Ilion’s present climate is wholly dependent on the presence of a shallow ocean at the substellar point. A tidally-locked planet would look very different if there were a landmass here instead. The land would be extremely hot and dry at zenith, leaving only a ring of habitability between the substellar point and the terminator. Ilion is not that way. The sun’s heat and air currents whip the humid air at the Greater Ajax Ocean into a permanent, stable tempest. Periodically, a secondary storm will split from this system and head toward the continents. Of these, the hardest hit is Pandaros, where rainstorms supply the forests with water beyond what the trees produce themselves. Pandaros is by far the wettest continent, followed by Aeneas, where Elephant Gulf supplies ample fog to the temperate south. A surprising number of storms travel in the other direction and make it all the way to Polyxena. Near the west terminator, these systems mix with the cold subterminator air and manifest as blizzards of biblical proportion. Polyxena’s climate is highly sensitive to changes in solar output. At times, conditions render it uninhabitable. The continent’s few permanent residents must cope by migrating, hibernating, or sowing seeds that wait for favorable conditions before sprouting.
Barren/Ice – The peaks of mountains and areas that receive little or no sunlight do not support life.
Tundra and alpine tundra – The permafrost region is inhabited by blackbushes, cliffhangers, and other wind-resistant black plants. Furred megafauna live off the plants and, where possible, sea life. The dominant predators are nomadic pack hunters and archersnakes. In the mountains, red plants dust the sunward slopes where the snow has melted. High altitudes are exposed to higher energy rays, especially during stellar flares, giving red plants the advantage.
Savanna – Savanna on Ilion is a transitional habitat with scattered black trees, red undergrowth, and a tropical climate.
Rash and Wetlands – Rash is a marshy habitat populated by a community of fast-growing red plants that looks like diseased skin. Part of this is due to the activity of social archers that cultivate a pus-colored microbial soup for nourishment. Some of the plants are shaped like basins that collect and hoard pools of water between rainfalls. These pools host amphibious and freshwater organisms and attract small land animals that fish and drink from the puddles. More importantly to the plants, the pools are absolutely necessary to raise their larval young, which will eventually leave the water and plant themselves somewhere far away. Few black plants can take hold of the soil before being choked out by the rash.
Non-rash wetlands are found in areas with less sun and are dominated by black plants.
Desert – Deserts are populated by a broad range of plants and animals. Desiccation-resistant allorosea give the sand a pinkish tint in certain areas. Northern regions of the Great Deiphobus Desert are lifeless. Deserts on Ilion vary as widely as they do on Earth.
Temperate and alpine forest – Forests can be black-dominated, red-dominated, or mixed. Blackforests are most commonly found in colder, drier regions, while redforests are found in warm climates that receive sporadic rain.
Rainforest – Three major habitats are labeled “rainforest,” but the jungles couldn’t be any more different from one another. A giant silken web nicknamed “the fog of war” reduces the floor of Aeneas to a microbial soup that lives off the byproducts of its activity. A pervasive predatory plicozoan known as devil’s archer excludes most megafaunal life from the lower levels of the Pandaros rainforest. Redcap forests dominate Deiphobus’s tropics, where a dense layer of red epiphytes carpets the canopy, blocking most of the light from entering the lower layers. Luminescent microbes and animals inhabit the shadowed understory and forest floor.
The redcap forests are endemic to the continent of Deiphobus, where a relative abundance of certain minerals in the soil allows for an impressive accumulation of biomass. Combine this with the fact that fixed nitrogen is produced in large quantities by Ilion’s black plants and black algae and the result is a dense jungle capped by a thick canopy of red plants. Canopy plants begin their lives as epiphytes until the detritus can no longer support them. At this point they send roots all the way to the forest floor. Competition is high and many species have adopted a parasitic lifestyle instead. Said the first biologist to describe the habitat:
“The forest floor defies its label, as there is no floor to speak of beneath the confusion of roots and trunks. There is no telling what grows up and what grows down; add sideways into the mix and all bets are off. Tracing a root to its origin is as fruitless as wading through the mess. All the machetes in Colombia couldn’t conquer this jungle.” – Bernadette Cole, biologist, Phoenix
One redcap forest holds the distinction of harboring the largest floating fruit in the world. The so-called “airships” are spacious enough to fit three grown men inside and can support the weight of one. They remain moored to their parent plant until ready to disperse. A combination of mucus and spines prevents creatures large and small from climbing the tether and consuming the developing airship. Because these fruits are a costly investment, a single plant can only produce one every two or three Earth years. The remainder of their reproduction is vegetative. Needless to say, airship docks are K-strategists.
Shrubland/Woods – Shrubland is typically hilly or rocky land dominated by low-lying black and red plants. Shrubland overlaps heavily with savanna and rash, as fluctuations in rainfall can quickly turn one into the other. Woods are shrublands with trees, distinct from savanna for having a climate more temperate than tropical. Woods can transition into forests or exist on their own.
Pelagic, abyssal, and tropical – A broad assortment of sea life inhabits the oceans. A limited community on the dark side relies on currents from the tropical region to supply the residents with prey animals, plankton, and warm water. There is less food in these regions but there is more dissolved oxygen and fewer predators. Many animals migrate here to breed.
Freshwater – Rivers and lakes shape the land as they do on Earth. They are inhabited by a variety of lifeforms including buoyphytes, which are discussed below.
Buoyphyte – buoyphytes are red plants that float in nutrient-rich water. They are the foundation of three types of habitat. Tropical buoyphytes cluster into islands in the middle of the ocean at the substellar point. The islands are kept afloat by a core of air sacs and hollow vines from long-dead plants. They are stable enough to support large animals and even trees. Temperate coastal buoyphytes are a bit more tenuous. Freshwater buoyphytes range from surface scum to thick mats that obscure entire lakes.
Ice – Pack ice is home to migratory populations of piscivorous species of wooly starrus and other megafauna, much like the coastal tundra habitats. Glaciers and ice lakes sometimes melt and shift to reveal colonies of black algae that have lain dormant for decades. Alive or dead, these so-called “inkblots” are of great interest to exobiologists looking for insight into the planet’s history.
Hydrothermal – So far, hydrothermal vents are the only known self-sustaining ecosystems on the dark side. They are found to a lesser extent on the stellar hemisphere, but by far the largest system of habitable vents lies in the abyssal zone southeast of Mentes.
Razor Reef – Fully aquatic razor plaques form colonies in tropical reefs. Like the name suggests, these crystalline structures are scalpel-sharp and tipped with infectious pseudofungus and other flora. Large animals are all but excluded from these zones. Those that are carried in by the current will likely wind up in shreds and die at the site, providing nutrients for the reef life. A diverse community of hard-shelled animals and small, nimble swimmers thrive off the reef’s trappings. Tiny thoracostomes have adapted to scrape the fungus off the blades without being cut themselves. Plants benefit as well from the rich waters, replenishing oxygen where it is needed the most.