While it's a valid concern to worry about changing albedo of part of continent, that minor effect will be dwarfed by trees capturing CO2 and creating O2 during

While it's a valid concern to worry about changing albedo of part of continent, that minor effect will be dwarfed by trees capturing CO2 and creating O2 during photosynthesis. Not to mention trees IIRC can cause clouds to form and thus bring more water to the region.