Lab Research and News

kelsey mcwilliams got awarded a fellowship

Thu, 25 Apr 2013 00:00:00 -0400

Kelsey McWilliams got awarded an undergraduate summer fellowship from the Delaware Water Resources Center to do research on CO2 and CH4 fluxes in a watershed in Delaware.

CONGRATULATIONS!!!!!!

see: http://ag.udel.edu/dwrc/index.html

research presented at EGU meeting

Tue, 16 Apr 2013 00:00:00 -0400

Rodrigo Vargas presented an oral talk at the 2013 EGU meeting in Vienna, Austria

Vargas R, Collins SL, Thomey M , Johnson J, Brown R, Natvig D, Friggens M. How multi-year manipulation of precipitation influences net primary production and soil CO2 efflux in a desert grassland. EGU meeting. April 8-12, 2013. Vienna, Austria

meeting presentation

Sat, 6 Apr 2013 00:00:00 -0400

Rodrigo Vargas gave an oral presentation at the: Open Science Conference on Climate Extremes and Biogeochemical Cycles in the Terrestrial Biosphere: impacts and feedbacks across scales. Meeting in Seefeld, Austria.

Vargas R. How a hurricane disturbance influences extreme CO2 fluxes and variance in a tropical forest. Climate Extremes and Biogeochemical Cycles meeting. April 2-5, 2013. Seefeld, Austria

see: http://www.bgc-extremes2013.org/

seminar

Mon, 1 Apr 2013 00:00:00 -0400

Rodrigo Vargas gave a seminar at CRA-RPS (Centro di Ricerca per lo Studio delle relazioni fra pianta e suolo), Rome, Italy.

Vargas R. Looking deeper into the soil: the role of fine roots and plant photosynthesis on soil respiration in forests. March 26, 2013. CRA-RPS. Rome, Italy

Rodrigo was hosted by Dr. Silvano Fares during his stay in Rome.
Please visit: http://rps.entecra.it/staff_member_17

research presented at the SCME meeting

Sat, 23 Mar 2013 00:00:00 -0400

Rodrigo Vargas participated in presentations at the Congreso de la Sociedad Científica Mexicana de Ecología. The meeting was held at Villahermosa, Tabasco, México.

Vargas R. et al (15 co-authors). El papel de la red de flujos ecosistémicos en las biogeociencias de México: MexFLUX. Congreso de la Sociedad Científica Mexicana de Ecología, March 18-22, 2013. (Oral presentation)
Vargas R. Paz, F, de Jong B, Etchevers JD. Estado actual de la investigación de los reservorios de carbon en el sistema tierra-atmósfera. Congreso de la Sociedad Científica Mexicana de Ecología, March 18-22, 2013. (Oral presentation)

workshop attendance

Sat, 16 Mar 2013 00:00:00 -0400

Rodrigo Vargas attended the workshop “Conceptualizing an Institute for Sustainable Earth and Environmental Software” at the National Center for Ecological Analysis and Synthesis in Santa Barbara, CA.

While advances in scientific software have revolutionized science over the past two decades (e.g., the Internet, computational genome sequencing, computational modeling), persistent barriers such as massive code complexity, prevalence of ad hoc rather than engineered designs for scientific software, pervasive lack of software testing, development of stove-piped and proprietary systems, and lack of formal versioning and management of software evolution and maintenance prevent the scientific community from realizing the full benefits that modern scientific software could offer [1]. Software commonly used in the earth and environmental science community ranges from commercially available data management, analysis, and modeling tools (e.g., Excel, Matlab, ArcGIS), to general purpose open source projects that might serve a wide variety of communities (e.g., "R", Apache Hadoop, Kepler), to software products resulting from scientific research that are targeted at specific science questions (e.g., the Century model in ecology [2] or the Regional Ocean Modeling System (ROMS) in oceanography [3]). Simultaneously, the earth and environmental science community has recognized the dire need for integrated, trans-disciplinary approaches to science that can produce understanding of natural and human impacted systems at much broader temporal and spatial scales than previously were possible. Issues such as the impacts of biodiversity loss on fisheries’ sustainability [4], global climate change impacts in marine and terrestrial systems [5], and impact of soil carbon sequestration on food security [6] all require software advances to allow synthesis and analysis of coupled systems at hitherto unexplored scales across previously disjoint disciplines. These science challenges require integrating data with software for modeling and analysis from multiple disciplines to reach scientific understanding on issues critically important to society; overcoming these challenges will form the core mission for the Institute for Sustainable Earth and Environmental Software (ISEES):

ISEES Mission: Catalyze the community to vastly improve the capabilities, interoperability, and sustainability of software systems needed for reproducible, coupled environmental and earth systems science that is critically relevant to society.

NACP Meeting

Sun, 10 Feb 2013 00:00:00 -0500

Alejandro Cueva and Rodrigo Vargas participated in the NACP meeting in Albuquerque, NM. Rodrigo Vargas was part of the organizing committee of the NACP meeting.

Vargas R, et al (33-co-authors). Overview of carbon cycle science initiatives in land and ocean across Mexico. NACP meeting. February 4-7, 2013. Albuquerque, NM, USA.
Cueva A*, Bahn M, Litvak M, Pumpanen J, Vargas R. Ana analysis of random errors for different approaches to calculate soil CO2 efflux through the gradient method. NACP meeting. February 4-7, 2013. Albuquerque, NM, USA.

workshop participation

Thu, 24 Jan 2013 20:50:04 -0500

Rodrigo Vargas participated in the 7th regional workshop on Forest Monitoring: Technical America Initiatives GEO FCT ND in Merida, Mexico.

Vargas R, Harmon M, Bond-Lamberty B. Challenges for simulating the impacts of disturbances on forest carbon cycling.

Within GEO FCT work frame the Americas (Peru, Ecuador, Mexico and Colombia) has been
working since 2011 in an intense capacity building initiative for Forest Monitoring and carbon
reporting. Workshops and technical exchanges thus began in 2011 with special support by
the US SilvaCarbon Program (led by USGS), U.S. Forest Service, FCMC –USAID Program, GEO
Secretariat, and also initially supported by the US Moore Foundation. The GEO FCT Americas
group includes Colombia, Ecuador, Mexico and Peru, with some participation from Guyana, and
Costa Rica. The following is the list of the past trainings in the Americas.

Further information can be found at:
GEO-FCT http://www.geo-fct.org/, SilvaCarbon http://www.silvacarbon.org/

Research presented at AGU Fall meeting 2012

Tue, 11 Dec 2012 10:49:11 -0500

A total of 4 posters from the Vargas’ Lab were presented during the AGU fall meeting 2012. Thanks to all the students and colleagues who participated in this research.

Posters presented:
B23E-0495. Inter-annual variability of evapotranspiration in two semiarid ecosystems with different climate patterns
Samuel Villarreal; Rodrigo Vargas; Enrico A. Yepez; Stephen V. Smith; Christopher Watts; Julio Rodriguez; Jaime Garatuza; Juan Martinez; Angel Castro; Eulogio Lopez

B41C-0284. A multisite and multi-model analysis of random errors in soil CO2 efflux across soil water conditions
Alejandro Cueva; Michael Bahn; Jukka Pumpanen; Rodrigo Vargas

B13B-0501. Teleconnections between upwelling along the Pacific coast of Baja California and marine and terrestrial gross primary production
Janet J. Reimer; Rodrigo Vargas; Gilberto Gaxiola-Castro; Martin Hernandez-Ayon; Ruben Lara-Lara

B23G-0528. On the longevity of desert plants and the production of new fine roots
Rodrgo Vargas; Claudia I. Czimczik; Stephen Bullock; Xiaomei Xu; Sonja Djuricin

Sessions organized:

B22C. B22C. Nonstructural Carbon in Plants: Observations, Modeling, and Theory I
Convener(s): Claudia Czimczik (Univ California), Mariah Carbone (NCEAS), Rodrgo Vargas (Univ of Delaware) and Andrew Richardson (Harvard University)

New Master graduates

Sat, 1 Dec 2012 10:33:29 -0500

Elievf Leon and Samuel Villarreal are the first MSc graduates from the Vargas Lab. Congratulations!

Elievf Leon received her MSc degree from CICESE on November 29, 2012 with the thesis: Heterogeneidad espacial de la dinámica y controles de la respiración del suelo en un ecosistema Mediterráneo.

Samuel Villarreal received her MSc degree from CICESE on November 30, 2012 with the thesis: Variablilidad interanual de la evapotransíración en dos ecosistemas semiáridos con patrones de precipitación distintos.

Congratulations to both of them!

The results from these theses will be submitted for peer review in international journals by early 2013....keep tuned!

seminar

Mon, 15 Oct 2012 10:29:44 -0400

Rodrigo Vargas gave a seminar at the University of New Mexico entitled: Advancing carbon cycle science in North America: opportunities in land and ocean across Mexico

Environmental problems and ecological understandings are not delineated within specific sociopolitical boundaries, thus solutions must be sought and fostered through international programmatic/scientific collaborations. Both scientists and policymakers recognize the importance of the role of carbon cycle science (CCS) in North America, but North American synthesis studies often do not include the role of Mexico. This seminar will highlight opportunities for advancing land and ocean CCS in Mexico in order to move towards a true North American continental scale understanding. First, we provide the socio-ecological context of Mexico relevant for CCS. Second, we compare the existing relationships among scientific/governmental entities and funding agencies that contribute to CCS in the United States and Mexico. Third, we discuss the state-of-the-art of CCS in Mexico and outline opportunities and challenges within country with emphasis on land- ocean-atmosphere interactions. Finally, we call for continental-scale developments and resources towards a tri-national carbon research, infrastructure, and education network.

A highlight of the trip was to have a beer with Ecological Society of America (ESA) president Scott Collins.

Rodrigo Vargas joins the university of delaware

Mon, 1 Oct 2012 21:00:14 -0400

Rodrigo Vargas is now an Assistant Professor at the Department of Plant and Soil Sciences at the University of Delaware.

new publication environmental research letters

Tue, 25 Sep 2012 22:16:32 -0400

Vargas (2012) How a hurricane disturbance influences extreme CO2 fluxes and variance in a tropical forest. Environmental Research Letters. 7:035704

A current challenge is to understand what are the legacies left by disturbances on ecosystems for predicting response patterns and trajectories. This work focuses on the ecological implications of a major hurricane and analyzes its influence on forest gross primary productivity (GPP; derived from the moderate-resolution imaging spectroradiometer, MODIS) and soil CO2 efflux. Following the hurricane, there was a reduction of nearly 0.5 kgC m−2 yr−1, equivalent to ∼15% of the long-term mean GPP (∼3.0 ± 0.2 kgC m−2 yr−1; years 2003–8). Annual soil CO2 emissions for the year following the hurricane were >3.9 ± 0.5 kgC m−2 yr−1, whereas for the second year emissions were 1.7 ± 0.4 kgC m−2 yr−1. Higher annual emissions were associated with higher probabilities of days with extreme soil CO2 efflux rates (>9.7 μmol CO2 m−2 s−1). The variance of GPP was highly variable across years and was substantially increased following the hurricane. Extreme soil CO2 efflux after the hurricane was associated with deposition of nitrogen-rich fresh organic matter, higher basal soil CO2 efflux rates and changes in variance of the soil temperature. These results show that CO2 dynamics are highly variable following hurricanes, but also demonstrate the strong resilience of tropical forests following these events.

View press release here

new publication Remote sensing of environment

Mon, 10 Sep 2012 12:34:16 -0400

Ryu et al. (2012) Continuous observations of tree leaf area index at ecosystem scale using upward-pointing digital cameras. Remote Sensing of Environment. 126:116-125

Understanding the dynamics of leaf area index (LAI) at ecosystem scale is critical for evaluating and modeling the response of vegetation to environmental variability and change. We present an approach for quantifying daily ecosystem LAI that integrates automatic acquisition of a small number of reference photos, viewed towards the zenith, and a larger number of photos covering a spatially extensive area that were manually acquired during periodic field trips. We present an image archive spanning three years for an oak-savanna ecosystem in California to identify the timing of phenological and disturbance events, and to quantify the seasonal to interannual variability of tree LAI at ecosystem scale. The digital camera-derived LAI, corrected for clumping effects, agreed well (r2=0.94, root mean square error=0.05) with independent estimates of LAI from litterfall traps and the LAI-2000 Plant Canopy Analyzer. Using the Moderate Resolution Imaging Spectroradiometer (MODIS) LAI product, which combined grass and tree LAI, we obtained realistic seasonal patterns of ecosystem LAI that corresponded with tree LAI from the digital cameras for the period when grass was dead. The digital camera method is an easy and inexpensive way to monitor LAI at ecosystem scale. This method can be used for testing and improving phenology models, evaluating remote-sensing-derived LAI products, and quantifying forest structures in rapidly changing environments.

sistema nacional de investigadores

Thu, 6 Sep 2012 13:04:14 -0400

Rodrigo Vargas has been promoted by the Sistema Nacional de Investigadores (SNI) to Level 2 (out of 3; being 3 the highest level). This program is sponsored by the Consejo Nacional de Ciencia y Tecnología (CONACyT), which act as the national science foundation of Mexico. The SNI has been designed to recognize the academic productivity of Mexican researches and only 20% of all researchers in Mexico belong to this category (see here).

new publication JGR-Biogeosciences

Sun, 2 Sep 2012 23:18:39 -0400

Schaefer et al. 2012. A model-data comparison of gross primary productivity: Results from the North American Carbon PRogram site synthesis. JGR-Biogeosciences 117:G03010

Accurately simulating gross primary productivity (GPP) in terrestrial ecosystem models is critical because errors in simulated GPP propagate through the model to introduce additional errors in simulated biomass and other fluxes. We evaluated simulated, daily average GPP from 26 models against estimated GPP at 39 eddy covariance flux tower sites across the United States and Canada. None of the models in this study match estimated GPP within observed uncertainty. On average, models overestimate GPP in winter, spring, and fall, and underestimate GPP in summer. Models overpredicted GPP under dry conditions and for temperatures below 0C. Improvements in simulated soil moisture and ecosystem response to drought or humidity stress will improve simulated
GPP under dry conditions. Adding a low-temperature response to shut down GPP for temperatures below 0C will reduce the positive bias in winter, spring, and fall and improve simulated phenology. The negative bias in summer and poor overall performance resulted from mismatches between simulated and observed light use efficiency (LUE). Improving simulated GPP requires better leaf-to-canopy scaling and better values of model parameters that control the maximum potential GPP, such as ɛmax (LUE), Vcmax (unstressed Rubisco catalytic capacity) or Jmax (the maximum electron transport rate).

new publication biogeosciences

Thu, 2 Aug 2012 00:12:27 -0400

Kim et al. (2012) Effects of rewetting and thawing on soil gas fluxes: a review of current literature and suggestions for future research. Biogeosciences 9:2459-2483

The rewetting of dry soils and the thawing of frozen soils are short-term, transitional phenomena in terms of hydrology and the thermodynamics of soil systems. The impact of these short-term phenomena on larger scale ecosystem fluxes is increasingly recognized, and a growing number of studies show that these events affect fluxes of soil gases such as carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), ammonia (NH3) and nitric oxide (NO). Global climate models predict that future climatic change is likely to alter the frequency and intensity of drying-rewetting events and thawing of frozen soils. These future scenarios highlight the importance of understanding how rewetting and thawing will influence dynamics of these soil gases. This study summarizes findings using a new database containing 338 studies conducted from 1956 to 2011, and highlights open research questions. The database revealed conflicting results follow- ing rewetting and thawing in various terrestrial ecosystems and among soil gases, ranging from large increases in fluxes to non-significant changes. Studies reporting lower gas fluxes before rewetting tended to find higher post-rewetting fluxes for CO2, N2O and NO; in addition, increases in N2O flux following thawing were greater in warmer climate regions. We discuss possible mechanisms and controls that regulate flux responses, and recommend that a high temporal resolution of flux measurements is critical to capture rapid changes in gas fluxes after these soil perturbations. Finally, we pro- pose that future studies should investigate the interactions between biological (i.e., microbial community and gas production) and physical (i.e., porosity, diffusivity, dissolution) changes in soil gas fluxes, apply techniques to capture rapid changes (i.e., automated measurements), and explore synergistic experimental and modelling approach.

seminar

Sun, 8 Jul 2012 23:09:41 -0400

Rodrigo Vargas gave a seminar at UNAM entitled: El pulso de los ecosistemas de México: avances y retos en mediciones de flujos de agua y carbono

Las colaboraciones internacionales son indispensables para lograr soluciones a los problemas ambientales a escala regional y global. Científicos y políticos reconocen la importancia de los ciclos del agua y carbono en los problemas ambientales de América del Norte, sin embargo la mayoría de los estudios regionales no incluyen la participación de México. Debido a las diferencias ecológicas, climáticas y socioeconómicas entre los tres países que conforman América del Norte es fundamental incorporar las características únicas de México para un mejor entendimiento de los ciclos biogeoquímicos a nivel regional. Esta presentación proporcionará una síntesis de avances, retos y oportunidades sobre mediciones de flujos de agua y carbono en ecosistemas terrestres de México. Se discutirá cómo la variabilidad climática y los eventos extremos influyen en los flujos de agua y carbono en distintos ecosistemas y distintas escalas espacio-temporales. Finalmente se proporcionará el marco conceptual para el establecimiento de una red nacional de medición de flujos de agua y gases de efecto invernadero en México denominada MexFlux.

member of science committee

Thu, 28 Jun 2012 00:27:16 -0400

Rodrigo Vargas has been appointed as member of the science steering committee of the Mexican Carbon Program (Programa Mexicano del Carbono) to coordinate the section “Atmosphere Interactions”.

new publication environmental science and policy

Tue, 12 Jun 2012 00:42:24 -0400

Vargas R et al. (2012) Opportunities for advancing carbon cycle science in Mexico: towards a continental scale understanding. Environmental Science and Policy. 21:84-93

Solutions to current global environmental problems throughout fundamental ecological understandings are only reached through international programmatic and scientific collaborations. Both scientists and policymakers recognize the importance of the role of carbon cycle science (CCS) in North America, however regional ecological studies in North America often do not include the role of Mexico. Given the sharp ecological, climatic and socioeconomic differences among the three countries conforming North America it is fundamental to incorporate Mexico’s unique contributions toward regional CCS. We provide a synthesis of opportunities and challenges for advancing land and ocean research in Mexico in order to move toward a complete North American continental scale CCS. First, we provide the socio- ecological context of Mexico relevant to CCS. Second, we compare the existing relationships among scientific/governmental entities and funding agencies that contribute to CCS in the United States and Mexico. Third, we discuss Mexico’s state-of-the-art CCS, and synthesize its recent advances with emphasis on land– and ocean–atmosphere interactions. We highlight continental-scale opportunities toward a tri-national carbon research, infrastructure, and education network.

This publication has been highlighted in several websites:
http://www.mexicocyt.org.mx/noticias_eventos/6015
http://www.planetaazul.com.mx/site/2012/06/19/evaluan-acciones-de-mexico-contra-el-cambio-climatico/
http://todos.cicese.mx/index.php?option=com_content&view=article&id=406%3Aoportunidades-para-el-avance-de-la-ciencia-en-el-ciclo-del-carbono-en-mexico-y-norte-america&catid=7%3Aarticulos-especiales&Itemid=82&showall=1
http://www.el-mexicano.com.mx/informacion/noticias/1/3/estatal/2012/06/20/585527/ciclo-del-carbono-actor-relevante.aspx