Evening Mist

After two hours afternoon rain and the sun came out again, the forest was engulfed with mist. But there is a certain area with thicker mist rising, like someone was burning. Why?

Trees produce a lot of vapour. The lowest area collects most rain water and hence has thicker vegetation. When there is temperature change, old to warm, mist forms. Together with surface vapours, thicker mist seems to rise from low area.