In Ontario, invasive Phragmites australis threatens to displace many species including the endangered species Sida hermaphrodita and Ammannia robusta. Germination and growth assays measured the effect of P. australis aqueous extracts from the leaves, rhizomes, and roots on S. hermaphrodita and A. robusta. Germination was inhibited by some of the treatments, but growth was not. The tissues inhibited germination differently for S. hermaphrodita (leaf> rhizome> root) compared to A. robusta (root> rhizome> leaf) indicating that the allelopathic effect was species-specific. However, the laboratory results show that allelopathic effects are weak. This result is consistent to the field study results showing an increase in S. hermaphrodita area and density over time. Results from this project inform management options by indicating which part of the plant needs to be targeted. In this case, all the tissues had some phytotoxic effects, indicating that biomass may need to be removed or long-term management implemented., Invasive Species, Species at Risk, Seed Germination, Seedling Growth, Allelopathy
Dikes and culverts have limited access to off-channel rearing habitats important to juvenile coho salmon (Oncorhyncus kisutch). This study assessed the success of a floodplain reconnection project in Squamish, BC, at providing rearing habitats. Recommendations on restoration priorities within the area were also provided. A single-season, multi-scale occupancy model was used to estimate the probability of occurrence and detection of juvenile coho during the summer. Regression models were used to assess water and habitat quality and identify relationships with juvenile coho metrics. Culverts were also scored for fish passage. The results of this study indicate that the reconnection project was overall successful. Coho non-detections occurred in areas with poor dissolved oxygen and culvert passage issues. Restoration actions should focus on improving water quality in these areas, and protection of areas of high CPUE. Positive relationships between stream productivity and coho metrics indicates the importance of future studies on macroinvertebrate supply., coho salmon, escape cover, rearing habitat, floodplain reconnection, urban channels, Mamquam River
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.
Since the 1980s, at least 160 ha of marsh vegetation has died off in Sturgeon Bank and Westham Island, located within the Fraser River Estuary. Proposed causes for this marsh recession include sediment deficit, relative sea-level rise, increased salinity, and goose herbivory. At Westham Island, the loss of tidal marsh vegetation is locally distinct in that it occurs in a closed polygon shape versus along the leading edge of the marsh, suggesting that goose herbivory is a principal cause. Goose herbivory on tidal marsh vegetation has become a global problem as many geese populations are becoming hyperabundant. In the Fraser River Estuary, Canada goose (Branta canadensis) and snow goose (Anser caerulescens) numbers have been increasing exponentially. I conducted a field experiment, testing two novel goose herbivory deterrents at Westham Island’s foreshore tidal marsh: metal and snow fencing placed flat against the substrate. I used a randomized complete block design with six replicates and three treatments: metal fencing, snow fencing
and control (no fencing). Each treatment's effectiveness was assessed by monitoring changes in common three-square bulrush (Schoenoplectus pungens) every two weeks throughout the summer season (June-September 2022) in terms of stem density, percent cover, and percent of stems grazed. Results indicated that there was no difference in stem density, percent cover, and percent of stems grazed between the two fencing types. However, compared to bulrush in the controls, both snow and metal fencing treatments yielded a higher stem density and percent cover (x̄% difference = 82.9%, 53.1%, respectively) as well as a lower percent of stems grazed. These results suggest that both fencing materials are equally effective at deterring goose herbivory in a tidal marsh. Additional assessments are needed to clarify whether this technique can be scaled up to promote marsh recovery throughout the entire area of recession., tidal marsh recession, goose herbivory deterrents, goose management, Canada geese, common three-square bulrush, snow fencing, chain-link fencing
The Salish Sea is critical habitat for several whale species including the humpback whale (Megaptera novaeangliae). Boundary Pass is part of the Salish Sea and connects the Pacific Ocean to several commercial shipping ports in the Pacific Northwest Region of North America. Since 1997, the number of Humpback whales continues to increase in this area, meanwhile the number of vessels is also increasing such that Boundary Pass is among the busiest shipping routes in the region. This high vessel traffic in the area leads to acoustic disturbances that degrades whale foraging opportunities for humpback whales. Commercial vessels transporting goods through whale habitat causes an increased risk of vessel collisions with humpback whales. Humpback-whale movements in Boundary Pass was recorded through systematic scan surveys conduction from a vantage point between June and August. Whale occupancy was compared to oceanographic variables and vessel presence. We found humpback whales were most likely to be present during ebb tides of speeds of -2 m/s under the influence of low tides and also whales were active in areas overlap with shipping lane in the area. Based on our founding in the area about humpback whale connection with biophysical properties of region I hypothesized that whale distribution in area and it relation to low tide and ebb current is most probably under the influence of food abundance in those periods of time. This study concludes with policy recommendations for improving humpback whale foraging grounds by reducing acoustic harassment and risk of ship strikes in the Boundary Pass., Humpback whale, movements, oceanographic variables, Boundary pass, Salish sea, Vessel strike, tide, currents, SST, salinity
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)
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
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