Flora and Fauna of Discovery Park: Site 6: Disturbance

In a broadly defined sense, a disturbance is anything that removes living biomass from a system. This can take on a variety of forms such as fires, earthquakes, grazing, wind, disease, pests, and land use conversion (e.g. urbanization). Disturbance often serves to create a heterogeneous landscape that creates a variety of habitats. For example, grazing by animals might prevent any trees from growing in that area, and keeps it a grassland setting, since grass is one of the few groups of species that can survive heavy grazing. In fact, this is exactly what is happening here; escaped domestic rabbits have made it into Discovery Park and have been breeding like crazy. This is a location where we have often seen rabbits grazing. If you look at the vegetation, much of it is grass, which is short and sparse, even though other areas have quite tall grass. In fact, this entire area is surrounded by tall Red Alder trees, but there isn’t a single sapling in this gap. It seems that the rabbits prefer this location to graze; possibly because the surrounding trees provide cover and a quick getaway should a predator come along. This is a perfect example of heterogeneity. In an area that would otherwise be all Red Alder forest, there is this little patch of grassland, maintained by the rabbit shepherds of the grasslands. Now for bunny pictures!