Great Basin Naturalist


Chemical composition of some major forage plants of mountain summer ranges of southeastern Utah is reported. Grasses are shown to contain significantly less nitrogen, phosphorus, potassium, calcium, and magnesium than either forbs or shrubs. Forbs and shrubs are demonstrated to differ significantly only in potassium content; forbs tested contained more potassium than shrubs. The chemical composition of the forage plants is discussed in relation to mule deer reproductive rates. It is concluded that protein and mineral content of the forage of the two ranges considered (the LaSal and Henry mountains) is less likely to affect reproductive rates than is the relative digestibility of grasses, forbs, and shrubs.