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

Master of Science in Ecological Restoration Applied Research Projects

Breeding waterfowl use of restored wetlands in the Cariboo region of British Columbia
This study investigated effects of wetland size and emergent vegetation cover on breeding waterfowl and young at 12 restored wetlands in the Cariboo region of British Columbia. Repeated ground surveys were conducted throughout summer 2019 to determine total abundance, density and species richness of waterfowl. Surveyed wetlands varied in size and emergent cover. Large (16-19 ha) wetlands had greater breeding total abundance and lower breeding and brood densities than smaller wetlands. Total abundance of breeding waterfowl and young were highest when wetlands had less than 60% emergent cover. Previous studies suggest that high densities of waterfowl decrease young survival. Restorations created to benefit several species of breeding waterfowl may want to restore wetlands that are large (>16 ha) and have less than 30% emergent vegetation cover. These wetlands had higher total abundances and lower densities than other categories studied, however, certain species may depend on smaller wetlands which should be researched further., Cariboo region, wetland restoration, breeding waterfowl, emergent vegetation
A climate adaptation plan: Identifying thermal refugia for salmonids in the Tsolum River
Stream temperatures in the Pacific Northwest are increasing due to climate change, resulting in thermal stress for salmonids. Groundwater is a cooler source of water into streams, providing thermal refugia. The goal of this Applied Research Project was to identify groundwater input areas in the Tsolum River, using temperature loggers to trace the thermal signal of groundwater. A total of 28 water temperature loggers and 2 air temperature loggers were deployed within the watershed in the summer of 2019. Results showed that 12 sites may be influenced by groundwater input. Restoration/management actions such as riparian planting, gravel bar live staking, and restrictions on groundwater withdrawal are recommended to decrease stream temperatures. This study demonstrated that temperature loggers can be deployed within streams to identify areas of groundwater input. The identification of thermal refugia within the Tsolum River and other salmonid-bearing streams will help to protect salmonids from climate change impacts., climate adaptation, thermal refugia, Tsolum River, groundwater
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
Effects of Canada Goose (Branta canadensis) and Snow Goose (Chen caerulescens) herbivory on tidal marsh recession at the Westham Island Marsh
In the Fraser River Estuary of British Columbia, tidal marshes have been receding and converting into unvegetated mudflats since the 1980s. While there are many hypotheses for this recession, the effect of avian herbivory is poorly understood. This study assessed how Canada Goose (Branta canadensis) and Snow Goose (Chen caerulescens) herbivory affected cover of tidal marsh vegetation that was comprised mainly of three-square bulrush (Schoenoplectus pungens) in the Westham Island tidal marsh. I conducted two field-based exclosure experiments, marsh edge and mudflat, that used exclosure plots to reduce specific goose herbivory in a randomized block design. Each experiment consisted of four blocks each of which was comprised of four treatments: open to goose herbivory, excluded all goose herbivory, primarily excluded Canada Goose herbivory, or primarily excluded Snow Goose herbivory. The marsh edge experiment used exclosures centered on the vegetated edge of the marsh, while the mudflat experiment was conducted in the unvegetated mudflat and were transplanted with S. pungens. Based on results from July to October of 2020, percent cover of tidal marsh vegetation was about 20% lower in plots open to Canada Goose herbivory versus those that excluded geese. Snow Goose herbivory could not be accurately assessed as they arrived when S. pungens were dormant. Thus, deterring goose herbivory may be an important consideration for land managers in restoring tidal marshes. Additionally, I compared percent cover from drone-derived remote sensing to traditional ground-based visual estimates of percent cover of S. pungens in the tidal marsh. One per month, from July to October of 2020, I used a drone to take photos of the exclosures from the previous experiments, and used pixel counts to calculate the percent cover of S. pungens. I then used a t-test to compare the drone-derived percent cover to the ground-based estimates and found no significant difference (t = 0.58, p = 0.56). I then plotted a linear regression model and found a strong correspondence between both methods (R² = 0.99, p = 1.3e-139). So, remote sensing using drones appears to be an effective alternative to visual estimates of percent cover of tidal-marsh vegetation in the Westham island tidal marsh., Tidal marsh recession, Goose herbivory, Canada Goose, Snow Goose, Schoenoplectus pungens, Drones
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)
The impacts of exotic Typha on benthic invertebrate communities in the South Arm of the Fraser River Estuary
In recent decades, the exotic cattail Typha angustifolia and its hybrid Typha x glauca have invaded the Fraser River estuary. The impacts from this invasion on benthic macroinvertebrate communities, however, are yet to be studied. Macroinvertebrates play important roles in food chains, trophic dynamics, and nutrient cycling and are potentially at risk from this invasion. In this study, I compared the benthic invertebrate communities between exotic cattail stands and native vegetation stands at 25 paired sites. Sediment cores were analyzed for invertebrate abundance, biomass, and Shannon Wiener diversity index, and it was found that biomass and abundance were lower in exotic cattail when compared to native vegetation, however, there was no difference in diversity. Given the proximity to side channels, tidal inundation time would be a logical explanation for the differences in the benthic communities; however, it was not found to be a significant predictor. Given the invasive nature of exotic cattail and the correlations that were found, cattail should be removed in restoration projects where possible., Fraser River, Typha x glauca, Estuary, Invasive species, Typha angustifolia
Mapping floodplain fish habitat in the heart of the Fraser River and restoration options for impacted attributes on selected large mid-channel islands
The purpose of this project is to develop an ecological restoration plan for degraded habitats on mid-channel islands in the lower Fraser River. The study focuses on Herrling, Carey, and Strawberry islands, large mid-channel islands located in the gravel reach between Mission and Hope, British Columbia. These islands are known to be critical off-channel rearing habitat for many fish species including the threatened White Sturgeon (Acipenser transmontanus) and interior and lower Fraser watershed Chinook Salmon (Oncorhynchus tshawytscha) populations. These islands are also home to many riparian plant and animal species. The flood-pulse concept (FPC) states that seasonal fluctuations in water levels for streams such as the Fraser River contribute substantially to the ecological function of the floodplain ecosystem where this phenomenon occurs. This often results in improved growth and survival rates for fish species that rely on a laterally-moving littoral zone of inundation. This phenomenon is thought by many to be the key to a properly functioning ecosystem in the lower Fraser River. Using a Digital Elevation Model (DEM) for the Fraser River between Hope and Mission, British Columbia, freshet flows (high water elevations) are presented to define the spatial extent of over-bank watering of Strawberry, Carey and Herrling islands. This over-bank watering provides lateral connectivity to floodplain islands. Based on extensive sampling in other studies, this lateral movement results in the creation of high-quality juvenile fish rearing habitat. A restoration plan is presented for those areas of Strawberry, Carey and Herrling islands degraded by recent land clearing for agriculture where they overlap sections defined as fish habitat from the spatial analysis., gravel reach, mid-channel islands, floodplain fish habitat, flood pulse concept, juvenile Chinook Salmon, lower Fraser River, White Sturgeon
Phytoremediation of contaminated soils
Phytoremediation poses an ecologically friendly and cost-effective alternative to other remediation methods such as chemical or thermal treatment. However, in contaminated sites such as retired oil wells and brine spills, it is common to have a co-contamination of salt and polyaromatic hydrocarbons (PAHs). The co-contamination of salt and PAHs may decrease the rate and effectiveness of bioremediation. Here we investigated the effect soil salinity has on the rate of phytoremediation, plant survivability and biomass. A 90-day greenhouse study was performed, growing alfalfa (Medicago sativa L.) in soils treated with varying salt (NaCl) concentrations in the presence of pyrene and benzo[a]pyrene. No significant differences were observed in the presence or absence of PAHs. Salt treatments has significant affects on plant biomass, nodulation, and successful germination., Bioremediation, Polyaromatic hydrocarbons, Alfalfa, Salt, Phytoremediation
Restoration of the upper Salmon River watershed: projected effects of diversion removal on salmonid abundance
The Salmon River, located within the Laich-kwil-tach First Nations’ traditional territory on Vancouver Island, supports a diverse community of anadromous and resident salmonids despite having cumulative effects from historical resource development (Burt 2010a). Currently, BC Hydro’s diversion dam and transfer canal on the Salmon River provides water for hydroelectric power production in Campbell River, but restricts the upstream and downstream movement of native salmonids (Anderson 2009, BC Hydro 2012). This report addresses removing the Salmon River diversion and providing coho salmon (Oncorhynchus kisutch) and steelhead trout (O. mykiss) unrestricted access into the upper Salmon River watershed. This restoration project will mitigate projected effects of climate change on freshwater life stages of the Salmon River salmonids by addressing increasing stream temperatures and seasonal low flows. Completing this restoration project is the first step in recovering the salmonid productivity of the upper Salmon River., salmonid productivity, Salmon River, coho salmon, steelhead trout, ecological restoration, dam removal
Simplified structure or fewer arthropods to eat?
In agricultural landscapes, hedgerows provide critical habitat for songbirds. Himalayan Blackberry (Rubus armeniacus; HBB) is a widespread invasive species in the Pacific Northwest that has been linked to lower breeding songbird diversity. My study explored two possible explanatory mechanisms: educed structural complexity and lower arthropod abundance as a food source. I conducted avian point counts in 51 hedgerow segments at two locations in the Lower Mainland of British Columbia. In these segments, I quantified vegetation structure using a Foliage Height Diversity (FHD) metric derived from LiDAR data. I sampled arthropod abundance on the foliage of woody understory vegetation. I used multiple regression to identify best fit generalized linear models. Songbird diversity decreased with HBB % cover and increased with FHD. However, arthropod abundance was unrelated to bird metrics, and similar between HBB and other native shrubs. This suggests that hedgerows should be managed to control HBB and maximize vegetation structure., songbird diversity, agricultural landscapes, Himalayan Blackberry, hedgerows, arthropods, LiDAR
Throwing shade
Reed canarygrass (Phalaris arundinacea) is an invasive grass common in wetlands and riparian areas throughout the Pacific Northwest. It is highly adaptable and resistant to many control methods, but is vulnerable to shading. We sought to control reed canarygrass by establishing desirable native shrubs to overtop and shade it. Plots were rototilled, mulched, live-staked, and monitored for 2-6 growing seasons. We tested 1) effective planting densities by live-staking hardhack (Spiraea douglasii) at 50, 30, and 15 cm spacing, 2) relative species performance by planting hardhack, red-osier dogwood (Cornus sericea), and thimbleberry (Rubus parviflorus), all at 30 cm densities, and 3) alternative site preparation methods by using cardboard mulch or excavating the top 20 cm of topsoil. Higher planting density significantly reduced reed canarygrass cover and biomass. Both hardhack and red-osier dogwood successfully suppressed reed canarygrass, though thimbleberry did not. No significant differences between site preparation methods were observed., reed canarygrass, Phalaris arundinacea, invasive species management, live staking, planting density, Spiraea douglasii