Determine types of attachment to world (soil, plant, debris, animals)

I think this makes sense:

ipso - an indestructible map tile like stone, dirt, sand is the world itself
resources - when on a sand tile, harvesting a sand resource is possible. At first, this is probably a limitless thing that doesn't degrade the tile.
grasses - vegetation that can grow, spread, be trampled, etc., but which has only a "coverage" property, not a discrete height, age, etc. like plants.
plants - bushes, trees which are anchored to the map, but grow and propagate atop it. Their destruction and some growth stages may cause debris. Plants take up space on the map and can impact movement and visibility.
animals - like plants, but include locomotion. Characters act as animals on the map.
debris - loose items that are unattached to the map, but reside loose in a location like fallen fruit, perhaps rock piles, sticks, dropped tools, etc.
structures - initially non-existent (unless this concept is used to generate natural features...) constructed objects that impose on the map like plants, but do not propagate or grow (though they may degrade...). Vehicles are structures that can be moved about the map, but only through the intervention of an agent.

cubap / trade