An environmental biology researcher delivers an academic oral presentation on sustainable silviculture in southwestern Spain:
"In the cork oak forests of Andalusia, known locally as alcornocales, commercial bark extraction relies on precise biological indicators. The cork oak, *Quercus suber*, can survive for over two centuries, but harvesting its outer phellem layer requires strict adherence to forestry regulations. The fundamental rule established by regional conservation authorities mandates that a young tree must achieve a trunk circumference of at least 70 centimeters, measured at chest height, before its initial extraction, termed the *desborre*. Once this baseline is attained, subsequent debarking occurs exclusively during the peak summer weeks of July and August. Elevated ambient temperatures naturally loosen the outer cork from the delicate living phellogen layer beneath. Furthermore, foresters enforce an obligatory interval of nine to twelve years between successive harvests to ensure complete bark regeneration. To prevent vascular necrosis, extraction crews utilize curved manual axes rather than mechanized saws, guaranteeing the vascular cambium remains undamaged."
Based on the presentation, which specific condition must be satisfied before conducting the first bark extraction on a young cork oak?
- AThe tree must undergo a mandatory nine-to-twelve-year rest period before its first debarking.
- The tree's trunk must reach a minimum circumference of 70 centimeters measured at chest height.Answer
- CThe stand of trees must attain an average age of two centuries within the protected forest.
- DThe outer bark must be loosened using mechanical saws during the cooler winter months.