Master of Science in Ecological Restoration Applied Research Projects | BCIT Institutional Repository

Master of Science in Ecological Restoration Applied Research Projects

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Blue carbon dynamics across the Metro Vancouver region
This research project aims to assess the carbon sequestration dynamics of three tidal marshes under different environmental conditions in the Metro Vancouver region. By identifying the site conditions that influence carbon sequestration, areas can be prioritized, and restoration activities can be adapted to increase or maintains the marsh’s ability to do so. This project was done in partnership with Parks Canada and will contribute to a larger study of ‘blue carbon’ across British Columbia. For this project, I collected sediment cores from the eastern portion of Boundary Bay in Delta, BC, Brunswick Point in Ladner, BC, and a constructed salt marsh in Tsawwassen, BC, to assess soil carbon content and carbon stocks. Porewater salinity, vegetation data and depth measurements were collected at these sites as well. Percent carbon content ranged between 3.98 ± 1.48% and 5.78 ± 5.93% between the three marshes and the marsh carbon stock ranged between 93.95 Mg C and 2,994.51 Mg C. Across the three marshes, core carbon stock for the high marsh cores was found to be significantly higher than the core carbon stock for the low marsh cores, suggesting that marsh zonation influences carbon stock. The data analysis and literature review determined that vegetation and porewater salinity had the greatest influence on a marsh’s ability to sequester and store carbon. The results indicate that the high marsh with low salinities and a diverse plant community have the highest carbon sequestration potential. As marshes with conditions similar to that of the Boundary Bay marsh as well as polyhaline marshes should be prioritized for restoration. These findings will aid in the development and implementation of restoration projects to increase a marsh’s ability to sequester carbon., blue carbon, tidal marsh, carbon stock, British Columbia, coastal management, restoration, marsh restoration
Comparing soil nematode composition in bluebunch wheatgrass P. spicata root to the occurrence of invasive plants C. stoebe and L. dalmatica
The viability of native bunchgrass ecosystems throughout the PPxh BEC subzone and in Kenna Cartwright Park (KCP) in Kamloops B.C. are under threat by invasive plants. Once established, invasive plants are difficult to eradicate and can predominate the landscape. I collected soil samples from a relatively undisturbed bunchgrass reference site composed of native bluebunch wheatgrass (Pseudoroegneria spicata), and I collected soil samples from a bunchgrass site occupied by the invasive plants, spotted knapweed (Centaurea stoebe) and dalmatian toadflax (Linaria dalmatica), to compare the soil nematode communities. My results reveal differences in the community-level biodiversity and abundance of soil nematodes between sites. The Maturity Index and the Plant Parasitic Index indicate that the native bunchgrass site had a “Structured” soil food web and that the site occupied by invasive plants had a “Basal” soil food web. My results indicate soil nematodes are useful as bioindicators of soil properties and these data provide useful criteria to help prioritize sites for ecological restoration., Nematology, Invasive plants, Pseudoroegneria spicata, Biological indicators, Ecological restoration
A contrast of two novel deterrents of goose herbivory at Westham Island foreshore tidal marsh
Since the 1980s, at least 160 ha of marsh vegetation has died off in Sturgeon Bank and Westham Island, located within the Fraser River Estuary. Proposed causes for this marsh recession include sediment deficit, relative sea-level rise, increased salinity, and goose herbivory. At Westham Island, the loss of tidal marsh vegetation is locally distinct in that it occurs in a closed polygon shape versus along the leading edge of the marsh, suggesting that goose herbivory is a principal cause. Goose herbivory on tidal marsh vegetation has become a global problem as many geese populations are becoming hyperabundant. In the Fraser River Estuary, Canada goose (Branta canadensis) and snow goose (Anser caerulescens) numbers have been increasing exponentially. I conducted a field experiment, testing two novel goose herbivory deterrents at Westham Island’s foreshore tidal marsh: metal and snow fencing placed flat against the substrate. I used a randomized complete block design with six replicates and three treatments: metal fencing, snow fencing and control (no fencing). Each treatment's effectiveness was assessed by monitoring changes in common three-square bulrush (Schoenoplectus pungens) every two weeks throughout the summer season (June-September 2022) in terms of stem density, percent cover, and percent of stems grazed. Results indicated that there was no difference in stem density, percent cover, and percent of stems grazed between the two fencing types. However, compared to bulrush in the controls, both snow and metal fencing treatments yielded a higher stem density and percent cover (x̄% difference = 82.9%, 53.1%, respectively) as well as a lower percent of stems grazed. These results suggest that both fencing materials are equally effective at deterring goose herbivory in a tidal marsh. Additional assessments are needed to clarify whether this technique can be scaled up to promote marsh recovery throughout the entire area of recession., tidal marsh recession, goose herbivory deterrents, goose management, Canada geese, common three-square bulrush, snow fencing, chain-link fencing
Eco-cultural restoration of wetlands at Tl’chés (Chatham Islands), British Columbia, Canada
My research project examined the restoration possibilities for two culturally important wetland ecosystems at Tl’chés (Chatham Islands, British Columbia, Canada). The first wetland is a sacred bathing pool and holds cultural significance, the second is a remnant silverweed and springbank clover (Potentilla anserine ssp. pacifica and Trifollium wormskjoldii) root garden. These wetlands are necessary ecosystems for the wildlife on Tl’chés as wetlands are rare, but also an integral part of Songhees’ cultural practices. My work was done at the invitation from elder Súlhlima (Joan Morris) who was one of the last resident of the islands and retains hereditary rights there, and Songhees Chief Ron Sam and band council. The goal of my project was to develop a restoration plan to restore the wetlands to pre-abandonment conditions, so cultural practices can continue, and to benefit the islands native plant and animal species. The project highlights the value of combining traditional ecological knowledge (TEK) and traditional resource and environmental management (TREM) practices with ecological restoration., Eco-cultural restoration, wetland ecosystems, traditional ecological knowledge (TEK), traditional resource and environmental management (TREM), estuarine root gardens, Songhees First Nation
Ecological restoration options for Clear Lake and South Lake (Riding Mountain National Park), Manitoba
Options for ecological restoration are discussed for the Clear Lake – South Lake complex of Riding Mountain National Park, Manitoba. This project consisted of a) a review of studies conducted on Clear Lake and South Lake and b) a stream water quality sampling program. The review of previous studies was to gain an in-depth understanding of historical processes which shaped Clear Lake and South Lake. Previous condition, current condition and ecological stressors are all identified based on literature from Riding Mountain National Park. The stream water quality sampling program identifies major sources of nutrients into Clear Lake. Ecological restoration options pertain specifically to the Clear Lake – South Lake complex. South Lake restoration options include supplemental planting, dredging and chemical treatments. A novel technique designed to disrupt wind driven nutrient loading is also discussed. These methods are designed to return the South Basin to a macrophyte dominated system. Addressing hypolimnetic oxygen deficiency, two forms of hypolimnetic aeration are discussed to improve water quality in Clear Lake including a ‘Full lift’ design as well as a Speece Cone. Three options regarding the isthmus and connectivity between Clear Lake and South Lake are examined including a fishway installation and a wattle fence installation.
The effect of prescribed burns on soil characteristics and plant communities in Garry Oak ecosystems. A case study on a three-year post-burn site on Tumbo Island, Gulf Islands National Park Reserve
This research project evaluates the outcomes of returning prescribed fire to endangered Garry oak meadows as a restoration treatment. This project was done in partnership with Parks Canada and involved a case study on a three-year post-burn site on Tumbo Island in the Gulf Islands National Park Reserve. Soil chemical properties were analyzed three years post burn in the summer of 2019 and compared to pre and post-burn vegetation survey results. Analysis identified beneficial changes in soil chemistry still present three years post treatment. Invasive species occurrences increased across the site, regardless of treatment, and around half of the invasive species occurrences were recorded on burn treatments areas in 2018. Prescribed burns on shallow soil Garry oak meadow sites showed beneficial outcomes for soil chemistry, reduced conifer encroachment, increased diversity and Arbutus (Arbutus menziesii) seedling recruitment. These findings aid in determining restoration plans for shallow soil Garry oak meadows, highlighting the numerous benefits from prescribed fire, while also suggesting that additional treatments in conjunction with prescribed fire will be needed to control invasive plants when planning to restore these ecosystems., shallow soil, Garry oak meadows, restoration, prescribed fire, soil nutrients, invasive plant species
The effect of vegetation structure and abiotic variables on oviposition-site selection by amphibians
Assessing restoration success for pond-breeding amphibians frequently focuses on hydrology, water quality and vegetation, while neglecting the requirements of amphibians that use the restored areas for breeding. Both biotic and abiotic conditions can influence oviposition-site selection of amphibians that do not provide parental care. This study examines how vegetation structure and abiotic variables affect oviposition-site selection by amphibians. The goal of my study was to better understand the requirements of pond-breeding amphibians. In 2017, I surveyed egg masses in four ponds at the Sunshine Coast Botanical Garden in Sechelt, B.C. I identified 667 egg masses of four native amphibian species that varied in abundance and species richness among ponds. I recorded five biotic variables (i.e., vegetation cover, vegetation type, stem density, stem diameter, and canopy closure) and two abiotic variables (i.e., water depth and solar radiation) at egg-mass sites and random sites where no egg masses were detected. Logistic regression analysis with backward elimination revealed that stem count (p = 0.008) and water depth (p = 0.0001) significantly influenced oviposition-site selection. The results also showed that higher stem density and shallower water depth increased the likelihood of egg masses being present. My study indicated that quantifying stems in the water column characterized vegetation density better than estimating percent cover of vegetation. Shallow areas that have structurally complex vegetation might provide an advantage for the offspring by increasing refuge, food resources, and favourable thermal conditions for egg development. Hence, restoration projects could incorporate vegetation structure and shallow areas in their pond designs to potentially increase the abundance and diversity of amphibian communities, thereby contributing to successful restoration projects., ecological restoration, amphibians, oviposition, Rana aurora, Pseudacris regilla, Ambystoma gracile, Amystoma macrodactylum, vegetation structure, abiotic variables
The effects of canopy closure on precipitation throughfall
Since the 1860s the watershed of Spanish Bank Creek has experienced many ecological disturbances due to extensive old-growth logging and urban development. Most notably, these disturbances have altered the vegetative composition and hydrology throughout the watershed. The historic old-growth forest has been replaced by species typical of earlier seral stages, as well as invasive species such as English ivy (Hedera helix). This disturbed vegetation mosaic is characterized by an arrested ecological trajectory that perpetuates degraded conditions. Urban development has eliminated over a third of the historic length of Spanish Bank Creek and storm drains were installed to direct residential drainage into the stream. The combination of a disturbed forest and degraded hydrology intensifies runoff and associated sediment transport, and decreases the hydraulic retention time of the watershed. This has led to a significant decline in abundance of chum, coho, and cutthroat salmonids in Spanish Bank Creek. Previous research has established how trees partition precipitation into throughfall, stemflow, and interception, however there are few studies examining the effects of canopy closure on throughfall within the context of ecological restoration. Thus, the objective of this paper is to determine if increasing canopy closure can be used as a restoration model to decrease throughfall, and consequently increase the hydraulic retention time of the watershed. Results indicated that greater canopy closure was associated with decreased precipitation throughfall. From these results I formulated a restoration goal and several treatments that would increase canopy closure, and also ameliorate the degraded vegetative composition and hydrology of the watershed. The restoration treatments prescribed in this paper constitute five years of physical enhancements from which self-sustaining biological processes will continue to restore ecosystem function and structure. Successful implementation of these restoration treatments will positively affect regional biota, as well as users of the Pacific Spirit Regional Park who come to recreate, learn, and connect.
Evaluating stream degradation in Villa De Allende, Mexico
I examined the anthropogenic effects on the water quality of headwater streams in the western mountains of the state of Mexico. Rural development has negative effects on the ecology of local streams by diverting and pumping surface and groundwater, removing riparian forests for the construction of buildings, roads, and agricultural fields, and dumping refuse in stream channels. Local development, construction, roads, and agriculture also are sources of pollution that enter the streams during rain events. These negative ecological effects are common to many streams in the watershed of the Chilesdo dam. The combined effects of human development negatively affect the quality of surface water and groundwater aquifers. The issue of anthropogenic effects on the water quality of headwater streams is relevant ecologically because of likely effects on flora and fauna that depend on these streams and because of the role of headwater streams in the context of the larger watershed. Effects on upstream areas directly affect people, animals, and plants downstream. This issue is relevant economically because rural communities depend on the availability of water of suitable quality for agriculture and livestock. In addition, local water quality directly affects the cost of water purification downstream at dams that feed the Cutzamala system, a major source of Mexico City’s drinking water. This issue is relevant socially because the local community depends on this water for domestic consumption. Compromising water quality and abundance could destabilize the lives of local people because poor water quality and water contamination are a public health concern. Additionally, climate change is likely to make this resource scarcer. Projections for all major scenarios used by the International Panel on Climate Change indicate elevated year-round temperatures and decreased overall precipitation in the region (IPCC 2013). I addressed concerns over water quality by testing differences among streams with anthropogenic alterations and a stream that had few anthropogenic alterations. I sampled benthic macro-invertebrate communities as indicators of water quality within the streams. Benthic invertebrates are a useful bio-indicator for water quality and environmental disturbances in river systems because different taxonomic groups of invertebrates have different tolerances to water pollution. I measured the abundance and taxonomic richness of invertebrates that exhibit different sensitivities to water quality. My results revealed that taxonomic richness was lower in streams that had anthropogenic alterations. My results also revealed that the abundance of “sensitive” and “somewhat sensitive species” were lower and that the abundance of “pollution-tolerant species” was higher in streams with anthropogenic alterations. The stream with few anthropogenic alterations had the highest taxonomic richness and largest number of sensitive and somewhat sensitive species. These results indicate that human activities are having negative effects on water quality. Given my results, I suggest that restoration of degraded streams should reduce water diversion, riparian encroachment, and refuse disposal. I propose solutions to guide these restoration efforts. My data suggests that a coordinated local and regional effort is required to reduce the negative effects of human development and to restore local streams to an ecological condition that will sustain water quality and quantity to enable local communities and the local environment to thrive.
Experimental control of Spotted Knapweed (Centaurea stoebe) within critical habitat of the endangered Half-moon Hairstreak Butterfly (Satyrium semiluna)
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., vegetation mapping, species at risk, host plant, invasive species, ecological restoration, Aminopyralid
Factors limiting the expansion of black-tailed prairie dog colonies at their northern extent
Prairie dogs (Cynomys ludovicianus) are considered a keystone species due to their ecological role in maintaining the prairies. In Canada, they are federally listed as a threatened species. This study was conducted to identify the limiting factors to the expansion of prairie dog colonies in Grasslands National Park, Saskatchewan. I tested different hypotheses to compare landforms, vegetation, and soil characteristics in three treatments: consistently occupied (Consistent), inconsistently occupied (Inconsistent), and never occupied (Buffer) by prairie dogs. I sampled four prairie dog colonies (blocks) from 17 July 2019 to 28 August 2019 using a randomized complete block design. I used ANOVA to test variables for significant differences among treatments. My results showed that hills, water channel, shrublands, grass cover, shrub cover and vegetation height classes (>30 cm) were significantly higher (p <0.05) in Buffer compared to Consistent and Inconsistent. Shrubs and tall vegetation should be mowed down to enhance the expansion of prairie dog colonies for restoring their population., restoration, prairie dogs, Cynomys ludovicianus, colony expansion, barriers, habitat use
Geochemical and biological response of an intertidal ecosystem to localized restoration efforts
Geochemical and biological attributes of three intertidal areas in the Squamish Estuary with different levels of disturbance (low, medium, and high) were assessed to determine short-­term ecosystem responses to localized restoration efforts conducted one year previously on a former log handing site. Sediment and macroinvertebrate variables were analyzed among sites to characterize the ecosystems response and provide insight on the nature and process of an assisted successional trajectory. Invertebrate composition and biomass were lowest on the site with the highest level of disturbance. The high disturbance site also contained the highest percentage of fine sand (0.0067 mm to 0.25 mm). This confirms that in the short term there are distinct site responses to disturbance and ameliorative restoration efforts – even in a highly dynamic estuarine environment. The medium site contained more invertebrates than the low disturbance site indicating that something other than localized disturbance is affecting the invertebrate community on the low site. All sites exhibited a less-­rich and less diverse invertebrate community than that of historical records (circa. 1970-­1980). Invertebrate community in the east delta today is more typical of estuarine environments with higher salinity levels -­ which indicates more widespread levels of disturbance throughout the Estuary is affecting the study sites. This study highlights the importance of considering temporal and spatial scales when setting restoration goals, objectives and creating monitoring plans. Additional monitoring of sediment, invertebrate, and other variables on restored and reference sites is recommended to characterize typical recolonization and reassembly attributes of restoring intertidal estuaries in coastal British Columbia. This would provide evidence and rigor in determining effective restoration techniques and management strategies for a critical and increasingly threatened ecosystem., Macroinvertebrates, Restoration, Sediment, Benthic ecology, Estuaries, Intertidal flats
Hypolimnetic upwelling in coastal embayments of Lake Ontario; implications for restoration
Coastal wetlands are an important ecosystem in the Great Lakes basin, providing spawning grounds and warm-water refuge for numerous fish and benthic invertebrate species during cold water upwelling events. Urbanization along the northwestern shore of Lake Ontario has led to a depletion of coastal wetlands, replacing them with artificial embayments. Three artificial embayments, the Credit River estuary, and one coastal marsh in Mississauga, ON were studied to determine if the artificial embayments function as warm-water refuge during upwelling events. Temperature loggers were placed in each study site and temperature was recorded every 15 minutes from July to October 2017. Upwelling events were isolated from the data, and frequency, magnitude, and duration of upwelling was determined. Most study sites had a frequency of 4 upwelling events throughout the study period. The average duration of upwellings varied from 30 to 70 hours, and the average temperature change ranged from -7.1ᵒC to -11.9ᵒC. All of the study sites seemed to buffer upwellings by reducing the magnitude of temperature change and increasing the duration of upwelling events to varying degrees. These results will inform the creation of future wetlands, restoration of existing embayments, and conservation of Great Lakes coastal wetlands., ecological restoration, coastal embayments, coastal marsh, upwelling, warm-water refuge, Lake Ontario
Impacts of roads and cranberry agriculture on bog wetland hydrology with restoration recommendations for Langley Bog
Bog wetlands store a disproportionate amount of carbon for their size, making their conservation an important part of climate change mitigation. The goal of this project is to investigate how roads and agriculture impact the hydrology and vegetation composition of Langley Bog and to provide restoration recommendations. Langley Bog, in Langley Township, BC, is a formerly mined peatland with a fill road running through the center and surrounded to the north and west by cranberry farms. From November 2020 to November 2021, depth to water table and pH were measured monthly at nine wells. Twelve vegetation transects were completed in July 2021. Sites adjacent to the road were correlated with a decrease in summer water level, while sites adjacent to the cranberry farms were correlated with an increase in spring pH levels. A positive relationship was found between an increase in water-table level and percent cover of wetland obligate species. Roads may be lowering the water table through subsidence and drainage. The cranberry farms may be increasing the pH through the deposition of fertilizer. These impacts may have been exacerbated by the unusually dry 2021 summer season. To raise the water table, tree and road removal is recommended to restore lateral flow and decrease evapotranspiration. Culverts installed under the primary fill road will provide additional hydrologic connectivity. Building a berm at outlet points will also help prevent water loss, keeping a higher water table. To increase carbon sequestration, Sphagnum mosses are to be reintroduced to denuded areas in Langley Bog. Tree removal will help in moss establishment by maintaining open bog conditions free from shading. Existing rare ecosystems present in Langley Bog would benefit from the removal of point source pollutants and invasive species on the site. Given the urgency of climate change, restoring the functionality of Langley Bog and protecting the existing stored carbon is a practical and achievable way to move Metro Vancouver a step closer to carbon neutrality., peatlands, ecological restoration, water levels, pH, sphagnum
Investigating regeneration in a raised ombrotrophic bog after peat extraction
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., Atkins-Durbrow Hydropeat method, Ditch blocking, Ecological restoration, Peat extraction, Raised ombrotrophic bog, Burns Bog
Investigating the role of elevated salinity in the recession of a large brackish marsh in the Fraser River estuary
At least 160 ha of the Sturgeon Bank low marsh in the Fraser River delta died off between 1989 and 2011. Humans have heavily modified the Fraser River estuary since the late 1800’s, including installing a series of jetties throughout the leading edge of the delta to train the course of the river. I established a reciprocal transplant experiment to determine the role of elevated salinity in the marsh recession and generate information needed to eventually revegetate areas of receded marsh as part of an intergovernmental collaboration to investigate the causes of this marsh recession. I propose specific actions to better monitor, maintain, and restore the Fraser River delta foreshore brackish marshes in response to ongoing ecological degradation of the estuary. The predicted effects of climate change and sea-level rise may cause us to rethink options for restoring the Sturgeon Bank marsh., Restoration, Fraser River, Schoenoplectus pungens, Reciprocal transplant experiment, Marsh recession, Brackish marsh

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