Yatir forest - 3000 hectaresBoreal forest (the Taiga) - 20...

Yatir forest - 3000 hectares
Boreal forest (the Taiga) - 20 million hectares

There is compelling evidence that the Taiga (the world's largest forest - 27% of global forested area) is undergoing rapid vegetation changes and community restructuring due to the earth's warming climate.

http://www.sciencedaily.com/releases/2011/03/110325022352.htm

Which would you be more concerned about?

(You should note that the Taiga is unlikely to take any significant advantage of CO2 increases, as it's primary limits are nutrient and temperature.)