Botanical guide of the austral forest
After more than 20 million years since its appearance in Antarctica, the Austral forest has continued to evolve and better adapt to the harsher climate of the continent. After a severe loss of many woodland habitats in the Middle Lentocene, plant biodiversity has increased exponentially in the last millions of years, especially thanks to migrating birds and descendants of sowering ravens, which have easily dispersed seeds from other continents.
Near the treeline dense forests are rare, due to herbivores' disturbance. Only in very steep environments closed canopies of small but secular trees can be found. The most cold-adapted species are mostly spruces, pines and austral beeches, respectively of the genus Omnipicea, Magnipinus and Ignothofagus. Small shrubs like dwarf antarctic cypresses (Pseudocupressus reptans) live in the undergrowth, depending on the soil composition.
These dwarfed forests are found mostly in the mountainous regions of Weddell and Marie Byrd. In Polarica those ecosystems can only be found in the Larsen mountain range, where tree line reach high elevations (around 1000 meters above sea level).
Lowlands forests are the more biodiverse ecosystems of Polarica, especially the one found in Belgrano: Austriquercetum is the most widespread floral association and also the richest. The dominant species is Austriquercus tenebrosus, an extremely large austral oak that can be 50 meters high (164 feet). Acorns are smaller than classic oaks, with rostrids being the most common seed dispersal. In the undergrowth, shrubs of firebush (Criohamelia buxus), fastberries (Panrubus sp.) and woody strawberries (Lignifragaria sp.) are the main food for small vertebrates.
In contrast to Belgrano, the Aurora forest has nearly no undergrowth due to the darkness created by the canopy. Several species of Bamboo firs are present (Fastiabies sp.) both evergreen and deciduous. Mosses and ferns are practically the only abundant plants under the Aurora canopy, which are eaten by rostrids and ducktails. Tree density is very high, making it very difficult to move for very large vertebrates: no animals larger than 300 kg are found here.
The Aurora forest is also the last stronghold of a once very common group of plants in Antarctica: the canelos.
These plants were adapted to cold coastal habitats, where thermal shocks are minimal thanks to sea influence. Now, these habitats are mostly faded, in favor of temperate or cool coastal forests. Other more adapted plants have taken the canelo niche, like tree-reeds (Idroxilopoa sp.) and mangrove willows (Thalassisalix sp.).
The disappearance of canelos has already started the crisis of a certain group of birds. Their days are numbered.
