Ecological Restoration - Theses, Dissertations, and other Required Graduate Degree Essays

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Nanaimo River Estuary Restoration: An Assessment of Berm Removal on Benthic Macroinvertebrates in Tidal Channels

Date created: 
2016-04-16
Abstract: 

Macroinvertebrates in two berm-impacted tidal channels (Site A and Site B) were compared to a natural channel (Site C) to determine short-term response to berm removal restoration using a BACI study design. Multivariate analysis indicates that the benthic community composition shifted from before berm removal to after berm removal conditions but not in a predictable organized way. Total abundance was highest at Site A in both conditions (before and after berm-removal). Invertebrate diversity was similar and low among sites. Biomass was highest at Site C. Organic matter percentage was highest at Site C in both conditions and it appeared to increase in Site A and Site B after berm removal. Silt & Clay (>0.0063mm) were statistically different in Site C compared to Site A and Site B although very fine sand was the highest in percentage among sites and in both conditions. Berms affect channel and benthic invertebrate dynamics; time and more research are needed to fully restore the Nanaimo estuary.

Document type: 
Graduating extended essay / Research project
Senior supervisor: 
Ruth Joy
Department: 
Environment: Ecological Restoration
Thesis type: 
(Project) M.Sc.

A mitigation plan for salmonid spawning habitat in the Lower Seymour River, North Vancouver

Author: 
Date created: 
2018-04-19
Abstract: 

The Seymour River is a mountainous river located in North Vancouver. Over the past century, this river has been subjected to many anthropogenic activities that have cumulatively altered the natural flow and sediment regime. The Seymour Falls Dam, located in the middle of the watershed, intercepts gravel transport from the upper watershed into the lower reaches. This combined with the intense channelization within the lower 4 km of the river, which has created conditions incapable of gravel deposition and retention, has led the lower reaches to become gravel deficient. This gravel deficiency has caused the degradation of traditional spawning grounds of chum (Oncorhynchus keta), and pink salmon (Oncorhynchus gorbuscha). This study aims to: 1) determine if there is a gravel deficiency for chum and pink salmon spawning in the lower 1.5 km reaches and, 2) provide recommended mitigative treatments of gravel addition to increase suitable spawning area, and therefore increase salmon productivity of the Seymour River. A site assessment was conducted on the lower 1.5 km of the Seymour River and included sampling of the five key parameters that define spawning habitat (i.e., water depth, velocity, dissolved oxygen, water temperature and substrate). A particular focus was given on analysing the substrate as it was expected to be deficient for spawning due to the predetermined conditions in the watershed such as the dam and the channelization. Results of the site assessment confirmed that substrate is a limiting factor for chum and pink salmon spawning in this area as the bed surface is composed of large cobbles and boulders too large for these specific species to move to dig a redd. Therefore, a mitigation plan of gravel addition is proposed to increase spawning habitat and conserve these salmon runs.

Document type: 
Graduating extended essay / Research project
File(s): 
Senior supervisor: 
Ken Ashley
Department: 
Environment: Ecological Restoration
Thesis type: 
(Project) M.Sc.

An ecological restoration plan for a weedy field at The University of British Columbia Okanagan

Author: 
Date created: 
2019-04-15
Abstract: 

Grassland ecosystems are rare, in decline, and support a multitude of at-risk species in British Columbia. At the University of British Columbia Okanagan in Kelowna BC, a 3.3 ha site at the entrance of the campus is outlined as Okanagan grassland in campus design plans but currently lacks native bunchgrass communities. The goal of this restoration plan is to return grassland plant communities to the site despite the pervasiveness of noxious weeds. I characterised site conditions through soil and vegetation surveys. Restoration recommendations include managing noxious weeds through mowing, hand-pulling and some herbicide application. The site will be replanted with bunchgrass vegetation, two pockets of ponderosa forest, and two types of shrub communities. A walking path, signage, and two xeriscape gardens will also be included to control human use of the landscape. Long-term monitoring will be incorporated into classroom curricula to tie monitoring to learning opportunities.

Document type: 
Graduating extended essay / Research project
File(s): 
Senior supervisor: 
Miranda Hart
Department: 
Environment: Ecological Restoration
Thesis type: 
(Project) M.Sc.

Alaksen National Wildlife Area: Reservoir suitability for the introduction of the endangered Western Painted Turtle

Author: 
Date created: 
2019-04-16
Abstract: 

Alaksen National Wildlife Area located in Delta, BC is home to freshwater species in the former tidal marsh. The current agricultural landscape has left a legacy of high concentrations of heavy metals, trace amounts of organochlorine pesticides, and excess nutrients within the sediments and water of the brackish Fuller and Ewen Reservoirs. Arsenic and phosphorous exceeded Canadian water quality guidelines, while arsenic, chromium, copper, iron, manganese, nickel, and phosphorus exceeded sediment quality guidelines. There were trace pesticides known to be endocrine disrupters detected in the water and sediment, and combined low level toxicity effects are a concern. A preliminary ecological risk assessment on the metals was completed and the results indicate that there is a possibility of adverse effects for benthic invertebrates, but negligible risk for endangered Western Painted Turtles. However, compounding all the ecosystem stressors along with rising sea levels leads ANWA not an ideal place to introduce this species.

Document type: 
Graduating extended essay / Research project
File(s): 
Senior supervisor: 
Vicki Marlatt
Department: 
Environment: Ecological Restoration
Thesis type: 
(Project) M.Sc.

Restoring hydro-impacted wetlands for secretive marsh birds

Author: 
Date created: 
2019-04-17
Abstract: 

Secretive marsh birds can be difficult to detect and are dependent on wetlands, leaving them vulnerable to wetland loss or alteration. This study examines the influence of management-altered hydrological regimes on five secretive marsh bird species in the West Kootenay and Columbia Wetlands in British Columbia, Canada. Focal species occupied wetlands with less frequently altered hydrological regimes more often and in greater numbers. Occupancy models suggested that woody vegetation, tall vegetation, and open water are important drivers of occupancy for these species. Wetlands most frequently experiencing heavily altered hydrological regimes had more open water and less tall vegetation, both of which were negatively associated with wetland occupancy. Water management operations may be promoting altered vegetation communities within these wetlands, in turn promoting lower occupancy of secretive marsh bird species. Restoration recommendations include: prioritizing lower elevation wetlands, limiting woody vegetation encroachment, and experimentally restoring the hydrological regime of affected wetlands.

Document type: 
Graduating extended essay / Research project
File(s): 
Senior supervisor: 
David Green
Department: 
Environment: Ecological Restoration
Thesis type: 
(Project) M.Sc.

The effects of tree thinning and broadcast burning on the quality of ungulate winter range: A case study within a southern interior forest in British Columbia

Author: 
Date created: 
2018-04-20
Abstract: 

Food limitation on ungulate winter range (UWR) has been a suspected factor in the regional declines of Odocoileus hemionus (mule deer) in the Pacific Northwest. Accordingly, enhancing browse resources in this critical habitat is increasingly recommended. At a dry forest site in Southeast B.C. called Fiva Creek (IDF dm1), I investigated the effects of two commonly prescribed methods for enhancing browse production: tree thinning and prescribed burning. Treatments were implemented between 2005–2008 and included three levels of thinning (all burned) and control areas (uncut and unburned). The response variables I measured included browse cover, canopy closure, security cover, visibility, and pellet abundance. I also evaluated browsing pressure on the indicator plant, Saskatoon (Amelanchier alnifolia). Using linear mixed-effects ANOVA tests, I assessed how thinning (with follow-up burning) influenced forest and vegetation properties. There was no evidence of a treatment effect on browse production; however, browsing pressure was very high across the site (i.e., > 80% of A. alnifolia twigs showed evidence of browsing). Additionally, canopy cover was below recommended levels in all thinned treatments. My results suggested that restoration treatments actually diminished the quality of UWR at Fiva Creek. Further investigations are needed to develop effective UWR restoration methods.

Document type: 
Graduating extended essay / Research project
File(s): 
Senior supervisor: 
Douglas Ransome
Department: 
Environment: Ecological Restoration
Thesis type: 
(Project) M.Sc.

Investigating regeneration in a raised ombrotrophic bog after peat extraction

Author: 
Date created: 
2019-04-12
Abstract: 

Burns Bog is a raised ombrotrophic bog in Delta, British Columbia and faced with myriad disturbances. This study is focused on the impact and restoration of peat extraction by the Atkins-Durbrow Hydropeat method. Depth to water table, relative abundance and distribution of vegetation, and the degree of peat decomposition at consistent-depth intervals were investigated to elucidate the status of passive and active ecological restoration in three fields previously harvested for peat approximately one decade apart and compared to a fourth unharvested field. Summary statistics, Redundancy Analysis, and regression were used to compare restoration status and trends in hydrology, vegetation composition, and peat accumulation. A lag period between cessation of harvest and implementation of restoration, coupled with rapid anthropogenic climate change, serve as impediments to restoration here. Intervention in the form of improved rainfall retention, assisted recolonization, and the introduction of nurse species are recommended to improve bog function and resiliency.

Document type: 
Graduating extended essay / Research project
File(s): 
Senior supervisor: 
Ken Ashley
Department: 
Environment: Ecological Restoration
Thesis type: 
(Project) M.Sc.

Using 10-years of population monitoring data to assess breeding productivity of the Oregon Spotted Frog (Rana pretiosa)

Author: 
Date created: 
2018-04-17
Abstract: 

Relationships between changing environmental variables and amphibian populations have been understudied. Yet, alterations to temperature and precipitation have been suggested as contributors to the decline of some pond-breeding species, such as the Oregon Spotted Frog (Rana pretiosa). R. pretiosa has been classified as the most endangered amphibian within Canada, yet the cause for its decline is unknown. Therefore, this paper examined associations between temperature and precipitation and R. pretiosa population trends using a 10-year data set from two breeding populations in the Lower Mainland of British Columbia. Timing of oviposition was positively related to higher temperature and increased precipitation within both populations (p<0.05). No statistical relationship was determined between egg mass productivity and temperature of precipitation; however, this paper proposes that further research, consistent protocols and longer study periods, is mandated to determine environmental variables as a possible predictor of population success. This paper recommends the evaluation of breeding success through survivorship studies, as such methods provide insight into productivity as the primary determinant for population recruitment. Further, ecological restoration efforts can be implemented to help ameliorate negative consequences climate change poses on reproductive success.

Document type: 
Graduating extended essay / Research project
File(s): 
Senior supervisor: 
Leah Bendell
Department: 
Environment: Ecological Restoration
Thesis type: 
(Project) M.Sc.

Experimental control of spotted knapweed (Centaurea stoebe) within critical habitat of the endangered half-moon hairstreak butterfly (Satyrium semiluna): A pilot study of Blakiston Fan, Waterton Lakes National Park, Alberta

Date created: 
2018-04-18
Abstract: 

Spotted knapweed (Centaurea stoebe) is a non-native invasive forb found throughout North America that suppresses native vegetation and reduces biodiversity. The designation of Blakiston Fan (Waterton Lakes National Park, Alberta) as critical habitat for the endangered half-moon hairstreak butterfly (Satyrium semiluna) brought forward concerns of the effects of knapweed management practices on the hairstreak and its native larval and nectar host plants. This pilot study used a randomized complete block design to examine the within-season change in cover of spotted knapweed and silky lupine (Lupinus sericeus) in response to herbicide application and two timings of manual removal (i.e., mid-June and late-July). This study also examined changes in the vegetation community and relative abundance of hairstreak butterflies across the fan. Significant treatment effects (p= 0.006, f3, 12= 6.89) were seen in the change in percent cover of spotted knapweed two weeks post-treatment between herbicide and control plots. There was no significant difference in the change in lupine percent cover among treatments (p= 0.075, f3, 12= 2.96). Cover of native host plants and hairstreak abundance were greatest in the south fan. Increases in knapweed cover were lowest in the south fan. Based on these results, a triaged management plan was recommended with restoration efforts focused on the south fan. Recommendations for the south fan include selective herbicide application to limit spotted knapweed distribution, closure of horse trails, and a native planting and seeding experiment. Management of the north and central fan was recommended to focus on the control of knapweed monocultures through intensive herbicide application and establishing biological control agents for long-term control. Further research of the hairstreak lifecycle is needed to understand the primary mechanism of decline, as well as, research into the response of native nectar host plants to knapweed control. Monitoring the response of the vegetation community and relative abundance of hairstreaks following the Kenow fire of 2017 is key in prioritizing restoration actions for Blakiston Fan.

Document type: 
Graduating extended essay / Research project
File(s): 
Senior supervisor: 
Douglas Ransome
Department: 
Environment: Ecological Restoration
Thesis type: 
(Project) M.Sc.

The effect of nitrogen fertilization on the physiology and morphology of Sphagnum capillifolium in an ombrotrophic bog

Date created: 
2018-04-16
Abstract: 

Degraded peatlands release 100-200 g-CO2 eqv. m-2 yr-1 in net emissions and account for more than 10% of global CO2 emissions. The success of bog restoration is dependent on creating suitable moisture conditions for the donor material to establish, propagate, and develop a new layer of Sphagnum that has hydrophysical and water retention properties similar to natural peatlands. Techniques to improve moisture retention during the transplant process and increase water holding capability of the restored Sphagnum layer have been identified as an area of bog restoration that requires more research. Samples were collected from plots fertilized with six different nitrogen treatments at Mer Bleue Bog in Ottawa, Canada. Net CO2 assimilation, fresh weight, dry weight, water content, and dissolved nutrient measurements were made to determine the potential effectiveness of incorporating nitrogen fertilization into the North American approach to peatland restoration. High levels of nitrogen fertilization exerted deleterious effects on individual morphology, growth density, water holding and retention capacity, CO2 assimilation, and nutrient dynamics and decomposition. Fertilization with 1.6 g m-2 yr-1 of ammonium has the potential to ameliorate water retention capacity through more robust individual morphology and denser growth patterns and increases carbon assimilation and photosynthetic capacity. The results indicate integrating low levels of ammonium fertilization into bog restoration techniques can potentially increase restoration success.

Document type: 
Graduating extended essay / Research project
File(s): 
Senior supervisor: 
Leah Bendell
Department: 
Environment: Ecological Restoration
Thesis type: 
(Project) M.Sc.