Glendon Photo Essay
Number of students in plant ecology class were paired and assigned to address the current status of the riverbank in Don River near York University Glendon campus. On November 18, just before the weather became harsh, my partner Nigel and I were assigned to take photos between stretch 2 and 3 of the Don River. Due to the blockade by numerous falling trees, most of the photos taken only covers the south side of the riverbank towards the Glendon campus.
Upon arriving to the stretch we were assigned, we noticed an old concrete bridge accompanied by heavily eroded trails, and the rest of the stretch was also eroded away with many trees showing roots and falling over towards the riverbank. Based on these observations, it was clear that the riverbank was undergoing heavy erosion process. With big trees starting to fall over towards the riverbank, many small plant species were present to prevent further slumping of the soil, but it did not seem to be effective. Moreover, most of the plants that are holding the soil were invasive species, including dog-strangling vine. An example of the introduced species contributing the stabilization can be found in the article by D’Antonio & Meyerson (2002), which also mentioned the dilemma surrounding exotic species and restoration. The removal of invasive plant species would benefit in terms of protecting the habitat biodiversity and richness of the natives, but it would also accelerate the erosion process, ultimately destroying the habitat itself.
Following the riverbank, we also stumbled upon many damaged gabions that were installed in the past in attempts to prevent erosion, but most of the gabions were pushed towards the riverbank by landslides and deformed due to heavy erosion. In 2009, Don Watershed Plan was initiated to prevent further destruction and encourage regeneration. But the stretch we addressed seemed un-touched since the initial installations of gabions. The details of the Don River watershed plan can be found here.
So what can we do to prevent further erosion? For immediate measures, re-installation of the gabions could prevent the further destruction of the riverbank, which would provide more time to develop long-lasting, and effective methods for stabilization. With addition to the gabions, planting native plant species would help holding the soil together, as well as increasing species richness and biodiversity of the riverbank habitat.
Lastly, when we were taking photos of the riverbank, I could not help noticing a stench coming from the river itself, which is more likely caused by human influences in the surrounding area. Managing the riverbank erosion is an important part of the conservation, but we cannot overlook the human-induced pollution which also influences the species richness and biodiversity. Hopefully the issue of pollution is also addressed in the future, so that Don River can return to its prime, becoming a home to many plants and animals.
D’Antonio, C., & Meyerson, L. A. (2002). Exotic plant species as problems and solutions in ecological restoration: a synthesis. Restoration Ecology, 10(4), 703-713.