Does Fire Frequency Effect Diversity in Ponderosa Pine Communities?
Jennie Rambo and Dr. Stanley H. Faeth Department of Biology Fire was an important factor in maintaining ponderosa pine ecosystems in the southwest prior to European settlement. Overt fire suppression in concert with other postsettlement activities is associated with reduced growth and diversity of herbaceous plants in these systems (Covington, et al., 1997). We compared species richness and abundance of understory plants in 4 replicates of 1 ha. plots burned at 1-, 4-, and 8- year intervals, and control plots (no burning since 1913) in Long Valley Experimental Forest, northern Arizona. Plant species richness and abundance was greatest in plots burned at 4-year intervals, and lowest in non-burn plots. In addition, annual burns yielded relatively high species richness, but areas subjected to 8-year burning intervals were marked by greater abundances compared to annual fire and absence of fire.
