On the world of Tuule many analogues to life on Earth. The existence of photosynthetic plant life itself is a marvel of convergent evolution. The structure of forests, however, is quite different from that of Earth. Being tidally locked, Tuulian photosynthesizers do not have the luxury to grow in any direction they please. And while you may think the uninterrupted stream of sunlight is more beneficial, Tuule’s atmosphere is subject to regular storms usually lasting 4-5 days at a time, as well as outlier storms that can last for even longer. Naturally, the plants of Tuule have evolved to live with these environmental aspects.
Cliff-Forests are the most prevalent forested formation, defined by their gradual slope facing the north (sunny) side, and a sheer drop-off facing the south (cold) side. These form because of plants trying to out-compete each other for sunlight. Here’s how it works. A row of trees grow. A second row of trees grow, but they grow a bit higher, otherwise they would be blocked by the first plant’s shadow. Another row grows behind that, and another, and another, until the trees hit their limit for how high they can grow. As time goes on, the accumulation of plant matter forms into a natural sloped hill until the hill itself hits it’s height limit and stays a cliff, or collapses and forms a valley. Cliff forests are prevented from forming in front of themselves because of vast wall fungi that feed off of detritus and water that flows down the hill. They also keep from forming in front of each other because Tuule trees are usually one singular individual plant interconnected through root and scaffolding, and larger forests are ones that keep themselves alive. Nevertheless, forests from other plants can form in front of others, creating Sawtooth Hills. This kind of formation is distinguishable by the formation of multiple hills with gradual slopes leading to steep drop-offs. The hills in shadow no longer sustain forests, instead housing things like skyscraper plants, non-photosynthetic life, and waterways where the base of one hill meets the cliff of another.