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Group News 2024: November: Jingfeng is the winner of the UNH Faculty Excellence in Research Award in 2024. The university created a video to honor him [YouTube video: UNH Faculty Excellence: Jingfeng Xiao] October: Our work is featured by USDA Forest Service: The Future of Water: A New Tool Helps Show the Relationship Between Climate, Plants, and Water Our projections of future water yield with climate and vegetation change for each HUC-8 watershed in the CONUS (2008-2099) are available for visualization online: https://usfs.maps.arcgis.com/apps/dashboards/5055d33b5553470c960f5648f2077ee9. September: Jingfeng and collaborators published a paper in Journal of Forestry: Do Experimental Forests and Ranges of the southeastern United States represent the climate, ecosystem structure, and ecosystem functions of the region? [PDF] Our collaboration with Dr. John Kim at USDA Forest Service has led to the funding of a two-year project: Projecting Future Net Primary Productivity and Vegetation Shifts in Alaska Using a Dynamic Vegetation Model Under Climate Change Scenarios ($339,215). Henrique will work on this project starting from March 2025. August: Jingfeng presented research results at the 11th International Carbon Dioxide Conference (ICDC) in Manaus, Brazil. Henrique's paper titled Climate and vegetation change impacts on future conterminous United States water yield is published in Journal of Hydrology. [PDF]. The MC2 projections of potential vegetation (vegetation type and LAI) and WaSSI projections of water yield, evapotranspiration (ET), and soil moisture for the CONUS, and the adapted WaSSI model code can be downloaded from our data depository. Jingfeng gave a talk at the USCCC Annual Meeting. The title of the tlak is: Towards understanding diurnal cycling of ecosystem processes acros the globe. June: Our collaborator Dr. Junjie Liu led a nice paper in Science Advances: The reduced net carbon uptake over northern hemisphere land causes the close-to-normal CO2 growth rate in 2021 La Niña. Our GOSIF GPP product contributed to this work. [PDF]. May: Our global, OCO-2 based SIF product (GOSIF) and GPP product (GOSIF GPP) have been extended to 2023. Both products (0.05-deg; 8-day, monthly, & annual; 2000-2023) can be downloaded from Global Ecology Data Repository. Since 2019, they have been used in ~270 journal articles. April: Our collaborators Drs. Shengli Tao and Zuirui Ao led a paper in Science. We find that among 82 major cities across China, 45% are subsiding >3 mm per year, and 16% are subsiding >10 mm per year. The sinking of cities is likely due to groundwater withdrawal and building weight. [PDF] Weizhi, a former visiting scholar, published a nice synthesis study on carbon fluxes of China’s coastal wetlands and impacts of reclamation and restoration in Global Change Biology. [PDF] Jingfeng gave an invited talk on monitoring vegetation phenology using solar-induced chlorophyll fluorescence at the International Assocation of Landscape Ecology-North America (IALE-NA) annual meeting in Oklahoma City. March: Jingyi published a paper on dryland evapotranspiration estimation with remote sensing solar-induced chlorophyll fluorescence in Remote Sensing of Environment [PDF]. This is mainly based on her PhD work. January: Our Machine learning and FLUXNET based Carbon and Water Fluxes (MF-CW) product is available online. MF-CW is a 0.5-degree gross primary production (GPP), evapotranspiration (ET), and water use efficiency (WUE) product for the globe (1982-2016) and is upscaled from FLUXNET observations. The data can be downloaded from our Global Ecology Data Repository. 2023: December: Jingyi presented her work on the generation of global gridded, hourly estimates of evapotranspiration (ET) based on ECOSTRESS data and machine learning at AGU. Jingfeng talked about forest structural diversity and global water use efficiency at the conference. September: NCAR Climate Data Guide publishes an Expert Developer Guide on our GOSIF product, a global dataset of dataset of solar-induced chlorophyll fluorescence. August: In our Science paper published on August 11, 2023, we find that assumed increases in global ecosystem water use efficiency have stalled since 2001 due to rising vapor pressure deficit, which offsets CO2 fertilization and depresses photosynthesis but enhances evapotranspiration. [Free full text in PDF] (Highlighted by Science on the very top of its homepage) Xing Li, a former group member, published a nice paper in Science Advances: New-generation geostationary satellite reveals widespread midday depression in dryland photosynthesis during the 2020 western U.S. heatwave. [PDF] Yue Chang, a former group member, published a nice paper in Sustainable Cities and Society: Monitoring diurnal dynamics of surface urban heat island for urban agglomerations using ECOSTRESS land surface temperature observations. [PDF] July: Erin's paper came out in Remote Sensing of Environment: Structural and species diversity explain aboveground carbon storage in forests across the United States: evidence from GEDI and forest inventory data. [PDF] May: A Changing Estuary Lined With Red (by NASA Earth Observatory) covers papers on red beaches including our paper in Ecosphere in 2018 (Human activities accelerated the degradation of saline seepweed red beaches by amplifying top-down and bottom-up forces). A new vegetation phenology dataset in northern terrestrial ecosystems is published in Scientific Data by Dr. Jing Fang et al. Based on our GOSIF GPP data, this phenology dataset consists of start, end, and length of growing season (SOS, EOS, LOS) (0.05-deg; 2001-2020). [PDF] Our new paper just came out in Science Advances: Persistent and enhanced carbon sequestration capacity of alpine grasslands on the Earth’s Third Pole. Our research found that carbon sequestration capacity of alpine grasslands on the Tibetan Plateau has undergone persistent enhancement under a warmer and wetter climate. [PDF] 2022: December: Erin, Jingfeng, and collaborators (Jeff Atkins, Qinfeng Guo) convened/chaired a session on forest structural diversity and ecosystem fucntions at AGU. Jingfeng presented on the long overdue gap-filld, partitioned AmeriFlux dataset and diurnal variations of urban heat island and also convened/chaired a session on upscaling of networked observations using machine learning and modeling with collaborators Yiqi Luo, Stefan Metzger. November: A new postdoctoral research scientist, Henrique Duarte, joined our group. He will simulate future forest ecosystem dynamics for the eastern U.S. Henrique will work closely with scientists at the Forest Service: Ge Sun, Steve McNulty, John Kim. October: Jingfeng gave a talk on elucidating the relationship between solar-induced fluorescence and gross primary production with TROPOMI data at the USCCC Annual Meeting. Jingfeng gave a talk on towards benchmarking and improving Earth System Models on the UNH-DOE National Lab Day. A new postdoctoral research scientist, Jingyi Bu, joined our group. She will study ecosystem functioning and processes with state-of-the-art satellite data. August: Erin presented our new results on impacts of structural and biological diversity on aboveground carbon storage in temperate forests based on GEDI and forest inventory data at the ESA and CSEE Joint Meeting in Montreal, Canada. We gap-filled, partitioned flux data for nearly 300 AmeriFlux and NEON sites. The gaps of the meteorological data were filled with ERA5-Land reanalysis data, and the flux measurements were gap-filled and partitioned using standardized procedures. The data cover the period from the early 1990s to 2021. If you are interested in using the data, feel free to contact the PI. Jingfeng gave an invited seminar on Remote Sensing of Diurnal Variations in Ecosystem Processes at Department of Earth and Environmental Science, Xi'an Jiaotong University. May: Our new paper led by Dr. Baolin Xue is published in Water Resources Research: Divergent hydrological responses to forest expansion in dry and wet basins of China: Implications for future afforestation planning. [PDF] Our new paper led by Dr. Decheng Zhou is published in Earth's Future: Urbanization contributes little to global warming but substantially intensifies local and regional land surface warming. [PDF] April: Jingfeng gave an invited seminar on understanding photosynthesis from ecosystems to the globe at Department of Civil and Environmental Engineering, University of Connecticut on April 15, 2022. February: Yue's new paper came out today. We combined data from GOES-R and ECOSTRESS to explore the diurnal variations of surface urban heat island and thermal differentiation among various land covers over the Boston Metropolitan Area. Both GOES-R and ECOSTRESS have diurnal sampling capability. We take advantage of the strengths of the geostationary satellite (high-frequency observations within each day/night) and ECOSTRESS (high spatial resolution). [PDF] Our new paper is published in Science of the Total Environment. Our findings show that daytime and nighttime warming has no opposite effects on vegetation phenology and productivity in the northern hemisphere, and properly dealing with the multicollinearity problem is critical for understanding the effects of asymmetric warming on vegetation activity. January: Our global, fine-resolution SIF (GOSIF) and GPP (GOSIF GPP) products released in 2019 have been used by numerous scientists around the world and have led to ~60 journal articles to date. These articles are on various topics such as productivity, carbon cycle, phenology, drought, and model evaluation. 2021: November: USGS and NASA Earthdata highlights Yue's paper in Remote Sensing of Environment: Exploring diurnal thermal variations in urban local climate zones with Xing's paper titled TROPOMI observations allow for robust exploration of the relationship between solar-induced chlorophyll fluorescence and terrestrial gross primary production is published in Remote Sensing of Environment. [PDF] September: Jingfeng gave an invited talk at the OCO-2/OCO-3 Science Team Telecon: Studying ecosystem processes with SIF measurements from the OCO missions. Erin Crockett joined our group as a postdoctoral research scientist and is officially hired via the ORISE program, and he will work with scientists at the Forest Service on a USDA-funded project. Erin got his PhD from McGill University very recently. Welcome, Erin! August: We shared our recent research results at the ECOSTRESS Science Team Meeting (virtually). Jingfeng gave an invited talk on remote sensing of ecosystem processes at Southern Research Station, USDA Forest Service (virtually). Jingfeng gave a talk at the Asia Oceania Geosciences Society (AOGS) 18th Annual Meeting (virtually). The talk is titled Exploring diurnal cycles of surface urban heat island intensity in Boston with land surface temperature data derived from GOES-R geostationary satellites. Jingfeng gave a talk at the USCCC 17th Annual Meeting (virtually). The title of the talk is Studying diurnal variations of ecosystem processes from space. July: Our perspective article is published in Nature Plants. With emerging satellite observations, we can now study diurnal cycling of plant functioning and ecosystem processes (e.g., GPP, ET, WUE) from space. w/ @jawzsh Hiro Hashimoto @kazuhito_ichii June: Yue's paper titled Exploring diurnal thermal variations in urban local climate zones with ECOSTRESS land surface temperature data is published in Remote Sensing of Environment. This is one of the few earliest urban studies based on ECOSTRESS observations. [PDF] April: Jingfeng and Dr. Ge Sun (Forest Service) are funded for studying ecosystem functions of southern forests. Xiaojuan's paper titled Improving the global MODIS GPP model by optimizing parameters with FLUXNET data is one of the most downloaded Agricultural and Forest Meteorology articles in the last 90 days (as of April 21, 2021). [PDF] March: Our global, 0.05-deg SIF and GPP products (GOSIF & GOSIF GPP) are now extended to 2020. The entire datasets (8-day/monthly, 0.05-deg, 2000-2020) are available at our data repository. GOSIF is based on OCO-2 SIF, and GOSIF GPP is derived from GOSIF and SIF-GPP relationships. Jingfeng gave an invited talk at the FLUXNET Seminar Series on March 5, 2021. The talk is titled Assessing drought impacts on terrestrial photosynthesis with satellite data from OCO-2 and SMAP. Xing's paper titled ECOSTRESS estimates gross primary production with fine spatial resolution for different times of day from the International Space Station is now published in Remote Sensing of Environment. We can now study the diurnal cycling of plant carbon uptake from space. [PDF] February: Haibo's paper titled Improving the capability of the SCOPE model for simulating solar-induced fluorescence and gross primary production using data from OCO-2 and flux towers is now published in Remote Sensing. [PDF] January: Xiaojuan's paper titled Improving the global MODIS GPP model by optimizing parameters with FLUXNET data is now published in Agricultural and Forest Meteorology. We optimized parameters and quantified parameter uncertainty for the MODIS GPP model for all vegetation types with data from 110 FLUXNET sites and the MCMC method. It is an effort towards improving the globall MODIS GPP product. [PDF] Jingfeng has agreed to serve as an associate editor for Ecological Processes, an international, peer-reviewed, open access journal devoted to ecological studies with a focus on the underlying processes of the dynamics and functions of ecological systems at multiple spatial and temporal scales. 2020: December: For the first time, we used observations from new generation geostationary satellites to study diurnal cycling of surface urban heat island (SUHI). With GOES-R land surface temperature data, we found that (1) SUHI intensity in Boston varied over the course of diurnal cycle; (2) maximum and minimum SUHI intensity occurred near noon and at night, respectively; (3) maximum SUHI intensity was ~2–3 °C higher in urban-core than in suburban area; (4) relations of SUHI intensity with drivers varied over the course of diurnal cycle. Great job, Yue! [Full article] Hang's paper titled Canopy photosynthetic capacity drives contrasting age dynamics of resource use efficiencies between mature temperate evergreen and deciduous forests is now published in Global Change Biology. [PDF] Eight group members and alumni presented research findings at the AGU Fall Meeting (Online Everywhere). Jingfeng presented the findings of our ECOSTRESS project at the ECOSTRESS Science and Applications Team Meeting. November: Jing Zhao's paper titled Physiological and environmental control on ecosystem water use efficiency in response to drought across the northern hemisphere has been published in Science of the Total Environment. [PDF] October: Xing's paper titled Synergistic use of SMAP and OCO-2 data in assessing the responses of ecosystem productivity to the 2018 U.S. drought has been published in Remote Sensing of Environment. [PDF] Jingfeng and Xing gave a plenary talk on mapping terrestrial photosynthesis globally with solar-induced chlorophyll fluorescence and FLUXNET observations at the 2020 AmeriFlux Annual Meeting (October 6-8, 2020; Virtual meeting). September: Jingfeng has been promoted to full research professor. Thanks, all our postdocs/scholars, students, collaborators, and funding agencies. Jingfeng gave an invited talk at Geospatial Sciences Center of Excellence (GSCE), South Dakota State University (remotely). The talk is titled Understanding global land photosynthesis with solar-induced chlorophyll fluorescence measured from space. August: Are you interested in DNDC - a widely used biogeochemical model for simulating CO2, CH4, & N2O from site to globe? Now DNDC has the capability to simulate surface energy exchange & radiative forcing. Read our Global Biogeochem. Cycles paper led by Jia: Improving a biogeochemical model to simulate surface energy, greenhouse gas fluxes, and radiative forcing for different land use types in Northeastern United States. July: Hang's paper titled Heatwave effects on gross primary production of northern mid-latitude ecosystems has been published in Environmental Research Letters. Heat waves depress photosynthesis for most ecosystem types except C4 sites. Forests are most resistant and resilient; C4 ecosystems have weaker stomatal control on water loss. Understanding the post-effect of heat waves is also vital. June: A nice web app for Manchester residential yard carbon stock measurements has been recently released: https://tracebiogeochemistry.shinyapps.io/carbon/. Residents can see above/belowground C & tree species in their own yards in comparison to other yards that we sampled. This is funded by our NASA Carbon Cycle Science project (NNX14AJ18G), and created by our project team members Apryl Perry and Alix Contosta. May: Xing's paper titled Global climatic controls on interannual variability of ecosystem productivity: similarities and differences inferred from solar-induced chlorophyll fluorescence and enhanced vegetation index has been published in Agricultural and Forest Meteorology. [PDF] March: Our new AFM paper shows that canopy conductance is the dominant factor regulating forest ecosystem WUE in spring & autumn, while the fraction of diffuse radiation (FDR) is the main driver in summer by depressing ET and promoting GPP. Nice work, Hang! February: The new paper led by Dr. Li Zhang -Increased carbon uptake and water use efficiency in global semi-arid ecosystems came out in ERL today. In this study, we upscaled FLUXNET data to the globe and examined the trends in C uptake, ET, and WUE and their drivers for semi-arid regions globally over the period 1982-2015. Precipitation is the most important factor enhancing carbon uptake, ET, and WUE. Jingfeng and Xing attended the ECOSTRESS Science and Applications Team Meeting at Ventura, California (February 11-13, 2020) and presented our early results from our recently funded ECOSTRESS project. January: Our paper titled Biogeochemical and socioeconomic drivers of above- and below-ground carbon stocks in urban residential yards of a small city is published today in Landscape and Urban Planning. This is an outcome of our NASA Carbon Cycle Science project on the interactions between carbon cycling, land use and climate change within mixed agricultural, forested, suburban, and urban landscapes. Nice work, Alix! 2019: December: Our global, high-resolution SIF (GOSIF) and GPP (GOSIF GPP) products have been extended to 2018. Meanwhile, we have also adopted a scale factor and different data types to reduce data volume and expedite data downloading. Both GOSIF and GOSIF GPP (2000-2018; 0.05 degree; 8 day/monthly) are available for downloading at our data repository. November: The manuscript on our work on the carbon stocks of urban residential yards has been acceped by Landscape and Urban Planning. The lead author is Alexandra Contosta. This work was funded by our NASA Carbon Cycle Science project (PI Xiao). Our new global, 0.05-degree product of gross primary production (GPP) - GOSIF GPP is now available for downloading at our data repository (download GOSIF GPP). This product is based on GOSIF (a global, OCO-2 based SIF product) and SIF-GPP relationships. October: We can now map photosynthesis solely from solar-induced chlorophyll fluorescence. This new method can avoid uncertainties from traditional input data (e.g., climate, soil) and even land cover maps. Xing's manuscript titled "Mapping Photosynthesis Solely from Solar-Induced Chlorophyll Fluorescence: A Global, Fine-Resolution Dataset of Gross Primary Production Derived from OCO-2" is now published in Remote Sensing. This paper presents a new and independent approach for mapping photosynthesis globally and a new global, gridded GPP product (0.05 degree, 8-day). September: Our proposal in response to NASA's ECOSTRESS Science Team solicitation has been selected for funding ($474,616, 11/2019-10/2022, PI Jingfeng Xiao). We will use ECOSTRESS observations to look at plant water use and carbon uptake. Our review article Remote sensing of the terrestrial carbon cycle: A review of advances over 50 years is online in Remote Sensing of Environment. Weizhi's new paper Insect outbreaks have transient effects on carbon fluxes and vegetative growth but longer-term impacts on reproductive growth in a mangrove forest is available online in Agricultural and Forest Meteorology. Haibo's new paper Carbon fluxes across alpine, oasis, and desert ecosystems in northwestern China: the importance of water availability is available online. August: Weizhi's paper titled Insect outbreaks have transient effects on carbon fluxes and vegetative growth but longer-term impacts on reproductive growth in a mangrove forest has been accepted by Agricultural and Forest Meteorology, Nice job, Weizhi! The review article titlted "Remote sensing of the terrestrial carbon cycle: A review of advances over 50 years" has been accepted by Remote Sensing of Environment. This review is led by Jingfeng Xiao and contributed by Frederic Chevallier, Cecile Gomez, Luis Guanter, Jeffrey A. Hicke, Alfredo R. Huete, Kazuhito Ichii, Wenjian Ni, Yong Pang, Abdullah F. Rahman, Guoqing Sun, Wenping Yuan, Li Zhang, and Xiaoyang Zhang. This review article is part of the '50 Years of Environmental Remote Sensing Research: 1969 – 2019' special issue to celebrate the 50th anniversary of Remote Sensing of Environment. Haibo's paper titled Carbon fluxes across alpine, oasis, and desert ecosystems in northwestern China: the importance of water availability has been accepted by Science of the Total Environment. Nice job, Haibo! Jingfeng gave an invited talk on solar-induced chlorophyll fluorescence and terrestrial photosynthesis based on OCO-2 and flux tower data at the Ecological Society of America (ESA) annual meeting at Louisville, KY. The talk is mainly based on Xing's recent work on SIF. July: Xiaojuan's paper titled Evaluating the performance of satellite-derived vegetation indices for estimating gross primary productivity using FLUXNET observations across the globe is published in Remote Sensing. Nice job, Xiaojuan! June: Rossella's paper titled Disentangling the role of photosynthesis and stomatal conductance on rising forest water-use efficiency has been accepted by Proceedings of the National Academy of Sciences of the United States of America. This study was supported by our NASA Terrestrial Ecology project (PI: Scott Ollinger, Co-Is Heidi Asbjornsen and Jingfeng Xiao) and our NSF Macrosystems Biology project (PI: Scott Ollinger, Co-I Jingfeng Xiao). May: Weizhi's paper titled Carbon fluxes and stocks in a carbonate-rich chenier plain is accepted by Agricultural and Forest Meteorology. April: Our new paper titled No trends in spring and autumn phenology during the global warming hiatus has been accepted by Nature Communications. Nice work, Xufeng! March: Di's paper titled Mapping dynamics of soil organic matter in croplands with MODIS data and machine learning algorithms is published in Science of the Total Environment. Our global, OCO-2 based SIF product (GOSIF) is freely available at our data depository. GOSIF consists of global, 0.05-degree SIF estimates at 8-day intervals over the period 2000-2017. Compared with the coarse-resolution SIF (e.g., 1-degree, monthly) that was directly aggregated from OCO-2 soundings (2014-present), GOSIF has finer spatial resolution, globally continuous coverage, and a much longer record. Our GOSIF product is useful for assessing terrestrial photosynthesis and ecosystem function and benchmarking terrestrial biosphere and Earth system models. [Download GOSIF data] Xing's paper titled A Global, 0.05-Degree Product of Solar-Induced Chlorophyll Fluorescence Derived from OCO-2, MODIS, and Reanalysis Data is published today in Remote Sensing. January: Our response to a letter commenting on our 2018 GCB paper is now available online: Solar-induced chlorophyll fluorescence exhibits a universal relationship with gross primary productivity across a wide variety of biomes. Di's manuscript titled Comparison on two synergy approaches for hybrid cropland mapping is now published in Remote Sensing. Di also ended her visit and returned to China. A review article on urban heat islands titled Satellite remote sensing of surface urban heat islands: Progress, challenges, and perspectives is now published in Remote Sensing. This review is led by Decheng Zhou and Jingfeng Xiao. Decheng is an associate professor at Nanjing Univ. of Information & Science Technology. Steve Frolking at ESRC also coauthored the paper. 2018: December: Xiaojuan will end her 16-mo visit at our group and return to China by the end of the month. She has been working on carbon dynamics and evaluation of vegetation indices and other satellite data products. Jingfeng, Xing, Xiaojuan, and Hang attended the AGU meeting at Washington DC. Jingfeng gave two presentations (with one on flux uncertainty and one on spring phenology) and organized two sessions (with one on carbon cycle uncertainty and one on soil organic carbon). Xing gave a presentation on the relationship between SIF and photosynthesis. October: Hang Xu joined the group for his 18-month visit. Hang is currently a PhD student at Beijing Forestry University. He will be conducting research in ecosystem ecology and modeling. Welcome, Hang! September: Weizhi and Haibo ended their one-year visits at our group and returned to China. Weizhi has been working on carbon dynamics, disturbance, and successions of coastal wetlands. Haibo has been synthesizing carbon fluxes in drylands and optimizing models with new satellite measurments. August: Jingfeng gave invited talks at Institute of Subtropical Agriculture and Central South University of Forestry and Technology. Jingfeng gave a 2-hour lecture on how to write good scientific articles at the USCCC Writing Workshop and gave an invited talk on our recent work on solar-induced chlorophyll fluorescence at the USCCC Annual Meeting. The proposal led by Haibo is now funded by National Science Foundation of China. This three-year project (￥600, 000) will focus on vegetation production upscaling in arid regions by integrating solar induced chlorophyll fluorescence data with ecological models. July: Jingfeng gave invited talks at Peking University, Institute of Remote Sensing & Digital Earth (Chinese Academy of Sciences), Chinese Academy of Agricultural Sciences, and Xi'an Jiaotong University. June: Our GCB paper on the universal relationship between solar-induced fluorescence and photosynthesis globally is highlighted by Nature Climate Change on June 29, 2018: Mapping photosynthesis. University of New Hampshire. "Researchers shine a light on more accurate way to estimate climate change." ScienceDaily, 5 June 2018. UNH TODAY. UNH Researchers Shine a Light on More Accurate Way To Estimate Land-based Photosynthesis. 5 June 2018. Weizhi's manuscript on saline seepweed red beaches is accepted for publication by Ecosphere. Salt marshes dominated by saline seepweed (Suaeda heteroptera) provide important ecosystem services such as sequestering carbon (“blue carbon”), maintaining healthy fisheries, and protecting shorelines. "Red beaches" also constitute stunning landscapes and attract lots of tourists every year. Our study finds that human activities accelerated the degradation of these red beaches by influencing top-down (e.g., grazers) and bottom-up (e.g., sediment accretion) forces. May: PhD student Di Chen from Chinese Academy of Agricultural Sciences arrived for her nine-month visit. Welcome, Di! April: Our new manuscript led by Xing is accepted by Global Change Biology. This study reveals the relationship between chlorophyll fluorescence and photosynthesis at the ecosystem scale across a wide variety of biomes globally for the first time using observations from OCO-2 and flux towers. This is a pioneering study. It demonstrates the potential of finer-resolution chlorophyll fluorescence from OCO-2, TROPOMI, and FLEX in ecosystem functioning and carbon cycling studies. February: Xing's paper has been accepted by Environmental Research Letters. Our study shows that the reduction in photosynthesis of Amazon forests during the 2015 drought was partly offset by higher absorbed solar radiation. January: Xufeng's paper titled No consistent evidence for advancing or delaying trends in spring phenology on the Tibetan Plateau is published in Journal of Geophysical Research: Biogeosciences today. 2017: December: Yibo's manuscript is pubished in Remote Sensing of Environment. Our study demonstrates that satellite-derived leaf area index (LAI) products exhibit large discrepancies and can also lead to substantial uncertainty in carbon and water fluxes simulated by terrestrial biosphere models. Jingfeng, Xing, Haibo, and Xiaojuan attended the AGU Fall Meeting in New Orleans. Jingfeng chaired two sessions and also presented recent results on urban heat island. Xing presented recent findings on solar-induced chlorophyll fluorescence. Haibao introduced recent work on parameter estimation. Xufeng's manuscript on phenology has been accepted by JGR: Biogeosciences. The major finding of the study is that there is no consistent evidence for advancing or delaying trends in spring phenology on the Tibetan Plateau. Our study helps settle a long-term debate on spring phenology on the Tibetan Plateau. November: Jingfeng attended the review committee meeting of the 2nd State of Carbon Cycle Report (SOCCR-2) at the National Academy of Sciences. SOCCR-2 will be a timely and valuable report on the current status of the North American carbon cycle. It has been great to serve on this committee. Xing presents his recent work on the photosynthesis of Amazon forests in response to drought at the 11th Graduate Climate Conference at Woods Hole, MA (November 10-12). October: We had a group visit to the White Mountains on a sunny, warm day in mid-October. This is a good time to see fall foliage. September: Xing's manuscript on chlorophyll fluorescence has been accepted by Remote Sensing of Environment. This study is timely by demonstrating that chlorophyll fluorescence observed by the Orbiting Carbon Observatory-2 (OCO-2) is strongly related to flux tower GPP in temperate forests. This is the first time that space-measured fluoresence is linked with photosynthesis at the ecosystem scale for temperate forests. Jingfeng attended the 5th Integrated Land Ecosystem-Atmosphere Processes Study (iLEAPS) Science Conference at Oxford, UK and presented our recent work on the constraining of ecosystem carbon uptake using new satellite data observations (J. Xiao and X. Li). We had a group dinner at Bella's Casual Dining on the evening of September 17th (Sunday). Ms. Xiaojuan Huang (visiting PhD student) and Drs. Haibo Wang and Weizhi Lu (visiting scholars) joined our group and will conduct research in global ecology during their one-year stay. Welcome and have a fruitful year! August: Jingfeng attended the 12th International Congress of Ecology in Beijing, China (August 21-25) and presented our new work on OCO-2 fluoresence (J. Xiao and X. Li). Jingfeng attended the 14th United States-China Carbon Consortium (USCCC) annual meeting at Taiyuan, China (August 18-20th). He led a breakout discussion session on a potential synthesis paper and also presented new work on terrestrial photosynthesis. July: Jingfeng serves on a NASA review panel in Washington DC. April: Dr. Baolin Xue's paper on global patterns of woody residence time is accepted by Global Biogeochemical Cycles. March: Jingfeng Xiao serves on a review comittee of the National Academies of Sciences, Engineering, and Medicine. Feburary: Dr. Weizhi Lu's synthesis paper on wetland carbon fluxes is published in Global Change Biology. Dr. Junmei Tang's paper titled Impacts of land use and socioeconomic patterns on urban heat island is published in International Journal of Remote Sensing. November 16, 2016 - Dr. Xufeng Wang is returning to China today. Xufeng has been a visiting scholar in our group for one year, and has done nice work on long-term trends in phenology, productivity, and carbon uptake. 2016: November 16, 2016 - Dr. Xufeng Wang is returning to China today. Xufeng has been a visiting scholar in our group for one year, and has done nice work on long-term trends in phenology, productivity, and carbon uptake. November 2, 2016 - Meeting report in Eos: Improving Carbon Cycle Projections for Better Carbon Management October 10, 2016 - Dr. Li Zhang's paper titled Drought events and their effects on vegetation productivity in China is accepted by Ecosphere today. September 21-23, 2016 - The 2016 AmeriFlux PI meeting was held at Golden, CO. Jingfeng Xiao served as one of the meeting organizers and also presented results on the contrasting of annual CO2 fluxes between inland and coastal wetlands. September 23, 2016 - UNH TODAY: Seeing the Data for the Trees: With major grant and innovative techniques, UNH researchers study forest biodiversity and climate change September 21, 2016 - Rossella's paper titled "Evapotranspiration and water use efficiency in relation to climate and canopy nitrogen in U.S. forests" is accepted by Journal of Geophysical Research: Biogeosciences today. Congratulations! This work is supported by NASA through Terrestrial Ecology and Carbon Cycle Science. September 7, 2016 - Our paper titled "Recent trends in vegetation greenness in China significantly altered annual evapotranspiration and water yield" (Liu et al.) is published in ERL today. September 2, 2016 - We are funded by the National Science Foundation (NSF) through the MacroSystems Biology Program to exmaine the influence of biological diversity on land-atmosphere exchange in forests by confronting theory with data ($1,244,070, 01/2017-12/2021, Co-PI, PI Scott V. Ollinger). August 15, 2016 - Yibo's manuscript titled Recent trends in vegetation greenness in China significantly altered annual evapotranspiration and water yield is accepted by Environmental Research Letters today. Congratulations, Yibo! July 13, 2016 - Jingfeng Xiao gave an invited talk titled Translating flux observations from towers to regions, continents, and the globe: What have we learned? at Beijing Normal University. July 6, 2016 - Jingfeng Xiao gave an invited talk titled Applications of remote sensing and in-situ measurements in ecohydrology at Nanjing University of Information Science and Technology, Nanjing, China. June 26, 2016 - Jingfeng Xiao (and other USCCC participants) had a field trip and visited a 6,600 acre forest plantation, a forest farm, and the Shuiguan Great Wall (a segment of the Great Wall of China). June 26, 2016 - The meta-analysis manuscript on global wetland C fluxes led by Dr. Weizhi Lu is accepted by Global Change Biology. The title of the manuscript is Contrasting ecosystem CO2 fluxes of inland and coastal wetlands: A meta-analysis of eddy covariance data. June 25, 2016 - Jingfeng Xiao attended the 13th USCCC (US-China Carbon Consortium) annual meeting in Beijing and presented results on the Earth’s “greening” and “browning” that Xufeng Wang worked on. Jingfeng also chaired the USCCC PI discussion session as the USCCC co-chair. June 22, 2016 - Preface: Impacts of extreme climate events and disturbances on carbon dynamics. Preface to our special issue in Biogeosciences (Guest Editors: Jingfeng Xiao, Shuguang Liu, Paul Stoy). May 4, 2016 - Our NASA Carbon Cycle Science project team had a meeting today to discuss the progress and plans for urban field work on the collection of greenhouse gas fluxes (carbon dioxide, methane, nitrous oxide), soil organic carbon, and biomass. April, 2016 - Jingfeng Xiao served on a NASA review panel. March 2, 2016 - Yibo is ending his one-year visit and will be flying back home tomorrow. Yibo has been a great addition to the group. We had a lunch gathering today. Safe travels, Yibo! February 26, 2016 - PhD student Xing Li from University of Electronic Science and Technology of China arrived today for his one-year visit. Welcome, Xing! February 3, 2016 - We are now funded by NASA to develop ecosystem carbon indicators for the U.S. National Climate Assessment. (PI: Jingfeng Xiao; Co-I: Alexander Prusevich) January 5, 2016 - Haibo Wang finished his 3-month visit to our group and returned to China. 2015: December 14-18, 2015 - Yibo Liu presented results on water use efficiency and responses to drought at the AGU meeting. December 14-18, 2015 - Jingfeng Xiao gave an invited talk on what we learned from upscaling efforts at the AGU meeting and also presented results from the Carbon Cycle Science project. November 20, 2015 - Our new paper Contributions of natural and human factors to increases in vegetation productivity in China is published in Ecosphere today. This study disentangles the relative contributions of various natural (climate change, atmospheric CO2 concentrations, N deposition) and human (afforestation, improved agricultural practices) factors to increasing vegetation productivity. November 1, 2015 - Dr. Xufeng Wang from the Cold and Arid Region Environment and Engineering Research Institute, Chinese Academy of Sciences joined our group today for his 12-month visit. Welcome, Xufeng! October 19, 2015 - This is a really saddening news. Prof. Changsheng Li passed away on Sunday night. This is a great loss to his family, the scientific community, and our center. Changsheng is the architect of the DNDC model and also a Co-I of our ongoing NASA-funded project. -> More October 14, 2015 - Dr. Haibo Wang from the Cold and Arid Region Environment and Engineering Research Institute, Chinese Academy of Sciences joined our group today for his 3-month visit. Welcome, Haibo! September 8, 2015 - Yibo Liu published a new paper in Scientific Reports. The title of Yibo's paper is Water use efficiency of China's terrestrial ecosystems and responses to drought (http://www.nature.com/articles/srep13799). August 8, 2015 - Jingfeng Xiao attended the NSF MacroSystems Biology PI Meeting and presented project results. August 1, 2015 - Jingfeng Xiao presented results from our NASA Carbon Cycle Science project and chaired a synthesis discussion session at the USCCC 12th Annual Meeting in Shanghai, China. July 16, 2015 - Jingfeng Xiao gave an invited talk on what we learned from upscaling efforts at the FLUXNET Synthesis Workshop in Beijing, China. June 26, 2015 - Jingfeng Xiao has been officially promoted to Research Associate Professor. Congratulations! April 21, 2015 - Jingfeng Xiao's new paper has been accepted by Ecosphere. The title of the paper is Contributions of natural and human factors to increases in vegetation productivity in China. April 20, 2015 - Jingfeng Xiao attended the NASA Carbon Cycle & Ecosystems Joint Science Workshop and presented preliminary results on our Carbon Cycle Science project. March 30, 2015 - Alexandra's paper titled Generalization and evaluation of the process-based forest ecosystem model PnET-CN for other biomes is published in Ecosphere. [PDF] [code] March 17, 2015 - Our 2014 paper Data-driven diagnostics of terrestrial carbon dynamics over North America in Agricultural and Forest Meteorology is highlighed by the North Ameican Carbon Program (Highlight) February 1, 2015 - Jingfeng Xiao presented results at the 5th NACP meeting and also attended the AmeriFlux annual meeting. January 23, 2015 - Jingfeng Xiao published paper titled Satellite evidence for significant biophysical consequences of the “Grain for Green” Program on the Loess Plateau in China in Journal of Geophysical Research: Biogeoscience. 2014: December 15-16, 2014 - Jingfeng Xiao chaired the session Observing and Predicting Impacts from Ecological and Climatological Disturbances II with Leo Liu, and also presented results on the impacts of recent droughts on North American carbon dynamics at the AGU Fall Meeting. December 4, 2014 - Weifeng Wang's paper on harvesting effects on carbon fluxes and stocks published in Biogeosciences [PDF] July 31, 2014 - Jingfeng Xiao gave an invited talk at the Research Center for Eco-Environmental Sciences (RCES), Chinese Academy of Sciences. The title of the talk is Assessing land-atmosphere carbon and water exchange using flux measurements, satellite data, and modeling approaches. July, 2014 - Jingfeng Xiao is elected as Co-Chair of USCCC (the United States-China Carbon Consortium) at the 11th USCCC Annual Meeting in Lanzhou, Gansu, China July 19, 2014 - A new manuscript is published by Agricultural and Forest Meteorology: Xiao, J. F., Ollinger, S.V., Frolking, S., Hurtt, G.C., Hollinger, D.Y., Davis, K.J.,Pan, Y., Zhang, X., Deng, F., Chen, J., Baldocchi, D.D., Law, B.E., Arain, M.A. Desai, A.R., Richardson, A.D., Sun, G., Amiro, B., Margolis, H., Gu, L, Scott, R.L., Blanken, P.D., Suyker, A.E. (2014). Data-driven diagnostics of terrestrial carbon dynamics over North America. [PDF] June 27, 2014 - Jingfeng Xiao gave an invited talk titled Eddy covariance technique is revolutionizing biogeochemical studies at the Center for Earth System Science, Tsinghua University on June 27, 2014. May 5, 2014 - Jingfeng Xiao gave a short talk titled "Assessing the uncertainty of ecosystem models using AmeriFlux observations" at the 2014 AmeriFlux Annual PI Meeting at Potomac, MD. April 11, 2014 - We are now funded by NASA to conduct a new study to incorporate a new urban dataset from SeaWinds into a multi-sensor analysis of global daytime and nighttime urban heat islands” (NASA, The Science of Terra and Aqua, $725,312, 2014-2017; PI Steve Frolking, Co-Is Jingfeng Xiao, Annemarie Schneider, Mark Friedl) March 24, 2014 - We are now funded by NASA to conduct research on the interactions between carbon cycling, land use and climate change within mixed agricultural, forested, suburban, and urban landscapes” (NASA, Carbon Cycle Science, $1,144,441, 2014-2017, PI Jingfeng Xiao, Co-Is Changsheng Li, Alexandra R. Contosta, Ruth K. Varner, Junmei Tang) March 24, 2014 - A new paper titled China's sizeable and uncertain carbon sink: A perspective from GOSAT is published online in Chinese Science Bulletin. [PDF] February 22, 2014 - A new paper titled Uncertainty in model parameters and regional carbon fluxes: A model-data fusion approach is published in Agricultural and Forest Meteorology. This paper highlights a model-data fusion approach for quantifying the uncertainty of model parameters and regional carbon fluxes. [PDF] February 1, 2014 - Jingfeng Xiao published a book chapter titled Assessing Net Ecosystem Exchange of Carbon Dioxide Between the Terrestrial Biosphere and the Atmosphere Using Fluxnet Observations and Remote Sensing (Book: Biophysical Applications of Satellite Remote Sensing, Springer, edited by J. hanes) 2013: December 9-13, 2013 - Jingfeng Xiao gave an talk on the cross-site synthesis of carbon and water fluxes in China and co-chaired a session on Impacts of Extreme Climate Events and Disturbances on Carbon Dynamics at the AGU Fall Meeting. November 22, 2013 - Jingfeng Xiao gave an invited talk titled eddy covariance flux observations and global ecology at the Institute of Botany, Chinese Academy of Sciences November 21, 2013 - Jingfeng Xiao gave an invited talk on extreme climate events and carbon cycle at the International Institute for Earth System Science, Nanjing University. September 15, 2013 - Our new manuscript titled Carbon fluxes, evapotranspiration, and water use efficiency of terrestrial ecosystems in China is published in Agricultural and Forest Meteorology online [PDF]. August 4-9, 2013 - Alexandra Thorn presented her recent work on the generalization of a forest ecosystem model - PnET-CN to other biomes at the ESA 98th Annual Meeting. July 22-25, 2013 - Jingfeng Xiao served on the NASA Interdisciplinary Research in Earth Science (IDS) Review Panel. February 22, 2014 - A new paper titled Uncertainty in model parameters and regional carbon fluxes: A model-data fusion approach is published in Agricultural and Forest Meteorology. This paper highlights a model-data fusion approach for quantifying the uncertainty of model parameters and regional carbon fluxes. [PDF] February 1, 2014 - Jingfeng Xiao published a book chapter titled Assessing Net Ecosystem Exchange of Carbon Dioxide Between the Terrestrial Biosphere and the Atmosphere Using Fluxnet Observations and Remote Sensing (Book: Biophysical Applications of Satellite Remote Sensing, Springer, edited by J. hanes) December 9-13, 2013 - Jingfeng Xiao gave an talk on the cross-site synthesis of carbon and water fluxes in China and co-chaired a session on Impacts of Extreme Climate Events and Disturbances on Carbon Dynamics at the AGU Fall Meeting. November 22, 2013 - Jingfeng Xiao gave an invited talk titled eddy covariance flux observations and global ecology at the Institute of Botany, Chinese Academy of Sciences November 21, 2013 - Jingfeng Xiao gave an invited talk on extreme climate events and carbon cycle at the International Institute for Earth System Science, Nanjing University. September 15, 2013 - Our new manuscript titled Carbon fluxes, evapotranspiration, and water use efficiency of terrestrial ecosystems in China is published in Agricultural and Forest Meteorology online [PDF] August 4-9, 2013 - Alexandra Thorn presented her recent work on the generalization of a forest ecosystem model - PnET-CN to other biomes at the ESA 98th Annual Meeting. July 22-25, 2013 - Jingfeng Xiao served on the NASA Interdisciplinary Research in Earth Science (IDS) Review Panel. June 18-20, 2013 - Jingfeng Xiao co-chaired the International Symposium on Global Change Research 2013: Coupled Natural & Human Systems, Nanjing, China. June, 2013 - Jingfeng Xiao gave invited talks at the the 7th International Symposium on Modern Ecology (Guangzhou) and Institute of Botany, Chinese Academy of Sciences (Beijing). June 6-7, 2013 - Jingfeng Xiao and Alexandra Thorn attended the NSF MacroSystems Biology PI meeting. May 23, 2013 - Jingfeng Xiao gave an invited talk titled Land-atmosphere carbon and water exchange derived from flux observations, satellite data, and modeling at Yale-NUIST Center on Atmospheric Environment. May 13-14, 2013 - Weifeng Wang attended a training workshop for macrosystems research at Duke University. April 1, 2013 - A paper on the evaluation of continental scale model simulations by Raczka et al. is in press and available in preprint in Ecological Monographs (PDF). Feb 18, 2013 - Spring droughts could reduce plant growth and carbon uptake. The ERL paper is featured in environmentalresearchweb. 2012: December 3-7, 2012 - Jingfeng Xiao gave an oral presentation titled A perspective on impacts of extreme climate events and disturbances on carbon dynamics from FLUXNET observations at the AGU Fall Meeting, San Francisco, CA. November 7-9, 2012 - Jingfeng Xiao attended the NASA Carbon Management System Science Team Meeting at NASA GSFC. October 3, 2012 - Jingfeng Xiao gave an invited talk titled Interannual variability of global land-atmosphere carbon fluxes: A perspective from FLUXNET observations and upscaling at Boston University, Biogeosciences Program. June 29, 2012 - Jingfeng Xiao gave an invited talk on the carbon cycle at the Center for Earth System Science, Tsinghua University. June 16-18, 2012 - Jingfeng Xiao attended the 9th US-China Carbon Consortium (USCCC) Annual Meeting in Changsha, China, June 15-18 and introduced the progress, challenges, and opportunities of USCCC flux synthesis work. June 12-14, 2012 - Jingfeng Xiao gave an invited talk titled 'Finding your niche in ecology" at the 3rd International Young Ecologist Forum in Kaifeng, Henan, China, June 12-14. May 22-24, 2012 - Jingfeng Xiao attended the 17th Wildland Shrub Symposium Las Cruces, New Mexico, and gave an invited talk on carbon cycling in shrublands. April 23, 2012 - New grant from NASA Terrestrial Ecology Program: Exploring relationships among water use efficiency, canopy nitrogen and carbon cycling acrossNorth American ecosystems to improve land surface models, $780,205, 2012-2015 (PI Scott Ollinger, Co-Is Heidi Asbjornsen and Jingfeng Xiao) March 20, 2012 - Jingfeng Xiao gave an invited talk on gridded flux products derived from flux networks at the DOE Workshop: Strategies to Promote Integrated Experiment-Model Approaches to Terrestrial Ecosystem Study (Bethesda, Maryland, March 19-21, 2012). March 12-14, 2012 - Jingfeng Xiao and Alexandra Thorn attended the first NSF Macrosystems Biology PI meeting at Boulder, CO and introduced the progress of our project January 19, 2012 - Advances in upscaling of eddy covariance measurements of carbon and water fluxes in JGR - Biogeosciences (Introduction to special issue, J. Xiao et al.) [PDF] 2011: December 6, 2011 - Jingfeng Xiao convenes and chairs a session Impacts of Extreme Climate Events and Disturbances on Carbon Cycling at the AGU Fall Meeting with Dr. Shuguang Liu September 1, 2011 - Jingfeng Xiao and coauthors publish a paper titled Upscaling carbon fluxes from towers to the regional scale: influence of parameter variability and land cover representation on regional flux estimates is published in JGR - Biogeosciences.[PDF] July 18-31, 2011 - Jingfeng Xiao gave invited talks at Beijing Normal University, Institute of Geographical Sciences & Natural Resources, Chinese Academy of Sciences, and 8th USCCC Workshop in China. June 7, 2011 - Jingfeng Xiao gave an invited talk at the FLUXNET and Remote Sensing Open Workshop: Towards Upscaling Flux Information from Towers to the Globe (Berkeley, CA, June 7-9, 2011). The title of the talk is Success and Failure of Implementing Data-driven Upscaling Using Flux Networks and Remote Sensing. May 18, 2011 - Jingfeng Xiao is awarded a three-year grant by Macrosystems Biology program, NSF: Assessing Ecosystem Carbon Dynamics over North America by Integrating Eddy Covariance, MODIS, and New Ecological Data through Upscaling and Model-data Synthesis, $517,685, 2011-2014, Jingfeng Xiao (PI), Scott Ollinger (Co-PI). May 13, 2011 - Jingfeng Xiao has a manuscript titled Upscaling carbon fluxes from towers to the regional scale: influence of parameter variability and land cover representation on regional flux estimates is accepted by JGR - Biogeosciences. Mar 15, 2011 - Jingfeng Xiao is selected as a Science Definition Team member for NASA Carbon Monitoring System (CMS), $74,999, 2011-2012 (PI). Feb 01, 2011 - Jingfeng Xiao led a plenary talk titled Advances in Upscaling of Carbon and Water Fluxes from Towers to Regional, Continental and Global Scales at the AmeriFlux/NACP meeting at New Orleans, LA. 2010: Dec 22, 2010 - Fluxnet releases the latest issue of FluxLetter focusing on the upscaling of fluxes through various approaches, including Upscaling Fluxes from Towers to Regional, Continental and Global Scales Using Data-driven Approaches by Jingfeng Xiao. Dec 13-17, 2010 - Jingfeng Xiao gave an invited talk titled Data-Driven Diagnostics of North American Terrestrial Carbon Dynamics at the 2010 AGU Fall Meeting at San Francisco, CA. June 23-25, 2010 - Jingfeng Xiao was invited to participate in the 7th US-China Carbon Consortium (USCCC) Meeting, Huangshan, Anhui (China) June 16-18, 2010 - Jingfeng Xiao was invited to present on the International Symposium on Forest, Carbon and Water in Response to Climate Change, Tengchong, Yunnan (China) |
We report a terrestrial carbon sink in the conterminous U.S. at 0.63 pg C yr−1. 
U.S. carbon sink varied between 0.51 and 0.70 pg C yr−1 over the period 2001-2006. 
The severe droughts in 2002 and 2006 substantially reduced the U.S. carbon sink. 
Disturbances reduced carbon uptake or resulted in carbon release at regional scales. 
Our results provide an alternative and novel constraint to the U.S. carbon sink.