reference wetlands. This study compares Prairie Wolf Slough (PWS), a restored wetland, to two reference wetlands, both located less than 10 miles from Prairie Wolf Slough with similar hydrology, soils, and vegetation. I measured soil reactive phosphorus (SRP) in soil cores (to a depth of 0.15 meters). ANOVA analysis found no significant difference in SRP in the restored wetland compared to the reference wetlands. Although the hypothesis was not supported, the findings can be used as preliminary data for further investigation of phosphorus in wetlands
ECONOMIC AND ENVIRONMENTAL IMPACTS OF NUTRIENT LOSS REDUCTIONS ON DAIRY AND DAIRY/POULTRY FARMS
Livestock Production/Industries,
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