3,932 research outputs found
Pursuing Geoengineering for Atmospheric Restoration
Geoengineering is fraught with problems, but research on three approaches could lead to the greatest climate benefits with the smallest chance of unintentional environmental harm. The authors propose a model for thinking about geoengineering based on the concept of restoration, suggesting the term “atmospheric restoration.” Under this model geoengineering efforts are prioritized based on three principles: to treat the cause of the disease itself, to reduce the chance of harm, and to prioritize activities with the greatest chance of public acceptance.
Based on these principles, the authors propose three forms of geoengineering that could provide the greatest climate benefits with the smallest chance of unintentional harm to the environment. Forest protection and restoration is an opportunity available now. The other two, industrial carbon removal and bioenergy linked to carbon capture and storage, need extensive research to make them effective and to reduce their costs. These options will be cheaper than most forms of geoengineering and will provide many additional benefits, including improved air and water quality, national security, balance of trade, and human health.
Our climate is already changing, and we need to explore at least some kinds of carbon-removal technologies, because energy efficiency and renewables cannot take CO2 out of the air once it’s there. Some scientists increasingly argue that we need to do research on sunshade technologies as a backup plan if climate change starts to accelerate dangerously. This argument has merit. However, the sooner we invest in and make progress on reducing greenhouse gas emissions today and promote ways to restore the atmosphere through carbon-scrubbing technologies in the future, the less likely we are ever to need global sunshades. The principle of atmospheric restoration should guide us in curing climate change outright, not in treating a few of its symptoms
Soil Heterogeneity and its Exploitation by Plants
In this dissertation I first examine the ability of individual plants in the field to garner localized soil nutrients. I then measure actual soil variability around perennial plants and use various statistics to quantify the scale and degree of that variability.
Soil patches on opposite sides of Pseudoroegneria spicata tussocks were treated with distilled water or a nutrient solution containing N, P, or K in three field experiments. When P was augmented in the enriched soil patches, rates of P uptake increased significantly for roots from enriched patches compared with roots in control patches. Rates of ammonium and potassium uptake were apparently unchanged. When N was augmented in the enriched patches, rates of ammonium and potassium uptake increased significantly. When K was augmented in the enriched patches, no changes were seen for any of the nutrients.
Plant shading was found to limit the ability of Agropyron desertorum tussocks to increase rates of nutrient uptake in enriched soil microsites. Roots of unshaded plants selectively increased phosphate uptake capacity in enriched patches by up to 73%, but shading limited this response. Enrichment of the soil patches resulted in significantly greater phosphate concentrations in roots of both shaded and unshaded plants.
Nutrient heterogeneity in the soil at a native sagebrush-steppe site was quite high, with ammonium and nitrate varying by over two orders of magnitude and phosphate and potassium close to one order of magnitude within a 10x12- m area. Within 0.5x0.5-m subplots around individual plants, ammonium and nitrate varied by an average factor of 11 and 12, respectively, with less average variation for phosphate and potassium. Geostatistical semivariograms showed that soil ammonium, nitrate, phosphate, potassium, pH, and organic matter all showed detectable autocorrelation only at scales of less than 1.0 to 1.5 m. Indices of microbial activity showed no detectable autocorrelation even at the smallest measurement scale of 12.5 cm. From the degree and scale of heterogeneity encountered, I conclude that root plasticity and active foraging in a heterogeneous soil environment are likely to be important to the nutrient balance of many plants
Root Exploitation of Fertile Soil Microsites
Root exploitation of enriched soil microsites was examined for the tussock grasses Agropyron desertorum and Agropyron spicatum and the shrub Artemisia tridentata. Two mechanisms of exploitation of the microsites were examined: root proliferation and changes in nutrient uptake capacity. One day after nutrient solution was applied to small soil patches, the mean relative growth rate of Agropyron desertorum roots in enriched patches was two to four times greater than for roots of the same plants in soil patches treated with distilled water. This rapid and striking root proliferation occurred in response to N-P-K enrichment as well as to P or N enrichment alone. Agropyron spicatum showed no tendency to proliferate roots in enriched soil patches during the two-week experiments. The shrub Artemisia tridentata proliferated roots within one day of initial solution injection in the N-enrichment experiment, but root proliferation of this species was more gradual and less consistent in other experiments. The ability of Agropyron desertorum partly explain its to proliferate superior ability roots to rapidly may exploit soil nutrients compared to Agropyron spicatum in Great Basin rangelands of North America.
Changes in nutrient uptake capacity in enriched soil patches were also studied for each species. rapid changes in uptake capacity of plant roots Large and from the field were observed after creation of nutrient-rich patches in the soil. Phosphate uptake of excised roots from enriched soil patches was roots of control patches as much as 80% greater than for treated with distilled water. These increases in uptake capacity took place within one week of patch treatment for all three species. A follow-up experiment showed increases within three days of patch treatment. These results showing rapid physiological plasticity in roots exploiting nutrient patches have important implications for nutrient belowground competition among plants
Dietary Comparisons of Red-Winged Blackbirds, Brown-Headed Cowbirds, and European Starlings in North-Central Ohio
Author Institution: Department of Biological Sciences, Bowling Green State University ; Environmental Studies Center, Bowling Green State UniversityStomach contents from 99 red-winged blackbirds, 97 brown-headed cowbirds, and 69 European starlings collected along the southern edge of Lake Erie in north-central Ohio were compared using aggregate volume measurments. Agricultural products comprised 73.9%, 54.8%, and 28.1% of the redwing, cowbird, and starling diets, respectively. Corn accounted for 70.8%, 26.2%, and 3.3% of the diets, respectively. Animal material represented 7.6%, 3.4%, and 30.3% of the diets, respectively. Injurious insects comprised 13-5% of the starling diet but were relatively unimportant in the diets of redwings and cowbirds. Beneficial arthropods were relatively unimportant in all the diets
IT Instruction Methodology and Minimum Competency for Accounting Students
Information Systems education has long been recognized as an important aspect of accounting education for prospective accountants, and is even more critical in our rapidly changing environment. Brigham Young University has three courses to provide accounting students in the 150 hour Master of Accountancy program with the necessary IT skills. The final class is a capstone course to provide enhanced IT skills to students immediately before graduation. This course is taught cafeteria style allowing students to select which IT topics to study and to develop skills from a menu of options. In this paper, we explain how the course is structured. Results of a survey of recent graduates are presented which indicates which topics are most helpful in their employment. It also indicates that the course is generally meeting its objectives to better prepare students for their first job. Based on the survey results, areas of improvement are also identified
Mineral Estate Conservation Easements: A New Policy Instrument to Address Hydraulic Fracturing and Resource Extraction
In a few short years, hydraulic fracturing has transformed the oil and natural gas industries and changed the landscape of energy policy, while generating major conflicts over local land use decisions. Individuals and communities have turned to the law to restrict oil and natural gas production with mixed success. While little explored, there is also potential for private efforts to restrict fracking.
We propose a novel tool, the Mineral Estate Conservation Easement (MECE), to provide landowners with the ability to restrict hydraulic fracturing and other oil and gas subsurface activities in areas of particular social or ecological vulnerability. The article assesses whether a MECE is compatible with current state conservation easement acts, whether it would qualify for a tax deduction, and legislative actions that would strengthen the status of MECEs.
Overall, we find that MECEs hold great potential as a private land use tool to restrict hydraulic fracturing in specific settings. While its legal status is well supported in most jurisdictions, in others uncertainty remains, though this could easily be remedied in most cases with minor statutory or regulatory amendments
The interpretive approach to religious education : challenging Thompson's interpretation
In a recent book chapter, Matthew Thompson makes some criticisms of my work, including the interpretive approach to religious education and the research and activity of Warwick Religions and Education Research Unit. Against the background of a discussion of religious education in the public sphere, my response challenges Thompson’s account, commenting on his own position in relation to dialogical approaches to religious education. The article rehearses my long held view that the ideal form of religious education in fully state funded schools of a liberal democracy should be ‘secular’ but not ‘secularist’; there should be no implication of an axiomatic secular humanist interpretation of religions
A global meta-analysis of soil exchangeable cations, pH, carbon, and nitrogen with afforestation
Afforestation, the conversion of non-forested lands to forest plantations, can sequester atmospheric carbon dioxide, but the rapid growth and harvesting of biomass may deplete nutrients and degrade soils if managed improperly. The goal of this study is to evaluate how afforestation affects mineral soil quality, including pH, sodium, exchangeable cations, organic carbon, and nitrogen, and to examine the magnitude of these changes regionally where afforestation rates are high. We also examine potential mechanisms to reduce the impacts of afforestation on soils and to maintain long-term productivity.
Across diverse plantation types (153 sites) to a depth of 30 cm of mineral soil, we observed significant decreases in nutrient cations (Ca, K, Mg), increases in sodium (Na), or both with afforestation. Across the data set, afforestation reduced soil concentrations of the macronutrient Ca by 29% on average (P \u3c 0.05). Afforestation by Pinus alone decreased soil K by 23% (P \u3c 0.05). Overall, plantations of all genera also led to a mean 71% increase of soil Na (P \u3c 0.05). Mean pH decreased 0.3 units (P \u3c 0.05) with afforestation.
Afforestation caused a 6.7% and 15% (P \u3c 0.05) decrease in soil C and N content respectively, though the effect was driven principally by Pinus plantations (15% and 20% decrease, P \u3c 0.05). Carbon to nitrogen ratios in soils under plantations were 5.7–11.6% higher (P \u3c 0.05). In several regions with high rates of afforestation, cumulative losses of N, Ca, and Mg are likely in the range of tens of millions of metric tons. The decreases indicate that trees take up considerable amounts of nutrients from soils; harvesting this biomass repeatedly could impair long-term soil fertility and productivity in some locations. Based on this study and a review of other literature, we suggest that proper site preparation and sustainable harvest practices, such as avoiding the removal or burning of harvest residue, could minimize the impact of afforestation on soils. These sustainable practices would in turn slow soil compaction, erosion, and organic matter loss, maintaining soil fertility to the greatest extent possible
Additively manufacturable micro-mechanical logic gates.
Early examples of computers were almost exclusively based on mechanical devices. Although electronic computers became dominant in the past 60 years, recent advancements in three-dimensional micro-additive manufacturing technology provide new fabrication techniques for complex microstructures which have rekindled research interest in mechanical computations. Here we propose a new digital mechanical computation approach based on additively-manufacturable micro-mechanical logic gates. The proposed mechanical logic gates (i.e., NOT, AND, OR, NAND, and NOR gates) utilize multi-stable micro-flexures that buckle to perform Boolean computations based purely on mechanical forces and displacements with no electronic components. A key benefit of the proposed approach is that such systems can be additively fabricated as embedded parts of microarchitected metamaterials that are capable of interacting mechanically with their surrounding environment while processing and storing digital data internally without requiring electric power
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