Search cIRcuit

Master of Science in Ecological Restoration Applied Research Projects

: 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