Executive Summary: Portions of broad-scale ecoregions of the Great Plains, and Southern Semiarid Highlands were generally projected as mostly suitable for large fires of low severity within 31 years. Under a 2070 future climate scenario of high CO2 emission (HadGEM2-ES RCP8.5) a significant increase in suitability for large low severity wildfires was seen in Wyoming and Montana, which was accompanied by a decrease in suitability for the Madrean Archipelago and portions of central and west Texas. Broad scale niche model for the Southwestern Willow Flycatcher under current climate was centered within the known breeding range mostly along riparian areas. Under a 2070 future climate scenario of high CO2 emission (HadGEM2-ES RCP8.5) a significant increase in suitability for flycatchers was seen in the southern portion of the breeding range along southern Arizona, New Mexico and far west Texas. Projections of Old World niche models of the subtropical tamarisk beetle onto North America reveal that this species should spread from New Mexico into large portions of the Sonoran Desert currently not occupied by tamarisk beetles. Dispersal models indicate that spread of this tamarisk beetle across Arizona could occur within the next two years and occupy the central range of the Southwestern Willow Flycatcher. Simulations with fine scale niche models of the flycatcher on Tonto Creek indicate as much as 25-50% of flycatcher habitat in heavy tamarisk areas could be lost due to dieback from tamarisk beetle defoliation over several years. A restoration simulation scenario of planting willows along excavated side channel pools could restore lost flycatcher habitat within a few years. Classification of tamarisk, willow, cottonwood, and mesquite from remote sensing imagery was used to develop fire canopy removal and fire mortality indices for the Tonto Creek study site. The fire mortality index revealed the high susceptibility of tamarisk dominated stands occupied by flycatchers to wildfire. Our simulations indicate that the potential hazard from wildfire to flycatcher habitat can be exacerbated by tamarisk beetle defoliation activity, which can also delay habitat recovery. However, willows and cottonwoods may recover more quickly than tamarisk in the presence of tamarisk beetle activity. Surveys along the Gila River near Fort Thomas revealed good populations of Southwestern Willow Flycatchers at planned restoration sites, but no Western Yellow-billed Cuckoo were found.
Contents of the Final Report:
Report A. Large Wildfire Severity Suitability Index Models for projecting fire regimes of southwestern North America in current and future climates with the aid of a Random Subset Feature Selection Algorithm, 41 pp.
Report B. Interfacing of fire regimes and distributions of three riparian species of concern in southwestern North America under current and future climates with the aid of a Random Subset Feature Selection Algorithm, 30 pp.
Report C. Ecological niche modeling for projecting North American distributions for Old World subtropical tamarisk beetles (Diorhabda sublineata; Coleoptera: Chrysomelidae), 33 pp.
Report D. Projecting dispersal of subtropical tamarisk beetles towards habitat of endangered Southwestern Willow Flycatchers, 13 pp.
Report E. Distinguishing riparian tamarisk/willow and mesquite habitats for endangered bird species using high resolution multispectral imagery, 20 pp.
Report F. Southwestern Willow Flycatcher habitat suitability and connectivity under simulated conditions of tamarisk beetle herbivory and willow restoration, 29 pp.
Report G. Fine-scale Fire Canopy Removal and Fire Mortality Indices and assessing risk to sensitive riparian species on Tonto Creek, Arizona, 40 pp.
Report H. Gila River, AZ, Southwestern Willow Flycatcher and Yellow-billed Cuckoo surveys and nest monitoring for proposed restoration sites, 2015, 32 pp.
