/ n ature ▁dich ot omy ▁and ▁the ▁idea ▁that ▁all ▁species ▁are ▁e colog ically ▁dependent ▁on ▁each ▁other , ▁as ▁well ▁as ▁with ▁the ▁ab i otic ▁constitu ents ▁of ▁their ▁bi ot ope . ▁ ▁A ▁smaller ▁unit ▁of ▁size ▁is ▁called ▁a ▁micro ec os ystem . ▁For ▁example , ▁a ▁mic ros ystem ▁can ▁be ▁a ▁stone ▁and ▁all ▁the ▁life ▁under ▁it . ▁A ▁macro ec os ystem ▁might ▁involve ▁a ▁whole ▁e cor eg ion , ▁with ▁its ▁d rain age ▁bas in . ▁ ▁W ilder ness ▁ ▁W ilder ness ▁is ▁generally ▁defined ▁as ▁areas ▁that ▁have ▁not ▁been ▁significantly ▁modified ▁by ▁human ▁activity . ▁W ilder ness ▁areas ▁can ▁be ▁found ▁in ▁pres erves , ▁est ates , ▁far ms , ▁conservation ▁pres erves , ▁ran ches , ▁national ▁for ests , ▁national ▁par ks , ▁and ▁even ▁in ▁urban ▁areas ▁along ▁rivers , ▁g ul ches , ▁or ▁otherwise ▁und e velop ed ▁areas . ▁W ilder ness ▁areas ▁and ▁protected ▁par ks ▁are ▁considered ▁important ▁for ▁the ▁surv ival ▁of ▁certain ▁species , ▁e colog ical ▁studies , ▁conservation , ▁and ▁sol itude . ▁Some ▁nature ▁writers ▁believe ▁w ilder ness ▁areas ▁are ▁vital ▁for ▁the ▁human ▁spirit ▁and ▁cre ativity , ▁and ▁some ▁e colog ists ▁consider ▁w ilder ness ▁areas ▁to ▁be ▁an ▁integral ▁part ▁of ▁the ▁Earth ' s ▁self - s ust aining ▁natural ▁e cos ystem ▁( the ▁b ios phere ). ▁They ▁may ▁also ▁preserve