Daniela Cusack
dcusack[AT]nature.berkeley.edu
Personal webpage,
CV
I am interested in global change and the interactions of ecosystem carbon and nitrogen cycles. I am
doing my dissertation research on the effects of nitrogen deposition on carbon and nitrogen cycling in tropical forests.
I am currently working in Puerto Rico on long-term nitrogen deposition plots
established by Bill McDowell from the University of New Hampshire. My main focus is the response of soil carbon storage and
turnover to chronic nitrogen ammendments. Another project of mine is investigating how elevated nitrogen affects
biological nitrogen fixation in the soil, forest floor, and forest canopies. I
finished my Master's in Environmental Science at the Yale
School of Forestry and Environmental Studies. My Master's project with
Dr. Florencia Montagnini was studying the regeneration of native forest
species on tropical plantations. In Costa Rica, plantations have been
used as a reforestation method, and I investigated the success of
different timber species at recruiting understory regeneration in
Sarapiquí, Costa Rica. Previously, I was on a Fulbright Scholarship in
Costa Rica from 1999-2000, studying the political and ecological impacts
of ecotourism. I graduated with a B.A in Latin American Studies from
Wesleyan University, CT in 1999. My honors thesis at Wesleyan was on
agricultural extension and the success of microfinance projects in
Southern Chile.
Publications:
Cusack, D. F., W. W. Chou, W. H. Yang, M. E. Harmon, W. L. Silver, the
LIDET team (2008). Controls on Long-Term Root and Leaf Litter Decomposition
in Neotropical Forests. Global Change Biology, doi:
10.1111/j.1365-2486.2008.01781.x.
Sinsabaugh, R. L., Lauber, C. L., Weintraub, M., Ahmed, B., Allison, S. D.,
Crenshaw, C., Contosta, A. R., Cusack, D., Frey, S., Gallo, M. E., Gartner,
T. B., Hobbie, S. E., Holland, K., Keeler, B. L., Powers, J. S., Stursova,
M., Takacs-Vesbach, C., Waldrop, M., Wallenstein, M., Zak, D. R., Zeglin, L.
H. (2008).
Stoichiometry of Soil Enzyme Activity at Global Scale. Ecology
Letters, 11: 1252-1264.
Marin-Spiotta, E., D. F. Cusack, R. Ostertag, and W. Silver (2008).
“Trends
in Above and Belowground Carbon with Forest Regrowth After Agricultural
Abandonment in the Neotropics.” Pp. 22-72. In: Post Agricultural Succession
in the Neotropics. R.W. Myster, Ed. Springer, New York, NY.
Chacón, N., W. Silver, E. Dubinsky and D. Cusack (2006).
Iron Reduction and
Phosphorous Solubilization in Humid Tropical Forest Soils: The Roles of
Labile Carbon Pools and an Electron Shuttle Compound. Biogeochemistry
78(1): 67-84.
Cusack, D., and L. Dixon, 2006. Community-Based Ecotourism and
Sustainability: Cases in Bocas del Toro Province, Panama and Talamanca,
Costa Rica. Journal of Sustainable Forestry, 22(1/2):157.
pp. 157-163 pp. 164-173 pp. 174-182
Montagnini, F., D. Cusack, B. Petit, and M. Kanninen, 2005.
Environmental Services of Native Tree Plantations and Agroforestry
Systems in Central America. Journal of Sustainable Forestry 21(1): 51-67.
Cusack, D.F., and F. Montagnini, 2004.
The Role of Native Species
Plantations in Recovery of Understory Woody Diversity in Degraded
Pasturelands of Costa Rica. Forest Ecology and Management 188:1-15.
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Steven Hall
stevenhall[AT]berkeley.edu
I’m a first year PhD student in the Silver lab. At Berkeley, I hope
to explore mechanisms controlling trace gas emissions and carbon
accumulation in low-redox environments, with the hope of influencing
ecosystem management strategies designed to mitigate greenhouse gas
production. Much of my previous research has centered on the
restoration of temperate and neotropical wetlands, where I evaluated
impacts of altered disturbance regimes on plant communities and
documented the potential of indigenous management to restore degraded
systems. This led to an MS degree at the University of Wisconsin,
advised by Dr. Joy Zedler in collaboration with Dr. Roberto Lindig at
UNAM-CIEco in Mexico. Inevitably, this work in wetland restoration
piqued my interest in soil biogeochemical processes. Currently, I’m
keeping my feet dry while working at the earth’s arid extreme,
testing whether soils from Chile’s Atacama desert can be stimulated
to produce trace gases. I expect to be back in the muck before too
long, however.
Hall, S.J., R. Lindig-Cisneros, and J.B. Zedler. 2008. Does
harvesting sustain diversity in central Mexican wetlands? Wetlands
28:776-792.
Hall, S.J., and J.B. Zedler. In Press. Constraints on sedge meadow
self-restoration in urban wetlands. Restoration Ecology.
Hall, S.J. In Press. Invasive species datasheets for Typha x glauca
and Typha domingensis. CABI Invasive Species Compendium. Centre for
Agricultural Bioscience International, Wallingford, UK.
Smith, S. D., P. R. Izquierdo S., S. J. Hall and D. A. Baum. In
Press. Comparative pollination biology of sympatric and allopatric
Andean Iochroma (Solanaceae). Annals of the Missouri Botanical Garden.
Hall, S.J. In Review. Cultural disturbances and local ecological
knowledge mediate cattail invasion in Lake Pátzcuaro, México.
Marissa Lafler
mlafler[AT]nature.berkeley.edu
Marissa is the lab manager.
Dan Liptzin
liptzin[AT]nature.berkeley.edu
I am a postdoc in the Silver group studying the role of oxygen in controlling nutrient cycling in tropical forests in Puerto Rico. Specifically, I am investigating how iron cycling (oxidation and reduction) regulates phosphorus availability and trace gas production both low elevation rain forest and cloud forest soils. The results so far suggest that oxygen concentrations are very dynamic in these soils and that the iron reduction can lead to increases in microbial phosphorus immobilization. My dissertation at the University of Colorado revolved around the hypothesis that tree-wind interactions may cause treeline to be a hotspot for atmospheric deposition and nutrient inputs. Two of the most interesting results were that 1) spatial patterns were predictable at multiple scales, but the differences upwind and downwind of individual trees were as great as the difference between forest and tundra and 2) snow depth was not a major control on soil properties. Overall, I am broadly interested in the biotic and abiotic controls on ecosystem function and how global changes are altering ecosystems.
Publications
Liptzin, D. and T.R. Seastedt. Patterns of snow, dust, and soil nutrients at multiple scales in the forest-alpine tundra ecotone of Niwot Ridge, Colorado. Submitted to JGR-Biogeosciences.
Liptzin, D., D. Helmig, M.W. Williams, B. Seok, G. Filippa, K. Chowanski, J. Hueber. (In revision) Process-level controls on CO2 fluxes from a seasonally snow-covered subalpine meadow soil, Niwot Ridge Colorado. Biogeochemistry.
Seok, B., M.W. Williams, D. Helmig, D. Liptzin, K. Chowanski, and J. Hueber. (In revision) An automated system for continuous measurements of trace gas fluxes through snow: an evaluation of the gas diffusion method at a subalpine forest site, Niwot Ridge, Colorado. Biogeochemistry.
Filippa, G., M. Freppaz, D. Liptzin, B. Seok, K. Chowanski, B. Hall, D. Helmig, and M.W. Williams. Winter and summer nitrous oxide and nitrogen oxides fluxes from a seasonally snow-covered. (In revision) Biogeochemistry.
Miller, M.P., D.M. McKnight, J.D. Cullis, A. Greene, K. Vietti, and D. Liptzin. (In revision) Factors controlling streambed coverage of Didymosphenia geminata in two regulated streams in the Colorado Front Range. Hydrobiologia
Flanagan, C.M., D.M. McKnight, D. Liptzin, M.W. Williams, and M.P. Miller. Response of the Phytoplankton Community in an Alpine Lake to Drought Conditions:Colorado Rocky Mountain Front Range, U.S.A.(In press) Arctic, Antarctic, and Alpine Research.
Malanson, G.P., D.R. Butler, D. B. Fagre, S. J. Walsh, D.F. Tomback, L. D. Daniels, L. M. Resler, W. K. Smith, D. J. Weiss, D. L. Peterson, A.G. Bunn, C. A. Hiemstra, D. Liptzin, P.S. Bourgeron, Z. Shen, and C. I. Millar. 2007. Alpine Treeline of Western North America: Linking Organism-to-Landscape Dynamics. Physical Geography 28:378-396
Cleveland, C. C. and D. Liptzin. 2007. C:N:P stoichiometry in soil: Is there a "Redfield ratio" for the microbial biomass? Biogeochemistry 85: 235-252 / DOI 10.1007/s10533-007-9132-0.
Liptzin, D. 2006. A Banded Vegetation Pattern in a High Arctic Community on Axel Heiberg Island, Nunavut, Canada. Arctic, Antarctic, and Alpine Research 38:216-223.
Liptzin, D, and P.M.S. Ashton. 1999. Early-successional dynamics of single-aged mixed hardwood stands in a southern New England forest, USA. Forest Ecology and Management. 116:141-150.
Braulio Quintero
Braulio is a technician with the Silver lab at the Luquillo LTER in Puerto Rico. Braulio was born in San Juan, Puerto Rico,
and quickly moved out of the city to the quaint little town of Mayagüez on the western side of the island. In Mayagüez he forged
his interest of the natural sciences on the backyard of his house. As a kid surrounded by big Cecropia trees, Palms, lizards and
tree frogs (Coqui). He obtained a Bachelor’s and Master’s degree in Biology from the University of Puerto Rico-Mayagüez. His graduate
research was done on forest regeneration on abandoned farmlands of western Puerto Rico. He highly interested in ecology, especially how
anthropogenic activities as farming and urbanization affect tropical ecosystems. His other main interest is mushroom biology. He enjoys
surfing, biking and as of lately rock climbing.
Someday he will ascend Mt. Everest, if it’s the last thing he does.
Becca Ryals
bryals[AT]nature.berkeley.edu
I joined the Silver lab as a graduate student in 2006. I am interested
in the effects of climate change and land-use management on
biogeochemical processes as well as climate change policy.
Currently, I am working on a project examining the effects of
long-term nitrogen additions on soil trace gas effluxes across
California biomes. I graduated from Duke University with a Masters
in Environmental Management with a focus in ecosystem management
and climate policy. For my Master’s project, I investigated the
potential for carbon sequestration in deep soils in at the Duke
Free Air CO_2 Enrichment experiment, under the advisement of Dr. Rob Jackson. As an undergraduate, I conducted research on phytoremediation of methyl tertiary-butyl ether, a persistent groundwater pollutant from gasoline, with Dr. Deborah Hokien at Marywood University, where I earned a B.S. in Environmental Science.
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Simonetta Rubol
simonetta.rubol[AT]ing.unitn.it
Soils are a dominant source of nitrous oxide, N2O, a potent greenhouse gas. Soils release an estimated 9.5 Tg N2O -N year-1 (65% of global emissions according to IPCC, 2001a). The complexity of drivers of N2O production and emissions has hindered our ability to predict the magnitude and spatial dynamics of N2O fluxes. Soil moisture can be considered a key driver because it influences oxygen supply, which feeds back on N2O sources (nitrification versus denitrification) and sinks (reduction to N2). Soil water content is directly linked to dissolved oxygen and to redox potential, which regulate microbial metabolism and chemical transformations in the environment. The target of my research is to explore the role of soil moisture and feed backs to soil redox dynamics by using a predictive model of soil N2O emissions operating at the daily scale . The results are validated by using a soil column in which is possible to monitor the water dynamics and the N-cycle through a system of sensors. The obtained data is then related to field work and chambers measurements in order to incorporate the role of spatial variability.
Carlos Torrens
ctorrens01[AT]fs.fed.us
Carlos is a Biological Science Technician with the International Institute of
Tropical Forestry (USDA Forest Service) in Puerto Rico. He started working with Whendee in 1989
on her dissertation research in the Luquillo Experiment Forest.
He helped establish the long
term transect study in 1994, and has been doing climate monitoring and litter collection
on the project since then.
The goal of the project is to understand climate impacts on forest productivity and biogeochemical
cycling along an elevational gradient. Carlos has also worked on Whendee's oxygen project,
and is currently contributing to the Luquillo LTER Canopy Trimming project.
Tana Wood
tanawood[AT]nature.berkeley.edu
Tana is a post-doc who is studying drought effects on carbon dioxide emissions from tropical forest soils.
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Wendy Yang
wendy_yang[AT]berkeley.edu
CV
I am a fifth-year Ph.D. student with broad interests in carbon and nitrogen cycling,
global climate change and land-use change. My dissertation research focuses on investigating the controls on
nitrous oxide and dinitrogen emissions from denitrification in upland soils. I have been collaborating with Dr. Jeff Severinghaus
at UC-San Diego to develop the N2/Ar method for measuring surface soil N2 fluxes in the field. I am also working
to understand nitrous oxide dynamics at Sherman Island in the Sacramento-San Joaquin Delta where there is high potential
for nitrous oxide emissions. Earlier in my graduate
career, I collaborated with
Dr. Bibit Traut, at the time a
post-doc in the Silver lab, to investigate controls on denitrification end-products in salt marsh soil
at Pt. Reyes, CA that receive high nitrogen inputs from
agricultural runoff. Before starting graduate school, I spent one year in the Silver lab
as a technician working with
Wendy Chou in the Sierra foothills. As an undergraduate,
I conducted research at Harvard Forest with Dr. Steven Wofsy and wrote my honors thesis on
the contribution of coarse woody debris respiration to the carbon budget of a northern
hardwood forest. I graduated from Harvard
in 2003 with a B.A. in Environmental Science and Public Policy.
Liu, W.H., D.M. Bryant, L.R. Hutyra, S.R. Saleska, E. Hammond Pyle, D.C. Curran, and S.C.
Wofsy, 2006.
Woody debris contribution to the carbon
budgets of selectively-logged and maturing mid-latitude forests.
Oecologia 148:108-117.
Sack, L., P. Melcher, W.H. Liu, E. Middleton, T. Pardee, and N.M.
Holbrook, 2006.
How strong is intra-canopy leaf
plasticity in temperate deciduous trees?
American Journal of Botany 93:829-839.
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