undergraduate theses - 阿根廷vs墨西哥竞猜 collection of bachelor's theses from 阿根廷vs墨西哥竞猜 https://knowledgecommons.lakeheadu.ca/handle/2453/4349 2024-09-04t14:17:27z 2024-09-04t14:17:27z cost-benefit analysis of scarification in the boreal forest easton, liam https://knowledgecommons.lakeheadu.ca/handle/2453/5355 2024-07-23t09:01:49z 2024-01-01t00:00:00z cost-benefit analysis of scarification in the boreal forest easton, liam soil scarification is a site preparation method that improves growing conditions for seedlings. the practice has associated benefits and costs putting its feasibility into question within the boreal forest. the costs include aspects of environmental degradation in that it causes increased runoff impacting hydrological features and decreases microbial activity within the soil. additionally, there are economic costs associated with the practice being the cost to purchase, maintain, and fuel scarification machinery, as well as operator wages. this is offset by greatly increased success rates of regeneration. seedlings experience expedited growth in both the short and long term as well as decreased mortality rates. ultimately, the benefits of scarification do outweigh the cost in the majority of scenarios within the boreal forest making it a feasible practice. sites where the benefits may be expected to be dampened include sites with shallow soils, thin organic layers, excessive slope, or sites implementing natural regeneration rather than seeding or planting. 2024-01-01t00:00:00z a review of the toronto zoo's head-starting program for recovery of the blanding's turtle in rouge valley national urban park crilling, keegan https://knowledgecommons.lakeheadu.ca/handle/2453/5352 2024-06-28t09:01:35z 2024-01-01t00:00:00z a review of the toronto zoo's head-starting program for recovery of the blanding's turtle in rouge valley national urban park crilling, keegan conservation reintroduction programs are valuable tools in supporting endangered or extinct species in the wild. with the many ways humans are causing adverse environmental impacts, it is crucial that we put effort into reversing our adverse effects to avoid large-scale irreversible changes to ecosystems. places like zoos and sanctuaries already have facilities and staff extensively trained in caring for animals. these locations can be the key institutions to support various wildlife conservation projects. the blanding’s turtle head-starting program at the toronto zoo and the turtle reintroduction into rouge valley national urban park are successful steps in restoring a population of an endangered species. the year that the individuals were released over the period 2014-2020 did impact the turtles’ chances of survival, with particularly low survival in 2020, but there was equal success with male and female releases and variable but equal success with hard and soft releases. 2024-01-01t00:00:00z biodiversity loss due to the increase of monoculture lawns scott, kalila https://knowledgecommons.lakeheadu.ca/handle/2453/5351 2024-06-28t09:00:30z 2024-01-01t00:00:00z biodiversity loss due to the increase of monoculture lawns scott, kalila lawns have evolved over time, starting as functional spaces in medieval gardens to appearing as the manicured, european-inspired landscapes we know today. the widespread use of monoculture lawns in north america signifies a shift towards a curated environment. these lawns come with consequences for biodiversity due to intensive maintenance like frequent mowing, chemical treatments, and watering. this study explores the history of lawns, the impact of maintenance on biodiversity, and potential sustainable lawn care approaches. this thesis highlights the negative impacts of having monoculture lawns, such as reducing insect populations, disrupting soil quality, and polluting water ecosystems with chemicals. it emphasizes the need for society and municipal regulations to shift towards more eco-friendly lawn management practices. this review stresses the importance of addressing the downsides of monoculture lawns through proactive measures and exploring sustainable alternatives. 2024-01-01t00:00:00z energy density of fish within an aquaculture experiment tipping, grant https://knowledgecommons.lakeheadu.ca/handle/2453/5350 2024-06-27t09:00:35z 2024-01-01t00:00:00z energy density of fish within an aquaculture experiment tipping, grant understanding how small-bodied fish are affected by aquaculture is important to help complete the picture on how aquaculture affects all levels of the ecosystem. i analysed the energy density for small-bodied fish in the presence of aquaculture. the experiment was done in a whole lake ecosystem within the boreal shield. this study focused specifically on finescale dace within two similar lakes; lake 375 had aquaculture operating for 5 years and lake 373 was monitored as a reference lake. aquaculture likely had a positive impact on the energy density of finescale dace as they had access to an increased food source. while the energy density of minnows was higher in lake 375 than lake 373, there was a higher overwinter mortality rate in lake 375. based on findings presented here and from information reported elsewhere, i conclude that previously reported minnow overwinter mortality was largely due to an increase of predation of minnows from lake trout, rather than due to energetic deficits. while aquaculture appears to benefit the minnows where they displayed increased energy density and population densities, overwinter mortality may cause the minnow population densities to become unpredictable and volatile with an aquaculture operation. 2024-01-01t00:00:00z