stratification is well developed in

1. tropical rain forests
2. grasslands
3. alphine vegetations
4. temperate forests

Stratification is well developed in tropical rain forests.
In the wild, seed dormancy is usually overcome by the seed spending time in the ground through a winter period and having its hard seed coat softened up by frost and weathering action. By doing so the seed is undergoing a natural form of "stratification" or pretreatment. This cold moist period triggers the seed's embryo, its growth and subsequent expansion eventually break through the softened seed coat in its search for sun and nutrients.