A short lesson of antarctic toponymy
The Sanctuary Peninsula, though relatively small, boasts a diverse environment and is far from being a white homogeneous environment. Here, the last megafauna shape the territory, creating several subregions, each harboring important relictual species to be discussed in future posts.
The largest and most productive subregion is undoubtedly the Follia Plateau, which hosts a steppe-like environment fairly analogous to the trample steppe of earlier Biancocene stages, but more defaunated. Although the total biomass is lower compared to the past, the even colder temperatures and arid conditions prevent rapid shrub expansion and encroachment. Due to this and the significant trampling action of herbivores, this area is an important carbon sink. It's estimated that the permafrost of the entire Plateau contains up to 800 billion tons of CO2, along with large amounts of other greenhouse gases like methane and nitrous oxide, altogether exceeding 10 billion tons. The high density of these gases, even compared to the mammoth steppe, is due to the longer duration of the trample steppe, which has stored these gases over the last 30 million years. There's no doubt that a significant factor in the ongoing cooling event is the carbon sink effect caused by the Antarctic fauna. The trample steppe, once a highly productive ecosystem home to an outstanding number of species, is now becoming the bane of the same organisms, annihilated by ice expansion.
The relatively high productivity of the Follia Plateau contrasts sharply with the gigantic and hostile mass of ice and snow covering almost all of Antarctica, known as Land-no-Land. No plants survive in this barren landscape, which has completely destroyed any possibility for a terrestrial environment to form. The few surviving animal species can be found along the icy coast, where they mainly feed on marine wildlife.
The Follia Plateau and Land-no-Land are separated by an intermediate habitat divided into two subregions: the Polar Desert Arc and Greenrock. The Polar Desert Arc is a small strip of moss-dominated habitat separating the western part and the far larger Greenrock that separate the eastern part; the latter, despite its harsh conditions, still hosts a small number of terrestrial species.
These subregions are separated by a small geographic barrier, the Seamount. Once a small seamount arc below sea level, it has emerged due to the ever-lowering sea levels. Besides being a significant barrier blocking warm air that would otherwise transform Greenrock into a steppe-like environment, the Seamount is an important area for relicts. Its steep environment prevents high-density megafauna, and the more arid conditions caused by the permeable volcanic soil reduce grassy plants in favor of small shrubs and creeping plants with long roots. The black nutrient-rich volcanic soils and abundance of thermogenic shrubs, like doorpeas, make this subregion relatively productive despite being at the edges of the polar desert. This subregion is the last stronghold of many scansorial and browsing species that would otherwise be wiped out by the ice and steppe expansion.
Seamount is the only mainland area where dense shrublands can still form. In the northernmost point of the peninsula, a large estuarine area called Neve Delta becomes too wet for many steppe-adapted species, giving way to a wetland environment rich in reeds and short shrubs. These areas never form a closed canopy; the only true relictual forest is found on a rocky insular archipelago east of the Neve Delta, called Pacific Rim. This subregion is connected to the mainland for only half the year, when sea ice forms. This creates a strong migration filter for many terrestrial animals, reducing the overall herbivorous biomass on these islands. As a result, trees and shrubs dominate, forming a woody environment that covers almost every point of each island. Here can be found the tallest trees of Antarctica (a brumble tree species), with an "outstanding" height of 7 meters! The Pacific Rim are seamounts that emerged in the last million years and are part of the same volcanic arc as the Seamount. If global cooling continues, the lowering sea level will eventually connect the archipelago to the mainland, prolonging the survival of the Follia Plateau fauna for a few other million years, but dooming any shrubland and forest-adapted species.
Aside from the Pacific Rim, there are other insular areas east of the Follia Plateau. Due to their proximity to the mainland, these islands have undergone environmental homogenization, with only two anonymous islands maintaining a somewhat shrubby environment, though not as rich as Neve Delta, Seamount, and Pacific Rim.
