Cut of a heartwood tree trunk.

Heartwood and Sapwood

Trunk layers - Slide Show - Trunk and branches - Trees Inside Out

Tree Stem Vs. Tree Branches: Pictures, Charts, How To Identify Parts of a Tree

Wood Decay in Trees

Katherine KUKSA, Associated Professor, PhD, Saint Petersburg State University, Saint Petersburg, SPBU, Department of Geomorphology

Parts of a tree, showing bark, sapwood, and heartwood. (Modified from

Reduction Pruning - HeartWood

What are the layers of a tree trunk? - Quora

Location map of the Tunka rift basin.

How to Do a Scratch Test on Trees & Plants - Stark Bro's