Designing a Planet Part 1 - Ecosystem

A core part of the 40k universe is the diversity of planets and systems, how a planet looks, what natural resources it contains, the climate and ecosystems it contains, etc.  Because of this I am going to begin a series on how to design a planet (this could be scaled down to a nation for games like Warmachine; I plan on doing a series on designing cities and towns later).  Where I like to start is the ecosystem and life upon the planet.  I happen to really like Jungle planets like Catachan so we will run through what should happen when designing a planet with jungle being the example I use.  First what makes this jungle unique and catchy, how do we want people to remember this planet's ecosystem and know it isn't just jungle planet number 47?  Perhaps we could make parts of the jungle alive in terms of plants that actually are predators, or perhaps the plants are always moving so that paths are constantly changing, putting predators in the path of travelers.  I happen to like the idea of the moving jungle that is consciously putting people in danger of predators so we will run with that.

So what kind of animals would thrive in an environment that is mobile and never static?  They clearly must be either fast animals that are able to outrun the predators when the paths lead to encounters with bigger creatures.  The top carnivores would not have to be stealthy if the jungle was bringing everything to them, its biggest asset would be sheer strength to take down other creatures.  Because this is a jungle and there are all sorts of plants that could ensnare animals perhaps some creatures use vines and trap other things in simple nets or use tripwires, inhabiting the tree branches above until their prey is caught.  Being slow means death in most cases so nothing would be particularly armored, just well muscled and lithe to cause maximum damage quickly.  Smaller, climbing creatures for the trees that perhaps have similarities to monkeys, small and fast creatures that are more cat like for the lesser predators, the top of the pyramid would be like a bear combined with a komodo dragon for sheer size though faster and so would be slightly thinner though still have ferocious teeth and claws.  Poison would certainly fit within the ecosystem as plants to fight the herbivores/omnivores while also perhaps created in the glands of certain predators that are better at attacking and retreating, followed by tracking their quarry till it dies and then consuming it.

What happened above was a series of developments that depended on reasonable conclusions as well as certain design choices.  Because I chose to make the jungle move, I had to determine what characteristics would survive and thrive in that environment.  Finding those characteristics of strength, speed, and agility I determined what the different tiers of the ecosystem would work like and how they could interact with each other.  I even made sure that parts of the ecosystem were a major part of how the animal's strategies for survival would work in the case of the vine traps or the poison, something that could also come into play in a story that you write with your characters from off planet or on planet, a tool that could save or kill a character at some point in time depending on your direction of story.