Red Alder Sacrifice

The extended seasonal summer drought causes many of our deciduous tree species to drop leaves as early as mid July to late August. It seems to be a strategy for limiting transpiration via their foliage. The Red Alder in particular employs this strategy, even to the extent of sacrificing whole limbs. Alders around and near the ponds, which one would think are better hydrated, have lower limbs that have died over the summer. Upper limbs seem to not be given up for the sake of the whole organism's survival, as the lower limbs are. I posit lower limbs are of lesser value to the tree, and thereby not as great a sacrifice as the upper, higher value photosynthesizing limb's leaves are. No other tree species that have dropped their leaves early, seem to have lower limb die-back. It appears to be a strategy unique to the Red Alder.

Posted on September 9, 2017 10:19 PM by