ecology of the Rocky Mountains
... that aspens and whitebark pines are keystones to the ecology of the Rocky Mountains?
... that <a href="./Aspen" id="mw_Q" rel="mw:WikiLink" title="Aspen">aspens</a> and <a class="mw-redirect" href="./Whitebark_pine" id="mw_g" rel="mw:WikiLink" title="Whitebark pine">whitebark pines</a> are <a href="./Keystone_species" id="mw_w" rel="mw:WikiLink" title="Keystone species">keystones</a> to the <b id="mwAQA"><a href="./Ecology_of_the_Rocky_Mountains" id="mwAQE" rel="mw:WikiLink" title="Ecology of the Rocky Mountains">ecology of the Rocky Mountains</a></b>?