Restoration does not necessitate the addition of new plant materials. Passive restoration, for example, includes the cessation of an environmental stress. In many instances, letting an agricultural field go fallow or limiting grazing can encourage the reestablishment of desired native plant species over short or long timescales. However, in Arizona’s arid landscapes (particularly on clay soils), this is unlikely to occur on management relevant timescales [1]. If you are interested in thinking about this approach, the surrounding vegetation community should be taken into account: Are there adequate seed sources proximal to the site? Is the adjacent vegetation composed of desirable native species or invasive species? Are desired species able to move onto and establish into the site? There are also many approaches that include the addition of physical structures that enhance revegetation through seed capture, weed control through shading, erosion control through the impediment of water movement, and soil moisture enhancement. This can include downed-woody debris. For example, to enhance soil stability (protect from wind and water erosion), provide microclimates that enhance seed recruitment and seedling establishment (protection from grazing and the elements), and provide a source of nutrient input for the soil, it can be helpful to pile downed-woody debris over the site after seeding has been conducted. This can include trees or shrubs that were removed removed during construction or restoration at the site. Rock structures can also be used to reduce water movement and trap seeds and organic material. Since these approaches do not require soil disturbance, they can be employed in the absence of an archeology review.
