Christianne Hagerman is on a mission to save the iconic Hemlock trees in the popular Kentville Ravine Park.
The Acadia Alumni (BSc Biology, 2019) has been interested in the environment her entire life. When asked about her passion Christiane references an impactful book from her childhood, “one of my favorite storybooks was called The Great Kapok Tree. It tells a tale of a great mother tree under threat of being logged in the Amazonian rainforest”. During her undergraduate degree, Christianne volunteered and was employed on various projects in the E.C. Smith Herbarium and Acadia Seedbank. She says, “my work with the Seed Bank and Herbarium at Acadia really launched me into this field, and I’ve benefited from having such close access to experts in the field, such as Alain Belliveau!” Recently she has turned her passion into a plan to save Kentville’s Ravine Park from an invasive insect called Hemlock Woolly Adelgid (HWA).
HWA is an invasive insect that spreads rapidly in the province because there are no natural predators, or tree resistance. The insect quickly kills trees by sucking out the sap, which leads to needle abscission. The trees die from lack of nutrition, both from the interrupted sap flow and limited photosynthesis without needles.
HWA has been in Nova Scotia for four years and despite mitigation efforts, the pest has moved from Yarmouth County as far up the province as Berwick, just 35 kilometres from the Kentville Ravine. The pest is expected to reach Kentville by spring making Christianne’s efforts timely.
Hemlock trees are an important old growth tree in the Acadian, or Wabanaki, Forest Region. Old growth forests are defined as having trees older than 100 years and it takes decades for Hemlocks to establish. Old growth forests are most efficient at CO2 uptake, thus playing a vital role in limiting the pace of climate change, while also providing habitat to many different species, including rare and endangered species. Hemlock are the dominant tree species in the Kentville Ravine, if HWA were to take hold many trees would die or have to be cut down to limit further spread. This would irreversibly change the forested park, which provides a heatsink and windbreak for the bordering towns of Kentville and New Minas, while also providing important access to nature-based recreation.
There is a treatment to protect hemlock trees, but it is costly and time consuming to administer. The systemic pesticide imidacloprid can be manually injected into each tree, resulting in mortality of any HWA that attempt to feed on the tree’s sap. The treatment is an important measure to prevent a mass death of hemlocks.
The cost to protect one tree with imidacloprid is $45 and Christianne has started a fundraiser to protect the trees in the Kentville Ravine Park. She is also working in collaboration with the Town of Kentville to develop an action plan to combat the threat of HWA in the Ravine Park.
Christanne explains, “This project is a grass-roots initiative, focussed on community support. I’ve been in close contact with the folks who organized a similar project at Sporting Lake Nature Reserve to help with my plans for the Kentville Ravine Project”. The Sporting Lake Nature Reserve was recently successful in protecting over 2000 hemlock trees with a volunteer effort coordinated by Nature Nova Scotia.
When asked about next steps, Christianne explains she hopes to protect over 200 hemlock trees in the Kentville Ravine Park. She says conservationists around the province are also eager to form a cross-province network of community efforts to address HWA spread. Protecting Hemlock will require collaborative support of community volunteers, conservation groups, and all levels of government.