To maintain its continuity, a municipal forest should have trees of all ages with a preponderance of them young. Annual plantings ensure that younger trees are in place to replace aging ones, and the benefits of the forest, whether shade, clean air, blossoms, fruit, autumn color, or psychological balm may be enjoyed by city dwellers without interruption. Imagine the reverse: if all trees were the same age, a significant portion of the canopy would be lost by old age alone. Only volunteers would be left to carry on.
