Master of Science in Ecological Restoration Applied Research Projects

: Structural influence of old field on breeding summer songbirds, and overwintering raptor communities; Old field is a unnatural habitat that usually occurs as a result of agricultural land abandonment and is the product of early-stage natural succession on a previously managed field. In an agricultural setting with monoculture crops, old fields provide more vegetative complexity through ground cover diversity and shrubs and hedgerows. In Delta, British Columbia, several old-field sites are managed for wildlife and provide nesting habitat for songbirds over the summer, as well as foraging habitat for overwintering raptors during fall and winter months. I surveyed two old-field sites near Boundary Bay, and two field sites at the Vancouver Landfill to compare the influence of old-field vegetation on different bird communities and improve understanding on species using the landfill. I conducted fixed-radius point counts for songbirds, and standing counts for raptors. Comparing replicate field types (n=2) I found that overall diversity of songbirds was higher in old field, and also associated with structural features like shrubs and trees, while abundances of Savannah Sparrows (Passerculus sandwichensis) decreased with proximity to shrubs and trees. My results support the conclusion that installing structural vegetation features at the landfill would maximize breeding songbird diversity. I also found the landfill to support higher diversity of wintering raptor species, but old field supported consistently higher abundances. This suggests that the landfill is currently functioning as lower quality wintering habitat, and that different management techniques should be considered.

: Sturgeon Bank marsh recession: A preliminary investigation into the use of large woody debris as a tool for restoring a degraded foreshore marsh; Large woody debris removal has been ongoing in the Fraser River Delta since the late 1800’s. I investigated how offshore winds and the absence of large wood may have contributed to the recession of the Sturgeon Bank Marsh. I suggest large wood increases marshland resilience and promotes new marsh establishment by attenuating wave energy, decreasing sediment mobilization, deterring herbivory, and promoting the establishment of vegetated islands from which the marsh can expand. I analyzed historical wind data for patterns in offshore wind duration and installed several pieces of large wood onto the tidal flats of the Sturgeon Bank. I developed a technique for anchoring wood in the intertidal and give my recommendations for further development. Finally, I conclude the recession of the Sturgeon Bank Marsh was the result of multiple interacting stressors and coin the term keystone structural element to describe the function of large wood within a foreshore marsh., large woody debris, keystone structural element, marsh recession, ecological restoration, wave sheltering, coastal marsh

: Testing primed white rot fungi for bioremediation of petroleum hydrocarbon contaminated soil & bioremediation options plan for Napo concession area in Ecuador.; Bioremediation has gained traction for its sustainable principles. Although, advancements in effectiveness are still needed to enable widespread application. This research has two major components. First, priming fungi could prove to be a useful tool to increase efficiency of white-rot fungi when used to bioremediate petroleum hydrocarbons contaminated soil. This study evaluated T. versicolor colonized in two substrates to test this theory. TPH was extracted from the soils using hexane shaking method, and measured on a CG-MS. The study results were not conclusive, and more research should be conducted to determine if priming white-rot fungi can increase the effectiveness of degradation of TPH in contaminated soils. Second, historical and unethical oil production in Ecuador has left an environmental and human health disaster. The goal of this study was to produce a high-level bioremediation plan that can be used and amended for site specific applications in Ecuador.

: The dynamics of wetland water loss in Churn Creek protected area; Twelve Churn Creek Protected Area wetlands were characterized to gain an understanding of the potential factors affecting their water loss. Monitoring consisted of pond area, depth, and temperature measurements at twelve wetlands, and additional comprehensive monitoring at five wetlands, encompassing (1) randomized quadrat emergent vegetation sampling with canopy climate monitoring and beneath-canopy water property monitoring; (2) permanent radial soil transect sampling through compaction, electrical conductivity, moisture, and temperature measurements. Findings revealed that the rate of water loss at each wetland is dependent on its specific biological, chemical, and physical characteristics. A wetland’s elevational position in the landscape, as well as its basin shape and size, and vegetative cover and density, all played a prominent role in determining the rate of water loss. These findings underscored the importance of prioritizing vegetated wetlands in future monitoring efforts and serve as a foundation for comprehensive studies in CCPA and British Columbia grassland ecosystems., closed-basin wetland, wetland hydrology, wetland water loss, pond evapotranspiration, semi-arid grasslands, wetland water balance

: 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.

: 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

: The impact of roadway mortality on a long-lived freshwater turtle, Chrysemys picta bellii; Road mortality poses a significant threat to freshwater turtles globally, including the western painted turtle (Chrysemys picta bellii). Even low levels of road mortality can severely impact the long-term survival of these long-lived reptiles. While mitigation infrastructure is employed to reduce mortality, its effectiveness may vary depending on the location and species involved. Population viability analysis can be a valuable alternative for wildlife managers to assess the viability of the populations they monitor and the potential impact of management decisions, but are most useful when data from target populations is available. This research project aimed to evaluate the long-term persistence of a rural western painted turtle population experiencing road mortality. The study first investigated the effectiveness of a turtle tunnel and drift fencing in reducing road mortality. Parameters derived from the population were then used to model the long-term viability of the turtle population in the program Vortex under various scenarios of ongoing road mortality. This study analyses three years of mark-recapture, ratio telemetry tracking, and road mortality surveys done by contractors and summer hires of the Ministry of Water, Land, and Resource Stewardship at Baynes Lake, BC. The turtle population was estimated to be 1,451 (SD= 75) individuals, with a female-biased sex ratio (1.5 females: 1 male). Only a quarter of sexually mature females were found to be gravid in a given year, with gravid females laying only one clutch. Subadult and adult survivorship were calculated using the same dataset employed for the population estimate, resulting in a survivorship rate of 96.4% (SD = 1.3%) per year. Radio telemetry was used to assess the number of road crossings made in a given year. Gravid females were found to make a higher average number of road crossings (1.6 road crossings per season) than males (0.1 road crossings per season) or non-gravid females (0.7 road crossings per season). In 2021, an under-road turtle tunnel was installed in Baynes Lake, followed by the installation of drift fencing in the spring of 2023. Over time and after the implementation of drift fencing, more turtles were observed encountering the installed turtle tunnel. However, evidence regarding the complete traversal of the turtle tunnel was not conclusive. Before the installation of the turtle tunnel, casual community-led surveys in 2021 estimated a mortality rate of 1% of the population. Mortality rates, calculated over the duration of the survey periods, decreased after the installation of the turtle tunnel (0.1 mortalities per day in 2022) and further decreased after drift fencing was installed (0.03 mortalities per day). The long-term viability of the Baynes Lake population was modeled in Vortex, with additive road mortality modeled as a percentage loss of the population. The road mortality rate of 1% additive mortality, seen before road mortality reduction strategies, resulted in a 60% decrease of the initial population after 100 years. This indicates that even low levels of additive adult road mortality can lead to declines in the Baynes Lake western painted turtle population. Sensitivity testing of the model indicates that the Baynes Lake population is highly sensitive to changes in adult/subadult and juvenile mortality. Pre-mitigation mortality levels had the potential to dramatically impact the population of Baynes Lake. It is crucial to acknowledge and address what may appear to be relatively low levels of roadway mortality in rural areas, as even these seemingly modest rates can have a significant impact on western painted turtle populations., Western painted turtle, Chrysemys picta bellii, roadway mortality, population viability modeling, population estimate, scavenge rate

Main menu

Master of Science in Ecological Restoration Applied Research Projects

Pages

Pages

Main menu

You are here

Master of Science in Ecological Restoration Applied Research Projects

Pages

Pages