Effects of Long-term Grazing on Cryptogam Crust Cover in Navajo National Monument, Arizona

Abstract

The effects of long-term grazing (40 years) on cryptogamic crusts of Navajo National Monument were investigated. Both vascular and nonvascular communities were heavily impacted with the cryptogamic community showing the greatest reduction in cover. Lichens and mosses were the most damaged, while the algae were much more tolerant. Individual cryptogam species were affected in similar patterns with all identifiable species showing reduced cover. Vascular plant species were also affected with grasses showing the greatest reduction under grazing pressure.