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
As of 2017, more than 4 billion people live in urban areas (Ritchie 2018). As people continue to move from rural to urban areas, the concentration of greenhouse gases (GHGs) in urban areas will continue to rise. However, this may be mitigated by increasing carbon sequestration by expanding urban forests (Baines et al. 2020). While the BC government has implemented reforestation projects on logged, provincial land, and has released a Community Toolkit for municipalities to increase their treed environments, there is still available land to be planted between the provincial and municipal land (Cullington et al. 2008). Trees are an important tool for CO2 sequestration and storage. The open landscapes of the Trans-Canada Highway right-of-ways presents an underutilized opportunity to increase the treed environment for carbon sequestration and storage along this open vehicle corridor. This project seeks to model the current carbon sequestration level and the carbon sequestration potential for different vegetation types along the Trans-Canada Highway and develop recommendations for revegetation plans to increase carbon sequestration along this heavily used vehicle corridor. The study site resides along a 20 km stretch of the Trans-Canada Highway in Chilliwack, British Columbia. This area was chosen as it is an agricultural community with very few treed areas. The area was split into the Chilliwack North Polygon (CNP) and the Chilliwack South Polygon (CSP) on ArcMap, on which a grid of 20 m by 20 m squares were laid, which is necessary for transferring the data collected in the field into i-Tree Eco v6.0 (n.d.).
The program i-Tree Eco uses measurements, such as diameter at breast height (DBH) and ground cover class, taken in the field to estimate ecosystem services and structural characteristics of the Chilliwack area. Throughout the CNP and CSP areas, 12 were selected based on accessibility, safety, and site representation. The program i-Tree Canopy v7.0 (n.d.) was also used to bolster this information by estimating tree cover and tree benefits for the Chilliwack area through satellite imagery by randomly selecting 500 sampling points throughout the CNP and CSP areas. Grass surveys were conducted in 1 m by 1 m quadrats placed in an area representative of the selected 20 m by 20 m quadrat (i.e. a homogenous area that represents the majority of the vegetation in the plot). Grasses were identified on site to genus or species whenever possible, and their percent cover measured. Soil samples were also taken within the 1 m by 1 m quadrat within the first 15 cm. As these sample sites house anthroposols, sampling within the first 15 cm was selected to capture conditions in the root zone for plant growth. The soil samples taken were used to determine soil texture and soil pH for planting purposes. Finally, a review of highway management practices was done to identify areas where improvements can be made to increase carbon sequestration. Practical management suggestions are based on the results from the above-mentioned analyses. The program i-Tree Eco v6.0 (n.d) indicated that the CNP had the greatest carbon storage of 172,787.3 kg/ha, while the CSP had 15,270.8 kg/ha. The CNP is able to store 11,554.2 tonnes of carbon while the CSP was only able to store 546.1 tonnes of carbon. However, the CNP had an annual net carbon sequestration of - 57.2 tonnes/yr while the CSP has 2.5 tonnes/yr. Red alder (Alnus rubra) comprised 52.3% of tree species recorded and had the highest carbon storage of 6,322.7 tonnes, followed by bigleaf maple (Acer macrophyllum) with 3,186.0 tonnes, black cottonwood (Populus trichocarpa) with 1416.3 tonnes, western hemlock (Tsuga heterophylla) with 1155.6 tonnes, and paper birch (Betula papyrifera) with 19.7 tonnes. The annual net carbon sequestration of red alders however was - 2.2 tonnes/yr, while bigleaf maple had the highest with 3.7 tonne/yr. The program i-Tree Canopy v7.0 (n.d.) indicated that overall, there was 125.37 tonnes of carbon sequestered annually in trees within the CNP and CSP, with 3,734.34 tonnes stored. The ground cover composition of the CNP had a greater composition of shrub (61.1%) and tree (16%) compared to the CSP, while the CSP had greater plantable space (65.4%).
This data was used to characterize the study area and model the current carbon sequestration and storage. New management strategies were proposed and native vegetation suitable for the study area was identified.
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
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)
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.
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
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
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
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
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
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