Ecology (from Ancient Greek οἶκος (oîkos) 'house' and -λογία (-logía) 'study of') is the natural science of the relationships among living organisms and their environment. Ecology considers organisms at the individual, population, community, ecosystem, and biosphere levels.
enables the representation of associative (non-hierarchical) links, which can also be used to represent part-whole links that are not meant as hierarchical relationships.