Journal of Natural Resources and Life Sciences Education最新文献

Forestry higher curricula reform is being debated globally. This study examines the views of students on aspects related to forestry education and the profession, focusing on how these views differ across the study years of a higher education forestry program. The objective of the study was to investigate the differences across study years with regard to the students’ forestry-related concerns, the value they give to competencies and experiences, and their preferences with respect to future work and studies. The case study of a 5-year Brazilian undergraduate program was selected, analyzing the responses to a questionnaire of 268 students. Results indicate students in the later years of their study program have a much broader variety of forestry-related concerns, have a greater interest in choosing a different university for doing a Master's degree, and more often consider working as consultants upon graduation. Additionally, students in the later years give a higher importance to competencies related to traditional forestry areas (silviculture, management, policy), computer-related subjects (Forest Information Systems, statistics, computer skills), and generic communication competencies (oral and writing skills). On the contrary, students in the first years give a higher value to environmental and climate change–related issues and to international forestry, as well as to achieving their best. Our findings show there are numerous differences in students’ perceptions across the study years of a program. The consideration of these differences in the reform of forestry and life science curricula, aiming at increasing the attractiveness and effectiveness of the programs, is suggested.

Concerns are growing regarding the availability of sustainable energy sources due to a rapidly growing human population and a better understanding of climate change. In recent years, the United States has focused much attention on developing domestic energy sources, which include coal-bed methane (CBM). There are vast deposits of the natural gas within the Powder River Basin (PRB), Wyoming. A sharp increase in exploration and development of CBM in the region has led to a decline in the surrounding greater sage-grouse (Centrocercus urophasianus) populations in developed areas. This case study presents the issues surrounding CBM development and sage-grouse conservation within the PRB and provides instructors with online resources and classroom activities that can be used to stimulate and develop students’ active learning and critical thinking skills.

We piloted an educational model, the Sustainable Agriculture Scholars Program, linking research in organic agriculture to experiential learning activities for summer undergraduate employees in 2007 and 2008. Our objectives were to: (1) further student understanding of sustainable agriculture research, (2) increase student interest in sustainable agriculture careers, and (3) use community service as a vehicle for learning. The three learning environments were on-farm and laboratory research settings, weekly meetings and field trips to discuss research and observe farming practices, and a service-learning project. We collected feedback from participants through a post-program focus-group style evaluation in Year 1 and pre/post individual evaluations with participants and a non-participant comparison group in Year 2. Students learned about linkages between research and practice within all environments. Farm visits were the primary learning site, specifically through observations of sustainable agriculture practices related to lab work and interactions with farmers. Students described how farm visits made lab work relevant; however, there were few instances describing how lab work was relevant to farming communities. Our preliminary findings from this pilot study suggest that participation in the program led to increased interest in sustainable agriculture careers and increased desire to pursue research in some students.

Managing fish resources in the ocean, known as marine fisheries management, often involves disagreement among many groups of people: commercial fishers, recreational anglers, national and local conservationists, and several branches of government. While managing marine fisheries in federal waters, the federal government must rebuild marine fish populations while balancing the economic demands of these competing groups. Red snapper (Lutjanus campechanus) is a particularly useful example, involving more than 200,000 people and $80 million each year in the Gulf of Mexico. After a lawsuit won by conservation groups in 2007, the National Marine Fisheries Service was required to tighten management while selecting from many possible management tools. We envision that students will read this case study and participate in classroom discussion using the questions and teaching notes that are included. Students will then be divided between recreation and commercial user groups, and will advocate for their user group in a classroom role play in an attempt to persuade a third group: student resource managers. These student resource managers will ultimately select a set of allocation and management actions for the red snapper fishery that will decrease total catch as required by the 2007 court case, which can be compared with real-world decisions. This study aims to illustrate the complex conflicts and economic issues that surround fisheries management decisions. The learning objectives are: (1) to develop and demonstrate students’ ability to craft arguments in a debate, and (2) to build student experience working as a team doing research and planning an argument.

Herbicides are effective because they each target a specific metabolic pathway in plants. In order for a herbicide to kill a plant, it must first be absorbed by the plant's leaves or roots. Once the herbicide is absorbed, it will enter a cell which possesses the metabolic pathway the herbicide was designed to target. This lesson follows the fate of the herbicide after it has entered the plant via leaf or root tissue, and explains the factors controlling transport of a herbicide into plant cells. This lesson describes (1) the barriers to herbicide entry, such as the plant cell membrane, (2) the role that the herbicide's chemical properties have on the rate of cellular absorption, and (3) experimental approaches to understanding herbicide absorption at the cellular level.

Copper fungicides and bactericides are often used in tomato cultivation and can cause toxic Cu levels in soils. In order to combat this, organic matter can be applied to induce chelation reactions and form a soluble complex by which much of the Cu can leach out of the soil profile or be taken up safely by plants. Organic acids such as citric, fulvic, and malic acids are contained in organic matter, and complex well with Cu. Both the chelation reaction and the effectiveness of soil organic matter in the chelating process are pH dependent, and generally a more alkaline soil will be less affected by high Cu levels. In addition to organic matter application, lime may also be added in order to raise the pH and aid the process by which Cu is removed. Other benefits are also derived from soil organic matter application in addition to soil remediation. Organic matter improves soil structure, exchange capacity, and water holding content. Application of organic matter is thus a viable option for restoring toxic Cu soils.

Integrating livestock into a cropping system by allowing ruminant animals to graze cover crops may yield economic and environmental benefits. The effects of grazing on soil physical properties, soil organic matter, nitrogen cycling and agricultural production are presented in this literature review. The review found that grazing cover crops generally led to increased bulk density, especially in no-till systems. On the other hand, the negative effects of grazing on penetration resistance and aggregate stability were more prominent under conventional tillage than no-till. The deleterious effects of grazing on soil physical properties were most severe when grazing was implemented at high intensity and on wet soils. Microbial biomass C was higher under grazed conditions than ungrazed conditions. Nitrogen was found to be higher when cover crops were grazed than not grazed; however, this was only true for conventional tillage systems. Generally, grazing cover crops did not negatively affect primary crop yields. Cover crops provided nutritious forage for cattle and reduced feed costs by offsetting the use of hay or other pasture.

It is difficult to demonstrate the soil water retention relationship and related concepts because the specialized equipment required for performing these measurements is unavailable in most classrooms. This article outlines a low-cost, easily visualized method by which these concepts can be demonstrated in most any classroom. Columns (62.5 cm tall) were constructed using 25, 2.5 cm tall sections of 7.62-cm (3-inch) i.d. polyvinyl chloride pipe, which were connected using transparent tape. Three different soil materials were packed to specified bulk densities in the columns, and saturated with water. These vertical columns were then allowed to drain into a simulated water table 2.5 cm above the bottom of the soil volume until drainage ceased. After drainage, columns were sectioned to determine water content distribution with depth along the column. It was assumed that matric potential was inversely related to height above the water table. Therefore, water content measurements and assumed potentials for each section provided data for a water retention curve with minimum potential of approximately –60 cm. During drainage, measurements of soil matric potential were taken at regular intervals using tensiometers installed within the column, validating assumptions about matric potential. Among soil materials tested, those with narrow particle-size distributions, ∼100% sand, gave the widest distribution of water contents in the observed matric potential ranges. This method, with proper explanation and execution, may be a valuable learning tool by which visual, auditory, and kinesthetic learners may be better able to understand the concepts pertaining to soil–water retention relationships.