New July 16, 2012 Congratulations to Min for his new publication!

TITLE:
Modeling temperature acclimation effects on carbon dynamics of forest ecosystems in the conterminous United States

Authors:
Min Chen, Qianlai Zhuang

ABSTRACT:
The projected rise in temperature in the 21st century will alter forest ecosystem functioning and carbon dynamics. To date, the acclimation of plant photosynthesis to rising temperature has not been adequately considered in earth system models. Here we present a study on regional ecosystem carbon dynamics under future climate scenarios incorporating temperature acclimation effects into a large-scale ecosystem model, the terrestrial ecosystem model (TEM). We first incorporate a general formulation of the temperature acclimation of plant photosynthesis into TEM, and then apply the revised model to the forest ecosystems of the conterminous United States for the 21st century under the future Intergovernmental Panel on Climate Change (IPCC) Special Report on Emissions Scenarios (SRES) climate scenarios A1FI, A2, B1 and B2. We find that there are significant differences between the estimates of carbon dynamics from the previous and the revised models. The largest differences occur under the A1FI scenario, in which the model that considers acclimation effects predicts that the region will act as a carbon sink, and that cumulative carbon in the 21st century will be 35 Pg C higher than the estimates from the model that does not consider acclimation effects. Our results further indicate that in the region there are spatially different responses to temperature acclimation effects. This study suggests that terrestrial ecosystem models should take temperature acclimation effects into account so as to more accurately quantify ecosystem carbon dynamics at regional scales.

New Dec 10, 2012 Congratulations to Zeli Tan, who passed qualifying exams to continue his PhD program at EAPS!

New Dec 10, 2012 Congratulations to Zhenong Jin, who passed qualifying exams to continue his PhD program at EAPS!

New Nov 7, 2012 Congratulations to Yujie He, who successfully defended her MS thesis research. She will continue pursuing her PhD in our lab.

New October 1, 2012 Welcome our newest PhD students to EBDL lab: Chang Liao, Shaoqing Liu, Jiahui Xu and Guangcun Hao!

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New July 14, 2012 Congratulations to Xinghua Sui, who led a study using TEM model, which was just published online in Climatic Change!

ABSTRACT:
Chinese temperate grasslands play an important role in the terrestrial carbon cycle. Based on the parameterization and validation of Terrestrial Ecosystem Model (TEM, Version 5.0), we analyzed the carbon budgets of Chinese temperate grasslands and their responses to historical atmospheric CO2 concentration and climate variability during 1951-2007. The results indicated that Chinese temperate grassland acted as a slight carbon sink with annual mean value of 7.3 Tg C, ranging from -80.5 to 79.6 Tg C yr-1. Our sensitivity experiments further revealed that precipitation variability was the primary factor for decreasing carbon storage. CO2 fertilization may increase the carbon storage (1.4 %) but cannot offset the proportion caused by climate variability (-15.3 %). Impacts of CO2 concentration, temperature and precipitation variability on Chinese temperate grassland cannot be simply explained by the sum of the individual effects. Interactions among them increased total carbon storage of 56.6 Tg C which 14.2 Tg C was stored in vegetation and 42.4 Tg C was stored in soil. Besides, different grassland types had different responses to climate change and CO2 concentration. NPP and RH of the desert and forest steppes were more sensitive to precipitation variability than temperature variability while the typical steppe responded to temperature variability more sensitively than the desert and forest steppes.

CITATION:
Sui, X., G. Zhou, and Q. Zhuang (2012) Sensitivity of carbon budget to historical climate variability and atmospheric CO2 concentration in temperate grassland ecosystems in China, Climatic Change, DOI 10.1007/s10584-012-0533-2

 

New June 8, 2012 A study on coupled thermal and hydrological dynamics for the Arctic ecosystems has been just published, led by Yueyang.

ABSTRACT:
Thawing and freezing processes are key components in permafrost dynamics, and these processes play an important role in regulating the hydrological and carbon cycles in the northern high latitudes. In the present study, we apply a well-developed soil thermal model that fully couples heat and water transport, to simulate the thawing and freezing processes at daily time steps across multiple sites that vary with vegetation cover, disturbance history, and climate. The model performance was evaluated by comparing modeled and measured soil temperatures at different depths. We use the model to explore the influence of climate, fire disturbance, and topography (north- and south-facing slopes) on soil thermal dynamics. Modeled soil temperatures agree well with measured values for both boreal forest and tundra ecosystems at the site level. Combustion of organic-soil horizons during wildfire alters the surface energy balance and increases the downward heat flux through the soil profile, resulting in the warming and thawing of near-surface permafrost. A projection of 21st century permafrost dynamics indicates that as the climate warms, active layer thickness will likely increase to more than 3 meters in the boreal forest site and deeper than one meter in the tundra site. Results from this coupled heat-water modeling approach represent faster thaw rates than previously simulated in other studies. We conclude that the discussed soil thermal model is able to well simulate the permafrost dynamics and could be used as a tool to analyze the influence of climate change and wildfire disturbance on permafrost thawing.

CITATION:
Jiang, Y., Q. Zhuang, and J. A. O'Donnell (2012), Modeling thermal dynamics of active layer soils and near-surface permafrost using a fully coupled water and heat transport model, J. Geophys. Res., 117, D11110, doi:10.1029/2012JD017512.

 

New May 23, 2012 Congratulations to Yujie, who won $1500 travel support to participate in a collaborative research in Alaska with Dr. Jen Harden at USGS! The support is from INTERFACE project funded by NSF, more information may be found at :(link)

New May 7, 2012 Yujie He was awarded a support to attend the Iowa High Performance Computing (IHPC) 2012 Summer School. Congratulations!

New May 4, 2012 Congratulations to Yaling Liu, who passed qualifying exam to continue her PhD program at EAPS!

New Apr. 27, 2012 Xiaoliang Lu led a study entitled "Modeling methane emissions from the Alaskan Yukon River basin, 1986-2005, by coupling a large-scale hydrological model and a process-based methane model" and has been published in Journal of Geophysical Research.

ABSTRACT: Much progress has been made in methane modeling for the Arctic. However, there is still large uncertainty in emissions estimates due to the spatial variability in water table depth resulting from complex topographic gradients, and due to variations in methane production and oxidation due to complex freezing and thawing processes. Here we extended an extant methane emission module within a biogeochemistry model, the Terrestrial Ecosystem Model (TEM), to include a large-scale hydrology model, the variable infiltration capacity (VIC) model. The VIC model provides the required inputs, including freezing and thawing fronts, soil temperature and moisture, to the methane module. The effect of topography on the redistribution of soil moisture and water table depth was explicitly modeled using the TOPMODEL approach. The coupled modeling framework was applied to the Yukon River basin at a spatial resolution of 1 km from 1986 to 2005. The simulations show that the average annual net emissions of CH4 from the region are 4.01 Tg CH4 yr-1. El Nino phenomena usually lead to positive emission anomalies, while decreases in net CH4 emissions may be associated with strong La Nina events. Precipitation was found to be more closely related to CH4 dynamics than to soil temperature and active layer depth during the study period. This study suggests that the effects of soil freezing and thawing processes and the effects of microtopography on hydrology should be considered in the quantification of CH4 emissions.
CITATION: Lu, X., and Q. Zhuang (2012), Modeling methane emissions from the Alaskan Yukon River basin, 1986-2005, by coupling a large-scale hydrological model and a process-based methane model, J. Geophys. Res., 117, G02010, doi:10.1029/2011JG001843.

 

New Apr. 20, 2012 A study entitled "Spatially Explicit Parameterization of a Terrestrial Ecosystem Model and Its Application to the Quantification of Carbon Dynamics of Forest Ecosystems in the Conterminous United States" by Min Chen and Qianlai Zhuang has been published in Earth Interactions.

ABSTRACT: The authors use a spatially explicit parameterization method and the Terrestrial Ecosystem Model (TEM) to quantify the carbon dynamics of forest ecosystems in the conterminous United States. Six key parameters that govern the rates of carbon and nitrogen dynamics in TEM are selected for calibration. Spatially explicit data for carbon and nitrogen pools and fluxes are used to calibrate the six key parameters to more adequately account for the spatial heterogeneity of ecosystems in estimating regional carbon dynamics. The authors find that a spatially explicit parameterization results in vastly different carbon exchange rates relative to a parameterization conducted for representative ecosystem sites. The new parameterization method estimates that the net ecosystem production (NEP), the annual gross primary production (GPP), and the net primary production (NPP) of the regional forest ecosystems are 61% (0.02 Pg C; 1 Pg 5 1015 g) higher and 2% (0.11 Pg C) and 19% (0.45 Pg C) lower, respectively, than the values obtained using the traditional parameterization method for the period 1948-2000. The estimated vegetation carbon and soil organic carbon pool sizes are 51% (18.73 Pg C) lower and 29% (7.40 Pg C) higher. This study suggests that, to more adequately quantify regional carbon dynamics, spatial data for carbon and nitrogen pools and fluxes should be developed and used with the spatially explicit parameterization method.
CITATION: Chen, M., Q. Zhuang (2012) Spatially Explicit Parameterization of a Terrestrial Ecosystem Model and Its Application to the Quantification of Carbon Dynamics of Forest Ecosystems in the Conterminous United States, Earth Interactions, DOI: 10.1175/2012EI400.1.

 

New Apr. 11, 2012 Congratulations to Xiaoliang just accepted a Post-Doctoral Scientist offer from the Ecosystems Center of the Marine Biological Laboratory at Woods Hole, MA!

 

New Apr. 11, 2012 Yujie He was just awarded with a WISP Travel Grant! She will travel to 2012 Ecological Society of America annual meeting, Portland, Oregon in August to present her study on CO2 and CH4 emissions during the Holocene Thermal Maximum in Alaska. Congratulations!

 

New Apr. 3, 2012 Xiaoliang Lu just defended his PhD dissertation, congratulations to Dr. Xiaolang Lu!

 

New Apr. 2, 2012 Congratulation to Qing Zhu, passed his preliminary exam and became a PhD candidate!

 

New Apr. 2, 2012 Congratulations to Zhangcai Qin, who just passed his preliminary exam and advanced to PhD candidacy!

 

New Apr. 2, 2012 Yueyang Jiang has successfully defended his PhD dissertation! Congratulations Dr. Jiang!

 

New Feb. 14, 2012 Yueyang led a study, entitled "Uncertainty analysis of vegetation distribution in the northern high latitudes during the 21st century with a dynamic vegetation model", has just been published in the journal, Ecology and Evolution.

ABSTRACT: This study aims to assess how high-latitude vegetation may respond under various climate scenarios during the 21st century with a focus on analyzing model parameters induced uncertainty and how this uncertainty compares to the uncertainty induced by various climates. The analysis was based on a set of 10,000Monte Carlo ensemble Lund-Potsdam-Jena (LPJ) simulations for the northern high latitudes (45oN and polewards) for the period 1900 to 2100. The LPJ Dynamic Global Vegetation Model (LPJ-DGVM) was run under contemporary and future climates from four Special Report Emission Scenarios (SRES), A1FI, A2, B1, and B2, based on the Hadley Centre General Circulation Model (GCM), and six climate scenarios, X901M, X902L, X903H, X904M, X905L, and X906H from the Integrated Global System Model (IGSM) at the Massachusetts Institute of Technology (MIT). In the current dynamic vegetation model, some parameters are more important than others in determining the vegetation distribution. Parameters that control plant carbon uptake and light-use efficiency have the predominant influence on the vegetation distribution of both woody and herbaceous plant functional types. The relative importance of different parameters varies temporally and spatially and is influenced by climate inputs. In addition to climate, these parameters play an important role in determining the vegetation distribution in the region. The parameter-based uncertainties contribute most to the total uncertainty. The current warming conditions lead to a complexity of vegetation responses in the region. Temperate trees will be more sensitive to climate variability, compared with boreal forest trees and C3 perennial grasses. This sensitivity would result in a unanimous northward greenness migration due to anomalous warming in the northern high latitudes. Temporally, boreal needle-leaved evergreen plants are projected to decline considerably, and a large portion of C3 perennial grass is projected to disappear by the end of the 21st century. In contrast, the area of temperate trees would increase, especially under the most extreme A1FI scenario. As the warming continues, the northward greenness expansion in the Arctic region could continue.
CITATION: Jiang, Y., Q. Zhuang, S. Schaphoff, S. Sitch, A. Sokolov, D. Kicklighter, and J. Melillo (2012). Uncertainty analysis of vegetation distribution in the northern high latitudes during the 21st century with a dynamic vegetation model, ecology and Evolution, doi: 10.1002/ece3.85.

 

New Feb. 14, 2012 Yueyang led another study, entitled "Modeling Large Fire Frequency and Burned Area in Canadian Terrestrial Ecosystems with Poisson Models", has been published in the journal, Environmental Modeling & Assessment.

ABSTRACT: Large wildland fires are major disturbances that strongly influence the carbon cycling and vegetation dynamics of Canadian boreal ecosystems. Although large wildland fires have recently received much scrutiny in scientific study, it is still a challenge for researchers to predict large fire frequency and burned area. Here, we use monthly climate and elevation data to quantify the frequency of large fires using a Poisson model, and we calculate the probability of burned area exceeding a certain size using a compound Poisson process. We find that the Poisson model simulates large fire occurrence well during the fire season (May through August) using monthly climate, and the threshold probability calculated by the compound Poisson model agrees well with historical records. Threshold probabilities are significantly different among different Canadian ecozones, with the Boreal Shield ecozone always showing the highest probability. The fire prediction model described in this study and the derived information will facilitate future quantification of fire risks and help improve fire management in the region.
CITATION: Jiang, Y., Q. Zhuang, and D. Mandallaz (2012). Modeling Large Fire Frequency and Burned Area in Canadian Terrestrial Ecosystems with Poisson Models, Environ Model Assess, DOI 10.1007/s10666-012-9307-5.

 

New Jan. 30, 2012Congratulations to Yujie He, who has been selected and supported to participate in the DOE workshop "Strategies to promote integrated experiment-model approaches to terrestrial ecosystem study" that will be held in Washington DC!

 

New Jan. 20, 2012A great article highlighting a recent paper (PCCRC paper 1147) led by EAS grad student Xudong Zhu, Rising methane emissions in response to climate change in Northern Eurasia during the 21st century, is featured in environmental research web:(link) The article is also copied below, and you can read the full paper here:(link).

 

New Dec. 30, 2011Congratulations to Yueyang Jiang who has just accepted an post-doctoral scientist offer from Marine Biological Laboratory at Woods Hole, MA!

 

New Dec. 20, 2011Congratulations! Prof. Qianlai Zhuang was awarded the Seed for Success Award, that is given in recognition of the accomplishments of single investigators and teams of investigators for their efforts in obtaining a $1 million or more research grant at Purdue during 2011.

 

New Dec. 20, 2011Using an artificial neural network approach and field observational data of N2O fluxes, we estimate that the global soil N2O source strength from natural ecosystems is 3.37 Tg (1 Tg . 1012 g) N per year with an uncertainty ranging from 1.96 to 4.56 Tg N per year in 2000. The study was just published in Atmospheric Environment. The citation is " Zhuang, Q., Y. Lu, and M. Chen (2011), An inventory of global N2O emissions from the soils of natural terrestrial ecosystems, Atmospheric Environment, 1352-2310, doi: 10.1016/j.atmosenv.2011.11.036."

 

New Dec. 2, 2011Our lab just published an analysis on methane emissions from Northern Eurasian with multiple wetland distribution datasets. Our uncertainty analyses indicated that the uncertainty in wetland extent had a larger effect on future CH4 emissions than the uncertainty in future climate. This study suggests that better characterization of the spatial distribution and the natural diversity of wetlands should be a research priority for quantifying CH4 fluxes in this region. The citation is " Zhu X., Zhuang Q., Chen M., Sirin A., Melillo J., Kicklighter D., Sokolov A., Song L. Rising methane emissions in response to climate change in Northern Eurasia during the 21st century. Environ. Res. Lett. 6 045211 doi:10.1088/1748-9326/6/4/045211".

 

New Dec. 1, 2011A study from our lab that focus on analyzing the eff ects of growing switchgrass and Miscanthus on Chinese marginal agricultural lands on biomass production and carbon emissions with a global scale biogeochemical model. We found that Miscanthus has tremendous potential to meet future biofuel needs, and to benefit CO2 mitigation in China. The citation is "Qin Z., Zhuang Q., Zhu X., Cai X., Zhang X. Carbon consequences and agricultural implications of growing biofuel crops on marginal agricultural lands in China. Environ. Sci. Technol.. DOI: 10.1021/es2024934"

 

New Nov. 8, 2011Congratulations to Zhangcai Qin, who just passed the qualifying exam for his PhD program!

 

New Nov. 28, 2011Yujie He and Xudong Zhu pass their qualifying exam for their PhD program, congratulations!

 

New Nov. 27, 2011Congratulations to Zhiwei Zhang, who has passed final exam on his Masters degree program!

 

New Oct. 10, 2011Welcome Ms. Lulu Song joining us as a jointed student between Chinese Academy of Sciences and Purdue University to pursue her PhD degree!

 

New Sept. 26, 2011our lab just published a study on US biofuel development and consequences of carbon dynamics in Global Change Biology – Bioenergy. The study concluded that Miscanthus could better serve as an energy crop than food crops or switchgrass, considering both economic and environmental benefits. The citation is "Qin, Z., Q. Zhuang, and M. Chen, Impacts of land use change due to biofuel crops on carbon balance, bioenergy production, and agricultural yield, in the conterminous United States, Glob Change Biol Bioenergy, 1757-1707, http://dx.doi.org/10.1111/j.1757-1707.2011.01129.x, DO - 10.1111/j.1757-1707.2011.01129.x".

 

New Sept. 26, 2011A study using Moderate Resolution Imaging Spectroradiome- ter (MODIS) Enhanced Vegetation Index (EVI), Land Sur- face Water Index (LSWI) and carbon flux data of AmeriFlux and the Terrestrial Ecosystem Model (TEM) has been just published in Biogeosciences.The study found that the regional GPP is between 7.02 and 7.78 Pg C yr-1 and net primary production (NPP) ranges from 3.81 to 4.38 Pg C yr-1 and net ecosystem production (NEP) varies within 0.08 to 0.73 Pg C yr-1 over the period 2000 to 2005 for the conterminous United States. The full citation is " Chen, M. and Q. Zhuang(2011), Q., Cook, D. R., Coulter, R., Pekour, M., Scott, R. L., Munger, J. W., and Bible, K.: Quantification of terrestrial ecosystem carbon dynamics in the conterminous United States combining a process-based biogeochemical model and MODIS and AmeriFlux data, Biogeosciences, 8, 2665-2688, doi:10.5194/bg-8-2665-2011".

 

New Sept. 15, 2011our lab just published a study on Canadian forest fires using extreme theory. The study found that (i) all three extreme statistical models perform well to characterize extreme fire events, but the GPD and PP models need extra care to fit the nonstationary fire data, (ii) anthropogenic and natural extreme fires have significantly different extreme statistics, and (iii) fires in different ecozones exhibit very different characteristics in the view of statistics. For details, please refer to "Yueyang Jiang, Qianlai Zhuang (2011), Extreme value analysis of wildfires in Canadian boreal forest ecosystems, Canadian Journal of Forest Research, 41:1836-1851, 10.1139/x11-102".

 

New August 26, 2011Welcome graduate students Zhenong Jin, Ian Pope, Linyuan Shang, and Zeli Tand , and Research Assistant Jayne Piepenburg joining our lab!

 

New August 16, 2011 our lab just published a study examining the land cover change in Yukon River Basin for the last couple of decades. The study is contribution to our NSF funded biocomplexity project investigating the interactions of permafrost, climate, and terrestrial ecosystems. The citation is " Lu, X. and Q. Zhuang (2011), Areal changes of land ecosystems in the Alaskan Yukon River Basin from 1984 to 2008, Environ. Res. Lett. 6 034012,doi: 10.1088/1748-9326/6/3/034012".

 

New July 22, 2011 Our lab is just funded by Department of Energy with a project, entitled "Collaborative Research: Quantifying Climate Feedbacks of the Terrestrial Biosphere under Thawing Permafrost Conditions in the Arctic". Prof. Qianlai Zhuang is the Lead PI in collaboration with Co-PIs C. A. Schlosser at MIT, J. M. Melillo at MBL, Woods Hole MA, and K. Anthony Walter at University of Alaska Fairbanks. The project is to test the following hypothesis "There exists a climate warming threshold beyond which permafrost degradation becomes widespread and stimulates large increases inmethane emissions (via thermokarst lakes and poorly-drained wetland areas upon thawing permafrost along with microbial metabolic responses to higher temperatures) and increases in carbon dioxide emissions from well-drained areas. Besides changes in biogeochemistry, this threshold will also influence global energy dynamics through effects on surface albedo, evapotranspiration and water vapor. These changes would outweigh any increased uptake of carbon (e.g. from peatlands and higher plant photosynthesis) and would result in astrong, positive feedback to global climate warming".

 

New February 4, 2011 A new study on further developing on the fixed-lag ensemble square root Kalman smoother and fixed-lag square root sigma-point Kalman smoother is just published. The new development treat nonlinear observation operators easily in atmospheric trace gases inversion. The citation is Tang, J. and Zhuang, Q., Technical Note: Propagating correlations in atmospheric inversions using different Kalman update smoothers, Atmos. Chem. Phys., 11, 921-929, doi:10.5194/acp-11-921-2011, 2011.

 

New December 28, 2010 Welcome Ms. Yaling Liu joins our lab to pursue her PhD with a Bachelor degree in Geography from Hubei University and a MS degree in meteorology from China Agriculture University.

 

New December 28, 2010 Our lab just published a study on investigating the growing season length of Alaskan terrestrial ecosystems. We found that, in response to the projected warming, by year 2099, (1) the snow-free days will be increased by 41.0 and 27.5 days, respectively, in boreal forest and tundra ecosystems and (2) the growing season lengths will be more than 28 and 13 days longer in boreal forest and tundra ecosystems, respectively, compared to 2010. The citation is "Tang, J., and Q. Zhuang (2010), Modeling soil thermal and hydrological dynamics and changes of growing season in Alaskan terrestrial ecosystems, Climatic Change, DOI 10.1007/s10584-010-9988-1."

 

New December 3, 2010 Congratulations to Yueyang Jiang who passed his Preliminary Exam and become a PhD candidate!

 

New December 1, 2010 Congratulations to Jinyun Tang who accepted a post-doctoral scientist offer from Lawrence Berkeley National Laboratory!

 

New November 27, 2010 Our lab just published a methane modeling study focusing on simulating methane production, oxidation, and transport (particularly ebullition) with different model complexities. The models were tested through a group of sensitivity analyses using data from two temperate peatland sites in Michigan. We demonstrate that only the four-substance model with a pressure-based ebullition algorithm is able to capture the episodic emissions induced by a sudden decrease in atmospheric pressure or by a sudden drop in water table. The citation is "Tang, J., Zhuang, Q., Shannon, R. D., and White, J. R. (2010) Quantifying wetland methane emissions with process-based models of different complexities, Biogeosciences, 7, 3817-3837, doi:10.5194/bg-7-3817-2010".

 

New November 23, 2010 Congratulations to Qing Zhu who passed his PhD Qualifying Exam and to Min Chen who passed his Preliminary Exam to advance to PhD candidacy!

 

New November 22, 2010 our lab just published a synthesis study of US carbon fluxes based on satellite and eddy flux observations. The study provides an estimate of net ecosystem carbon exchange (NEE) at high spatial (1 km) and temporal (8-day) resolutions in the US for the period 2001-2006. We find that the U.S. terrestrial carbon sink varied between 0.51 and 0.70 pg C yr-1 over the period. Citation: Xiao, J., Q. Zhuang, Beverly E. Law, Dennis D. Baldocchi, Jiquan Chen, Andrew D. Richardson, Jerry M. Melillo, Kenneth J. Davis, David Y. Hollinger, Sonia Wharton, Ram Oren, Asko Noormets, Marc L. Fischer, Shashi B. Verma, David R. Cook, Ge Sun, Steve McNulty, Steven C. Wofsy, Paul V. Bolstad, Sean P. Burns, Peter S. Curtis, Bert G. Drake, Matthias Falk, David R. Foster, Lianhong Gu, Julian L. Hadley, Gabriel G. Katul, Marcy Litvak, Siyan Ma, Timothy A. Martin, Roser Matamala, Tilden P. Meyers, Russell K. Monson, J. William Munger, Walter C. Oechel, U. Kyaw Tha Paw, Hans Peter Schmid, Russell L. Scott, Gregory Starr, Andrew E. Suyker, Margaret S. Torn (2011), Assessing net ecosystem carbon exchange of U.S. terrestrial ecosystems by integrating eddy covariance flux measurements and satellite observations, Agricultural and Forest Meteorology, Volume 151, Issue 1, 15 January 2011, Pages 60-69, ISSN 0168-1923, DOI: 10.1016/j.agrformet.2010.09.002.

 

New November 22, 2010 As a product of our NCEAS methane synthesis project, a study focusing on arctic methane bubble emissions was published in Limnol. Oceanogr.: Methods. Citation: Anthony, K. M. W., D. A. Vas, L. Brosius, F. S. Chapin III, S. A. Zimov, and Q. Zhuang (2010) Estimating methane emissions from northern lakes using ice bubble surveys, Limnol. Oceanogr.: Methods 8, 592¨C609.

 

New October 9, 2010 As a contribution to our NCEAS methane synthesis project, a study on mid-upper tropospheric methane in the high Northern Hemisphere using satellite retrieval, aircraft measurements, and model simulations was just published. Citation: Xiong, X., C. D. Barnet, Q. Zhuang, T. Machida, C. Sweeney, and P. K. Patra (2010), Mid-upper tropospheric methane in the high Northern Hemisphere: Spaceborne observations by AIRS, aircraft measurements, and model simulations, J. Geophys. Res., 115, D19309, doi:10.1029/2009JD013796.

 

New September 20, 2010 Our lab just won a NSF CDI type II project entitled "A Paradigm Shift in Ecosystem and Environmental Modeling: An Integrated Stochastic, Deterministic, and Machine Learning Approach". Prof. Zhuang is Lead Principal Investigator in collaboration with M. Crawford, H. Zhang, D. Xiu, J. Zhang at Purdue and J. Melillo at Marine Biological Laboratory in Woods Hole, MA and J. Reilly at MIT. This project will advance systems modeling approaches by developing a suite of stochastic modeling approaches, coupled with geostatistical and machine learning techniques. The novel developments, together with observed data, will advance ecosystem and environmental sciences through computational thinking.

 

New August 20, 2010 in collaboration with several other institutions, our lab just published a study focusing on carbon balance in the Arctic in recent years at Tellus. The full citation is "McGuire, A.D., D.J. Hayes, D.W. Kicklighter, M. Manizza, Q Zhuang, M. Chen, M. J. Follows, K. R. Gurney, J.W. McClelland, J. M. Melillo, B. J. Peterson, and R. G. Prinn (2010) An analysis of the carbon balance of the Arctic Basin from 1997 to 2006, Tellus, DOI: 10.1111/j.1600-0889.2010.00497.x."

 

New August 10, 2010 In collaboration with Chinese Academy of Sciences, our lab published a study focusing on carbon dynamics on the Tibetan Plateau during the 20th century. The full citation is "Zhuang Q., J. He, Y. Lu, L. Ji, J. Xiao, T. Luo, Carbon dynamics of terrestrial ecosystems on the Tibetan Plateau during the 20th century: an analysis with a process-based biogeochemical mode, Global Ecology and Biogeography,19,5, 649-662,2010. DOI: 10.1111/j.1466-8238.2010.00559.x".

 

New June 14, 2010 Congratulations to Xiaoliang Lu, who just published a research article on evaluating evapotranspriation and water-use efficiency of the terrestrial ecosystems in the U.S. with satellite and eddy flux data and modeling approach. The full citation is "Xiaoliang Lu, Qianlai Zhuang, Evaluating evapotranspiration and water-use efficiency of terrestrial ecosystems in the conterminous United States using MODIS and AmeriFlux data, Remote Sensing of Environment, Volume 114, Issue 9, 15 September 2010, Pages 1924-1939, ISSN 0034-4257, DOI: 10.1016/j.rse.2010.04.001".

 

New June 8, 2010 Prof. Zhuang has been named a William F. and Patty J. Miller Associate Professor in the College of Science. In his naming letter, Dr. Jeffrey T. Roberts, the Dean of College of Science at Purdue wrote "...The professorship, which was created through the generosity of Purdue alumni Bill and Patty Miller, recognizes Qianlai's extraordinary accomplishments as a leading researcher in climate change, and his potential for continuing scholarly accomplishments". Congratulations!

 

New May 9, 2010 Our lab just published a study focusing on carbon balance in the Midwest of the U.S. in Mitigation and Adaptation Strategies for Global Change. We found that, during the 21st century, vegetation and soil carbon fluxes and pools show an increase trend with a great inter-annual variability. The ecosystems serve as a carbon sink under future climate scenarios. This study provides the information of the biomass and NEP at a state- level in the Midwest, which will be valuable for the stakeholders in the region to better manage their land for the purpose of increasing carbon sequestration on the one hand and meeting the increasing demand of biomass on the other. The full citation are: Lu, Xiaoliang and Qianlai Zhuang (2010), Evaluating climate impacts on carbon balance of the terrestrial ecosystems in the Midwest of the United States with a process-based ecosystem model, Mitigation and Adaptation Strategies for Global Change,15, 5, 467-487,10.1007/s11027-010-9228-z.

 

New April 9, 2010 Congratulations to Prof. Zhuang who has been promoted to Associate Professor with tenure at Department of Earth & Atmospheric Sciences and Department of Agronomy at Purdue!

 

New April 9, 2010 Congratulations to Jinyun Tang, who has been awarded Bilsland Dissertation Fellowship for the 2010-2011 academic year!

 

New Feburary 1, 2010 Our lab just published a synthesis paper on estimating gross primary production based on eddy flux measurements in the US. We estimated GPP for each 1 km x 1 km cell across the U.S. for each 8-day interval over the period from February 2000 to December 2006. The estimated GPP for the conterminous US is between 6.91 and 7.33 Pg C yr- 1. The full citation is ¡°Jingfeng Xiao, Qianlai Zhuang, Beverly E. Law, Jiquan Chen, Dennis D. Baldocchi, David R. Cook, Ram Oren, Andrew D. Richardson, Sonia Wharton, Siyan Ma, Timothy A. Martin, Shashi B. Verma, Andrew E. Suyker, Russell L. Scott, Russell K. Monson, Marcy Litvak, David Y. Hollinger, Ge Sun, Kenneth J. Davis, Paul V. Bolstad, Sean P. Burns, Peter S. Curtis, Bert G. Drake, Matthias Falk, Marc L. Fischer, David R. Foster, Lianhong Gu, Julian L. Hadley, Gabriel G. Katul, Roser Matamala, Steve McNulty, Tilden P. Meyers, J. William Munger, Asko Noormets, Walter C. Oechel, Kyaw Tha Paw U, Hans Peter Schmid, Gregory Starr, Margaret S. Torn, Steven C. Wofsy, A continuous measure of gross primary production for the conterminous United States derived from MODIS and AmeriFlux data,. Remote Sensing of Environment , Volume 114, Issue 3, 15 March 2010, Pages 576-591, ISSN 0034-4257, DOI: 10.1016/j.rse.2009.10.013.

 

New December 9, 2009 In collaboration with scientists in Canadian Forest Services, our lab just published an analysis about the relationship between wildfire numbers and their burned areas in Canadian boreal forest ecosystems. In the study, wildfires were found to follow power¨Claw relationships between frequency densities (number of fires normalized to unit bins) and burned areas in all ecozones. Power¨Claw frequency¨Carea relationships also held for both anthropogenic fires and natural fires in the 1980s and 1990s. The full citation is Jiang Y, Zhuang Q, Flannigan MD, Little JM (2009) Characterization of wildfire regimes in Canadian boreal terrestrial ecosystems. International Journal of Wildland Fire 18, 992-1002. doi:10.1071/WF08096.

 

New November 18, 2009 in collaboration with scientists in Chinese Academy of Sciences and Russian Academy of Sciences, our lab just published a study focusing on carbon cycling in Mongolian Plateau during the 21st century. The study estimates the region acted as a C sink of 31 Tg C yr-1 in the 1990s, but this sink will likely decline in both magnitude and extent under future climate conditions. This change is due to the relatively larger enhancement of soil organic matter decomposition, which releases carbon to the atmosphere, than the corresponding enhancement of plant C uptake, by rising temperatures and atmospheric CO2 concentrations. The full citation is Y. Lu, Q. Zhuang, G. Zhou, A. Sirin, J. Melillo and D. Kicklighter (2009) Possible decline of the carbon sink in the Mongolian Plateau during the 21st century, Environ. Res. Lett. 4 045023 (8pp).

 

New September 14, 2009 In collaboration with Chinese Academy of Sciences, our lab just published a study focusing analyzing the drought effects on carbon dynamics in China during the 20th century with a tree-ring data and a process-based ecosystem model. The full citation: Xiao, J., Q. Zhuang, E. Liang, A.D. McGuire, A. Moody, D.W. Kicklighter, X. Shao, and J.M. Melillo, 2009: Twentieth-Century Droughts and Their Impacts on Terrestrial Carbon Cycling in China. Earth Interactions, 13, 1-31.

 

New August 11, 2009 Our second of a series of studies in quantifying the uncertainty of large-scale carbon dynamics has been just published in Journal of Geophysical Research- Atmosphere. In this study, a global sensitivity analysis and Bayesian inference framework was developed for improving the parameterization and predictability of a monthly time step process-based biogeochemistry model TEM. Our study suggests that the developed global sensitivity analysis and Bayesian framework could further be used to analyze and improve the predictability and parameterization of relatively coarse time step biogeochemistry models when the eddy flux and satellite data are available for other terrestrial ecosystems. The full citation is "Tang, J., and Q. Zhuang (2009), A global sensitivity analysis and Bayesian inference framework for improving the parameter estimation and prediction of a process-based Terrestrial Ecosystem Model, J. Geophys. Res., 114, D15303, doi:10.1029/2009JD011724."

 

New July 23, 2009 Our lab has been just funded by NSF Ecosystem Program to document ecosystem changes that occurred 10,000 years ago across Alaska and to assess effects of a warmer climate and different seasonality on nutrient and water cycling using the Terrestrial Ecosystem Model. The project is a collaborative effort with Lehigh University.

 

New April 8, 2009 Congratulations to Yueyang Jiang, who has successfully defended his MS thesis on "Modeling Wildfire Regimes in northern North America"and moved towards his PhD at Department of Earth & Atmospheric Sciences!

 

New April 7, 2009 Our lab has been just funded by NASA land-use and land-cover change program to investigate Changes of Land Cover and Land Use and Greenhouse Gas Emissions in Northern Eurasia: Impacts on Human Adaptation and Quality of Life at Regional and Global Scales. The collaborators include the Marine Biological Laboratory at Woods Hole, Massachusetts Institute of Technology, International Institute of Applied Systems Analysis, the Russian Academy of Sciences, the National Institute for Environmental Studies in Japan, and the Chinese Academy of Sciences.

 

New February 4, 2009 A feature article, one of the synthesis products of a Working Group led by Prof. Zhuang, supported by National Center of Ecological Analysis and Synthesis (NCEAS), was published this week in EOS. Citation: Zhuang, Q., J. M. Melack, S. Zimov, K. M. Walter, C. L. Butenhoff, and M. A. K. Khalil (2009), Global methane emissions from wetlands, rice paddies, and lakes, Eos, 90(5), 37-38.

 

New November 2, 2008 Our first of a series of study in quantifying the uncertainty of large-scale carbon dynamics has been just published in Journal of Geophysical Research Biogeosciences. The study uses a process-based biogeochemistry model, the Terrestrial Ecosystem Model (TEM), and a Bayesian inference framework to quantify the influence of parameterization equifinality on the estimates of carbon dynamics in boreal forest ecosystems during the 20th century. The full citation is Tang, J., and Q. Zhuang (2008), Equifinality in parameterization of process-based biogeochemistry models: A significant uncertainty source to the estimation of regional carbon dynamics, J. Geophys. Res., 113, G04010, doi:10.1029/2008JG000757.

 

New Oct 22, 2008 In collaboration with AmeriFlux principal investigators, our lab study on quantifying net ecosystem exchange (NEE) at 1km by 1km spatial resolution and 8-day temporal resolution for the continental US was just published in Agricultural and Forest Meteorology. Our study demonstrated that our empirical approach is effective for scaling up eddy flux NEE measurements using satellite data of MODIS to the continental scale and producing spatially-explicit NEE estimates across multiple biomes. Our estimates may provide an independent dataset from simulations with biogeochemical models and inverse modeling approaches for examining the spatiotemporal patterns of NEE and constraining terrestrial carbon budgets over large areas. The full citation: Jingfeng Xiao, Qianlai Zhuang, Dennis D. Baldocchi, Beverly E. Law, Andrew D. Richardson, Jiquan Chen, Ram Oren, Gregory Starr, Asko Noormets, Siyan Ma, Shashi B. Verma, Sonia Wharton, Steven C. Wofsy, Paul V. Bolstad, Sean P. Burns, David R. Cook, Peter S. Curtis, Bert G. Drake, Matthias Falk, Marc L. Fischer, David R. Foster, Lianhong Gu, Julian L. Hadley, David Y. Hollinger, Gabriel G. Katul, Marcy Litvak, Timothy A. Martin, Roser Matamala, Steve McNulty, Tilden P. Meyers, Russell K. Monson, J. William Munger, Walter C. Oechel, Kyaw Tha Paw U, Hans Peter Schmid, Russell L. Scott, Ge Sun, Andrew E. Suyker, Margaret S. Torn, 2008, Estimation of net ecosystem carbon exchange for the conterminous United States by combining MODIS and AmeriFlux data. Agricultural and Forest Meteorology, 148, 1827-1847

 

New Aug 15, 2008 In collaboration with the Chinese Academy of Sciences, our research on quantifying the net primary production of Chinese forest ecosystems is published in the journal of Mitigation and Adaptation Strategies for Global Change. The article is entitled "Quantification of Net Primary Production of Chinese Forest Ecosystems with Spatial Statistical Approaches". The study took a new approach in using geospatial statistics and ground-truth data to provide the estimate and its uncertainty of this important natural resource in China.

 

New Aug 12, 2008 Under the auspices of the National Center for Ecological Analysis and Synthesis (NCEAS), a special section focusing on recent methane cycling study has been published at Journal of Geophysical Research -- Biogeoscience organized by Prof. Qianlai Zhuang and Prof. Bill Reeburgh. The section presents results from new field studies, new instruments, and new approaches to the above areas. The section specifically addresses the issues of methane emissions in both natural and managed ecosystems, which are undergoing anthropogenic and natural perturbations of water table, permafrost thaw, volcanic deposition, sulfur deposition, and manure/fertilizer amendment. To better quantify the regional and global CH4 emissions, these effects and controls need to be considered in biogeochemistry models. The continuous and long-term observations of CH4 fluxes impacted by those factors and processes should still be a priority for the CH4 research community. For complete set of articles, one may find at http://www.agu.org/contents/sc/ViewCollection.do?collectionCode=METHANE1&journalCode=JG

 

New July 2, 2008 Our lab has been funded by DOE with a project " Quantifying Climate Feedbacks from Abrupt Changes in High-Latitude Trace-Gas Emissions" in collaboration with MIT, Marine Biological Laboratory, and University of Alaska. The goal is to quantify the potential for threshold changes in natural emission rates of trace gases, particularly methane and carbon dioxide, from pan-arctic terrestrial systems under the spectrum of anthropogenically forced climate warming, and the extent to which these emissions provide a strong feedback mechanism to global climate warming.

 

New March 25, 2008 --- Congratulations! Xiaoliang has just been selected as the Boeing award for Best Paper in Image Analysis and Interpretation by the American Society for Photogrammetry & Remote Sensing(ASPRS) with his paper, entitled “Removal of Noise by Wavelet Method to Generate High Quality Temporal Data of Terrestrial MODIS Products? The paper was published in Photogrammetric Engineering & Remote Sensing, 73(10) 1129-1139. The presentation of the award certificate will take place during the ASPRS 2008 Annual Conference in Portland, Oregon, April 30th.

 

New Dec 2, 2007 --- A study on relationship between boreal forest fires and dought conditions in the last half century has been just published online in Envionmental Research Letters ( Published 27 November 2007 Online at stacks.iop.org/ERL/2/044003).

 

New July 10, 2007 --- Our lab was just awarded by DOE with a project, entitled “Analysis Of Global Economic And Environmental Impacts of A Substantial Increase In Bioenergy Production? The goal of this research is to develop realistic assessments of the economic and environmental impacts of regional and global policies designed to stimulate bioenergy production and use. We will build on the unique strengths of GTAP to analyze economic impacts of alternative bioenergy policies at regional and global levels. We will use the TEM model to help develop the land supply curves and to validate environmental consequences of these policies and check their feasibility from the environmental and land use perspectives.

 

New May 24, 2007 --- Congratulations to our lab member Jinyun, Tang, who has just been selected as recipient of prestigious NASA Earth System Science (ESS) Fellowship!

 

New The EBDL is funded by the NSF Carbon and Water in the Earth System Program for the project, entitled "Collaborative Research: Impact of Permafrost Degradation on Carbon and Water in Boreal Ecosystems". Purdue University is the lead institution in this collaborative project; three other institutions are the United States Geological Surveys, University of Alaska Fairbanks, and Alaska Ecological Surveys. During five-year project period, this project will generate a new approach to modeling boreal forest systems by using research tasks designed to (1) assess interactive effects of climate change and fire on permafrost stability; (2) quantify how the varying modes of permafrost degradation initiate various thaw regimes on the landscape by affecting the microtopography, drainage, and soil thermal regimes of boreal systems; (3) determine how various thaw regimes such as drained or ponded systems affect carbon loss or accumulation in biomass and soils, and (4) characterize the export of dissolved organic carbon from watersheds in an effort to fingerprint the various thaw regimes induced by permafrost degradation.