. Elementary botany. Botany. 392 ECOLOG Y. effect, probably, in causing many of the young spruces over the center of the formation to die off. 706. This may also have been hastened by fires which would now more often sweep over the swamp during dry seasons. In partial evidence of this are many young spruce trees with scars near the ground where the bark has been destroyed. This gives admittance to wood-boring insects which farther aid in the proc-. Fig. 487. Dying black spruce in moor. (Photograph by the author.) I css of weakening and debilitating the trees. The dying off of the lower limbs o
. Elementary botany. Botany. 392 ECOLOG Y. effect, probably, in causing many of the young spruces over the center of the formation to die off. 706. This may also have been hastened by fires which would now more often sweep over the swamp during dry seasons. In partial evidence of this are many young spruce trees with scars near the ground where the bark has been destroyed. This gives admittance to wood-boring insects which farther aid in the proc-. Fig. 487. Dying black spruce in moor. (Photograph by the author.) I css of weakening and debilitating the trees. The dying off of the lower limbs of these marsh spruces suggests both the action of fire, as well as excessive moisture at times. Many of them now present only a small convex top of living branches. It is interesting to observe the gradation in this respect in different trees. 707. The weird aspect presented by a clump of these dying young spruce trees is heightened also by the changes in the form of the branches as they die. The living branches have a graceful sigmoid sweep with their free ends curving upwards as in many. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Atkinson, George Francis, 1854-1918. New York, H. Holt and company
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Keywords: ., bookcentury1800, bookdecade1890, bookpublisher, booksubjectbotany
