This paper defines pedodiversity within an environmental systems framework and uses understanding and maintenance of ecosystem function as the primary purpose for pedodiversity studies. We attempt a comprehensive definition of pedodiversity as a dynamic concept within geoecological systems and recommend how it may be effectively applied for functional as well as scientific purposes over a range of environments. We suggest that the concept not be aligned too rigidly with the more established ecological concept of biodiversity, though soil can be considered as comparable to living organisms in the sense of systematics. Instead, we suggest it be analogous with the philosophy of geodiversity: emphasising the ‘quality' of the variation within the pedosphere . There is a difference between measuring and evaluating the diversity of the entities of classification and the entities of ecosystem function. There is more value to exploring the diversity in soil function within geoecological systems, and agroecosystems. Are there such things as endangered soils? The perception of diversity is dependent upon scale, process and purpose. All aspects of geoecological scale must be considered to be fundamental to pedodiversity investigations, as should pedogenetic processes. For the wider acceptance and development of the concept we believe that ‘functional pedodiversity' demands the greater attention than ‘taxonomic diversity' from pedologists, although the latter is intrinsically part of the former. We can then include environmental and productive land management concepts, such as pedodiversity conservation, into the role pedodiversity assessment. Therefore there may be such things as endangered soil ecosystems rather than endangered soil types. The focus here is on ‘protection' of soils (however defined) for their role in providing ecosystem services. There is a need for ‘benchmarking' soil diversity within a sequence of perturbation process (from undisturbed to highly disturbed), as disturbed soils also have a geoecological role in ecosystem function. Therefore the ethos here is to approach land use management and planning from the perspective of maximizing and maintaining the ecoservices potential of soils and soil attributes for both human and environmental well-being. A case study is presented using STATSGO data in Ohio. There is little geographic coherence in the standard ecological diversity metrics on this data, so alternative strategies to define diversity were sought. “Protected' soil types in conservation-managed areas were identified through GIS analysis. The commonest soil ‘components' (types) in these managed areas were selected for benchmarking (‘pedotypes'). The disturbance, or modification, status was then assessed, so a sequence of increasing disturbance, known as ‘pedovariants', is devised. Then a diversity analysis is conducted on relevant geoecological attributes of these pedovariants of the pedotypes. This approach targets geoecological (soil ecosystem) pedotypes at risk as well as targeting geoecological attributes at risk.