oct14 - A close examination of the broad, gentle, grassy...

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10/14 Patterns of Vegetation Change in the Southwest: “The spread of mesquite and other shrubs in the Southwest has been documented with heavy grazing, seed dispersal by domestic animals and periodic droughts being advanced as causes contributing to the increase in shrubs” “The most dramatic changes occurred on gently sloping mesas where relatively dense stands of alligator juniper now dominate former grasslands and savannas. During the 56yrs between 1935-1991, grass lands and savannas have decreased from a combined 15% of the area to less than 2%. ..the combined effects of livestock, fire, and climate fluctuations appear reasonable”
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Unformatted text preview: A close examination of the broad, gentle, grassy slopes between the arroyos reveals a very scattering growing of mesquite which is in the form of twigs 2-3ft high with an occasional larger shrub in some of the more favorable localities one can not tell whether this growth indicates that this shrub is spreading or not present condition rather suggests possibility Pristine vegetationblack grama and yucca elata o Mesquite creeping in not use to be here o Creosote bush invading desert grasslands, becomes more dense and then there is more bare ground...
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