A short lesson of antarctic toponymy
In contrast to the glacial period, interglacial Antarctica undergoes significant glacial retreat and a substantial reduction in ice sheet volume due to milder temperatures. This leads to the expansion of wooded environments and shallow seas across the continent. With rising sea levels, the Fire Bridge is no longer a sufficient barrier to the ocean, resulting in the creation of temporary, yet breathtaking, kilometers-wide waterfalls known as the Fall of the Wall. These waterfalls inundate the Great Depresseaon, causing the reappearance of Centro Island. While not far from the mainland, the island's isolation fosters strong endemism among both small and large animals.
During interglacial periods, over 60% of the non-ice-covered territory is dominated by the coldvanna ecosystem, reaching its peak diversity. Although maintaining a mostly open environment, various coldvanna sub-biomes feature significant portions of closed canopy, especially at the base of mountain ranges. These wooded areas provide a habitat for numerous arboreal and scansorial species that would otherwise be restricted to a few areas during glacial periods.
Wetlands greatly increase during interglacials, thanks to the rise of precipitations. Bog and river-adapted species, like the webrumble, greatly benefit of this climatic opportunity.
The coldvanna differs from the trample steppe by having more abundant shrubs and solitary trees, but a less diverse herbaceous species due to its distinct climate. Similar to a colder version of a Mediterranean climate, the coldvanna experiences warm to hot, dry summers with maximum temperatures reaching up to 30°C (86 °F), while winters are very snowy, with temperatures dropping as low as -30°C (-22°F). The extensive snow cover impedes grazing for herbivores, forcing them to migrate or rely on woody species for sustenance. The slower melting of snow often delays the start of the growing season for herbaceous plants, leading to instances where tree buds open amidst lingering snow cover in early spring. Dicot diversity significantly decreases compared to the trample steppe, resulting in a lower carrying capacity for grazing species. Browsers and mixed feeders become the dominant herbivores, efficiently exploiting the resources of the coldvanna.
During interglacials, glacial biota is confined to relatively small and narrow areas of the continent, with a significant stronghold in the Incense Saltlake region. Here, the sea's humidity is trapped by surrounding mountain ranges, providing a dry climate during both summer and winter. Although narrow, the trample steppe biome doesn't suffer habitat fragmentation which help preserving the integrity of its faunal assemblage.
Due to the Fall of the Wall, the ice age ecosystem in the Great Depresseaon is abruptly swept away by the incoming ocean. In other areas, the disappearance of this ecosystem is more gradual and less catastrophic. The Fall of the Wall is responsible for the rapid annihilation of approximately half of the tramplerat population, which typically resides in the Great Depresseaon, occurring within a few hundred years.