- 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
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
- 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
Surface disturbances ranging from military training, recreation, energy exploration and development, and wildfires impact a large majority of federal lands in the western US, but the ecological and economic impacts are poorly understood. Explore this webpage to learn how Dr. Lesley DeFalco and her research team are currently evaluating and refining conventional approaches for post-fire restoration of Mojave desert tortoise critical habitat and developing ecological restoration strategies for shrubland communities impacted by energy exploration and development on the Colorado Plateau.
There is a growing consensus among resource managers to use native plant materials for ecological restoration of degraded drylands. Some plant species may be suitable for re-introduction across broad environmental gradients. Other species may fail under narrower conditions, or their re-introduction may have genetic consequences for local ecotypes, particularly when adapting to future climate changes. In coordination with the Bureau of Land Management, USGS is developing science-based priority species lists for native plants used in restoration, developing seed transfer zone guidelines and distance-based tools for managers collecting and using native seeds in restoration, evaluating local adaptation of native species across a network of common gardens across the Mojave Desert, and expanding these efforts to the Sonoran Basin and Range ecoregion.
The Mojave Desert is among the hottest and driest of the North American drylands, but in spite of these extreme conditions, and in part because of them, a diverse flora exists. This diversity of rare, endemic, and endangered species is threatened by the complex interaction between fluctuating climate and human-mediated disturbances. USGS studies have identified rare species “hotspots” for planning public multi-use access, evaluated the impact of vehicle-generated dust emissions on endangered plant physiology and growth, and identified salinity tolerance for an endangered inland marsh endemic. Explore this webpage to learn about current projects that provide essential guidance for informing management actions.
The Henderson Field Station supports research scientists leading projects in desert ecosystem restoration, genetics of iconic trees of the Mojave Desert, predator-prey studies on protected lands, and more. Select the next tab for a comprehensive summary of studies at this site.
Drawing a line in the sand: Effectiveness of off-highway vehicle management in California's Sonoran desert
Public land policies manage multiple uses while striving to protect vulnerable plant and wildlife habitats from degradation; yet the effectiveness of such policies are infrequently evaluated, particularly for remote landscapes that are difficult to monitor. We assessed the use and impacts of recreational vehicles on Mojave Desert washes (...Custer, Nathan; Defalco, Lesley A.; Nussear, Kenneth E.; Esque, Todd C.
The role of salinity tolerance and competition in the distribution of an endangered desert salt marsh endemic
Rare plants are often associated with distinctive soil types, and understanding why endemic species occur in unique environments is fundamental for their management. At Ash Meadows National Wildlife Refuge in southern Nevada, USA, we evaluated whether the limited distribution of endangered Amargosa niterwort (Nitrophila mohavensis) is explained by...DeFalco, Lesley; Scoles, Sara; Beamguard, Emily R.
Landscape genetic approaches to guide native plant restoration in the Mojave Desert
Restoring dryland ecosystems is a global challenge due to synergistic drivers of disturbance coupled with unpredictable environmental conditions. Dryland plant species have evolved complex life-history strategies to cope with fluctuating resources and climatic extremes. Although rarely quantified, local adaptation is likely widespread among these...Shryock, Daniel F.; Havrilla, Caroline A.; DeFalco, Lesley; Esque, Todd C.; Custer, Nathan; Wood, Troy E.
Yucca brevifolia fruit production, predispersal seed predation, and fruit removal by rodents during two years of contrasting reproduction
PREMISE OF THE STUDY: The distribution of Yucca brevifolia, a keystone species of the Mojave Desert, may contract with climate change, yet reproduction and dispersal are poorly understood. We tracked reproduction, seed predation, and fruit dispersal for two years and discuss whether Y. brevifolia is a masting species....Borchert, Mark I.; DeFalco, Lesley
Landscape genomics of Sphaeralcea ambigua in the Mojave Desert: a multivariate, spatially-explicit approach to guide ecological restoration
Local adaptation influences plant species’ responses to climate change and their performance in ecological restoration. Fine-scale physiological or phenological adaptations that direct demographic processes may drive intraspecific variability when baseline environmental conditions change. Landscape genomics characterize adaptive...Shryock, Daniel F.; Havrilla, Caroline A.; DeFalco, Lesley; Esque, Todd C.; Custer, Nathan; Wood, Troy E.
Desert tortoise use of burned habitat in the Eastern Mojave desert
Wildfires burned 24,254 ha of critical habitat designated for the recovery of the threatened Mojave desert tortoise (Gopherus agassizii) in southern Nevada during 2005. The proliferation of non-native annual grasses has increased wildfire frequency and extent in recent decades and continues to accelerate the conversion of tortoise habitat...Drake, Karla K.; Esque, Todd C.; Nussear, Kenneth E.; DeFalco, Lesley; Scoles, Sara; Modlin, Andrew T.; Medica, Philip A.
Direct and indirect effects of environmental variability on growth and survivorship of pre-reproductive Joshua trees, Yucca brevifolia Engelm (Agavaceae)
• Premise of study: Accurate demographic information about long-lived plant species is important for understanding responses to large-scale disturbances, including climate change. It is challenging to obtain these data from desert perennial plants because seedling establishment is exceptionally rare, and estimates of survival are...Esque, Todd C.; Medica, Phil A.; Shryock, Daniel F.; Defalco, Lesley A.; Webb, Robert H.; Hunter, Richard B.
Contrasting long-term survival of two outplanted Mojave Desert perennials for post-fire revegetation
Post-fire recovery of arid shrublands is typically slow, and planting greenhouse-raised seedlings may be a means of jump-starting this process. Recovery can be further accelerated by understanding the factors controlling post-planting survival. In fall 2007 and 2009, we outplanted seedlings of two contrasting native evergreen shrubs—fast-...Scoles-Sciulla, Sara J.; Defalco, Lesley A.; Esque, Todd C.
Life-history traits predict perennial species response to fire in a desert ecosystem
The Mojave Desert of North America has become fire-prone in recent decades due to invasive annual grasses that fuel wildfires following years of high rainfall. Perennial species are poorly adapted to fire in this system, and post-fire shifts in species composition have been substantial but variable across community types. To generalize across a...Shryock, Daniel F.; DeFalco, Lesley A.; Esque, Todd C.
Soil seed banks: preserving native biodiversity and repairing damaged desert shrublands
No abstract available.Defalco, Lesley A.; Esque, Todd C.
Estimating wildfire risk on a Mojave Desert landscape using remote sensing and field sampling
Predicting wildfires that affect broad landscapes is important for allocating suppression resources and guiding land management. Wildfire prediction in the south-western United States is of specific concern because of the increasing prevalence and severe effects of fire on desert shrublands and the current lack of accurate fire prediction tools....Van Linn, Peter F.; Nussear, Kenneth E.; Esque, Todd C.; DeFalco, Lesley A.; Inman, Richard D.; Abella, Scott R.
Short seed longevity, variable germination conditions, and infrequent establishment events provide a narrow window for Yucca brevifolia (Agavaceae) recruitment
PREMISE OF THE STUDY: The future of long-lived stand-forming desert plants such as Yucca brevifolia (Joshua tree) has come into question in light of climate variation and landscape-scale disturbances such as wildfire. Understanding plant establishment dynamics is important for mitigating the impacts of disturbances and promoting revegetation. •...Bryant, M.; Reynolds, J.; DeFalco, Lesley A.; Esque, Todd C.