A century from now, people on Mars might stroll through forests filled with juniper trees, kudzu vines, and heath shrubs. Maybe. Ecologist Paul Smith of the University of Bristol suggests that long-term residents of Mars could build small nature preserves, shielded from the harsh Martian environment by clear domes or layers of Martian crust. …He published his proposal in the Journal of Astrobiology. …He suggests about 20 hectares of forest park, carefully contained under protective pressurized domes or sheltered in lava tubes lit by mirrors and fiber optics. …They’ll need shielding against ultraviolet light and cosmic rays, pressurized air, artificial heating, a lot of added water, and some way to get toxic chemicals like perchlorates out of the regolith. …The idea of contained nature preserves on Mars could be viable in roughly a century.