Environmentalists are known as tree huggers. Although I have been a plant ecologist as a career over the past few decades, my research has stayed in “the weeds” – the smaller plants, as I general go by the title of weed ecologist.
However, last year I was offered the chance to study trees by the City of Burnaby. Melinda Yong, environmental coordinator for Burnaby Parks heard me talk about the threat of weeds invading with climate change. She was aware tree health was also in jeopardy, and she asked if I would like to study the issue in Central Park.
Walking through Central Park to scope out the project, I couldn’t help but notice a number of Western red cedars dying (below left), and well as some salal shrubs looking pretty spent (below right).
Eight months of data collection later by the team of 5 researchers I hired, I am happy to report the cedars were not so bad, especially in areas off the beaten path…the “beaten path” is not so healthy because soil gets compressed, compromising tree health, especially when spring precipitation is limited. One of our recommendations was to reduce the number of informal trails in Central Park – the park is a currently a tangle of them.
The research team (from left to right): Delia Anderson, Vanessa Jones, Virginia Oeggerli, Natalie Cook and Jessica Brouwer.
The other big news was the decline of the climax tree in coastal BC – the Western hemlock. Of the many hemlocks my team evaluated, 19% were in visible decline and 31% were already dead. Hemlocks require a lot of spring moisture, and the past 5 springs or so have been unusually dry.
Although we did uncover some bad news in our research, working with this team of young energetic scientists lead by Vanessa Jones was one of the highlights of my research career so far. Vanessa had graduated from TWU with her B.Sc. in April 2019, while the other four were still fitting their forays to Burnaby’s Central Park in between their undergraduate classes.
Here’s a short summary of what they did:
- A total of 2731 coniferous trees were sampled from 200 sample plots throughout the park
- 449 deciduous trees were sampled from 30 sample plots
- salal health was evaluated throughout the park
- 5 moisture probes were established to monitor moisture levels, during the project and beyond
- Bulk density of soil was also sampled, comparing the density of soils from unsanctioned trails to those from forested areas with no regular foot traffic. Thirty samples were taken from each of the comparative groups, totaling 60 samples
- An extensive set of GIS maps were produced to facilitate future park management, and included in a 57 page report featuring 49 figures and 11 tables
What to do? Here’s what we say in our report:
“In order to combat the negative impacts, we recommend continuing to restore areas of the park using drought-tolerant native plants, focusing on species that are already present in the park. We recommend planting mostly deciduous species, as they seem more able to persist amidst the expected climate changes, as well as planting young Douglas firs to increase the younger age classes of this relatively drought tolerant conifer. We also recommend monitoring the health of trees and other key indicators, such as soil moisture, to ensure careful tracking of anticipated climatic changes and their impacts, so Central Park can continue in its role as a highly cherished place in Burnaby.”
In other words, we recommend tree hugging!
See also the article that came out in the Burnaby Now at: https://www.burnabynow.com/news/researchers-find-significant-tree-decline-in-burnaby-s-central-park-1.24170348