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Show ( 5) Hayes Reservoir and Diamond Fork Area The original grass- dominated vegetation of this area has undergone considerable change. Much of the area is now cultivated and being grazed by livestocko The presence of a large number of introduced replacement species indicates that this area has been subjected to considerable activity. The sagebrush- grass community at Hayes Reservoir site is classified as poor range condition. Disturbances in the mountain brush and juniper woodland is indicated by the relatively few species in the communities. The streamside forest of the area has been adversely affected by many kinds of disturbances. Streambank cutting and erosion is severe. ( 6) Jordanelle Reservoir Site The vegetative cover of this location has undergone significant changes. Heavy grazing by livestock has caused the original grasses of the foothills to largely be replaced by sagebrush of relatively poor grazing quality. The wet meadow - streamside willow, the mountain brush and the streamside forest communities have also been heavily grazed, resulting in the establishment of many exotic species. The streamside forest has been reduced by logging, road building, miscellaneous construction and forest fire. ( 7) Utah Lake The aquatic and semi- aquatic vegetation of the lake has changed markedly since settlement. One major change that occurred during the early 1900' s was a dramatic alteration in species composition of the pond weeds ( Potamogeton spp.). The attached free floating stage of this weed has virtually disappeared from the lake. This change was attributed to the introduction of carp ( Cyprinus carpio) - a plant eating fish. Prior to 1925 vegetation changes other than those involving pond weeds had been minor. However, since 1925 changes have been extensive. Today native species have declined in abundance and in some locations communities are dominated by exotic species. Some of the important factors involved in causing the major changes of vegetation are draining of marshlands, manipulation of tributary streams, grazing along the shores, pollution by raw sewage, and siltation. 127 |
