PARENT SESSION
Oral Session # 52: Fire Ecology III: Grasslands; Scrub.
Presiding: J Grace
Wednesday, August 6. 1:30 PM to 5:00 PM, SITCC Meeting Room 102.

Vegetation recovery following fire in a desert grassland in New Mexico, USA.

Parmenter, Robert^*,1, ¹ Department of Biology, Albuquerque, NM, USA

ABSTRACT- The post-fire recovery of dominant plant species in a desert grassland on the Sevilleta Long Term Ecological Research site in central New Mexico was measured from 1992 through 2001. Pre- and post-burn data were collected on individual, permanently mapped plants. Annual regrowth data for the first 5 years were used to develop species-specific linear models to predict time requirements for complete fire recovery. Woody plants were measured again after 9 years to evaluate the model predictions. As expected, plant species displayed a wide range of tolerance to and recovery from fire. Mortality rates were highest in cacti (particularly chollas), and were lowest in grasses, yuccas, and certain shrub species. Regrowth rates across grass species ranged from 3 months to an estimated 6-7 years. Yucca recovered in a single year, and exhibited large increases in numbers of stump sprouts. Shrubs displayed widely varying regrowth rates among species, ranging from 1 to 13 years. Most species flowered and produced seeds within 2 years of the fire. Herbivory by black-tailed jackrabbits on several of the shrub species was particularly heavy in the first year following the fire, but declined to near zero in subsequent years. Overall, this grassland community is expected to show complete recovery from this particular fire event within 15 years. This time interval is consistent with estimates of natural fire return times in desert grasslands of New Mexico and Arizona.

Key words: Vegetation, Herbivory, Fire, Disturbance