With each year, new rings are created reflecting what might have happened during that period. For instance, more rain, fire, drought. We want the rings or tissue to be flowing in their normal patterns.
each ring? This can equate to fascia in the human body.
The line crossing the center can represent in the human body, a scar. Sometimes tough, rigid old or new scars interfere with the flow and health of the tissue. And scars always have a superficial and deep aspect to it.