Page:Climatic Cycles and Tree-Growth - 1919.djvu/36

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CLIMATIC CYCLES AND TREE-GROWTH.

few isolated peaks. The mountains are covered with pines from their crests to a little below the level of the city.

This Prescott group was obtained in 1911 for the purpose of testing the conclusions derived from the Flagstaff trees some years earlier.

Climatic Cycles and Tree-Growth Fig 6.jpg

Fig. 6.—Annual growth of trees near Prescott, Arizona.

It consists of 67 trees selected in 5 subgroups depending on their nearness to town. The farthest was 10 miles southeast and the nearest was 1 mile south. It was apparent that the agreement between growth and precipitation increased as the location of the actual rainfall station was approached. The nearest subgroup, containing 10