My research interests and expertise are closely related to system ecology and ecosystem simulation models.
During my PhD study, I used Professional Dynamo Plus to build an agro-forestry system model and performed system optimization on tree harvesting. From late 1990s, I began carbon simulation studies. I have used a number of models in my research, such as the CBM-CFS2, 3PG, TreeDYN, CENTURY, TRIPLEX, IBIS, GEMS-EDCM, and USPED. My current research also includes models like Biome-BGC, DAYCENT, ED, CLM and LUCAS. My other experiences/skills include GIS/RS data processing, back-propagation (BP) neural network modeling, NetCDF data processing/visualization, and leadership class supper computing (ALCF Mira/Theta). My Research activities have brought 50+ various peer-reviewed journal publications.
I have been participating in the development of the methodology and the implementation of GEMS and IBIS models for the USGS LandCarbon Project since 2010. Currently I am leading an ESTCP project that focuses on ecosystem model inter-comparisons and decision support. Beyond that, I also joined in a multi-organization effort on inland and coastal wetland modeling.
Science and Products
Wetland Carbon Working Group: Improving Methodologies and Estimates of Carbon and Greenhouse Gas Flux in Wetlands
Land Use and Climate Change Team
Federal Lands Greenhouse Gas Emissions and Sequestration in the United States: Estimates 2005-14 - Data Release
Simulated 1km resolution 1971-2015 ecosystem carbon variables from the IBIS model (2017/09/12)
Terrestrial ecosystem modeling with IBIS: Progress and future vision
Ecosystem carbon balance in the Hawaiian Islands under different scenarios of future climate and land use change
Identifying dominant environmental predictors of freshwater wetland methane fluxes across diurnal to seasonal time scales
Effects of 21st century climate, land use, and disturbances on ecosystem carbon balance in California
Grasslands
Federal lands greenhouse emissions and sequestration in the United States—Estimates for 2005–14
Integrating forest inventory data and MODIS data to map species-level biomass in Chinese boreal forests
Effects of contemporary land-use and land-cover change on the carbon balance of terrestrial ecosystems in the United States
Interannual variation in methane emissions from tropical wetlands triggered by repeated El Niño Southern Oscillation
Simulated effects of nitrogen saturation the global carbon budget using the IBIS model
Climate-driven increase of natural wetland methane emissions offset by human-induced wetland reduction in China over the past three decades
Mapping site index and volume increment from forest inventory, Landsat, and ecological variables in Tahoe National Forest, California, USA
Science and Products
- Science
Wetland Carbon Working Group: Improving Methodologies and Estimates of Carbon and Greenhouse Gas Flux in Wetlands
WARC researchers are working to quantify the impacts of future climate and land use/land cover change on greenhouse gas emissions and reductions.Land Use and Climate Change Team
We are a research team focusing on understanding the rates, causes, and consequences of land change across a range of geographic and temporal scales. Our emphasis is on developing alternative future projections and quantifying the impact on environmental systems, in particular, the role of land-use change on ecosystem carbon dynamics.We are interested in how land-use and climate systems will... - Data
Federal Lands Greenhouse Gas Emissions and Sequestration in the United States: Estimates 2005-14 - Data Release
This dataset includes ten years of emissions and sequestration estimates (2005-2014) in two separate tables, 1) the combustion and extraction of fossil fuels on Federal lands and 2) processes from the ecosystems on those Federal lands. The fossil fuel related estimates include the greenhouse gases carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O), and the ecosystems estimates include onSimulated 1km resolution 1971-2015 ecosystem carbon variables from the IBIS model (2017/09/12)
This simulated ecosystem carbon dataset is derived from simulations of the parallel Integrated Biosphere simulator (pIBIS). Annual carbon variables cover 1971-2015 at 1-km (960m) spatial resolution with 3052 rows and 4823 columns. Carbon stock and flux units are in kgC/m2 and kgC/m2/yr, respectively. Data are in NetCDF format and Albers equal area projection. Overall data creation steps: 1. The pI - Publications
Filter Total Items: 36
Terrestrial ecosystem modeling with IBIS: Progress and future vision
Dynamic Global Vegetation Models (DGVM) are powerful tools for studying complicated ecosystem processes and global changes. This review article synthesizes the developments and applications of the Integrated Biosphere Simulator (IBIS), a DGVM, over the past two decades. IBIS has been used to evaluate carbon, nitrogen, and water cycling in terrestrial ecosystems, vegetation changes, land-atmosphereEcosystem carbon balance in the Hawaiian Islands under different scenarios of future climate and land use change
The State of Hawai'i passed legislation to be carbon neutral by 2045, a goal that will partly depend on carbon sequestration by terrestrial ecosystems. However, there is considerable uncertainty surrounding the future direction and magnitude of the land carbon sink in the Hawaiian Islands. We used the Land Use and Carbon Scenario Simulator (LUCAS), a spatially explicit stochastic simulation modelIdentifying dominant environmental predictors of freshwater wetland methane fluxes across diurnal to seasonal time scales
While wetlands are the largest natural source of methane (CH4) to the atmosphere, they represent a large source of uncertainty in the global CH4 budget due to the complex biogeochemical controls on CH4 dynamics. Here we present, to our knowledge, the first multi-site synthesis of how predictors of CH4 fluxes (FCH4) in freshwater wetlands vary across wetland types at diel, multiday (synoptic), andEffects of 21st century climate, land use, and disturbances on ecosystem carbon balance in California
Terrestrial ecosystems are an important sink for atmospheric carbon dioxide (CO2), sequestering ~30% of annual anthropogenic emissions and slowing the rise of atmospheric CO2. However, the future direction and magnitude of the land sink is highly uncertain. We examined how historical and projected changes in climate, land use, and ecosystem disturbances affect the carbon balance of terrestrial ecoGrasslands
Key findings:Total grassland carbon stocks in the conterminous United States, estimated to be about 7.4 petagrams of carbon (Pg C) in 2005, are projected to increase to about 8.2 Pg C by 2050. Although U.S. grasslands are expected to remain carbon sinks over this period, the uptake rate is projected to decline by about half. In the U.S. Great Plains, land-use and land-cover changes are expected toFederal lands greenhouse emissions and sequestration in the United States—Estimates for 2005–14
In January 2016, the Secretary of the U.S. Department of the Interior tasked the U.S. Geological Survey (USGS) with producing a publicly available and annually updated database of estimated greenhouse gas emissions associated with the extraction and use (predominantly some form of combustion) of fossil fuels from Federal lands. In response, the USGS has produced estimates of the greenhouse gas emiIntegrating forest inventory data and MODIS data to map species-level biomass in Chinese boreal forests
Timely and accurate knowledge of species-level biomass is essential for forest managers to sustain forest resources and respond to various forest disturbance regimes. In this study, maps of species-level biomass in Chinese boreal forests were generated by integrating Moderate Resolution Imaging Spectroradiometer (MODIS) images with forest inventory data using k nearest neighbor (kNN) methods and eEffects of contemporary land-use and land-cover change on the carbon balance of terrestrial ecosystems in the United States
Changes in land use and land cover (LULC) can have profound effects on terrestrial carbon dynamics, yet their effects on the global carbon budget remain uncertain. While land change impacts on ecosystem carbon dynamics have been the focus of numerous studies, few efforts have been based on observational data incorporating multiple ecosystem types spanning large geographic areas over long time horiInterannual variation in methane emissions from tropical wetlands triggered by repeated El Niño Southern Oscillation
Methane (CH4) emissions from tropical wetlands contribute 60%–80% of global natural wetland CH4 emissions. Decreased wetland CH4 emissions can act as a negative feedback mechanism for future climate warming and vice versa. The impact of the El Niño–Southern Oscillation (ENSO) on CH4 emissions from wetlands remains poorly quantified at both regional and global scales, and El Niño events are expecteSimulated effects of nitrogen saturation the global carbon budget using the IBIS model
Over the past 100 years, human activity has greatly changed the rate of atmospheric N (nitrogen) deposition in terrestrial ecosystems, resulting in N saturation in some regions of the world. The contribution of N saturation to the global carbon budget remains uncertain due to the complicated nature of C-N (carbon-nitrogen) interactions and diverse geography. Although N deposition is included in moClimate-driven increase of natural wetland methane emissions offset by human-induced wetland reduction in China over the past three decades
Both anthropogenic activities and climate change can affect the biogeochemical processes of natural wetland methanogenesis. Quantifying possible impacts of changing climate and wetland area on wetland methane (CH4) emissions in China is important for improving our knowledge on CH4 budgets locally and globally. However, their respective and combined effects are uncertain. We incorporated changes inMapping site index and volume increment from forest inventory, Landsat, and ecological variables in Tahoe National Forest, California, USA
High-resolution site index (SI) and mean annual increment (MAI) maps are desired for local forest management. We integrated field inventory, Landsat, and ecological variables to produce 30 m SI and MAI maps for the Tahoe National Forest (TNF) where different tree species coexist. We converted species-specific SI using adjustment factors. Then, the SI map was produced by (i) intensifying plots to e