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
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
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
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
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
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
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.
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