All the environments favourable to a group of species and functionally linked between each other form an ecological continuum.
This continuum thus consists of nodal zones (hearts of forest massifs, rivers, etc.), buffer zones and the ecological corridors that link them together.
On a larger scale (regional, national), continuums constitute an ecological network.
All of the forests, their buffer zones (parks, gardens) and ecological corridors (hedges) form a forest ecological continuum. © Derek Jensen, Wikimedia public domain
Ecological continuum - 1 Photo