There are many unique woody plant species. Each adapted to a certain set of broad climate zones and then to a set of site conditions – variations in light, soil texture and moisture that vary within those climate zones.
A group of individuals of the same species that occupy a particular geographic area or region and have some degree of genetic similarity relative to comparisons between populations.
In any local population each tree with at least slightly different combinations of their species’ genes is considered an individual. These individuals cross pollinate to perpetuate even more unique individuals.