How to recognise it
Stand back and follow the trunk upward. A central leader keeps going to the top of the tree, thicker than any branch that joins it, with side branches spaced up and around it rather than all leaving at one point. Pines, firs and spruces usually keep a leader naturally. Many broadleaf trees do not: they fork, and the forks compete.
The trouble starts when a second stem of similar size grows up beside the leader. That makes codominant stems, and if bark gets trapped between them, included bark. Most of that begins in the first years of a tree's life, which is when cheap fixes are available.
Why it matters here
Many Northern Nevada subdivisions were planted in a single push, and the trees from those years are now big enough to matter. Hardwoods that fork low, such as many ash and honeylocust trees, carry heavy crowns on unions that were never corrected. Spring storms that dump wet snow on a fully leafed tree then test every fork at once. See ash and honeylocust.
A leader that is damaged, for example by a vehicle or a hard cut, tends to be replaced by several competing shoots. The fix is early and small.
What an arborist does about it
On a young tree the arborist chooses the strongest upright stem and slows its competitors with small cuts, then repeats over a few seasons. That is the job of structural pruning, and it is far gentler than trying to rescue a mature tree with a fork that has already split. On a mature tree the leader is protected rather than reshaped: the arborist avoids cuts that would remove it and looks hard at forks below it.
A leader can be lost in a storm. That is when a certified arborist decides whether a tree can regrow a new one or not.
Sources
- International Society of Arboriculture, Trees Are Good: Pruning Young Trees (brochure) (read October 17, 2026)