I can't comment on the particular facts of a member's situation. If it were an ecological gift, the mechanisms exist already in the Income Tax Act.
First, the land is certified by a government authority as ecologically sensitive. In Quebec it happens to be the provincial government that makes the determination that it is ecologically sensitive. Bureaucrats and biologists take a look, and it's significant environmentally sensitive land. The valuation is prepared by independent valuators chosen by the parties, and it goes to a committee within Environment Canada that assesses the valuation. These are two protection mechanisms that exist already.