Finally, never bury the tree trunk or apply any kind of material against the trunk. Covered ‘trunk flares’ can decay years down the road just when trees should be looking their best.

You can build a OO tree in O (NlogN) (at least I think that's the worst case). Deleting a node and its children is linear.

A new study provides the first estimates of lightning-killed trees, a crucial figure for understanding Earth's carbon cycle.