LIFE ZONES OF CARLSBAD REGION 17 



slopes and from 8,000 to 9,500 feet on southerly slopes, 

 varying somewhat in different ranges according to 

 steepness of slopes and elevation of base level. A high 

 valley or plain by holding the heat of the sun's rays 

 higher up elevates the life zones above it, while a low 

 base level allows them to come lower down. In the 

 Guadalupe and Sacramento mountains the general 

 levels of the zone are about normal, but on some very 

 steep, dry southwest slopes Transition zone species 

 are dominant from 8,000 to 10,000 feet. 



In New Mexico this zone is strongly marked by the 

 western yellow pine, with huge scaly trunks in wide 

 stretches of beautiful open forest, clean and grassy 

 underneath. Douglas spruce, southern white pine, 

 large-leaved maple, New Mexico oak and locust occupy 

 secondary places in this forest. Extensive open parks 

 or grassy glades appear, which along some of the stream 

 valleys are occupied by little farms. The great value 

 of this zone is its timber, grass, and water, its cool 

 climate, shade and beauty in the midst of a wide ex- 

 panse of low, hot plains. 



The characteristic mammals are white-tailed and 

 mule deer, two species of chipmunks, a small form of 

 the thirteen-lined ground squirrel, the Colorado wood 

 rat, Guadalupe meadow mouse, fulvous pocket gopher, 

 mountain cottontail, and brown bat. 



Some of the breeding birds of this zone in the Guada- 

 lupe and Sacramento mountains are the Merriam wild 

 turkey, band-tailed pigeon, spotted owl, screech owl, 

 hairy woodpecker, ant-eating woodpecker, red-shafted 

 flicker, broad-tailed hummingbird, green-tailed and 



