Did your River Birch shed MANY branches over this past Fall & Winter? This was typical for ALL River Birch in Urbana-Champaign. NOT a sign your tree is dying. JUST severely stressed.
In 2012, trees in Champaign experienced EXTREME summer heat and drought. A second summer drought in 2013 made damage worse. To survive environmental extremes, the tree has to change its physiology, or adjust its volume to deal with the environmental extreme.
River Birch can “intelligently” shrink its volume by selectively dropping twigs and small branches in the shade of its inner canopy (cladoptosis). Cladoptosis is effective tree survival (reduces the tree’s demand for water). This was a good thing for your Birch. It survived the heat and drought of 2012/13. But, cladoptosis is messy for us as the twigs rot and drop which they did this Winter.
The natural niche for River Birch is along stream banks in loose alluvial soil with a full and dependable supply of water. Because urban soils are the antithesis of loose alluvial soil and because seasonal droughts are common to Central Illinois, River Birch will always be a “messy tree.” However, until we have another hot and dry spell to match the extremes of 2012/13, we will likely not see this Winter’s glut of falling dead twigs and branches.
The most cost-efficient way to reduce drought-stress on your trees starts with mulching past tips of the branches. For a detailed analysis of your tree, contact our ISA Board Certified Master Arborist; Greg Smith @ email@example.com or 217.202.7490