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
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)
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
A bog is a type of wetland with a high water table, acidic soil and is nutrient poor. Camosun Bog is the oldest bog in the Lower Mainland of British Columbia, and remained undisturbed until development of the surrounding residential neighborhood caused changes to its groundwater conditions, threatening its current persistence. The goal of this study is to provide an updated examination of Camosun Bog’s groundwater conditions and to discuss relevant bog restoration measures. Groundwater elevation and chemistry (pH, conductivity, nitrogen and phosphorus) were monitored for several months in 2019. Results indicate that current groundwater elevations are lower in Camosun Bog than they were thirty years ago, especially in the north and northeast regions. Locations in the north and center parts of the open bog experienced groundwater nitrogen enrichment and higher pH, indicating that raising the water table should be the main goal of restoration for Camosun Bog.
Bog wetlands store a disproportionate amount of carbon for their size, making their conservation an important part of climate change mitigation. The goal of this project is to investigate how roads and agriculture impact the hydrology and vegetation composition of Langley Bog and to provide restoration recommendations. Langley Bog, in Langley Township, BC, is a formerly mined peatland with a fill road running through the center and surrounded to the north and west by cranberry farms. From November 2020 to November 2021, depth to water table and pH were measured monthly at nine wells. Twelve vegetation transects were completed in July 2021. Sites adjacent to the road were correlated with a decrease in summer water level, while sites adjacent to the cranberry farms were correlated with an increase in spring pH levels. A positive relationship was found between an increase in water-table level and percent cover of wetland obligate species. Roads may be lowering the water table through subsidence and drainage. The cranberry farms may be increasing the pH through the deposition of fertilizer. These impacts may have been exacerbated by the unusually dry 2021 summer season.
To raise the water table, tree and road removal is recommended to restore lateral flow and decrease evapotranspiration. Culverts installed under the primary fill road will provide additional hydrologic connectivity. Building a berm at outlet points will also help prevent water loss, keeping a higher water table. To increase carbon sequestration, Sphagnum mosses are to be reintroduced to denuded areas in Langley Bog. Tree removal will help in moss establishment by maintaining open bog conditions free from shading. Existing rare ecosystems present in Langley Bog would benefit from the removal of point source pollutants and invasive species on the site. Given the urgency of climate change, restoring the functionality of Langley Bog and protecting the existing stored carbon is a practical and achievable way to move Metro Vancouver a step closer to carbon neutrality., peatlands, ecological restoration, water levels, pH, sphagnum
Stormwater runoff from parking lots often contains a variety of elements and compounds in different forms and concentration that may pose risks to biota in receiving aquatic systems. Heavy metals including lead (Pb), cadmium (Cd) and polycyclic aromatic hydrocarbons (PAHs) are of particular concern in such runoff due to their prevalence, toxicity to aquatic organisms and persistence in environment. The ability of commercially available biochar to remove pollutants of concern through column treatments was assessed in this research. Different treatments of biochar were considered and their ability to remove pollutants was compared to soil. The biochar (Emergent and Cantimber) used in this study showed a significant higher molecular weight PAHs removal ability compared to soil and followed the order of Cantimber > Emergent > soil. The effects of heavy metals and PAHs on aquatic organisms and plants degradation can be mitigated by amending the soil media with biochar in the bioretention cells such as raingarden. This could be applied in real world where stormwater runoff can be treated before entering into river or stream therefore cutting the need of future restoration., Emergent Biochar, Cantimber Biochar, Parking lot stormwater, Low impact development, Heavy metals, PAHs, Constructed wetlands
Coastal wetlands are naturally resilient to changing sea levels; however, as rates of sea-level rise increase, the interaction between changing sea-level and ongoing human impacts will be a major driver in future coastal tidal marsh stability. My goal is to provide decision makers with recommendations to increase the resilience of the Fraser River delta front tidal marsh communities over the twenty-first century. I conducted a literature review to (1) examine the current knowledge base regarding effects of sea-level rise on tidal marshes and (2) identify current ecosystem-based adaptation strategies for increasing tidal marsh resilience to sea-level rise. Based on this review, recommendations are made for strategies that could be used to increase tidal marsh resilience in the Fraser River delta. Recommendations include (1) initiating delta-wide marsh accretion modeling to assess tidal marsh vulnerability under possible sea-level rise scenarios and (2) implementing sediment augmentation pilot projects for both direct (e.g., layered sediment lifts) and indirect (e.g., mud motor) sediment augmentation strategies to test ecosystem based adaptive management strategies as part of an adaptive management framework.