San Morin, an island in the Archaen ocean, was largely covered in a thick jungle.

Elements

San Morinian Jungle The central Morinian highlands were a thick jungle landscape featuring dense underbrush, weak and often muddy soils, and a plethora of animals. In winter, the ground vegetation fell to the ground, the fauna hibernated, and trees folded up into thin stalks. Some plants, generally called vine-bushes, formed small hills which could shelter animals during winter.

Sweet Tewper. These tubercules were the most prominent root in wild Morinian soils and had by far the most nutritious value. They easily grow in shadow and poor soils. They passed winter by breaking off the top leaves and regrowing from tubercule shoots. They fertilized with adhesive aerosol pollen and propagated by growing from seeds preserved in animal feces.

Wild pig. Boars were the largest mammals in the jungle. They used their thick tusks to rip open the soft humid ground to get to roots, feeding especially on sweet tewpers. Their corpulescence and powerful tusks made them invulnerable to smaller predators. They lived in small herds, milked their children over a period of a year, and hibernated in self-dug vine-caves during winter.

Tewp-Beetle. These small flightless insects pullulated on the jungle ground. They formed large colonies and fed on sweet tewper patches, digging into the soil. Their tough shell made them hard to eat by other insects, but they were plantivores. During winter, they dug into the ground and hibernated.

Tree Fruit. Many medium-sized jungle vegetation and trees grew rich fruit which formed an essential part of the ecosystem. Many fruit were actually parasites which grew on other plants, helping to pollinate their hosts in exchange. During winter, seeds remained in the folded trees and grew into fruit batches come spring.

Fruitlings. There were numerous types of fruitlings, notably all insects. They lived on trees and ground vegetation, eating primarily tree fruit. In winter, they laid eggs in tree crowns, the ground, or vine-caves.

Marsupials. Marsupials were very small insectivore mammals. They resided in trees where they nested and gathered fruitlings, and made jumps between outstreched branches to travel. In winter, they nested in the upper reaches of vine-caves. Small insectivore dinosaurs filled the same niche.

Jungle birds. Birds could feed on fruitlings, fruit, and sometimes tewp-beetles. There were no larger prey species. They nested in the far upper reaches of trees. They had a lot of control over how they flew and could often hover on the spot. During winter, they hibernated in self-built nests in folded trees.

Jackal monkeys. These small mammals ate tree fruit, marsupials, birds and tewp-beetles. They resided in tall trees during the growth season, falling back up trunks whenever they crossed a predator. Their white on black patterns gave them ghost-like faces. They dug small nests in vine-caves during winter. Small carnivorous dinosaurs filled the same niche as these monkeys.

Large Dinosaurs. A number of large dinosaurs strided across the ground level of the jungle. They ate marsupials, jackal monkeys, small dinosaurs, boars, and occasionally even other large dinosaurs. They appeared both in herds and as single predators. In winter, these cold-blooded animals simply hunkered down on the ground and let the snow cover them, or they dug under the slumped vegetation for minimal protection.

Exploitation

Human Gardening. Human settlements scattered across the jungle relied on both native sweet tewpers and boars for food. They removed the vegetation cover, sometimes with slash and burn methods, to set up intensive tewper fields. Alternatively, villagers simply planted tewper shoots in the forest and collected the more meager harvest. They also kept a couple boars per family in penned-off bits of forest for milk and meat.

Hunting - Gathering. Most humanoid tribes in the jungle survived with hunter-gatherer methods. They trapped boars, shot birds, raided nests for eggs, and picked fruit, sweet tewpers, and various berries. Thanks to the forest's dense concentration of flaura and fauna, small settlements could survive without moving.

Logging. Humans required wood for various uses, notably for building, making tools and other utensils, and as firewood. They cut down trees which they'd previously killed with basic stone axes, a task which was facilitated by jungle wood's sponginess. Trees were most often felled in winter, when the jungle was open, roads weren't impracticable because of mud and wood was the most needed.

Ecosystem Damage

Soil Destruction. Various uses of the jungle caused soil erosion, notably the creation of tewper fields, cutting roads, intensive boar cattling, and logging. Exposed jungle soil quickly washed away in the common rains, exposing bedrock and making it impossible for the jungle to regrow. Such exposed patches of land notably damaged marsupial populations, which couldn't cross the dangerous open land, and favored the larger dinosaurs.

Tewp-Beetle Plagues. Humanoid promotion of sweet tewper, both in fields and in the wild, augmented the overall tewper concentration and was a great boost to tewp-beetle populations, which could be very large and just move from culture to culture. This caused the eradication of wild tewpers and augmented marsupial and bird populations, which led to a decline in fruitling and tree fruit populations due to overexploitation, as well as damage to tree populations because they couldn't pollinate through the tree fruit.

Pig Diseases. Cattling led to much larger boar populations being kept in close confines, and often in close contact with their humanoid masters. While humans did plant vine-bushes so they didn't keep their pigs inside their homes in winter, their close contact with the animals led to the development of a number of diseases, including Black Death and Yellow Fever.

Jackal and Dinosaur Hunts. Humans hunted both jackals and small dinosaurs because they were a danger to both younger human specimens and to a village's wild food stores. Their disappearance led to a boom in marsupial populations, which then led to a decline in fruitling and fruit populations and caused widespread pollination problems in jungle vegetation. Carnivorous dinosaurs also grew more agressive and more likely to attack village pig herds and humanoids because they could find no other prey.

Forest Loss. Jungle wood was of a low quality for construction and logs had to be replaced every couple years because they rotted. It also burned quickly and supplied only moderate heat, meaning winter and smoking meat for preservation required huge amounts of wood. Because logging most often happened in winter, when trees were the most fragile, they had little hope of regrowing. This usage caused soil destruction and often resulted in it being impossible for the forest to regrow.