NURSERY PRACTICE FOR PRAIRIE-PLAINS PLANTING / 



A Seed Zoning Plan 



Figure 3 shows a tree-seed zoning plan for the greater portion of the 

 prairie-plains, prepared for the guidance of the Forest Service and 

 other agencies in tree-planting activities in that area. The importance 

 of latitudinal zones lies in the varying length of their growing seasons 

 and increasing severity of winter temperatures to the north. 



Figure 3. — Seed-collection zones for the Great Plains area (after B 



