Productivity and biometry of hybrid poplars with respect to establishment, regeneration, regional modeling, and utilization of bio-energy byproducts

Five studies were conducted to address some of the gaps in our current knowledge of hybrid poplar production. The first was a study of an alleycropping system in which winter triticale was grown as a source of early income between rows of hybrid aspen trees during the first three years of establishment, with the objective of evaluating whether the productivity of the system would be affected by topographic position and fertilizer rate. The results demonstrated that total aboveground biomass productivity was not significantly affected by topographic position, with the exception of the floodplain in the first year, where weed pressure was high. Fertilizer placed in the planting hole had positive and statistically significant effects; the trees receiving the highest fertilizer rate had nearly twice as much biomass as those receiving none. Fertilizer rate and age were found to be relatively strong predictors for total aboveground biomass, but the branch fraction of total aboveground biomass was better predicted by tree size. The objectives of the second study were to quantify the regeneration of hybrid aspen arising from roots sprouts following the harvest of a mature plantation, and to devise an equation to aid in row thinning the root sprouts to a density suitable for another short rotation. Using variable radius plot sampling, similar estimates of root sprout density and harvestable biomass were attained using basal area factors (BAFs) of 1.56 and 2.78 m2 ha&minus1. The latter did so with roughly half as many measurement trees, but also had a larger confidence interval; thus, a trade-off exists between reducing sampling time and obtaining more precise estimates. Using a BAF of 6.22 m2 ha&minus1 resulted in even wider confidence intervals, and lower estimates of root sprout density. The row thinning equation developed in the study was effective for predicting the size of the largest gap in the row based on the number of sprouts in the row, which (in conjunction with inventory data for sprout density) dictates the appropriate width of the unharvested row for a desired maximum gap size. The objectives of the third study were to use previously published productivity data to calibrate and validate a tree growth model (3PG) for hybrid cottonwood in the North Central U.S., and to use the validated model to map predicted yields for the region. The results suggest that 3PG is well suited for modeling hybrid poplar aboveground biomass productivity. Linear regression of actual versus predicted total aboveground biomass for the validation dataset demonstrated a strong fit (R2 = 0.89, RMSE = 8.1 Mg ha&minus1 ). When used to map mean annual biomass productivity (total aboveground dry biomass divided by age), predicted values ranged from 4.4 to 13.0 Mg ha&minus1 yr&minus1 across Minnesota and Wisconsin, with the highest productivity mainly concentrated in the area stretching from south&ndashcentral Minnesota across southern Wisconsin. The objective of the fourth study was to evaluate the feasibility of using fly ash (produced from a biomass boiler at an ethanol facility) as a foliar fertilizer for hybrid aspen trees in both greenhouse and field settings. The results demonstrated that several nutrients in the fly ash were absorbed by hybrid aspen both in the greenhouse and in the field; however, this absorption did not significantly affect tree growth in either setting. The ash appeared to be compatible with foliar nitrogen fertilizer, as inclusion of the fly ash did not significantly alter the effects of the nitrogen fertilizer on tree growth. Additional research should be done with crops known to benefit from foliar application of the nutrients found in the ash, particularly the nutrients shown in this study to be available for uptake by plants. The objective of the fifth study was to evaluate the feasibility of using biochar (produced by a fast pyrolysis bio&ndashoil reactor) as a substitute for vermiculite to grow hybrid poplar in the greenhouse. The results suggest that biochar can be an effective substitute for vermiculite when substituted on a volume basis. The biochar and vermiculite mixes similarly produced higher shoot and total biomass than the peat moss control; vector analysis indicates that this was primarily due to superior availability of K. The increased availability of K may be related to the elevated initial levels of K detected in the biochar and vermiculite mixes, rather than a superior ability of the mixes to adsorb cations from the soil solution. Thus, future studies should attempt to separate such pre&ndashloading effects from CEC effects, as well as test a wider selection of crops and biochars. In addition, the biochar mix was associated with lower root biomass than the vermiculite mix. Additional research is needed to determine the cause of this response, and whether it affects long term growth and survival of the trees

Worth 1,000 words

Thesis (M.S.)--Boston Universit

COVID-19 Impact on Business

COVID-19 has not only been a major public health crisis, but it has also caused an economic shock. Small businesses have been at the losing end of the U.S. economy for years, but nothing has hurt them as bad as the COVID-19 crisis. The pandemic has devastated thousands of small businesses while larger companies have fared well and, in some cases, thrived. Although there has been an increase in bankruptcy filings among public companies, the numbers are far lower than in the 2008 financial crisis (Lahart). This paper will explore what impact the pandemic has had on small businesses, large businesses, and different industries within those in the Northwest Arkansas area

Utilizing Experiential Collaboration to Enhance Facilitation Skills

Collaborative learning has the potential to produce changes in perspectives in an ever-changing world; experiential learning has the potential to contribute to creating a collaborative environment. Both of these processes utilize effective facilitation. This action research study examined the experiences of a training group for which I served as the facilitator and explored the question, “How do participants in a group for which I serve as a facilitator of collaborative learning within an experiential learning framework describe their experience?” Additionally, the study examined the question, “How do the research participants’ experiences inform my professional practice of facilitation of collaborative learning? Twenty college-age young adults in the training group provided data from multiple qualitative sources. Hermeneutic analysis of data focused on: (1) the participants’ descriptions of their experiences along with their perceptions and reflections of those experiences; and (2) their experiences with me as their facilitator. Findings of the study addressed the participants’ desires to learn from their training experience (transformative learning), detailed their struggles to push past personal boundaries (constructs of competence and control), and explored the supportive relationships that developed within the group (mutuality and reciprocity). Hermeneutic data analysis also provided insights into my practice of facilitation and gave support to the strength and structure that utilization of the experiential learning model brought to the group. The relationship between the intense experiential learning activities and the transfer of that learning to other activities and responsibilities was demonstrated through the participants’ descriptions as they noted their transformation into the role of facilitators. The practice of facilitation was enlightened by examining the constructs of problem solving, competence and control, and intensity of transfer of learning. Implications of this research study identify collaborative learning and experiential learning to be dynamic learning processes that are best achieved in a safe environment within a planned framework of intentionality that includes iterative cycles of planning, action, observing, reflecting, and replanning. Given the current trend of reduced training time, the resulting higher levels of transfer of learning can produce an increase in training results for participants and more effective facilitation skills for training facilitators

Generational Differences in Motivations of North Carolina Public Elementary School Teachers

This mixed-methods study addressed the generational differences in intrinsic and extrinsic motivation among elementary teachers in North Carolina. Intrinsic motivation to persist in the profession was examined through the lens of Pink’s theory that autonomy, mastery, and purpose determine a person’s degree of intrinsic motivation. Information relating to extrinsic motivation was also examined. Data were collected through a 33-question survey distributed via email and social media. Quantitative data were analyzed using the Kruskal Wallis H Test to determine significant differences. Qualitative data were coded and analyzed for themes leading to insight into internal and external motivations of elementary school teachers. Significant differences were found on multiple items and within the purpose construct. Triangulation of data indicate more similarities than differences among the three generations. All teachers indicate high levels of altruistic motivations; however, all generations are critical of policy direction in North Carolina, with only 10% of teachers agreeing or strongly agreeing with current state direction. Recommendations for further research include replication of this study, focusing on classroom teachers only, and comparison of traditional public and charter school teachers. Recommendations to encourage retention include investment in education for all of North Carolina’s children; significantly raising salaries of all teachers; abandonment of bonus/merit pay linked to test scores; restoration of Master’s Degree pay and providing opportunities for differentiated pay for assumption of additional duties; significantly increasing human capital and other resources in schools to meet student needs; full restoration of North Carolina Teaching Fellows program; and abandonment of high stakes testing