On the base of systematic principle this article discusses soil formation as an ecosystem component in the functional interaction of plant community and developed post technogenic substratum. Biological cycle of organic (plant) material is the mechanism that combining ecosystem components into integral unity, which is interlocked in the newly formed organic accumulative layer. Regular intake of plant matter into biological cycle forms stable substrate base of plant community and ecosystem self-reproduction. It is shown thatmorphological structure and features of organic-accumulative layer are changing on the stages of self-restored succession due toqualitative and quantitative change of plant community composition.The diversity of soil as an ecosystem component depends on the type of plant community.