Lesley DeFalco
Dr. Lesley DeFalco is a Plant Ecologist with the U.S. Geological Survey's Western Ecological Research Center.
RESEARCH INTERESTS
- Restoration of Aridlands
- Conservation biology
- Desert Community Ecology
- Ecological monitoring
- Effects of Anthropogenic Disturbance
- Evaluation of management
- Fire ecology
- Global climate change
- Invasive species ecology
- Physiological plant ecology
- Plant ecology
- Species interactions
- Threatened and endangered species
EDUCATION
PhD, Ecology, Evolution & Conservation Biology, University of Nevada, Reno, NV 2003
MS, Botany, Colorado State University, Fort Collins, CO 1995
BS, Biological Sciences, Colorado State University, Fort Collins, CO 1989
COMMITTEES
- Botanical Society of America
- California Native Plant Society (Mojave Chapter)
- Ecological Society of America
- Nevada Native Plant Society
- Society for Ecological Restoration (Southwest Chapter)
Science and Products
Filter Total Items: 41
Supplementing seed banks to rehabilitate disturbed Mojave Desert shrublands: Where do all the seeds go?
Revegetation of degraded arid lands often involves supplementing impoverished seed banks and improving the seedbed, yet these approaches frequently fail. To understand these failures, we tracked the fates of seeds for six shrub species that were broadcast across two contrasting surface disturbances common to the Mojave Desert—sites compacted by concentrated vehicle use and trenched sites where top
Authors
Lesley A. DeFalco, Todd C. Esque, Melissa B. Nicklas, Jeffrey M. Kane
Effectiveness of post-fire seeding in desert tortoise Critical Habitat following the 2005 Southern Nevada Fire Complex
In June 2005, lightning strikes ignited multiple wildfires in southern Nevada. The Southern Nevada Fire Complex burned more than 32,000 acres of designated desert tortoise Critical Habitat and an additional 403,000 acres of Mojave Desert habitat characterized as potentially suitable for the tortoise. Mortalities of desert tortoises were observed after the fires, but altered habitat is likely to pr
Authors
Lesley DeFalco, K. Kristina Drake, S. J. Scoles-Sciulla, Kyla L. Bauer
Desert wildfire and severe drought diminish survivorship of the long-lived Joshua Tree (Yucca brevifolia; Agavaceae)
Extreme climate events are transforming plant communities in the desert Southwest of the United States. Abundant precipitation in 1998 associated with El Ni??o Southern Oscillation (ENSO) stimulated exceptional alien annual plant production in the Mojave Desert that fueled wildfires in 1999. Exacerbated by protracted drought, 80% of the burned Yucca brevifolia, a long-lived arborescent monocot, an
Authors
L.A. DeFalco, T. C. Esque, S. J. Scoles-Sciulla, J. Rodgers
Demographic studies of Joshua trees in Mojave Desert National Parks: demography with emphasis on germination and recruitment
The study of population change with regard to reproduction, seed dispersal, and germination, establishment, growth, and survival/mortality is known as demography. Demographic studies provide managers with information to assess future trends on the density, distribution, health, and population changes of importance or value, including Joshua trees (Yucca brevifolia). Demographic research provides t
Authors
T. C. Esque, B. Reynolds, L.A. DeFalco, B.A. Waitman
Dust deposition effects on growth and physiology of the endangered Astragalus jaegerianus (Fabaceae)
Human expansion into the Mojave Desert is a significant threat to rare desert plants. While immediate habitat loss is often the greatest concern, rare plants situated near areas where soil surfaces experience frequent disturbance may be indirectly impacted when fine particulate dust accumulates on leaf surfaces. Remaining populations of the federally listed Astragalus jaegerianus (Lane Mountain mi
Authors
Upekala C. Wijayratne, Sara J. Scoles-Sciulla, Lesley A. Defalco
Seed banks in a degraded desert shrubland: Influence of soil surface condition and harvester ant activity on seed abundance
We compared seed banks between two contrasting anthropogenic surface disturbances (compacted, trenched) and adjacent undisturbed controls to determine whether site condition influences viable seed densities of perennial and annual Mojave Desert species. Viable seeds of perennials were rare in undisturbed areas (3-4 seeds/m2) and declined to <1 seed/m2 within disturbed sites. Annual seed densities
Authors
L.A. DeFalco, T. C. Esque, J.M. Kane, M.B. Nicklas
Seed reserves diluted during surface soil reclamation in eastern Mojave Desert
Surface soil reclamation is used to increase the re-establishment of native vegetation following disturbance through preservation and eventual replacement of the indigenous seed reserves. Employed widely in the mining industry, soil reclamation has had variable success in re-establishing native vegetation in arid and semi-arid regions. We tested whether variable success could be due in part to a d
Authors
S. J. Scoles-Sciulla, L.A. DeFalco
Variation in the establishment of a non-native annual grass influences competitive interactions with Mojave Desert perennials
Competition between native and non-native species can change the composition and structure of plant communities, but in deserts, the highly variable timing of resource availability also influences non-native plant establishment, thus modulating their impacts on native species. In a field experiment, we varied densities of the non-native annual grass Bromus madritensis ssp. rubens around individual
Authors
L.A. DeFalco, G.C.J. Fernandez, R.S. Nowak
The importance of physiological ecology in conservation biology
Many of the threats to the persistence of populations of sensitive species have physiological or pathological mechanisms, and those mechanisms are best understood through the inherently integrative discipline of physiological ecology. The desert tortoise was listed under the Endangered Species Act largely due to a newly recognized upper respiratory disease thought to cause mortality in individuals
Authors
C.R. Tracy, K.E. Nussear, T. C. Esque, K. Dean-Bradley, L.A. DeFalco, K.T. Castle, L.C. Zimmerman, R.E. Espinoza, A.M. Barber
Perennial vegetation data from permanent plots on the Nevada Test Site, Nye County, Nevada
Perennial vegetation data from 68 permanent plots on the Nevada Test Site, Nye County, Nevada, are given for the period of 1963 through 2002. Dr. Janice C. Beatley established the plots in 1962 and then remeasured them periodically from 1963 through 1975. We remeasured 67 of these plots between 2000 and 2003; the remaining plot was destroyed at some time between 1975 and 1993. The plots ranged fro
Authors
Robert H. Webb, Marilyn B. Murov, Todd C. Esque, Diane E. Boyer, Lesley A. DeFalco, Dustin F. Haines, Dominic Oldershaw, Sara J. Scoles, Kathryn A. Thomas, Joan B. Blainey, Philip A. Medica
Are Mojave Desert annual species equal? Resource acquisition and allocation for the invasive grass Bromus madritensis subsp. rubens (Poaceae) and two native species
Abundance of invasive plants is often attributed to their ability ot outcompete native species. We compared resource acquisition and allocation of the invasive annual grass Bromus madritensis subsp. rubens with that of two native Mojave Desert annuals, Vulpia octoflora and Descurainia pinnata, in a glasshouse experiment. Each species was grown in monoculture at two densities and two levels of N av
Authors
Lesley A. DeFalco, David R. Bryla, Vickie Smith-Longozo, Robert S. Nowak
Effects of desert wildfires on desert tortoise (Gopherus agassizii) and other small vertebrates
We report the results of standardized surveys to determine the effects of wildfires on desert tortoises (Gopherus agassizii) and their habitats in the northeastern Mojave Desert and northeastern Sonoran Desert. Portions of 6 burned areas (118 to 1,750 ha) were examined for signs of mortality of vertebrates. Direct effects of fire in desert habitats included animal mortality and loss of vegetation
Authors
T. C. Esque, C. R. Schwalbe, L.A. DeFalco, R.B. Duncan, T.J. Hughes
Science and Products
Filter Total Items: 41
Supplementing seed banks to rehabilitate disturbed Mojave Desert shrublands: Where do all the seeds go?
Revegetation of degraded arid lands often involves supplementing impoverished seed banks and improving the seedbed, yet these approaches frequently fail. To understand these failures, we tracked the fates of seeds for six shrub species that were broadcast across two contrasting surface disturbances common to the Mojave Desert—sites compacted by concentrated vehicle use and trenched sites where top
Authors
Lesley A. DeFalco, Todd C. Esque, Melissa B. Nicklas, Jeffrey M. Kane
Effectiveness of post-fire seeding in desert tortoise Critical Habitat following the 2005 Southern Nevada Fire Complex
In June 2005, lightning strikes ignited multiple wildfires in southern Nevada. The Southern Nevada Fire Complex burned more than 32,000 acres of designated desert tortoise Critical Habitat and an additional 403,000 acres of Mojave Desert habitat characterized as potentially suitable for the tortoise. Mortalities of desert tortoises were observed after the fires, but altered habitat is likely to pr
Authors
Lesley DeFalco, K. Kristina Drake, S. J. Scoles-Sciulla, Kyla L. Bauer
Desert wildfire and severe drought diminish survivorship of the long-lived Joshua Tree (Yucca brevifolia; Agavaceae)
Extreme climate events are transforming plant communities in the desert Southwest of the United States. Abundant precipitation in 1998 associated with El Ni??o Southern Oscillation (ENSO) stimulated exceptional alien annual plant production in the Mojave Desert that fueled wildfires in 1999. Exacerbated by protracted drought, 80% of the burned Yucca brevifolia, a long-lived arborescent monocot, an
Authors
L.A. DeFalco, T. C. Esque, S. J. Scoles-Sciulla, J. Rodgers
Demographic studies of Joshua trees in Mojave Desert National Parks: demography with emphasis on germination and recruitment
The study of population change with regard to reproduction, seed dispersal, and germination, establishment, growth, and survival/mortality is known as demography. Demographic studies provide managers with information to assess future trends on the density, distribution, health, and population changes of importance or value, including Joshua trees (Yucca brevifolia). Demographic research provides t
Authors
T. C. Esque, B. Reynolds, L.A. DeFalco, B.A. Waitman
Dust deposition effects on growth and physiology of the endangered Astragalus jaegerianus (Fabaceae)
Human expansion into the Mojave Desert is a significant threat to rare desert plants. While immediate habitat loss is often the greatest concern, rare plants situated near areas where soil surfaces experience frequent disturbance may be indirectly impacted when fine particulate dust accumulates on leaf surfaces. Remaining populations of the federally listed Astragalus jaegerianus (Lane Mountain mi
Authors
Upekala C. Wijayratne, Sara J. Scoles-Sciulla, Lesley A. Defalco
Seed banks in a degraded desert shrubland: Influence of soil surface condition and harvester ant activity on seed abundance
We compared seed banks between two contrasting anthropogenic surface disturbances (compacted, trenched) and adjacent undisturbed controls to determine whether site condition influences viable seed densities of perennial and annual Mojave Desert species. Viable seeds of perennials were rare in undisturbed areas (3-4 seeds/m2) and declined to <1 seed/m2 within disturbed sites. Annual seed densities
Authors
L.A. DeFalco, T. C. Esque, J.M. Kane, M.B. Nicklas
Seed reserves diluted during surface soil reclamation in eastern Mojave Desert
Surface soil reclamation is used to increase the re-establishment of native vegetation following disturbance through preservation and eventual replacement of the indigenous seed reserves. Employed widely in the mining industry, soil reclamation has had variable success in re-establishing native vegetation in arid and semi-arid regions. We tested whether variable success could be due in part to a d
Authors
S. J. Scoles-Sciulla, L.A. DeFalco
Variation in the establishment of a non-native annual grass influences competitive interactions with Mojave Desert perennials
Competition between native and non-native species can change the composition and structure of plant communities, but in deserts, the highly variable timing of resource availability also influences non-native plant establishment, thus modulating their impacts on native species. In a field experiment, we varied densities of the non-native annual grass Bromus madritensis ssp. rubens around individual
Authors
L.A. DeFalco, G.C.J. Fernandez, R.S. Nowak
The importance of physiological ecology in conservation biology
Many of the threats to the persistence of populations of sensitive species have physiological or pathological mechanisms, and those mechanisms are best understood through the inherently integrative discipline of physiological ecology. The desert tortoise was listed under the Endangered Species Act largely due to a newly recognized upper respiratory disease thought to cause mortality in individuals
Authors
C.R. Tracy, K.E. Nussear, T. C. Esque, K. Dean-Bradley, L.A. DeFalco, K.T. Castle, L.C. Zimmerman, R.E. Espinoza, A.M. Barber
Perennial vegetation data from permanent plots on the Nevada Test Site, Nye County, Nevada
Perennial vegetation data from 68 permanent plots on the Nevada Test Site, Nye County, Nevada, are given for the period of 1963 through 2002. Dr. Janice C. Beatley established the plots in 1962 and then remeasured them periodically from 1963 through 1975. We remeasured 67 of these plots between 2000 and 2003; the remaining plot was destroyed at some time between 1975 and 1993. The plots ranged fro
Authors
Robert H. Webb, Marilyn B. Murov, Todd C. Esque, Diane E. Boyer, Lesley A. DeFalco, Dustin F. Haines, Dominic Oldershaw, Sara J. Scoles, Kathryn A. Thomas, Joan B. Blainey, Philip A. Medica
Are Mojave Desert annual species equal? Resource acquisition and allocation for the invasive grass Bromus madritensis subsp. rubens (Poaceae) and two native species
Abundance of invasive plants is often attributed to their ability ot outcompete native species. We compared resource acquisition and allocation of the invasive annual grass Bromus madritensis subsp. rubens with that of two native Mojave Desert annuals, Vulpia octoflora and Descurainia pinnata, in a glasshouse experiment. Each species was grown in monoculture at two densities and two levels of N av
Authors
Lesley A. DeFalco, David R. Bryla, Vickie Smith-Longozo, Robert S. Nowak
Effects of desert wildfires on desert tortoise (Gopherus agassizii) and other small vertebrates
We report the results of standardized surveys to determine the effects of wildfires on desert tortoises (Gopherus agassizii) and their habitats in the northeastern Mojave Desert and northeastern Sonoran Desert. Portions of 6 burned areas (118 to 1,750 ha) were examined for signs of mortality of vertebrates. Direct effects of fire in desert habitats included animal mortality and loss of vegetation
Authors
T. C. Esque, C. R. Schwalbe, L.A. DeFalco, R.B. Duncan, T.J. Hughes