In an experiment on the effects of deforestation of a portion of a northern temperate deciduous forest, all the trees were removed from a small mountainside watershed area and herbicides were applied for three years to prevent regrowth. Measurements of the concentration of calcium (an important nutrient) in runoff water were taken both before and after the deforestation. Monthly measurements also were made in a similar watershed in another part of the same forest that had been left undisturbed. The findings are displayed in the graph below. (There is an image in your packet #101-105) 2002 test Based on the graph, which of the following best describes why losses of calcium did not occur immediately in the deforested watershed?
(A) It takes months to leach calcium from the soil.
(B) Other minerals were more soluble and were leached out first.
(C) The deforestation occurred during the winter when runoff was low.
(D) Calcium is hard to detect in small amounts.
(E) Leaves do not appear on deciduous trees until the spring.
Ans: (C) The deforestation occurred during the winter when runoff was low.
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