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Sasha Reed

Research Ecologist

Contact Info


Short Biography

I am a scientist with the U.S. Geological Survey and a member of the Southwest Biological Science Center. My research interests are centered within the fields of biogeochemistry and ecosystem ecology. Currently, I study terrestrial ecosystems in Utah, Arizona, New Mexico, California, Colorado, Hawai’i, Puerto Rico, Bolivia, Perú, and Costa Rica. While my study sites and the methods I use are diverse, with each of my projects I strive to determine the dynamic controls over fundamental ecosystem processes with the ultimate goal of providing information to help maintain the desirable features of Earth’s ecosystems in a world that is rapidly changing.
 
Publications
Hiltbrunner, E, R Aerts, T Buhlmann, K Huss-Danell, B Magnusson, DD Myrold, SC Reed, BD Sigurdsson, C Korner (In press) Spatially robust estimates of biological N2 fixation imply substantial human alteration of the
     tropical nitrogen cycle. Oecologia.
 
Sullvian, BW, WK Smith, AR Townsend, MK Nasto, SC Reed, RL Chazdon, CC Cleveland (2014) Spatially robust estimates of biological N2 fixation imply substantial human alteration of the tropical nitrogen
     cycle. PNAS doi:10.1073/pnas.1320646111.

Sullvian, BW, S Alvarez-Clare, SC Castle, S Porder, SC Reed, L Schreeg, AR Townsend, CC Cleveland (2014) Assessing nutrient limitation in complex forested ecosystems: Alternatives to large-scale fertilization experiments. Ecology 95: 668-681.

Cleveland, CC, SC Reed, AB Keller, DR Nemergut, SP O'Neill, R Ostertag, PM Vitousek (2014) Litter quality versus soil microbial community controls over decomposition: a quantitative analysis. Oecologia 2110: 12733-12737.

Smith, WK, CC Cleveland, SC Reed, SW Running (2013) Agricultural conversion without external water and nutrient inputs reduces terrestrial vegetation productivity. Geophysical Research Letters. 10.1002/2013GL058857.

Cleveland, CC, BZ Houlton, WK Smith, AR Marklein, SC Reed, W Parton, SJ Del Gross, SW Running (2013) Patterns of new versus recycled primary production in the terrestrial biosphere. PNAS. 110: 12733-12737.

Reed, SC, AR Townsend, CC Cleveland (2013) Relationships between phosphorus, molybdenum and free-living nitrogen fixation in tropical rain forests: Results from observational and experimental analyses. Biogeochemistry: Synthesis & Emerging Ideas Section 114: 1-13.

Vitousek, PM, DNL Menge, SC Reed, CC Cleveland (2013) Biological nitrogen fixation: rates, pattern, and ecological controls in terrestrial ecosystems. Philosophical Transactions of the Royal Soceicty B. 368: 20130119.

Lu, X-T, SC Reed, Q Yu, NP He, ZW Wang, XG Han (2013) Convergent responses of nitrogen and phosphorus resorption to nitrogen inputs in a semi-arid grassland. Global Change Biology 19: 2775-2784.

Keville, MP, SC Reed, CC Cleveland (2013) Nitrogen cycling responses to mountain pine beetle disturbance in a high elevation Whitebark Pine ecosystem. PLoS One 8: e65004. doi:10.1371.

Zelikova, TJ, R Hufbauer, SC Reed, T Wertin, C Fetting, J Belnap. (2013) Eco-evolutionary responses of Bromus tectorum to climate change: Implications for biological invasions. Ecology & Evolution 3: 1384-1387.

Keller, AB, SC Reed, AR Townsend, CC Cleveland (2013) Effects of canopy tree species on belowground biogeochemistry in a lowland wet tropical forest. Soil Biology & Biochemistry 58: 61-69.

Wickings, K, AS Grandy, SC Reed, CC Cleveland (2012) The origin of litter chemical complexity during decomposition. Ecology Letters 15: 1180-1188.

Reed, SC, AR Townsend, CC Cleveland, EA Davidson (2012). Stoichiometric patterns in foliar nutrient resorpton across multiple scales. New Phytologist 196: 173-180.

Reed, SC, KK Coe, JP Sparks, DC Housman, TJ Zelikova, J Belnap (2012) Increased precipitation results in rapid moss mortality and altered fertility in a dryland ecosystem. Nature Climate Change 2: 752-755.

Wood, TE, MA Cavaleri, SC Reed (2012) Tropical forest carbon balance in a warmer world: a critical review spanning microbial- to ecosystem-scale processes. Biological Reviews 87: 912-927. 

Reed, SC, T. Wood  & M. Cavaleri (2012) Tropical forests in a warming world. New Phytologist 193: 27-29.

Wertin, TM, SL Phillips, SC Reed, J Belnap (2012) Elevated CO2 did not mitigate the effect of a short-term drought on biological soil crusts. Biology & Fertility of Soils 48: 797-805.

Smith, WK, CC Cleveland, SC Reed, NL Miller, SW Running (2012) Bioenergy potential of the United States constrained by satellite observations and existing productivity. Environmental Science & Technology 46: 3536-3544.

Reed, SC, CC Cleveland, AR Townsend (2011). Functional ecology of free-living nitrogen fixation: a contemporary review. Annual Review for Ecology and Systematics 42: 489-512. 

Reed, SC, PM Vitousek, CC Cleveland (2011) Are patterns in nutrient limitation belowground consistent with those aboveground: Results from a 4 million year chronosequence. Biogeochemistry 106: 323-336.

Cleveland, CC, AR Townsend, P Taylor, MMC Bustamante, G Chuyong, P Grierson, K Harms, B Houlton, A Marklein, W Parton, S Porder, SC Reed, et al. (2011) Relationships among net primary productivity, nutrients and climate in tropical rain forests: A pan-tropical analysis. Ecology Letters 14: 939-947. 

Schmidt SK, CC Cleveland, DR Nemergut, SC Reed, AJ King, P Sowell (2011) Estimating phosphorus availability for microbial growth in an emerging landscape. Geoderma 163: 135-140.

Wickings, K, AS Grandy, SC Reed, CC Cleveland (2011) Management intensity alters decomposition via biological pathways. Biogeochemistry 104: 365-379.

Reed, SC, AR Townsend, PG Taylor, CC Cleveland. (2011) Phosphorus Cycling in Tropical Forests Growing on Highly-Weathered Soils. In: (Buneman EK, A Oberson, E Forssard) Phosphorus In Action—Biological Processes in Soil Phosphorus Cycling. Springer Publishing Co. vol. 26, pp. 339-369.

Cleveland, CC, WR Wieder, SC Reed, AR Townsend (2010) Experimental drought in a wet tropical forest increases soil carbon dioxide losses to the atmosphere. Ecology 91: 2313-2323.

Reed, SC, AR Townsend, DR Nemergut, SK Schmidt, AR Townsend (2010) Scaling from molecules to ecosystems: Exploring controls over free-living nitrogen fixation in terrestrial systems. VDM Publishers, Saarbrucken Germany.

Reed, SC, AR Townsend, CC Cleveland, DR Nemergut (2010) Microbial community shifts influence patterns in tropical forest nitrogen fixation. Oecologia 164: 521-531.

Cleveland, CC, BZ Houlton, C Neill, SC Reed, AR Townsend, YP Wang (2010) Using indirect methods to constrain symbiotic nitrogen fixation rates: A case study from an Amazonian rain forest. Biogeochemistry 99: 1-13.

Sattin SR, CC Cleveland, E Hood, SC Reed, AJ King, MS Robeson, NL Ascarrunz, DR Nemergut (2009) Functional shifts in perhumid, recently-deglaciated soils do not correlate with shifts in soil bacterial community composition. The Journal of Microbiology 47: 673-681.

Costello, EK, SRP Halloy, SC Reed, P Sowell, SK Schmidt (2009) Fumarole-supported islands of biodiversity within a hyper-arid, high-elevation landscape on Socompa Volcano, Puna de Atacama, Andes. Applied & Environmental Microbiology 75: 735-747.

Freeman, KR, MY Pescador, SC Reed, EK Costello, MS Robeson, SK Schmidt (2009) Soil CO2 flux and photoautotrophic community composition in high-elevation, ‘barren’ soil. Environmental Microbiology 11: 674-686. 

Schmidt, SK, SC Reed, DR Nemergut, AS Grandy, CC Cleveland, MN Weintraub, AW Hill, EK Costello, AF Meyer, AM Martin, JC Neff (2008) The earliest stages of primary succession in high-elevation (5000 meters above sea-level), recently deglaciated soils. Proceedings of the Royal Society B: Biological Sciences 275: 2793-2802. 

Reed, SC, CC Cleveland, AR Townsend (2008) Tree species control rates of free-living nitrogen fixation in a tropical rain forest. Ecology 89: 2924-2934.

Reed, SC, CC Cleveland, AR Townsend (2007) Controls over leaf litter and soil nitrogen fixation in two lowland tropical rain forests. Biotropica 39: 585-592.

Schmidt, SK, EK Costello, DR Nemergut, CC Cleveland, SC Reed, MN Weintraub, AF Meyer, AM Martin (2007) Microbial turnover and seasonal succession drive biogeochemical cycles in the alpine. Ecology 88: 1379-1385.

Reed, SC, TR Seastedt, CM Mann, KN Suding, AR Townsend (2007) Phosphorus fertilization stimulates nitrogen fixation and increases inorganic nitrogen concentrations in a restored prairie. Applied Soil Ecology 36: 238-242.                          

Cleveland, CC, SC Reed, AR Townsend (2006) Nutrient regulation of organic matter decomposition in a tropical rain forest. Ecology 87: 492-503.

Bowker, MA, SC Reed, J Belnap, SL Phillips (2002) Temporal variation in community composition, pigmentation, and Fv/Fm in desert cyanobacterial soil crusts. Microbial Ecology 43: 13-25.

Reed, SC, GJ Capitosti, Z Zhu & DA Modarelli (2001) Photochemical generation and matrix-isolation detection of dimethylvinylidene. Journal of Organic Chemistry 66: 287-291.

Reed, SC, DA Modarelli (1996) Conformational effects on the excited state 1,2-hydrogen migration in alkyldiazomethanes. Tetrahedron Letters 37: 7209-7212.




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My Science Topics


Science Topic
Subtopic
Ecology and Environmentbiodiversity
Ecology and Environmentdeserts
Ecology and Environmentecological processes
Ecology and Environmentecosystem functions
Ecology and Environmentecosystems
Ecology and Environmentforests
Ecology and Environmentgrasslands
Ecology and Environmenthabitat alteration
Ecology and Environmentshrublands
Environmental Issuesland use change
Environmental Issueswater quality
Natural Hazardsdroughts
Natural Hazardsfire control
Natural Resourcesforest resources
Natural Resourcesnatural resource management
Natural Resourcessoil resources
Natural Resourceswater resources



My USGS Science Strategy Areas

Understanding Ecosystems & Predicting Ecosystems Change

The Role of Environment and Wildlife in Human Health

Climate Variability & Change

Energy & Minerals for America's Future

Some of My Current Research Interests

Image of Current Focus for Some of My Current Research Interests
  • Climate change and its effects on terrestrial ecosystems: Climate change is predicted to significantly alter terrestrial ecosystems around the globe, with the potential to negatively affect a suite of ecosystem services. These changes also have the potential to create feedbacks that could alter the course of future climate change. I have a variety of projects - ranging from climate manipulations in southwestern U.S. drylands to elevation gradients in Hawai'ian forests - aimed at elucidating how terrestrial ecosystems will respond to climate change. In particular, I am interested in understanding the mechanisms behind observed ecosystem changes, with the overarching goal of not only bettering our understanding these systems, but of improving our predictions of future ecosystem function as well. The ability to span spatial and temporal scales is particularly important, and  I work closely with a number of collaborators in order to try and reach these research goals.
  • Biofuels development in the southwestern U.S.: Alternative energy offers a suite of potential benefits for lowering greenhouse gas emissions, adding to our economy, and reducing our dependence upon foreign oil. In particular, due to high solar energy and newer biofuel crop alternatives, bioenergy development in the southwestern U.S. could represent a significant source of biofuel energy. However, we know little about the potential for this region to act as an efficient biofuel energy source; what resources this development would require (irrigation, fertilization, etc.); what effects it would have on overall greenhouse gas budgets and local plant and animal communities; and what ecosystem consequences might follow from this development. I am currently part of a group conducting a multi-disciplinary assessment of biofuels in the southwestern U.S., integrating modeling efforts with field and laboratory assessments.
  • Invasive species, beetle infestation and ecosystem consequences: Beetles are affecting plant communities across the western U.S., and a relatively recent release of the Tamarisk Beetle (Diorhabda elongata) has caused major Tamarisk (Tamarix spp.) defoliation events along western river corridors. Understanding how this defoliation and likely death of Tamarisk will affect future riparian communities is at the heart of this research. I am part of a multi-Center USGS team working to assess the consequences of defoliation on exotic plant invasion, biogeochemical cycling, hydrology, plant-water interactions, and bird and mammal communities. The central goals are to understand what aspects of defoliation and mortality help determine the trajectory of future community composition and what management approaches might take advantage of this understanding to reduce exotic plant invasion.
  • Nitrogen deposition in the Four Corners Region, USA: Nitrogen deposition in the western U.S. has repeatedly been linked with lowered air quality, increased greenhouse gas emissions, altered plant community composition, reduced water quality, and modified fire regimes. Using modeling and field approaches in Arches, Canyonlands, and Mesa Verde National Parks, I am part of a research team investigating how increased nitrogen deposition in the Four Corners region could affect plant and soil communities and their function. In particular, we are asking questions about how nitrogen deposition could affect exotic plant invasion, the frequency of natural fire regimes, soil stability, greenhous gas emissions, water and air quality, and feedbacks between nitrogen deposition and multiple other aspects of terrestrial biogeochemical cycling.

Links

Image of Links

Southwest Biological Science Center: http://sbsc.wr.usgs.gov/

Canyonlands Research Station: http://sbsc.wr.usgs.gov/crs/

Canyonlands Research Center: http://www.canyonlandsresearchcenter.org

USGS Climate Monitoring-American Drylands (includes Canyonlands): http://data.usgs.gov/climateMonitoring/region/show?region=americandrylands


Contact Information

Sasha Reed
2282 2290 S WEST RESOURCE BLVD
Moab, UT 84532
screed@usgs.gov
435-719-2334
435-719-2350 - Fax
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