A few days ago my neighbor mentioned to me that several of her pine trees were dying and she thought this was due to pine beetles. We looked at the trees – their foliage had turned red as you would expect from deciduous trees in the fall, but these are evergreen trees. Even at a distance we could spot white blobs on the trunk, which from a closer position, appeared to be a crusty excrescence. This was a pine beetle attack. There are two main types of pine beetle in Georgia – the southern pine beetle and the black turpentine beetle and the culprits in this case are probably the black turpentine beetle since the infestation does not seem to extend above 8 ft and the white gum blob is typical for this beetle. With my neighbor’s consent, I will ask the forestry commission for their suggestions as to what we should do to prevent this problem spreading.
The reason I mention all this is the front page (and succeeding two full pages) article titled “The Threats to a Crucial Canopy” which appeared in today’s (10/1/11) New York Times. An excellent article on how trees are being impacted by rising temperatures and/or lack of water. Shortage of water stresses trees and makes them more vulnerable to beetle attacks and warmer temperatures are enabling beetles to survive winters, which previously would have killed them off. An interesting offset is that trees are apparently growing more vigorously as a result of increased carbon emissions, since trees and other vegetation depend on carbon as a food supply. So increased growth on the one hand and increased vulnerability from rising temperatures and water shortages. The article is well worth reading – http://www.nytimes.com/2011/10/01/science/earth/01forest.html?_r=1&ref=todayspaper