What a beautiful tree! Your picture appears to be a spruce tree rather than a pine. Can you confirm? The link below will help you determine which tree you have.
Because sap is like the engine that keeps nourishing ingredients running throughout the tree, small amounts of sap may ooze all year from pines. Usually that happens after they're pruned, when they begin budding or as the seasons change. Typically, you'll see the most sap flow in spring and early summer.
Pine trees secrete resin as a defense to close wounds from insects or other forces. The sap provides a protective layer or sealant over the injury . The
sap hardens forming an amber glob which turns dark in color over time. On fresh wounds, you'll notice a whitish layer of sap covering the damaged area.
A couple of possibilities are the pitch mass borer or Zimmerman pine moth. The pitch mass borer occurs on spruce and pine in eastern North America. It does not kill trees, but the pitch-filled larval tunnels in the wood cause defects in the lumber. You can use a knife to dig out the glob of pitch to see if there is a worm inside.
One or a few globs of sap are not usually serious, but should be watched to see if more develop. You should closely inspect your tree to see if there are other symptoms besides the globs of sap, i.e., browning or lost needles, deal limbs, insects of any kind, cankers (sores that may or may not be oozing), etc.
If this is a spruce, cytospera canker disease is one of a few possibilities. The information in the link below will give you information on that disease.
The link below discusses and pictures different spruce issues.
Looking at your photo on the right hand side, I believe I see
your lighter-colored roof through the branches. Is this an area of the
tree that has lost needles or branches?
If you can provide more information, i.e., confirm type of tree, how many globs of sap, any dead or dying branches, and provide close up pictures of anything you find, I may be able to give your a more positive ID of the issue.
Because this is such a large and beautiful tree, you may wish to consult a certified arborist to diagnose
and recommend any necessary treatments. An arborist is a
certified and generally insured expert in trees and their problems. He or she
can examine your tree and make recommendations regarding the health of the
tree, any needed judicial pruning, and whether or not (in his opinion) it
should be removed. You can find a certified arborist in your area here:
http://www.treesaregood.org/
Click on "Find an
Arborist" at the top of the page; then click on United States from the
pull-down menu. Then enter your State and City. This should bring up a list of
certified arborists nearest to you. Or you may be able to locate one under "Tree
Services" in your local Yellow Pages.
