Primeval redwood forests , coastal mangrove stands , sphagnum bogs , desert soil crusts , roadside weed patches , wheat fields , cultivated gardens and lawns ; all are meant by the term vegetation . Primeval redwood forests , coastal mangrove stands , sphagnum bogs , desert soil crusts , roadside weed patches , wheat fields , cultivated gardens and lawns ; all are encompassed by the term vegetation .