What ecological role do keystone species typically play?

Keystone species play a crucial role in maintaining the structure and stability of their ecological communities. This concept is derived from their ability to influence the diversity and abundance of other species within their ecosystem, thereby affecting the overall health and function of that environment. When a keystone species is removed or diminished, the effects can be profound, often leading to significant changes, such as the collapse of local populations and alterations in community dynamics.

For example, in a marine ecosystem, sea otters are considered a keystone species because they prey on sea urchins. The presence of sea otters helps control the urchin population, which in turn allows kelp forests to thrive. Without otters, urchin populations can explode, resulting in overgrazed kelp forests and diminished biodiversity. This illustrates how a keystone species can have a disproportionate impact on its ecosystem by maintaining balance and promoting a diverse community of organisms.

In contrast, while producers and consumers are essential to ecosystems, they do not necessarily confer the same level of influence as keystone species do. Furthermore, not all species that are foundational to food webs are classified as keystone species; the latter are defined by their unique role in maintaining ecological stability rather than their position within the food