Dr. Sasha Reed is an ecologist focused on understanding how our planet's ecosystems work and what factors determine the services they provide. The study sites and methods Sasha uses are diverse, and with each of her projects she strives to provide scientific information that helps our nation address challenges, solve problems, and maximize opportunities.
Sasha seeks to provide useful information for land managers, policy-makers, and the general public. Sasha uses both basic and applied scientific approaches to improve our understanding of the fundamental controls over ecosystems, to determine how these systems respond to change, and to explore solutions for addressing relevant problems. Sasha works closely with a range of collaborators - including federal agency partners (BLM, NPS, DOE, DoD, BIA, USFS, USFWS) - in designing research studies, conducting information and technology transfer, and performing outreach activities. Some of her primary research interests include understanding how drought and increasing temperatures affect ecosystems, exploring a diversity of energy options for meeting national demand, assessing the consequences of exotic plant invasion and ways to combat them, and establishing novel management options for increased effectiveness and efficiency in restoration and reclamation. Sasha attempts to conduct research that is innovative, collaborative, and useful.
Education
Ph.D. in Biogeochemistry, the University of Colorado at Boulder (August 2002-May 2008)
- Department of Ecology & Evolutionary Biology and Institute of Arctic & Alpine Research (INSTAAR), Boulder, CO. Co-advised by Alan R. Townsend and Steve K. Schmidt.
B.A. in Organic Chemistry, Colgate University (August 1993-May 1997)
- Department of Chemistry, Hamilton, NY. Graduated magna cum laude. Advised by David A. Modarelli.
Honors and Fellowships
- Elected Member-At-Large, Ecological Society of America (ESA). August 2020-August 2022.
- Ecological Society of America (ESA) Early Career Fellow. March 2016.
- Presidential Early Career Award for Scientists and Engineers (PECASE). October 2011.
- Star Award, Department of the Interior. October 2010, May 2000.
- Graduate Student Research and Creative Works Award, University of Colorado at Boulder. May 2008.
- USGS Student Career Experience Program (SCEP) Fellowship. June-August of 2006 & 2007.
- Student Policy Award, Ecological Society of America (ESA). September 2006.
- AAAS Program for Excellence in Science. August 2006.
- Lawrence Award. April 1996.
- Phi Ea Sigma University Honor Society Awarded Membership. April 1994-May 1997.
- Phi Eta Sigma Aid Committee Selected Board Member. September 1995-May 1997.
- Barry Goldwater Award Nominee. November 1994.
Professional Experience
Research Ecologist, USGS, Moab, UT, May 2008-present.
Research Ecologist, USGS-SCEP Program, Moab, UT, 2005-2007 summers only.
Fellow, NSF Graduate Research Fellowship. Awarded April 2003; deferred until September 2005-May 2008.
Fellow, NSF IGERT Fellowship, Carbon Climate and Society Initiative (CCSI). August 2003-August 2005.
Science and Products
Diverse data to improve Southwest fire forecasts: Joining novel remote sensing, post-fire dynamics, and intra-annual precipitation patterns
Using a multi-scale approach to synthesize measurements and models of C4 photosynthesis
GrassCast: A multi-agency tool using remote sensing, modeling, and on-the-ground science to forecast grassland productivity in the Southwest
Learning From the Past and Planning for the Future: Experience-Driven Insight Into Managing for Ecosystem Transformations Induced by Drought and Wildfire
Determining Successful Management and Restoration Strategies for Pinyon-Juniper Communities in the Face of Changing Climate and Wildfire
Implementing a Grassland Productivity Forecast Tool for the U.S. Southwest
Long-Term Vegetation Change on the Colorado Plateau
Novel multi‐scale synthesis of nitrogen fixation rates and drivers across the terrestrial biosphere
Southwest Energy Development and Drought (SWEDD)
Southwestern Riparian Zones, Tamarisk Plants, and the Tamarisk Beetle
Biofuels in the Southwest
How Increasing Temperatures Affect Tropical Forests
Ecological property data and experimental lab incubation results from a long-term nitrogen deposition simulation experiment in three semi-arid grasslands, Arches National Park, Utah, USA, 2013-2019
Data and software code from two long-term experiments (1996-2011 and 2005-2018) at three sites on the Colorado Plateau of North America
CO2 concentrations and microbial biomass data derived from incubation experiments on soils collected at Arches National Park in 2017 and 2018
Riparian vegetation, topography, and ground cover constituents along the Upper Colorado River near Moab, UT (2010-2017)
Erosion and Rehabilitation Data, Bandelier National Monument, New Mexico, USA
Environmental filtering controls soil biodiversity in wet tropical ecosystems
Biocrusts mediate a new mechanism for land degradation under a changing climate
Satellite solar-induced chlorophyll fluorescence and near-infrared reflectance capture complementary aspects of dryland vegetation productivity dynamics
Mapping biological soil crusts in a Hawaiian dryland
Quantifying the influence of different biocrust community states and their responses to warming temperatures on soil biogeochemistry in field and mesocosm studies
Climatic controls on soil carbon accumulation and loss in a dryland ecosystems
Vertical movement of soluble carbon and nutrients from biocrusts to subsurface mineral soils
Experimental warming and its legacy effects on root dynamics following two hurricane disturbances in a wet tropical forest
Response to “Connectivity and pore accessibility in models of soil carbon cycling”
Plant growth and biocrust-fire interactions across five North American deserts
Responses of soil extracellular enzyme activities and bacterial community composition to seasonal stages of drought in a semiarid grassland
Experimental warming across a tropical forest canopy height gradient reveals minimal photosynthetic and respiratory acclimation
Pre-USGS Publications
Science and Products
- Science
Filter Total Items: 14
Diverse data to improve Southwest fire forecasts: Joining novel remote sensing, post-fire dynamics, and intra-annual precipitation patterns
Fire has increased dramatically across the western U.S. and these increases are expected to continue. With this reality, it is critical that we improve our ability to forecast the timing, extent, and intensity of fire to provide resource managers and policy makers the information needed for effective decisions. For example, an advanced, spatially-explicit prediction of the upcoming fire season wouUsing a multi-scale approach to synthesize measurements and models of C4 photosynthesis
Plants convert carbon dioxide into sugars for food during photosynthesis, and this provides food for all animal life. However, photosynthesis is inhibited when a plant’s enzymes use oxygen instead of carbon dioxide. To avoid this use of oxygen, some plants developed a photosynthetic adaptation – called C4 photosynthesis – to concentrate carbon dioxide around the enzymes. While less than 5% of plan...GrassCast: A multi-agency tool using remote sensing, modeling, and on-the-ground science to forecast grassland productivity in the Southwest
Rangeland ecosystems are one of the largest single providers of agro-ecological services in the U.S. The plant growth of these rangelands helps determine the amount of forage available for our livestock and for wildlife, as well as information about fire likelihood and restoration opportunities. However, every spring, ranchers and other rangeland managers face the same difficult challenge —tryingLearning From the Past and Planning for the Future: Experience-Driven Insight Into Managing for Ecosystem Transformations Induced by Drought and Wildfire
Drought and wildfire pose enormous threats to the integrity of natural resources that land managers are charged with protecting. Recent observations and modeling forecasts indicate that these stressors will likely produce catastrophic ecosystem transformations, or abrupt changes in the condition of plants, wildlife, and their habitats, in regions across the country in coming decades. In this pDetermining Successful Management and Restoration Strategies for Pinyon-Juniper Communities in the Face of Changing Climate and Wildfire
Pinyon-juniper woodlands are important ecosystems in the western U.S. that provide numerous critical environmental, economic, and cultural benefits. For example, pinyon pines are a significant cultural resource for multiple Native American Tribes and provide necessary habitat for plants and wildlife (including at risk species, such as the pinyon-jay). Despite their importance, stress put on pinyonImplementing a Grassland Productivity Forecast Tool for the U.S. Southwest
Rangeland systems are some of our nation’s largest providers of agro-ecological services, sustaining plant productivity that is highly variable across seasons and years. Although the ability to predict the upcoming growing season’s rangeland productivity would have enormous economic and management value – such as for making decisions about cattle stocking rates, fire, restoration, and wildlife – t...Long-Term Vegetation Change on the Colorado Plateau
The Colorado Plateau, centered around the four corners area of the Southwest, and includes much of Arizona, Utah, Colorado, and New Mexico, is a large and important component of U.S. drylands. This important home to mountains, desert basins, dramatic canyons, and arid woodlands and grasslands is also one of North America’s most rapidly warming hot spots, with rates of warming of up to 2-3° C...Novel multi‐scale synthesis of nitrogen fixation rates and drivers across the terrestrial biosphere
Biological nitrogen fixation (BNF) is a critical biogeochemical process that converts inert atmospheric N2 gas into biologically usable forms of the essential nutrient nitrogen. A variety of free-living and symbiotic organisms carry out BNF, and in most regions worldwide, BNF is the largest source of nitrogen that fuels terrestrial ecosystems. As a result, BNF has far reaching effects on ecosystemSouthwest Energy Development and Drought (SWEDD)
Deserts of the southwestern US are replete with oil and gas deposits as well as sites for solar, wind, and geothermal energy production. In the past, many of these resources have been too expensive to develop, but increased demand and new technologies have led to an increase in exploration and development. However, desert ecosystems generally have low resilience to disturbance. More frequent...Southwestern Riparian Zones, Tamarisk Plants, and the Tamarisk Beetle
Introductions of bio-control beetles (genus Diorhabda) are causing defoliation and dieback of exotic Tamarix spp. in riparian zones across the western U.S., yet the factors that determine the plant communities that follow Tamarix decline are poorly understood. In particular, Tamarix-dominated soils are often higher in nutrients, organic matter, and salts than nearby soils, and these soil...Biofuels in the Southwest
Concerns about energy security and rising greenhouse gas emissions have stimulated an unprecedented increase in the push for alternative energy use, including the use of plant biomass as a source of renewable energy (bioenergy). However, meeting alternative energy goals, while also meeting food demands and mitigating potential detrimental effects of industrialized agriculture, has emerged as a...How Increasing Temperatures Affect Tropical Forests
Tropical forests take in and store more carbon than any other biome in the world, but increasing temperatures may pose a threat to this invaluable service. This research aims to explore how temperature affects key tropical forest functions, such as plant photosynthesis and soil respiration. To do this, the Tropical Responses to Altered Climate Experiment (TRACE) project will use infrared heating... - Data
Ecological property data and experimental lab incubation results from a long-term nitrogen deposition simulation experiment in three semi-arid grasslands, Arches National Park, Utah, USA, 2013-2019
These data were compiled to understand the responses of dryland ecosystem properties to long-term simulated atmospheric nitrogen deposition. Objective(s) of our study were to uncover any changes in soil biogeochemistry and ecosystem properties to long-term nitrogen amendments. These data represent ecosystem property data compiled over the nine-year history of a nitrogen deposition simulation experData and software code from two long-term experiments (1996-2011 and 2005-2018) at three sites on the Colorado Plateau of North America
These data were compiled to examine how climate change affects biocrust recovery from both physical and climate-induced disturbance. Objective(s) of our study were to uncover the trajectory of biological soil crust communities and soil stability following distrubance and under warming. These data represent biological soil crust surveys under 5 treatments at three sites. These data were collected aCO2 concentrations and microbial biomass data derived from incubation experiments on soils collected at Arches National Park in 2017 and 2018
These data were compiled to improve our understanding of how water, carbon (C), nitrogen (N), and phosphorus (P) interact to regulate below ground carbon cycling. Objective(s) of our study were to evaluate how soil heterotrophic carbon cycling responded to inputs of water, C, N, and P individually and interactively on the Colorado Plateau. These data represent soil microbial and CO2 respiration reRiparian vegetation, topography, and ground cover constituents along the Upper Colorado River near Moab, UT (2010-2017)
The data release presents observations of riparian vegetation, topography, and ground cover in two river reaches of the Upper Colorado River within a river segment extending 208 river kilometers (rkm), from near the Colorado/Utah border to the confluence of the Green River. Methods included field observations and analysis of the plant community five times over eight years in the fall of 2010, 2012Erosion and Rehabilitation Data, Bandelier National Monument, New Mexico, USA
These data were compiled for a restoration experiment testing the regenerative and functional response of biocrust inoculum reintroduced to a field setting. Regenerative traits measured included measurements of biocrust cover, chlorophyll content, and the roughness of the soil surface. Functional traits measured included nutrient cycling and soil stability. Additionally, these data were compiled f - Publications
Filter Total Items: 143
Environmental filtering controls soil biodiversity in wet tropical ecosystems
The environmental factors controlling soil biodiversity along resource gradients remain poorly understood in wet tropical ecosystems. Aboveground biodiversity is expected to be driven by changes in nutrient availability in these ecosystems, however, much less is known about the importance of nutrient availability in driving soil biodiversity. Here, we combined a cross-continental soil survey acrosBiocrusts mediate a new mechanism for land degradation under a changing climate
Global concerns for desertification have focused on the slow recovery of extensive and expanding drylands following disturbance, which may be exacerbated by climate change. Biological soil crusts (biocrusts) are photosynthetic soil communities found in drylands worldwide, which are central to the stability and resilience of dryland ecosystems, but vulnerable to global change. Here we use multipleSatellite solar-induced chlorophyll fluorescence and near-infrared reflectance capture complementary aspects of dryland vegetation productivity dynamics
Mounting evidence indicates dryland ecosystems play an important role in driving the interannual variability and trend of the terrestrial carbon sink. Nevertheless, our understanding of the seasonal dynamics of dryland ecosystem carbon uptake through photosynthesis [gross primary productivity (GPP)] remains relatively limited due in part to the limited availability of long-term data and unique chaMapping biological soil crusts in a Hawaiian dryland
Historical and ongoing land use patterns in the Hawaiian Islands have degraded the Islands’ drylands, causing erosion and detrimentally affecting adjacent coastal marine ecosystems. Biological soil crust (biocrust) communities have been shown to increase soil stability in drylands worldwide, but their efficacy in mitigating soil erosion in Hawaiian drylands is largely unknown. Using a combinationQuantifying the influence of different biocrust community states and their responses to warming temperatures on soil biogeochemistry in field and mesocosm studies
Biocrusts influence soil biogeochemistry by fixing carbon (C) and nitrogen (N) and through leachate inputs to soils. Functional rates can vary among biocrust community states and in response to edaphic properties, heterotrophic microbial activity, and global change. Using soils and biocrusts from the Colorado Plateau, Utah, USA, we aimed to quantify the influence of early-successional (ES) and latClimatic controls on soil carbon accumulation and loss in a dryland ecosystems
Arid and semiarid ecosystems drive year-to-year variability in the strength of the terrestrial carbon (C) sink, yet there is uncertainty about how soil C gains and losses contribute to this variation. To address this knowledge gap, we embedded C-depleted soil mesocosms, containing litter or biocrust C inputs, within an in situ dryland ecosystem warming experiment. Over the course of one year, chanVertical movement of soluble carbon and nutrients from biocrusts to subsurface mineral soils
Dryland ecosystems can be constrained by low soil fertility. Within drylands, the soil nutrient and organic carbon (C) cycling that does occur is often mediated by soil surface communities known as biological soil crusts (biocrusts), which cycle C and nutrients in the top ca. 0–2 cm of soil. However, the degree to which biocrusts are influencing soil fertility and biogeochemical cycling in deeper,Experimental warming and its legacy effects on root dynamics following two hurricane disturbances in a wet tropical forest
Tropical forests are expected to experience unprecedented warming and increases in hurricane disturbances in the coming decades; yet, our understanding of how these productive systems, especially their belowground component, will respond to the combined effects of varied environmental changes remains empirically limited. Here we evaluated the responses of root dynamics (production, mortality, andResponse to “Connectivity and pore accessibility in models of soil carbon cycling”
Here we respond to Baveye and colleagues' recent critique of our PROMISE model, describing how this new framework significantly advances our understanding of soil spatial heterogeneity and its influence on organic matter transformations.Plant growth and biocrust-fire interactions across five North American deserts
Biological soil crusts (biocrusts) are communities predominately comprised of lichens, bryophytes, fungi, algae, and cyanobacteria that form at the soil surface in dryland ecosystems worldwide. Biocrusts can influence the vascular plant community by altering surface hydrology, nutrient cycling, and the availability of microsites suitable for germination. Fire frequency has increased in many drylanResponses of soil extracellular enzyme activities and bacterial community composition to seasonal stages of drought in a semiarid grassland
Extreme drought can strongly impact belowground communities and biogeochemical processes, including soil microbial community composition and extracellular enzyme activities (EEAs), which are considered key agents in ecosystem carbon (C) and nutrient cycling. However, our understanding of how seasonal timing of drought during the growing season affects soil microbial communities and their activityExperimental warming across a tropical forest canopy height gradient reveals minimal photosynthetic and respiratory acclimation
Tropical forest canopies cycle vast amounts of carbon, yet we still have a limited understanding of how these critical ecosystems will respond to climate warming. We implemented in situ leaf-level + 3°C experimental warming from the understory to the upper canopy of two Puerto Rican tropical tree species, Guarea guidonia and Ocotea sintenisii. After approximately 1 month of continuous warming, wePre-USGS Publications
Sullivan, B.W., Alvarez-Clare, S., Castle, S.C., Porder, S., Reed, S.C., Schreeg, L., Townsend, A.R. and Cleveland, C.C., 2014. Assessing nutrient limitation in complex forested ecosystems: alternatives to large‐scale fertilization experiments. Ecology, 95(3), pp.668-681.Cleveland, C.C., Houlton, B.Z., Smith, W.K., Marklein, A.R., Reed, S.C., Parton, W., Del Grosso, S.J. and Running, S.W., 2013. Patterns of new versus recycled primary production in the terrestrial biosphere. Proceedings of the National Academy of Sciences, 110(31), pp.12733-12737.Reed, S.C., Cleveland, C.C. and Townsend, A.R., 2013. Relationships among phosphorus, molybdenum and free-living nitrogen fixation in tropical rain forests: results from observational and experimental analyses. Biogeochemistry, 114(1-3), pp.135-147.Wickings, K., Grandy, A.S., Reed, S.C. and Cleveland, C.C., 2012. The origin of litter chemical complexity during decomposition. Ecology Letters, 15(10), pp.1180-1188.Reed, S.C., 2008. Scaling from molecules to ecosystems: controls over free-living nitrogen fixation in terrestrial ecosystems. ProQuest.Sattin, S.R., Cleveland, C.C., Hood, E., Reed, S.C., King, A.J., Schmidt, S.K., Robeson, M.S., Ascarrunz, N. and Nemergut, D.R., 2009. Functional shifts in unvegetated, perhumid, recently-deglaciated soils do not correlate with shifts in soil bacterial community composition. The Journal of Microbiology, 47(6), pp.673-681.Costello, E.K., Halloy, S.R., Reed, S.C., Sowell, P. and Schmidt, S.K., 2009. Fumarole-supported islands of biodiversity within a hyperarid, high-elevation landscape on Socompa Volcano, Puna de Atacama, Andes. Applied and Environmental Microbiology, 75(3), pp.735-747.Freeman, K.R., Pescador, M.Y., Reed, S.C., Costello, E.K., Robeson, M.S. and Schmidt, S.K., 2009. Soil CO2 flux and photoautotrophic community composition in high‐elevation,‘barren’soil. Environmental Microbiology, 11(3), pp.674-686.Schmidt, S.K., Reed, S.C., Nemergut, D.R., Grandy, A.S., Cleveland, C.C., Weintraub, M.N., Hill, A.W., Costello, E.K., Meyer, A.F., Neff, J.C. and Martin, A.M., 2008. The earliest stages of ecosystem succession in high-elevation (5000 metres above sea level), recently deglaciated soils. Proceedings of the Royal Society of London B: Biological Sciences, 275(1653), pp.2793-2802.Reed, S.C., Cleveland, C.C. and Townsend, A.R., 2008. Tree species control rates of free-living nitrogen fixation in a tropical rain forest. Ecology, 89(10), pp.2924-2934.Reed, S.C., Cleveland, C.C. and Townsend, A.R., 2007. Controls over leaf litter and soil nitrogen fixation in two lowland tropical rain forests. Biotropica, 39(5), pp.585-592.Schmidt, S.K., Costello, E.K., Nemergut, D.R., Cleveland, C.C., Reed, S.C., Weintraub, M.N., Meyer, A.F. and Martin, A.M., 2007. Biogeochemical consequences of rapid microbial turnover and seasonal succession in soil. Ecology, 88(6), pp.1379-1385.Reed, S.C., Seastedt, T.R., Mann, C.M., Suding, K.N., Townsend, A.R. and Cherwin, K.L., 2007. Phosphorus fertilization stimulates nitrogen fixation and increases inorganic nitrogen concentrations in a restored prairie. Applied Soil Ecology, 36(2), pp.238-242.Cleveland, C.C., Reed, S.C. and Townsend, A.R., 2006. Nutrient regulation of organic matter decomposition in a tropical rain forest. Ecology, 87(2), pp.492-503.Bowker, M.A., Reed, S.C., Belnap, J. and Phillips, S.L., 2002. Temporal variation in community composition, pigmentation, and Fv/Fm of desert cyanobacterial soil crusts. Microbial Ecology, 43(1), pp.13-25.Reed, S.C., Capitosti, G.J., Zhu, Z. and Modarelli, D.A., 2001. Photochemical generation and matrix-isolation detection of dimethylvinylidene. The Journal of Organic Chemistry, 66(1), pp.287-299.Reed, S.C. and Modarelli, D.A., 1996. Conformational effects on the excited state 1, 2-hydrogen migration in alkyldiazomethanes. Tetrahedron Letters, 37(40), pp.7209-7212.