Methods and assumptions used in this impact analysis include the following:
Current trends in plant succession and vegetation health would continue.
Some existing plant communities likely would not be reestablished to pre-disturbance structure and density for more than 20 years.
Short-term vegetation impacts depend on the length of time it takes for a disturbed area to become revegetated, generally a 1- to 5-year timeframe.
Grassland and shrubland communities would be maintained with a mix of species composition, cover, and age classes.
Based on the definition of surface-disturbing activity (mechanized actions), an increased source of surface disturbance in the Planning Area will be from bentonite and gypsum development.
Surface disturbances increase the likelihood of the spread of invasive species in an area.
The placement of supplements can affect the distribution of livestock grazing in grassland and shrubland communities.
The primary conduit for the initial establishment of the spread of invasive species is through the road network.
Herbivory use in the form of grazing and browsing is important for maintaining the health of grassland and shrubland communities. Improper or unmanaged herbivory can decrease plant vigor and ground cover, lead to increased erosion, degrade soil nutrients and water retention, and impact rangeland health.
Grazing practices can maintain, improve, or degrade rangeland health. The Standards for Healthy Rangelands and Guidelines for Livestock Grazing Management for the Public Lands Administered by the BLM in the State of Wyoming (Appendix N) are designed to maintain or improve rangeland health and are applied under all alternatives.
Fire plays an intricate role in these communities, particularly shrubland communities.
Prescribed fire is a tool used to manage vegetative communities and can result in short-term adverse impacts with long-term beneficial impacts to wildlife, certain desirable wildlife habitats, and in some cases forage availability and productivity.