Landscape and landcover are not usually thought of as subclasses of landform, but are classed as such in SWEET. https://bioportal.bioontology.org/ontologies/SWEET/?p=classes&conceptid=http%3A%2F%2Fsweetontology.net%2FrealmLandOrographic%2FOrographic Perhaps even more confusing is listing "orographic" and "non orographic:\" as subclasses. https://bioportal.bioontology.org/ontologies/SWEET/?p=classes&conceptid=http%3A%2F%2Fsweetontology.net%2FrealmLandform%2FLandscape&jump_to_nav=true#visualization