PARENT SESSION
Oral Session #73: Restoration Using Fire.
Presiding: D. Falk
Thursday, August 8. 9:00 AM to 11:30 AM. Mohave Meeting Room, TCC.
Seeding and natural regeneration of herbaceous species on a large-scale restoration project in the Southwest.
SPRINGER, JUDITH*,1, DANIELS, MARK1, FULE, PETER1, COVINGTON, W.1, 1 Northern Arizona University, Flagstaff, AZ
ABSTRACT- Ponderosa pine forests, which cover millions of hectares in the West, have become highly susceptible to intense crown fires due in large part to 20th century fire suppression. While most restoration projects in these forests are still of a small-scale experimental nature, one large study area in northern Arizona has undergone small-diameter tree thinning and prescribed burning efforts over several hundred hectares. We have compiled three years of monitoring data on the natural regeneration response in 160 500-m2 long-term monitoring understory plots in four paired (treatment and control) experimental blocks that were not seeded. We also have collected 1-5 years of monitoring data from 40 500-m2 plots in much larger areas that have been thinned, burned and seeded with commercially available seeds from species inventoried in the study area. In the unseeded plots, species richness averaged fourteen species prior to restoration treatments and had increased approximately 29% by the second year. Average species richness in the seeded plots was seven prior to treatment, and had increased an average of over 300% by three years after treatment. Differences between species richness in the seeded areas and in the non-seeded experimental blocks are due not only to successful establishment of species by seeding, but also to many other factors including soils and climate. While introduction of new species, including non-native contaminants in the seed mix, is a major consideration, we note that seeding can be accomplished in these semi-arid ecosystems.
KEY WORDS: Pinus ponderosa, seeding, vegetation response, monitoring