Fires can cause the cambium under thin bark to expand and rupture, girdling the tree.

Fires can cause the cambium under thin bark to expand and rupture, girdling the tree.

• A. False
• B. True
• C. Sometimes
• D. Not sure

Answer: (B)

Heat injury to the cambium under thin bark can rupture cells and sever the vascular connection around the trunk. The cambium is the living growth layer just beneath the bark that produces phloem on the outside and contributes to wood production on the inside. For the tree to survive, nutrients and water must move around the circumference; this requires an intact ring of cambial tissue. If a fire damages the cambium all the way around, nutrient and water transport is blocked in a complete ring, which is girdling and often fatal because the upper parts of the tree can no longer receive resources or send them to the roots. Thinner bark offers less insulation, so heat more readily reaches the cambium. That’s why fires can cause the cambium under thin bark to rupture and girdle the tree.

Heat injury to the cambium under thin bark can rupture cells and sever the vascular connection around the trunk. The cambium is the living growth layer just beneath the bark that produces phloem on the outside and contributes to wood production on the inside. For the tree to survive, nutrients and water must move around the circumference; this requires an intact ring of cambial tissue. If a fire damages the cambium all the way around, nutrient and water transport is blocked in a complete ring, which is girdling and often fatal because the upper parts of the tree can no longer receive resources or send them to the roots. Thinner bark offers less insulation, so heat more readily reaches the cambium. That’s why fires can cause the cambium under thin bark to rupture and girdle the tree.