[Campbell Biology P.824] If a complete ring of bark including phloem is removed from a tree ... | Practice Question

If a complete ring of bark including phloem is removed from a tree trunk girdling , which of the following is the most likely long-term outcome for the tree, and why?

  • A: The tree will die quickly (in days) because water transport will be immediately halted.
  • B: The tree will die slowly (in weeks or months) because sugar transport to the roots will be disrupted, leading to root starvation.
  • C: The tree will die slowly (in weeks or months) because water and mineral transport to the leaves will be disrupted.
  • D: The tree will survive, as only the outer protective layer is removed.

Explanation

Girdling involves the removal of a complete ring of bark, which includes the phloem. The phloem is responsible for transporting sugars produced during photosynthesis in the leaves to other parts of the plant, especially the roots, which rely on these sugars for energy and growth. When the phloem is removed, the roots are starved of nutrients, leading to their eventual death and subsequently the death of the entire tree. This process takes time, hence the death is slow weeks or months , not immediate.