The most influential factors include the parent material (the rocks from which thesoil<span> has come), the </span>climate<span> and terrain of the region, as well as the </span>type<span> of plant life and </span>vegetation<span> present, and, of course, human influence. ... These </span>soils<span> but are less leached than the tundra </span>soils<span>.</span>
