Testing the Intermediate Disturbance Hypothesis in the Highland Creek Ravine

Disturbance regulates biodiversity by opening up niches, and thus allowing new species to colonize. The link between disturbance and species diversity can be explained by the intermediate disturbance hypothesis, which posits that areas experiencing, in terms of frequency and intensity, intermediate levels of disturbance will exhibit the highest levels of species diversity. By assessing species diversity across six sites different in their disturbance regimes in the Highland Creek ravine in Toronto, Ontario, Canada, the intermediate disturbance can be tested. This was done by obtaining samples of each species within a 4x4m quadrat set up at each site, estimating total percent cover, and identifying the species as either invasive or native. As predicted by the intermediate disturbance hypothesis, species diversity was found to be highest in plots three and four, which both experience intermediate levels of disturbance. Understanding more about the characteristics of an ecosystem that promote high species diversity is key to developing efficient conservation methods to conserve Earth’s floral biodiversity.