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

Master of Science in Ecological Restoration Applied Research Projects

Pages

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
Ecocultural restoration of a Coastal Root Garden on Tl’chés (Chatham Island), B.C.
Tl’chés is the Lekwungen name for the Chatham Islands — an archipelago located southeast of Victoria, British Columbia. Tl’chés is a central place in the traditional territory of the Lekwungen peoples, and today it is reserve land of the Songhees First Nation. This landscape was traditionally managed by prescribed burning and the cultivation of native plants. However, in the early 1950's, Lekwungen peoples left the archipelago, due to a lack of potable water and since then, the landscape has degraded drastically. The introduction of non-native plants has resulted in threats to the ecological, cultural resilience, and diversity of the landscape. My research focuses on developing a restoration plan for springbank clover in the coastal root garden. My restoration approach focuses on incorporating a Songhees-informed approach to restoration by integrating past practices and knowledge with the aim of answering: how to best restore the springbank clover population on Tl’chés?, Eco-cultural restoration, coastal root gardens, traditional ecological knowledge (TEK), Songhees First Nation, cultural keystone place (CPK)
Ecological restoration of the Little Qualicum River Estuary: Analysis of short-term sediment deposition
Restoration of the Little Qualicum River Estuary has focused on re-establishing the Carex lyngbyei channel edge vegetation lost to grubbing by the overabundant resident Canada goose population. Short-term sediment deposition rates were measured using weekly deployments of sediment traps between June and July 2019 to investigate how restoration is facilitating sediment retention to rebuild the marsh platform. Deposition rates varied between 6.82-107.88 g/m2/week with traps deployed on the denuded mud flat areas collecting more sediments than inside the older exclosures. It had been expected that the exclosures with a greater density of sedges would retain more sediment. Spatial variation may be attributed to differences in sampling elevations. Restoring C. lyngbyei may not increase localized sediment deposition directly but does protect the continued supply of organic input from the seasonal senescence of C. lyngbyei. The organic input from aboveground biomass may have a larger contribution to marsh accretion than allochthonous sediments., sediment deposition, Carex lyngbyei, estuary, restoration, Canada goose
An ecological restoration plan for a weedy field at the University of British Columbia Okanagan
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., Grassland, exotic plants, Noxious weeds, urban restoration, restoration plan
The effect of mowing and hand removal on the regrowth rate of Himalayan blackberry (Rubus armeniacus)
Himalayan blackberry (Rubus armeniacus Focke) is an invasive species in the Pacific Northwest. Mowing and hand removal are two of the common treatments used for controlling Himalayan blackberry. I examined the effectiveness of mowing, hand removal, and control treatments by measuring the mean number of stem and mean stem length during a growing season. Treatments were applied on March 2017. Bi-weekly sampling was from April to August 2017. Data were analyzed with a two-factor split-plot Analysis of Variance (ANOVA) test. The overall trend showed no statistically significant difference between mowing and hand removal treatments in one growing season. Integrated treatments (e.g. mowing + hand removal + planting) are recommended to be used to effectively reduce Himalayan blackberry cover because one removal treatment showed to be insufficient to eliminate Himalayan blackberry., Himalayan blackberry
The effect of nitrogen fertilization on the physiology and morphology of Sphagnum capillifolium in an ombrotrophic bog
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., water content, carbon dioxide assimilation, growth density, peatland restoration, ammonium, nitrate
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 time-since-burning and hand-pulling on the growth and stem density of Centaurea stoebe and Linaria dalmatica
Prescribed burning and hand-pulling are used to manage invasive plants but treatments can deferentially affect species. My objective is to determine the effect of time-since-burning and hand-pulling on stem density and growth of Centaurea stoebe (spotted knapweed) and Linaria dalmatica (Dalmatian toadflax). Prescribed burns occurred in March 2015 and 2016, while hand-pulling occurred in April and May of 2017. I conducted vegetation surveys in May, June, and July 2017. Growth rates differed among treatments and by species. Centaurea stoebe was not detected in the prescribed burn treatments. Hand-pulling increased stem density of C. stoebe, but individuals were smaller and 60% remained as basal rosettes compared to control. Linaria dalmatica were significantly taller in the burn treatments, and the stem density of L. dalmatica was greater in the prescribed burn and hand-pull treatments compared to control. The tallest L. dalmatica occurred in the 2-year post-burn site, indicating a time-since-burning interaction., invasive plants, prescribed burning, hand-pulling, Cetaurea stoebe, Linaria dalmatica
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.
Effects of logging-induced sediment loading on Chinook salmon rearing habitat in Tranquil Estuary, BC and implications for estuary restoration
Research on estuaries has increased in recent years, however, the effects of logging on estuaries and the effects of estuary habitat loss on Chinook salmon (Oncorhynchus tshawytscha) in the Pacific northwest is limited. To address habitat loss associated with logging, I used an extensive aerial photo record for Tranquil Creek estuary and an unlogged control to analyze changes in salt marsh area, elevation and volume, supplemented with a grain size distribution analysis. While I failed to find evidence of a difference between a logged and an unlogged estuary, some negative trends in salt marsh area and elevation observed over the observational period were indicative of changes that are unfavorable for juvenile Chinook salmon. Analytical methods presented here to assess changes in two remote coastal estuaries has contributed to the current knowledge on the effects of logging on estuarine ecosystems in coastal BC and provide tools for innovative estuary habitat restoration., aerial photograph analysis, Chinook salmon (Oncorhynchus tshawytscha), salt marsh, estuary restoration, logging, sediment
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
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., Mule deer, ungulate winter range, thinning, prescribed fire, restoration ecology
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
Exploring the relative effects of different wetland restoration sites on functional connectivity for the northern red-legged frog (Rana aurora)
Amphibian species are globally at risk, with a leading cause of decline attributed to habitat loss and fragmentation. The northern red-legged frog (NRLF) is one such species and listed as a Species of Special Concern by the Species at Risk Act. The Sunshine Coast Wildlife Project is creating new wetland habitat on the Sechelt Peninsula. In this research, I provide a tool to explore the relative effects on the functional connectivity of different potential restoration sites. A habitat suitability model (HSM) was created to describe the landscape in terms of conductance, or ease of movement for NRLF. Using this conductance map, I analysed the functional connectivity between wetlands by using Circuitscape, a software grounded in circuit theory. Three potential restoration options were compared against the existing landscape. Of the three options, one had a much greater effect in increasing the overall wetlands and its connectivity to the existing network of wetlands., Functional connectivity, wetland habitat restoration, northern red-legged frog (Rana aurora), circuit theory, Circuitscape, habitat suitability model (HSM)
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

Pages