How does urbanization affect biodiversity and species richness in Stanley Park?
Stanley Park and the effects from Urbanization
Stanley Park is home to one of Vancouver’s most beloved urban parks with stunning views along the seawall, scenic trails, and 400 hectares of west coast rainforest (City of Vancouver, n.d.). Along the forested peninsula lies ocean and shore on 3 sides, and city development just south of the park (Stanley Park Ecology Society, 2010). The vast amount of natural resources allows for a broad range of niches to fit in Stanley park’s resource spectrum. However, despite its wide range of natural resources, a major ecological concern arises that isn’t commonly addressed. How exactly has urbanization affected biodiversity and species richness in Stanley Park? Researchers analyzed the various factors that have affected biodiversity in the past couple of decades. Habitat Fragmentation due to urbanization, climate change, and invasive species seem to be the top 3 main stressors that have made the most impact (Stanley Park Ecology Society, 2010).
Figure 1. The comparison of land cover percentage between 1989 and 2009. The mixed category was classified as both deciduous and coniferous trees sampled together. Data was collected from Stanley Park in Vancouver BC, and sourced from Stanley Park Ecology Society (2010).
According to Stanley Park Ecology Society (2010), the park’s coniferous, deciduous and mixed forest trees reported a land cover percentage of 65% in 2013, with the remaining 35% land cover has been lost due to urbanization, specifically infrastructure, entertainment, and recreational facilities. Illustrated in Figure 1, deciduous forest covers had a decrease (from 11.7% to 6%) between 1989 to 2009, however mixed conifer and deciduous forests reported a land cover percentage of 8.3% to 15% between the years 1989 and 2009, a significant increase. Conifer forests stayed relatively constant over the years, going from 80% to 79%. These results partially are a result of logging (Stanley Park Ecology Society, 2010).
Biodiversity and Species Richness are affected by Urbanization.
Urbanization's effect on Beaver Lake in Stanley Park
Between Beaver Lake and Lost Lagoon was a section of the forest that was clear-cut and then burned years later, which was a major disturbance to all the species in that area. This allowed the area to be inhabited by many Douglas Fir trees and later cedar and hemlock trees (Bakewell, 1980). Deciduous plants and trees were also able to inhabit new canopy openings which is a result of succession. Beaver Lake itself also had a major succession in the past 100 years. The accelerated sedimentation of the lake started in 1938, when it was the Queen’s Jubilee and they had introduced fragrant water lilies to Beaver Lake (Stanley Park Ecology Society, 2010). Since Beaver Lake has always been a relatively small lake, actions were taken such as logging to expand the shore to maintain or even broaden its size to support more biodiversity. However, despite these efforts, the lake actually was decreasing in its volume and size (Steele 1988). These water lilies now cover over 50% of the lake and are considered an invasive species, causing a decrease in species richness within the lake and decrease in overall biodiversity. Urbanization has also affected Beaver Lake because the city water inflow caused the natural season fluctuations to become absent. This has caused a deficit in water in Beaver lake during the summer season, and eventually led to the whole lake drying up over time if this trend continued. In turn, this leads to decreased oxygen levels and an increase in temperature for the fish who inhabit Beaver Lake, causing the decline of biodiversity and decline of many fish populations (Stanley Park Ecology Society, 2010).
What about Soils?
Soils can be damaged from erosion, pollution, or compaction by humans, which can also break down when overused or too much organic matter has been lost over time. The damage to these soils can take generations to recover, and the major cause of soil damage are caused by road and trail construction and human caused erosion/compaction from off-trail activities (Stanley Park Ecology Society, 2010). The decline of healthy soil leads to a “snowball” effect, since soil allows for the growth of many trees, and those trees also act as habitats for various species. An example of this is a young deciduous tree that relies on healthy soil, which can act as a habitat for animals that rely on shrubs that grow berries (Stanley Park Ecology Society, 2010). This causes a limitation in resources, which can cause biodiversity to decrease.
How does City Development Play a Role?
Another major factor that has affected species richness, abundance and overall biodiversity is the construction of roads and urban infrastructure. According to the 1980 Forest maintenance program for Stanley Park, the forested parts of the park supposedly decreased between 1930 and 1980 by 25% and further decreased since 1980 by another 4%. This may be correlated with road construction, since road construction commenced in Stanley Park around 1888, and creation of new roads and urban infrastructure significantly increased between 1920 and 1924 due to the need for fire control. Proceeding, from 1934 and 1938, the creation of the Lion’s Gate Bridge and the Stanley Park Causeway occurred, which caused a physical barrier between the park, causing a major ecological change. This divider caused habitat fragmentation, a change in hydrology, and as a result caused a decrease in biodiversity (Stanley Park Ecology Society, 2010).
How are Species Affected by Roads and Paths in the Park?
Beyond physical barriers like the seawall, the park’s road network has fundamentally shifted how water and soil move through the landscape. Paved surfaces prevent natural absorption, leading to aggressive runoff that strips away topsoil (Stanley Park Ecology Society, 2010) . While trails are smaller and more porous, they still disrupt both the biological and physical integrity of the ecosystem. Human activity on these paths forces wildlife to adapt in ways that can be life threatening. According to Green and Higginbottom (2001), animal reactions typically fall into three categories: Avoidance, Habituation (tolerance), and attraction (species approaching people usually in search of food). When animals are constantly forced into avoidance mode, they lose valuable time and energy. Instead of focusing on essential survival tasks like foraging, defending their territory, or raising their young they are occupied with avoiding or fleeing from human interference (Environment Canada, 2006). There are 2 types of effects from the creation of roads on species in the park. The first is a direct effect due to their physical existence such as habitat fragmentation, habitat loss, and barriers to movement. The second type is indirect effects that are caused by interactions that they produce like closer human proximity and noise (Ministry of Water, Land and Air Protection, 2002).
Closing Statements
Stanley Park remains one of Vancouver’s most iconic attractions, but the evidence suggests its biodiversity has been steadily pressured by the city that surrounds it. Urbanization has reduced and rearranged forest cover through infrastructure growth and historical logging, while major developments like roads and the causeway have fragmented habitat and altered hydrology, limiting movement and shrinking viable ecosystems for many species. These physical changes are amplified by indirect impacts runoff and soil compaction that weaken forest health, invasive species such as fragrant water lilies that reduce species richness in Beaver Lake, and constant human presence that forces wildlife into costly avoidance behaviors. Taken together, habitat loss and fragmentation, degraded soil and water conditions, invasive species, and disturbance from recreation show that Stanley Park’s ecological stability depends not only on protecting its beautiful scenery, but on actively managing urban pressures to sustain species richness and long term biodiversity.