- November 27, 2024 - Biodôme : Secrets of the Biodôme
A Close-knit Nature
The diversity of living beings is fascinating, each of them forging close ties with its environment and with other species. That’s the principal message being conveyed in the Biodôme’s brand-new exhibition, A Close-knit Nature, featuring 975 naturalized specimens from its collection. The idea that every living being interacts with the others and with its environment isn’t new. As the saying goes, everything’s in everything. But how do we express that message as part of a captivating experience for visitors? A colleague of mine, in charge of documentary research for the exhibit, floated an idea: Keystone species. And that’s the thread of our exhibit!
What’s a keystone species?
In an ecosystem, all species play a role. But some of them have a much more important impact. A keystone species plays a crucial role in maintaining an ecosystem’s structure and stability. Its presence or absence can have disproportionate effects on the ecological community as a whole.
The expression “keystone species” is inspired by architecture. In an arch of cut stones, the keystone is the centrally located stone at the top. Without it, the whole thing collapses! In the same way, the disappearance of a keystone species can undermine an entire ecosystem, entailing extreme repercussions on the whole of the ecological community that go well beyond the species’ immediate absence.
Some keystone species
The exhibition A Close-knit Nature presents eight keystone species: the grey wolf, the beaver, woodpeckers, corals, hummingbirds, lemmings, the polar bear… and whale fall. Diagrams help visitors understand the essential role they play in their respective ecosystems.
But what distinguishes a keystone species? Here are some examples:
- Predator/prey relationships: the presence of predators makes it possible to regulate the populations of their prey. That’s the case with the grey wolf, which feeds primarily on deer. When deer are too numerous, they have a devastating impact on plant life, preventing other species from establishing themselves. At certain times, it’s the prey that regulate the population of their predators, as is the case with lemmings. Their population has an impact on that of their predators, like the snowy owl. The polar bear hunts seals and feeds mainly on its fat. The remains of an abandoned carcass is a godsend for other animals in the Arctic.
- Herbivores: they modify the structure and availability of habitats for other species by feeding abundantly on vegetation.
- Mutualists: pollinators, such as hummingbirds, are essential to plant reproduction. Certain plant species even depend on very specific species of hummingbird to reproduce.
- Ecosystem engineers: as they modify their environment, they create habitats for other species. That’s the case with the beaver, corals and woodpeckers. The holes dug and abandoned by the last of these become the habitats of choice for several species. The decomposition of whale carcasses, called whale fall, creates temporary ecosystems on the seafloor. Not to be missed is the video* showing impressive images of a whale carcass serving as a meal for numerous deep-sea species.
*Video montage of the whale carcass was carried out and kindly made available by: Ocean Exploration Trust, Nautilus Live and NOAA ONMS
An exhibition full of discoveries
We invite you to come out and admire these particular species and to discover the many links between them and the other specimens in the exhibit. Have fun seeing the invisible, forge your own links among species, and take advantage of the opportunity to trace new ones, with yourself.
It’s a date!
