Using dendroecological and archaeological methods and data we investigated the temporal dynamics of forest regeneration and fire history following depopulation of four large Pueblo IV period (1300-1600) villages on the Jemez Plateau, New Mexico. With tree rings we reconstructed the timing of reforestation on village footprints after depopulation–a novel approach to terminus ante quem dating of site occupation. Our tree-ring based forest age structure and fire history chronologies enabled us to reduce by 51 to 70 years the range of previous estimates of village depopulation dates derived primarily from terminal ceramic assemblages. One of the four village sites we investigated was depopulated in 1696, two were depopulated between 1625 and 1700 CE, while the fourth village was depopulated earlier (pre 1500), but the area was likely in continued use for agriculture or other seasonal purposes until the mid-1600s. Our results indicate that the Jemez were highly influential ecological agents. Forest structure and fire regime dynamics changed greatly after the departure of most people from these landscapes after circa 1650 CE. The terminus ante quem methods that we demonstrate in the Jemez Mountains have strong potential to constrain and refine low temporal resolution chronologies of human occupation at archaeological sites within other forested ecosystems of the Southwest and elsewhere.

The federally endangered Jemez Mountains salamander (Plethodon neomexicanus) is a geographically isolated species with limited dispersal ability found in northcentral New Mexico. Alterations to the historic fire regime have changed the forest structure and vegetative composition of P. neomexicanus habitat, threatening the future survival of this species. This study focuses on the use of broadcast prescribed fire on previously thinned P. neomexicanus potential habitat in Valles Caldera National Preserve, New Mexico to restore ecosystem processes, reduce potential for landscape-scale high-severity fire, and improve habitat conditions.Fire was highly effective in reducing fuel loads, while forest structure and composition remained essentially unchanged. The volume and count of woody cover objects were significantly reduced. However, ample woody cover objects remain on the landscape because pre-treatment levels were highly inflated due to more than a century of fire exclusion and suppression. Analysis of vegetation and substrate burn severity revealed nearly half of the sampled points were unburned, indicating that substantial fire refugia was left on the landscape post-fire. Despite reductions in cover object availability, the benefits on forest health outweigh the drawbacks. These results provide support for the use of broadcast prescribed fire in previously thinned areas, as a highly effective tool in managing fuel load to reduce the risk of stand replacing fire, which, along with climate change, is considered the most pressing threat to the persistence of P. neomexicanus. This study concludes that thinning and prescribed fire are compatible with P. neomexicanus habitat management and should be considered as future management options.