Location: Rangeland Resources & Systems ResearchTitle: Active old-field restoration in the most arid lands of the Great Basin
|LEGER, ELIZABETH - University Of Nevada|
|DAVISON, JAY - University Of North Carolina|
|MILLER, W WALLY - University Of Nevada|
|SULLIVAN, BENJAMIN - University Of Nevada|
|USELMAN, SHAUNA - University Of Nevada|
|BAUGHMAN, OWEN - University Of Nevada|
Submitted to: Society for Range Management Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 11/7/2017
Publication Date: 2/9/2018
Citation: Leger, E.A., Davison, J., Miller, W., Sullivan, B., Uselman, S., Porensky, L.M., Baughman, O. 2018. Active old-field restoration in the most arid lands of the Great Basin. Society for Range Management Meeting Abstracts, Sparks, NV, Jan 27-Feb 2, 2018.
Technical Abstract: Restoration of former agricultural fields can be challenging, especially in arid systems, where factors such as wind erosion, water stress, soil alteration, and competition from weeds can strongly affect plant establishment and growth. Experiments were conducted in two former agricultural fields in Nevada’s Mason Valley, testing the effects of irrigation timing, seed source, and seeding order on restoration outcomes. Multiple sources of grass and shrub seeds were drill seeded in four strategies: 1) simultaneously in year one, 2) shrubs only in year one, 3) grasses in year one followed by shrubs in year two, or 4) shrubs seeded alone in year two, after a year of weed control. Irrigation was applied to all treatments in either spring or fall + spring for two years, and we monitored emergence and survival for three years. All treatments affected performance, but results were highly context dependent. For example, in a higher fertility field, fall + spring irrigation increased shrub seedling emergence, while grasses had higher emergence in spring-only irrigation treatments. In contrast, in a lower-fertility field, there was no effect of irrigation timing on seedling densities of grasses or shrubs. In both fields, shrubs emerged best when seeded in year two, either alone or after grasses. In this treatment, shrubs from more local seed sources outperformed more distant collections while irrigation was ongoing, but, after dramatic declines in shrub densities after irrigation ceased, this effect did not persist. In contrast, commercially-available, non-local grasses initially outperformed more local grass sources under some scenarios, but after irrigation ceased, these advantages either disappeared or more local grasses outperformed commercial sources. Our trials indicate that supplemental irrigation and seed source can affect restoration outcomes in arid old fields, but results can vary greatly, even between fields in very close proximity. Because of these highly context-dependent results, a bet-hedging strategy that uses a variety of seed sources and irrigation treatments within an overall restoration plan may maximize the chances of restoration success.