After wildfires, plant communities are in danger of transitioning from perennial, fire resistant vegetation into communities dominated by flammable, annual species, such as cheatgrass. In an effort to stop this transition, seeding of native and desirable perennial vegetation is conducted by the Bureau of Land Management in at-risk areas on public lands.

The establishment of desirable, perennial vegetation can make areas less prone to burn in future years, and reseeding burned areas immediately following a fire may be the best (and possibly the last) opportunity to stop the transition from perennial to annual plant communities in the Great Basin.

In a moderate fire year, the cost to the state for these emergency fire rehabilitation projects has historically been around $1,000,000, but in catastrophic fire years, these costs have been up to $44,000,000 (Bureau of Land Management Public Land Statistics).

Establishing plants from seeds in a semi-arid environment can be very difficult, due to variability in the timing and amount of precipitation from year to year. We cannot change the weather, but we can affect the success of rehabilitation efforts in two ways: by improve our cultural practices (seeding method, timing, etc.) and by improving the suitability of seed planted in burned sites.

We will use a combination of field surveys and common garden experiments to infer how much establishment success is influenced by seed characteristics vs. random environmental variation. Our studies will target Elko and Winnemucca BLM districts. The results from this research will be translated into recommendations to land managers and seed producers regarding the most efficient use of resources in future reseeding efforts (i.e. developing better seeds or more effective cultural practices).

In summary, our goal is to improve the success of rehabilitation efforts in Nevada through a better understanding of the factors that promote successful post-fire reseeding.

Revegetation of recently burned areas of pinyon-juniper woodlands and Wyoming big sagebrush communities is an extensive, ongoing process in the Great Basin. Seeds used for revegetation face many barriers to establishment in these semi-arid environments.

Characteristics which are not inherent barriers include variation in rainfall and temperature and the presence of invasive species.

Characteristics which are inherent barriers to establishment include the availability of species and varieties with appropriate genetic characteristics to grow well in the climatic regime, microclimate, soil condition, and competitive environment where they are planted.

It is well understood that seed used for rehabilitation or restoration should ideally come from an environment that closely matches the target environment to be reseeded (McKay et. al 2005). However, decisions about which species to use for restoration are often limited by non-ecological factors such as seed availability and cost (MacArthur 2004). These revegetation efforts are compromised if the seeds of the species used cannot establish and survive, and no amount of time and money devoted to site preparation, seeding timing, or planting techniques can establish plants from unsuitable seeds.

Selecting appropriate species and varieties to use can affect not only how these seeds establish in their first year, but also how the population is able to respond to future stressors. Genetically imperfect source material may limit the ability of populations to persist over the long term, if they lack the genetic variation necessary to respond to changing conditions such as climate change or invasions of new exotic species (Rice and Emery 2003).

Because of limited budgets and limited seed availability, these issues cannot be fully considered by managers in their rehabilitation plans during big fire years. However, they can be considered by seed producers and those developing new seed sources for the Great Basin.

The long-term objectives of this project are to improve the success of fire rehabilitation efforts in the Great Basin, which are in turn intended to slow or reverse the transition of valuable native plant communities into areas dominated by invasive species.

This three-year project has three overall objectives:

1. Examine how the genetic traits of seed sources affect the success of post-fire seeding;
2. Investigate how site conditions at the time of burning affect the establishment of seeded species; and
3. Evaluate the interactions among the genetic traits of seeds and site conditions.