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Zhang W, Yu G, Chen Z, Zhu X, Han L, Liu Z, Lin Y, Han S, Sha L, Wang H, Wang Y, Yan J, Zhang Y, Gharun M. Photosynthetic capacity dominates the interannual variation of annual gross primary productivity in the Northern Hemisphere. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 849:157856. [PMID: 35934043 DOI: 10.1016/j.scitotenv.2022.157856] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2022] [Revised: 07/09/2022] [Accepted: 08/01/2022] [Indexed: 06/15/2023]
Abstract
Annual gross primary productivity (AGPP) of terrestrial ecosystems is the largest carbon flux component in ecosystems; however, it's unclear whether photosynthetic capacity or phenology dominates interannual variation of AGPP, and a better understanding of this could contribute to estimation of carbon sinks and their interactions with climate change. In this study, observed GPP data of 494 site-years from 39 eddy covariance sites in Northern Hemisphere were used to investigate mechanisms of interannual variation of AGPP. This study first decomposed AGPP into three seasonal dynamic attribute parameters (growing season length (CUP), maximum daily GPP (GPPmax), and the ratio of mean daily GPP to GPPmax (αGPP)), and then decomposed AGPP into mean leaf area index (LAIm) and annual photosynthetic capacity per leaf area (AGPPlm). Furthermore, GPPmax was decomposed into leaf area index of DOYmax (the day when GPPmax appeared) (LAImax) and photosynthesis per leaf area of DOYmax (GPPlmax). Relative contributions of parameters to AGPP and GPPmax were then calculated. Finally, environmental variables of DOYmax were extracted to analyze factors influencing interannual variation of GPPlmax. Trends of AGPP in 39 ecosystems varied from -65.23 to 53.05 g C m-2 yr-2, with the mean value of 6.32 g C m-2 yr-2. Photosynthetic capacity (GPPmax and AGPPlm), not CUP or LAI, was the main factor dominating interannual variation of AGPP. GPPlmax determined the interannual variation of GPPmax, and temperature, water, and radiation conditions of DOYmax affected the interannual variation of GPPlmax. This study used the cascade relationship of "environmental variables-GPPlmax-GPPmax-AGPP" to explain the mechanism of interannual variation of AGPP, which can provide new ideas for the AGPP estimation based on seasonal dynamic of GPP.
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Affiliation(s)
- Weikang Zhang
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Guirui Yu
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Zhi Chen
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Xianjin Zhu
- College of Agronomy, Shenyang Agricultural University, Shenyang 100161, China
| | - Lang Han
- School of Earth System Science, Tianjin University, Tianjin 300072, China; Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
| | - Zhaogang Liu
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yong Lin
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shijie Han
- School of Life Science, Henan University, Kaifeng 475004, China
| | - Liqing Sha
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun 666303, China
| | - Huimin Wang
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yanfen Wang
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Junhua Yan
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China
| | - Yiping Zhang
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun 666303, China
| | - Mana Gharun
- Department of Environmental Systems Science, ETH Zürich, Switzerland; Institute of Landscape Ecology, University of Münster, Germany
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Ruzol R, Staudhammer CL, Younger S, Aubrey DP, Loescher HW, Jackson CR, Starr G. Water use in a young
Pinus taeda
bioenergy plantation: Effect of intensive management on stand evapotranspiration. Ecosphere 2022. [DOI: 10.1002/ecs2.4100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Affiliation(s)
- Roel Ruzol
- Department of Biological Sciences University of Alabama Tuscaloosa Alabama USA
| | | | - Seth Younger
- Savannah River Ecology Lab University of Georgia Aiken South Carolina USA
| | - Doug P. Aubrey
- Savannah River Ecology Lab University of Georgia Aiken South Carolina USA
| | - Henry W. Loescher
- Battelle Environment and Infrastructure Boulder Colorado USA
- Institute of Alpine and Arctic Research (INSTAAR) University of Colorado Boulder Colorado USA
| | - C. Rhett Jackson
- Warnell School of Forestry and Natural Resources University of Georgia Athens Georgia USA
| | - Gregory Starr
- Department of Biological Sciences University of Alabama Tuscaloosa Alabama USA
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3
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Novick KA, Metzger S, Anderegg WRL, Barnes M, Cala DS, Guan K, Hemes KS, Hollinger DY, Kumar J, Litvak M, Lombardozzi D, Normile CP, Oikawa P, Runkle BRK, Torn M, Wiesner S. Informing Nature-based Climate Solutions for the United States with the best-available science. GLOBAL CHANGE BIOLOGY 2022; 28:3778-3794. [PMID: 35253952 DOI: 10.1111/gcb.16156] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Accepted: 02/04/2022] [Indexed: 06/14/2023]
Abstract
Nature-based Climate Solutions (NbCS) are managed alterations to ecosystems designed to increase carbon sequestration or reduce greenhouse gas emissions. While they have growing public and private support, the realizable benefits and unintended consequences of NbCS are not well understood. At regional scales where policy decisions are often made, NbCS benefits are estimated from soil and tree survey data that can miss important carbon sources and sinks within an ecosystem, and do not reveal the biophysical impacts of NbCS for local water and energy cycles. The only direct observations of ecosystem-scale carbon fluxes, for example, by eddy covariance flux towers, have not yet been systematically assessed for what they can tell us about NbCS potentials, and state-of-the-art remote sensing products and land-surface models are not yet being widely used to inform NbCS policymaking or implementation. As a result, there is a critical mismatch between the point- and tree-scale data most often used to assess NbCS benefits and impacts, the ecosystem and landscape scales where NbCS projects are implemented, and the regional to continental scales most relevant to policymaking. Here, we propose a research agenda to confront these gaps using data and tools that have long been used to understand the mechanisms driving ecosystem carbon and energy cycling, but have not yet been widely applied to NbCS. We outline steps for creating robust NbCS assessments at both local to regional scales that are informed by ecosystem-scale observations, and which consider concurrent biophysical impacts, future climate feedbacks, and the need for equitable and inclusive NbCS implementation strategies. We contend that these research goals can largely be accomplished by shifting the scales at which pre-existing tools are applied and blended together, although we also highlight some opportunities for more radical shifts in approach.
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Affiliation(s)
- Kimberly A Novick
- O'Neill School of Public and Environmental Affairs, Indiana University-Bloomington, Bloomington, Indiana, USA
| | - Stefan Metzger
- Battelle, National Ecological Observatory Network, Boulder, Colorado, USA
| | | | - Mallory Barnes
- O'Neill School of Public and Environmental Affairs, Indiana University-Bloomington, Bloomington, Indiana, USA
| | - Daniela S Cala
- O'Neill School of Public and Environmental Affairs, Indiana University-Bloomington, Bloomington, Indiana, USA
| | - Kaiyu Guan
- College of Agricultural, Consumer and Environmental Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
- National Center for Supercomputing Applications, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Kyle S Hemes
- Woods Institute for the Environment, Stanford University, Stanford, California, USA
| | - David Y Hollinger
- USDA Forest Service, Northern Research Station, Durham, New Hampshire, USA
| | - Jitendra Kumar
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Marcy Litvak
- Department of Biology, University of New Mexico, Albuquerque, New Mexico, USA
| | | | | | - Patty Oikawa
- Department of Earth & Environmental Science, California State University-East Bay, Hayward, California, USA
| | - Benjamin R K Runkle
- Department of Biological and Agricultural Engineering, University of Arkansas, Fayetteville, Arkansas, USA
| | - Margaret Torn
- Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - Susanne Wiesner
- Department of Biological Systems Engineering, University of Wisconsin-Madison, Madison, Wisconsin, USA
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4
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Trifonova T, Mishchenko N, Shutov P. Organic matter temporal dynamics in the river ecosystem basin using remote sensing. ONE ECOSYSTEM 2021. [DOI: 10.3897/oneeco.6.e61357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Environmental research addresses ecosystems of various hierarchical levels. One of the ecosystem types is the river basin. The basin approach has been applied in the research. We consider the river basin as a single ecosystem of complex landscape structure. The research objective was to assess the biological processes in various landscapes within a holistic natural geosystem – a catchment area. The Klyazma River Basin (a part of the Volga River of 40 thousand km2 area) was the research object. It is a complex combination of different landscapes, each marked by a diverse composition of geomorphological and soil-vegetation structures. According to the geomorphological structure and soil and vegetation cover, four landscape provinces and eight key sites have been identified in the studied catchment area where the ecosystem parameter have been measured. The study is based on remote sensing data and the Trends. Earth Land Degradation Monitoring. The calculation of productivity indicators (GPP, NPP) in carbon units and the land use structure analysis are based on Modis data. The soil organic carbon pool was determined by the UN FAO’s data, based on Trends. Earth and QGIS 2.18. The two-factor variance analysis ANOVA has been used for the data statistic processing. The cartographic analysis of the land use structure dynamics of the entire Klyazma Basin resulted in revealing the areas where various land transitions from one category to another have been identified. They are basically associated with the agricultural land overgrowth. The forest area increased by 9% during the period from 2001 to 2017. Considerable increase in the waterlogged, wetlands areas was observed in the eastern part of the Basin, in the Volga-Klyazma Province. The landscapes react differently to changes in climatic parameters and land use. Thus, the active revegetation of farmland by forests gives the increased rate of carbon accumulation in the soil. Landscapes covered with grasses and shrubs are more productive those covered with forest. On the other hand, woody biotopes are more stable in their development over time. Statistical analysis using the two-factor variation analysis ANOVA method resulted in demonstrating that phytoproductivity dynamics of the key sites does not depend on their productivity parameters nor on the site landscape structure, but is mainly determined by a time factor. In different landscapes the biological processes, characterising the organic matter dynamics in the form of plant production, organic matter accumulation and others are shown to differ both in rate and intensity and ambiguously respond to changes in climate parameters and land use. The river basin, as a single ecosystem, showed sufficient stability of the dynamic processes. This suggests that holistic natural ecosystems, such as catchment areas, have internal compensatory mechanisms that maintain the development stability for a long time, while unplanned land use remains the main damaging factor.
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Liu J, Zhou Y, Valach A, Shortt R, Kasak K, Rey-Sanchez C, Hemes KS, Baldocchi D, Lai DYF. Methane emissions reduce the radiative cooling effect of a subtropical estuarine mangrove wetland by half. GLOBAL CHANGE BIOLOGY 2020; 26:4998-5016. [PMID: 32574398 DOI: 10.1111/gcb.15247] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Accepted: 05/11/2020] [Indexed: 06/11/2023]
Abstract
The role of coastal mangrove wetlands in sequestering atmospheric carbon dioxide (CO2 ) and mitigating climate change has received increasing attention in recent years. While recent studies have shown that methane (CH4 ) emissions can potentially offset the carbon burial rates in low-salinity coastal wetlands, there is hitherto a paucity of direct and year-round measurements of ecosystem-scale CH4 flux (FCH4 ) from mangrove ecosystems. In this study, we examined the temporal variations and biophysical drivers of ecosystem-scale FCH4 in a subtropical estuarine mangrove wetland based on 3 years of eddy covariance measurements. Our results showed that daily mangrove FCH4 reached a peak of over 0.1 g CH4 -C m-2 day-1 during the summertime owing to a combination of high temperature and low salinity, while the wintertime FCH4 was negligible. In this mangrove, the mean annual CH4 emission was 11.7 ± 0.4 g CH4 -C m-2 year-1 while the annual net ecosystem CO2 exchange ranged between -891 and -690 g CO2 -C m-2 year-1 , indicating a net cooling effect on climate over decadal to centurial timescales. Meanwhile, we showed that mangrove FCH4 could offset the negative radiative forcing caused by CO2 uptake by 52% and 24% over a time horizon of 20 and 100 years, respectively, based on the corresponding sustained-flux global warming potentials. Moreover, we found that 87% and 69% of the total variance of daily FCH4 could be explained by the random forest machine learning algorithm and traditional linear regression model, respectively, with soil temperature and salinity being the most dominant controls. This study was the first of its kind to characterize ecosystem-scale FCH4 in a mangrove wetland with long-term eddy covariance measurements. Our findings implied that future environmental changes such as climate warming and increasing river discharge might increase CH4 emissions and hence reduce the net radiative cooling effect of estuarine mangrove forests.
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Affiliation(s)
- Jiangong Liu
- Department of Geography and Resource Management, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, China
| | - Yulun Zhou
- Department of Geography and Resource Management, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, China
| | - Alex Valach
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, CA, USA
| | - Robert Shortt
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, CA, USA
| | - Kuno Kasak
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, CA, USA
- Department of Geography, Institute of Ecology and Earth Sciences, University of Tartu, Tartu, Estonia
| | - Camilo Rey-Sanchez
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, CA, USA
| | - Kyle S Hemes
- Stanford Woods Institute for the Environment, Stanford University, Stanford, CA, USA
| | - Dennis Baldocchi
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, CA, USA
| | - Derrick Y F Lai
- Department of Geography and Resource Management, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, China
- Centre for Environmental Policy and Resource Management, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, China
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6
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Zhang Q, Barnes M, Benson M, Burakowski E, Oishi AC, Ouimette A, Sanders-DeMott R, Stoy PC, Wenzel M, Xiong L, Yi K, Novick KA. Reforestation and surface cooling in temperate zones: Mechanisms and implications. GLOBAL CHANGE BIOLOGY 2020; 26:3384-3401. [PMID: 32145125 DOI: 10.1111/gcb.15069] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Accepted: 02/15/2020] [Indexed: 06/10/2023]
Abstract
Land-use/cover change (LUCC) is an important driver of environmental change, occurring at the same time as, and often interacting with, global climate change. Reforestation and deforestation have been critical aspects of LUCC over the past two centuries and are widely studied for their potential to perturb the global carbon cycle. More recently, there has been keen interest in understanding the extent to which reforestation affects terrestrial energy cycling and thus surface temperature directly by altering surface physical properties (e.g., albedo and emissivity) and land-atmosphere energy exchange. The impacts of reforestation on land surface temperature and their mechanisms are relatively well understood in tropical and boreal climates, but the effects of reforestation on warming and/or cooling in temperate zones are less certain. This study is designed to elucidate the biophysical mechanisms that link land cover and surface temperature in temperate ecosystems. To achieve this goal, we used data from six paired eddy-covariance towers over co-located forests and grasslands in the temperate eastern United States, where radiation components, latent and sensible heat fluxes, and meteorological conditions were measured. The results show that, at the annual time scale, the surface of the forests is 1-2°C cooler than grasslands, indicating a substantial cooling effect of reforestation. The enhanced latent and sensible heat fluxes of forests have an average cooling effect of -2.5°C, which offsets the net warming effect (+1.5°C) of albedo warming (+2.3°C) and emissivity cooling effect (-0.8°C) associated with surface properties. Additional daytime cooling over forests is driven by local feedbacks to incoming radiation. We further show that the forest cooling effect is most pronounced when land surface temperature is higher, often exceeding -5°C. Our results contribute important observational evidence that reforestation in the temperate zone offers opportunities for local climate mitigation and adaptation.
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Affiliation(s)
- Quan Zhang
- State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan, China
- O'Neill School of Public and Environmental Affairs, Indiana University, Bloomington, IN, USA
| | - Mallory Barnes
- O'Neill School of Public and Environmental Affairs, Indiana University, Bloomington, IN, USA
| | - Michael Benson
- O'Neill School of Public and Environmental Affairs, Indiana University, Bloomington, IN, USA
| | - Elizabeth Burakowski
- Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, NH, USA
| | - A Christopher Oishi
- Coweeta Hydrologic Laboratory, Southern Research Station, USDA Forest Service, Otto, NC, USA
| | - Andrew Ouimette
- Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, NH, USA
| | - Rebecca Sanders-DeMott
- Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, NH, USA
| | - Paul C Stoy
- Department of Biological Systems Engineering, University of Wisconsin-Madison, Madison, WI, USA
- Department of Land Resources and Environmental Sciences, Montana State University, Bozeman, MT, USA
| | - Matt Wenzel
- National Ecological Observatory Network, Battelle, Jamestown, ND, USA
| | - Lihua Xiong
- State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan, China
| | - Koong Yi
- Department of Environmental Sciences, University of Virginia, Charlottesville, VA, USA
| | - Kimberly A Novick
- O'Neill School of Public and Environmental Affairs, Indiana University, Bloomington, IN, USA
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7
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Sanders-DeMott R, Ouimette AP, Lepine LC, Fogarty SZ, Burakowski EA, Contosta AR, Ollinger SV. Divergent carbon cycle response of forest and grass-dominated northern temperate ecosystems to record winter warming. GLOBAL CHANGE BIOLOGY 2020; 26:1519-1531. [PMID: 31553818 DOI: 10.1111/gcb.14850] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Accepted: 08/29/2019] [Indexed: 06/10/2023]
Abstract
Northern temperate ecosystems are experiencing warmer and more variable winters, trends that are expected to continue into the foreseeable future. Despite this, most studies have focused on climate change impacts during the growing season, particularly when comparing responses across different vegetation cover types. Here we examined how a perennial grassland and adjacent mixed forest ecosystem in New Hampshire, United States, responded to a period of highly variable winters from 2014 through 2017 that included the warmest winter on record to date. In the grassland, record-breaking temperatures in the winter of 2015/2016 led to a February onset of plant growth and the ecosystem became a sustained carbon sink well before winter ended, taking up roughly 90 g/m2 more carbon during the winter to spring transition than in other recorded years. The forest was an unusually large carbon source during the same period. While forest photosynthesis was restricted by leaf-out phenology, warm winter temperatures caused large pulses of ecosystem respiration that released nearly 230 g C/m2 from February through April, more than double the carbon losses during that period in cooler years. These findings suggest that, as winters continue to warm, increases in ecosystem respiration outside the growing season could outpace increases in carbon uptake during a longer growing season, particularly in forests that depend on leaf-out timing to initiate carbon uptake. In ecosystems with a perennial leaf habit, warming winter temperatures are more likely to increase ecosystem carbon uptake through extension of the active growing season. Our results highlight the importance of understanding relationships among antecedent winter conditions and carbon exchange across land-cover types to understand how landscape carbon exchange will change under projected climate warming.
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Affiliation(s)
- Rebecca Sanders-DeMott
- Department of Natural Resources and the Environment, College of Life Science and Agriculture, University of New Hampshire, Durham, NH, USA
- Earth Systems Research Center, Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, NH, USA
| | - Andrew P Ouimette
- Earth Systems Research Center, Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, NH, USA
| | - Lucie C Lepine
- Earth Systems Research Center, Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, NH, USA
| | - Sean Z Fogarty
- Department of Natural Resources and the Environment, College of Life Science and Agriculture, University of New Hampshire, Durham, NH, USA
| | - Elizabeth A Burakowski
- Earth Systems Research Center, Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, NH, USA
| | - Alexandra R Contosta
- Earth Systems Research Center, Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, NH, USA
| | - Scott V Ollinger
- Department of Natural Resources and the Environment, College of Life Science and Agriculture, University of New Hampshire, Durham, NH, USA
- Earth Systems Research Center, Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, NH, USA
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8
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Baldocchi DD. How eddy covariance flux measurements have contributed to our understanding of Global Change Biology. GLOBAL CHANGE BIOLOGY 2020; 26:242-260. [PMID: 31461544 DOI: 10.1111/gcb.14807] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Accepted: 08/07/2019] [Indexed: 06/10/2023]
Abstract
A global network of long-term carbon and water flux measurements has existed since the late 1990s. With its representative sampling of the terrestrial biosphere's climate and ecological spaces, this network is providing background information and direct measurements on how ecosystem metabolism responds to environmental and biological forcings and how they may be changing in a warmer world with more carbon dioxide. In this review, I explore how carbon and water fluxes of the world's ecosystem are responding to a suite of covarying environmental factors, like sunlight, temperature, soil moisture, and carbon dioxide. I also report on how coupled carbon and water fluxes are modulated by biological and ecological factors such as phenology and a suite of structural and functional properties. And, I investigate whether long-term trends in carbon and water fluxes are emerging in various ecological and climate spaces and the degree to which they may be driven by physical and biological forcings. As a growing number of time series extend up to 20 years in duration, we are at the verge of capturing ecosystem scale trends in the breathing of a changing biosphere. Consequently, flux measurements need to continue to report on future conditions and responses and assess the efficacy of natural climate solutions.
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9
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Quantifying the Impacts of Land-Use and Climate on Carbon Fluxes Using Satellite Data across Texas, U.S. REMOTE SENSING 2019. [DOI: 10.3390/rs11141733] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Climate change and variability, soil types and soil characteristics, animal and microbial communities, and photosynthetic plants are the major components of the ecosystem that affect carbon sequestration potential of any location. This study used NASA’s Soil Moisture Active Passive (SMAP) Level 4 carbon products, gross primary productivity (GPP), and net ecosystem exchange (NEE) to quantify their spatial and temporal variabilities for selected terrestrial ecosystems across Texas during the 2015–2018 study period. These SMAP carbon products are available at 9 km spatial resolution on a daily basis. The ten selected SMAP grids are located in seven climate zones and dominated by five major land uses (developed, crop, forest, pasture, and shrub). Results showed CO2 emissions and uptake were affected by land-use and climatic conditions across Texas. It was also observed that climatic conditions had more impact on CO2 emissions and uptake than land-use in this state. On average, South Central Plains and East Central Texas Plains ecoregions of East Texas and Western Gulf Coastal Plain ecoregion of Upper Coast climate zones showed higher GPP flux and potential carbon emissions and uptake than other climate zones across the state, whereas shrubland on the Trans Pecos climate zone showed lower GPP flux and carbon emissions/uptake. Comparison of GPP and NEE distribution maps between 2015 and 2018 confirmed substantial changes in carbon emissions and uptake across Texas. These results suggest that SMAP carbon products can be used to study the terrestrial carbon cycle at regional to global scales. Overall, this study helps to understand the impacts of climate, land-use, and ecosystem dynamics on the terrestrial carbon cycle.
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10
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Yi K, Maxwell JT, Wenzel MK, Roman DT, Sauer PE, Phillips RP, Novick KA. Linking variation in intrinsic water-use efficiency to isohydricity: a comparison at multiple spatiotemporal scales. THE NEW PHYTOLOGIST 2019; 221:195-208. [PMID: 30117538 DOI: 10.1111/nph.15384] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Accepted: 07/06/2018] [Indexed: 06/08/2023]
Abstract
Species-specific responses of plant intrinsic water-use efficiency (iWUE) to multiple environmental drivers associated with climate change, including soil moisture (θ), vapor pressure deficit (D), and atmospheric CO2 concentration (ca ), are poorly understood. We assessed how the iWUE and growth of several species of deciduous trees that span a gradient of isohydric to anisohydric water-use strategies respond to key environmental drivers (θ, D and ca ). iWUE was calculated for individual tree species using leaf-level gas exchange and tree-ring δ13 C in wood measurements, and for the whole forest using the eddy covariance method. The iWUE of the isohydric species was generally more sensitive to environmental change than the anisohydric species was, and increased significantly with rising D during the periods of water stress. At longer timescales, the influence of ca was pronounced for isohydric tulip poplar but not for others. Trees' physiological responses to changing environmental drivers can be interpreted differently depending on the observational scale. Care should be also taken in interpreting observed or modeled trends in iWUE that do not explicitly account for the influence of D.
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Affiliation(s)
- Koong Yi
- School of Public and Environmental Affairs, Indiana University Bloomington, 1315 East Tenth Street, Bloomington, IN, 47405, USA
| | - Justin T Maxwell
- Department of Geography, Indiana University Bloomington, 701 East Kirkwood Avenue, Bloomington, IN, 47405, USA
| | - Matthew K Wenzel
- School of Public and Environmental Affairs, Indiana University Bloomington, 1315 East Tenth Street, Bloomington, IN, 47405, USA
| | - D Tyler Roman
- US Department of Agriculture Forest Service, Northern Research Station, 1831 Highway 169 East, Grand Rapids, MN, 55744, USA
| | - Peter E Sauer
- Department of Geological Science, Indiana University Bloomington, 1001 East Tenth Street, Bloomington, IN, 47405, USA
| | - Richard P Phillips
- Department of Biology, Indiana University Bloomington, 1001 East Third Street, Bloomington, IN, 47405, USA
| | - Kimberly A Novick
- School of Public and Environmental Affairs, Indiana University Bloomington, 1315 East Tenth Street, Bloomington, IN, 47405, USA
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11
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Eddy Covariance vs. Biometric Based Estimates of Net Primary Productivity of Pedunculate Oak (Quercus robur L.) Forest in Croatia during Ten Years. FORESTS 2018. [DOI: 10.3390/f9120764] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We analysed 10 years (2008–2017) of continuous eddy covariance (EC) CO2 flux measurements of net ecosystem exchange (NEE) in a young pedunculate oak forest in Croatia. Measured NEE was gap-filled and partitioned into gross primary productivity (GPP) and ecosystem reparation (RECO) using the online tool by Max Planck Institute for Biogeochemistry in Jena, Germany. Annual NEE, GPP, and RECO were correlated with main environmental drivers. Net primary productivity was estimated from EC (NPPEC), as a sum of −NEE and Rh obtained using a constant Rh:RECO ratio, and from independent periodic biometric measurements (NPPBM). For comparing the NPP at the seasonal level, we propose a simple model that aimed at accounting for late-summer and autumn carbon storage in the non-structural carbohydrate pool. Over the study period, Jastrebarsko forest acted as a carbon sink, with an average (±std. dev.) annual NEE of −319 (±94) gC m−2 year−1, GPP of 1594 (±109) gC m−2 year−1, and RECO of 1275 (±94) gC m−2 year−1. Annual NEE showed high inter-annual variability and poor correlation with annual average global radiation, air temperature, and total precipitation, but significant (R2 = 0.501, p = 0.02) correlation with the change in soil water content between May and September. Comparison of annual NPPEC and NPPBM showed a good overall agreement (R2 = 0.463, p = 0.03), although in all years NPPBM was lower than NPPEC, with averages of 680 (±88) gC m−2 year−1 and 819 (±89) gC m−2 year−1, respectively. Lower values of NPPBM indicate that fine roots and grasses contributions to NPP, which were not measured in the study period, could have an important contribution to the overall ecosystem NPP. At a seasonal level, two NPP estimates showed differences in their dynamic, but the application of the proposed model greatly improved the agreement in the second part of the growing season. Further research is needed on the respiration partitioning and mechanisms of carbon allocation.
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12
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Ward EJ, Oren R, Seok Kim H, Kim D, Tor-Ngern P, Ewers BE, McCarthy HR, Oishi AC, Pataki DE, Palmroth S, Phillips NG, Schäfer KVR. Evapotranspiration and water yield of a pine-broadleaf forest are not altered by long-term atmospheric [CO 2 ] enrichment under native or enhanced soil fertility. GLOBAL CHANGE BIOLOGY 2018; 24:4841-4856. [PMID: 29949220 DOI: 10.1111/gcb.14363] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Revised: 06/30/2018] [Accepted: 05/22/2018] [Indexed: 06/08/2023]
Abstract
Changes in evapotranspiration (ET) from terrestrial ecosystems affect their water yield (WY), with considerable ecological and economic consequences. Increases in surface runoff observed over the past century have been attributed to increasing atmospheric CO2 concentrations resulting in reduced ET by terrestrial ecosystems. Here, we evaluate the water balance of a Pinus taeda (L.) forest with a broadleaf component that was exposed to atmospheric [CO2 ] enrichment (ECO2 ; +200 ppm) for over 17 years and fertilization for 6 years, monitored with hundreds of environmental and sap flux sensors on a half-hourly basis. These measurements were synthesized using a one-dimensional Richard's equation model to evaluate treatment differences in transpiration (T), evaporation (E), ET, and WY. We found that ECO2 did not create significant differences in stand T, ET, or WY under either native or enhanced soil fertility, despite a 20% and 13% increase in leaf area index, respectively. While T, ET, and WY responded to fertilization, this response was weak (<3% of mean annual precipitation). Likewise, while E responded to ECO2 in the first 7 years of the study, this effect was of negligible magnitude (<1% mean annual precipitation). Given the global range of conifers similar to P. taeda, our results imply that recent observations of increased global streamflow cannot be attributed to decreases in ET across all ecosystems, demonstrating a great need for model-data synthesis activities to incorporate our current understanding of terrestrial vegetation in global water cycle models.
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Affiliation(s)
- Eric J Ward
- Division of Environmental Science and Policy, Nicholas School of the Environment, Duke University, Durham, North Carolina
- Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, Tennessee
| | - Ram Oren
- Division of Environmental Science and Policy, Nicholas School of the Environment, Duke University, Durham, North Carolina
- Department of Forest Sciences, University of Helsinki, Helsinki, Finland
- Department of Civil and Environmental Engineering, Pratt School of Engineering, Duke University, Durham, North Carolina
| | - Hyun Seok Kim
- Division of Environmental Science and Policy, Nicholas School of the Environment, Duke University, Durham, North Carolina
- Department of Forest Sciences, College of Agriculture and Life Sciences, Seoul National University, Seoul, Korea
- Institute of Future Environmental and Forest Resources, Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul, Korea
- National Center for Agro-Meteorology, Seoul, Korea
- Interdisciplinary Program in Agriculture and Forest Meteorology, Seoul National University, Seoul, Korea
| | - Dohyoung Kim
- Division of Environmental Science and Policy, Nicholas School of the Environment, Duke University, Durham, North Carolina
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana
| | - Pantana Tor-Ngern
- Division of Environmental Science and Policy, Nicholas School of the Environment, Duke University, Durham, North Carolina
- Department of Environmental Science, Faculty of Science, Chulalongkorn University, Bangkok, Thailand
| | - Brent E Ewers
- Department of Botany and Program in Ecology, University of Wyoming, Laramie, Wyoming
| | - Heather R McCarthy
- Department of Microbiology and Plant Biology, University of Oklahoma, Norman, Oklahoma
| | - Andrew Christopher Oishi
- Division of Environmental Science and Policy, Nicholas School of the Environment, Duke University, Durham, North Carolina
- USDA Forest Service, Southern Research Station, Coweeta Hydrologic Laboratory, Otto, North Carolina
| | - Diane E Pataki
- Department of Biology, University of Utah, Salt Lake City, Utah
| | - Sari Palmroth
- Division of Environmental Science and Policy, Nicholas School of the Environment, Duke University, Durham, North Carolina
| | - Nathan G Phillips
- Department of Earth and Environment, Boston University, Boston, Massachusetts
| | - Karina V R Schäfer
- Department of Biological Sciences, Rutgers University, Newark, New Jersey
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13
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Thomas RQ, Jersild AL, Brooks EB, Thomas VA, Wynne RH. A mid-century ecological forecast with partitioned uncertainty predicts increases in loblolly pine forest productivity. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2018; 28:1503-1519. [PMID: 29999562 DOI: 10.1002/eap.1761] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Revised: 04/30/2018] [Accepted: 05/11/2018] [Indexed: 06/08/2023]
Abstract
Ecological forecasting of forest productivity involves integrating observations into a process-based model and propagating the dominant components of uncertainty to generate probability distributions for future states and fluxes. Here, we develop a forecast for the biomass change in loblolly pine (Pinus taeda) forests of the southeastern United States and evaluate the relative contribution of different forms of uncertainty to the total forecast uncertainty. Specifically, we assimilated observations of carbon and flux stocks and fluxes from sites across the region, including global change experiments, into a forest ecosystem model to calibrate the parameter distributions and estimate the process uncertainty (i.e., model structure uncertainty revealed in the residuals of the calibration). Using this calibration, we forecasted the change in biomass within each 12-digit Hydrologic (H12) unit across the native range of loblolly pine between 2010 and 2055 under the Representative Concentration Pathway 8.5 scenario. Averaged across the region, productivity is predicted to increase by a mean of 31% between 2010 and 2055 with an average forecast 95% quantile interval of ±15 percentage units. The largest increases were predicted in cooler locations, corresponding to the largest projected changes in temperature. The forecasted mean change varied considerably among the H12 units (3-80% productivity increase), but only units in the warmest and driest extents of the loblolly pine range had forecast distributions with probabilities of a decline in productivity that exceeded 5%. By isolating the individual components of the forecast uncertainty, we found that ecosystem model process uncertainty made the largest individual contribution. Ecosystem model parameter and climate model uncertainty had similar contributions to the overall forecast uncertainty, but with differing spatial patterns across the study region. The probabilistic framework developed here could be modified to include additional sources of uncertainty, including changes due to fire, insects, and pests: processes that would result in lower productivity changes than forecasted here. Overall, this study presents an ecological forecast at the ecosystem management scale so that land managers can explicitly account for uncertainty in decision analysis. Furthermore, it highlights that future work should focus on quantifying, propagating, and reducing ecosystem model process uncertainty.
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Affiliation(s)
- R Quinn Thomas
- Department of Forest Resources and Environmental Conservation, Virginia Tech, Blacksburg, Virginia, 24061, USA
| | - Annika L Jersild
- Department of Forest Resources and Environmental Conservation, Virginia Tech, Blacksburg, Virginia, 24061, USA
| | - Evan B Brooks
- Department of Forest Resources and Environmental Conservation, Virginia Tech, Blacksburg, Virginia, 24061, USA
| | - Valerie A Thomas
- Department of Forest Resources and Environmental Conservation, Virginia Tech, Blacksburg, Virginia, 24061, USA
| | - Randolph H Wynne
- Department of Forest Resources and Environmental Conservation, Virginia Tech, Blacksburg, Virginia, 24061, USA
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14
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ChristopherOishi A, Miniat CF, Novick KA, Brantley ST, Vose JM, Walker JT. Warmer temperatures reduce net carbon uptake, but do not affect water use, in a mature southern Appalachian forest. AGRICULTURAL AND FOREST METEOROLOGY 2018; 252:269-282. [PMID: 32280152 PMCID: PMC7147817 DOI: 10.1016/j.agrformet.2018.01.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Increasing air temperature is expected to extend growing season length in temperate, broadleaf forests, leading to potential increases in evapotranspiration and net carbon uptake. However, other key processes affecting water and carbon cycles are also highly temperature-dependent. Warmer temperatures may result in higher ecosystem carbon loss through respiration and higher potential evapotranspiration through increased atmospheric demand for water. Thus, the net effects of a warming planet are uncertain and highly dependent on local climate and vegetation. We analyzed five years of data from the Coweeta eddy covariance tower in the southern Appalachian Mountains of western North Carolina, USA, a highly productive region that has historically been underrepresented in flux observation networks. We examined how leaf phenology and climate affect water and carbon cycling in a mature forest in one of the wettest biomes in North America. Warm temperatures in early 2012 caused leaf-out to occur two weeks earlier than in cooler years and led to higher seasonal carbon uptake. However, these warmer temperatures also drove higher winter ecosystem respiration, offsetting much of the springtime carbon gain. Interannual variability in net carbon uptake was high (147 to 364 g C m-2 y-1), but unrelated to growing season length. Instead, years with warmer growing seasons had 10% higher respiration and sequestered ~40% less carbon than cooler years. In contrast, annual evapotranspiration was relatively consistent among years (coefficient of variation = 4%) despite large differences in precipitation (17%, range = 800 mm). Transpiration by the evergreen understory likely helped to compensate for phenologically-driven differences in canopy transpiration. The increasing frequency of high summer temperatures is expected to have a greater effect on respiration than growing season length, reducing forest carbon storage.
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Affiliation(s)
- A ChristopherOishi
- USDA Forest Service, Southern Research Station, Coweeta Hydrologic Laboratory, 3160 Coweeta Lab Road, Otto, NC 28763, USA
| | - Chelcy F Miniat
- USDA Forest Service, Southern Research Station, Coweeta Hydrologic Laboratory, 3160 Coweeta Lab Road, Otto, NC 28763, USA
| | - Kimberly A Novick
- School of Public and Environmental Affairs, Indiana University - Bloomington, 702 N. Walnut Grove Avenue, Bloomington, IN 47405, USA
| | - Steven T Brantley
- Joseph W. Jones Ecological Research Center, 3988 Jones Center Drive, Newton, GA 39870, USA
| | - James M Vose
- USDA Forest Service, Southern Research Station, Center for Integrated Forest Science, 5223 Jordan Hall, Box 8008, College of Natural Resources, Forestry and Environmental Resources, North Carolina State University, Raleigh, NC 27695, USA
| | - John T Walker
- U.S. Environmental Protection Agency, Office of Research and Development, 109 T.W. Alexander Dr., Durham, NC 27711, USA
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15
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Tang X, Li H, Ma M, Yao L, Peichl M, Arain A, Xu X, Goulden M. How do disturbances and climate effects on carbon and water fluxes differ between multi-aged and even-aged coniferous forests? THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 599-600:1583-1597. [PMID: 28531966 DOI: 10.1016/j.scitotenv.2017.05.119] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Revised: 05/11/2017] [Accepted: 05/14/2017] [Indexed: 06/07/2023]
Abstract
Disturbances and climatic changes significantly affect forest ecosystem productivity, water use efficiency (WUE) and carbon (C) flux dynamics. A deep understanding of terrestrial feedbacks to such effects and recovery mechanisms in forests across contrasting climatic regimes is essential to predict future regional/global C and water budgets, which are also closely related to the potential forest management decisions. However, the resilience of multi-aged and even-aged forests to disturbances has been debated for >60years because of technical measurement constraints. Here we evaluated 62site-years of eddy covariance measurements of net ecosystem production (NEP), evapotranspiration (ET), the estimates of gross primary productivity (GPP), ecosystem respiration (Re) and ecosystem-level WUE, as well as the relationships with environmental controls in three chronosequences of multi- and even-aged coniferous forests covering the Mediterranean, temperate and boreal regions. Age-specific dynamics in multi-year mean annual NEP and WUE revealed that forest age is a key variable that determines the sign and magnitude of recovering forest C source-sink strength from disturbances. However, the trends of annual NEP and WUE across succession stages between two stand structures differed substantially. The successional patterns of NEP exhibited an inverted-U trend with age at the two even-aged chronosequences, whereas NEP of the multi-aged chronosequence increased steadily through time. Meanwhile, site-level WUE of even-aged forests decreased gradually from young to mature, whereas an apparent increase occurred for the same forest age in multi-aged stands. Compared with even-aged forests, multi-aged forests sequestered more CO2 with forest age and maintained a relatively higher WUE in the later succession periods. With regard to the available flux measurements in this study, these behaviors are independent of tree species, stand ages and climate conditions. We also found that distinctly different environmental factors controlled forest C and water fluxes under three climatic regimes. Typical weather events such as temperature anomalies or drying-wetting cycles severely affected forest functions. Particularly, a summer drought in the boreal forest resulted in an increased NEP owing to a considerable decrease in Re, but at the cost of greater water loss from deeper groundwater resources. These findings will provide important implications for forest management strategies to mitigate global climate change.
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Affiliation(s)
- Xuguang Tang
- Chongqing Key Laboratory of Karst Environment, School of Geographical Sciences, Southwest University, Chongqing 400715, China; Key Laboratory of Watershed Geographic Sciences, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China; Institute of Agricultural Sciences, ETH Zurich, Zurich 8092, Switzerland.
| | - Hengpeng Li
- Key Laboratory of Watershed Geographic Sciences, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Mingguo Ma
- Chongqing Key Laboratory of Karst Environment, School of Geographical Sciences, Southwest University, Chongqing 400715, China
| | - Li Yao
- Chongqing Key Laboratory of Karst Environment, School of Geographical Sciences, Southwest University, Chongqing 400715, China
| | - Matthias Peichl
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå 90183, Sweden
| | - Altaf Arain
- McMaster Centre for Climate Change and School of Geography & Earth Sciences, McMaster University, Hamilton, ON L8S4K1, Canada
| | - Xibao Xu
- Key Laboratory of Watershed Geographic Sciences, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Michael Goulden
- Department of Earth System Science, University of California, Irvine, CA 92697-3100, USA
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16
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Tan ZH, Wu ZX, Hughes AC, Schaefer D, Zeng J, Lan GY, Yang C, Tao ZL, Chen BQ, Tian YH, Song L, Jatoi MT, Zhao JF, Yang LY. On the ratio of intercellular to ambient CO 2 (c i/c a) derived from ecosystem flux. INTERNATIONAL JOURNAL OF BIOMETEOROLOGY 2017; 61:2059-2071. [PMID: 28707041 DOI: 10.1007/s00484-017-1403-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Revised: 06/13/2017] [Accepted: 06/29/2017] [Indexed: 06/07/2023]
Abstract
The ratio of intercellular to ambient CO2 concentrations (c i/c a) plays a key role in ecophysiology, micrometeorology, and global climatic change. However, systematic investigation on c i/c a variation and its determinants are rare. Here, the c i/c a was derived from measuring ecosystem fluxes in an even-aged monoculture of rubber trees (Hevea brasiliensis). We tested whether c i/c a is constant across environmental gradients and if not, which dominant factors control c i/c a variations. Evidence indicates that c i/c a is not a constant. The c i/c a exhibits a clear "V"-shaped diurnal pattern and varies across the environmental gradient. Water vapor pressure deficit (D) is the dominant factor controls over the c i/c a variations. c i/c a consistently decreases with increasing D. c i/c a decreases with square root of D as predicted by the optimal stomatal model. The D-driving single-variable model could simulate c i/c a as well as that of sophisticated model. Many variables function on longer timescales than a daily cycle, such as soil water content, could improve c i/c a model prediction ability. Ecosystem flux can be effectively used to calculate c i/c a and use it to better understand various natural cycles.
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Affiliation(s)
- Zheng-Hong Tan
- Ecology Program, Institute for Tropical Agriculture and Forestry, Hainan University, Haikou, 570228, China
| | - Zhi-Xiang Wu
- Rubber Research Institute, Chinese Academy of Tropical Agricultural Sciences, Danzhou, 571737, China.
| | - Alice C Hughes
- Centre for Integrative Conservation, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, 666303, China
| | - Douglas Schaefer
- Key Lab of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, 666303, China
| | - Jiye Zeng
- National Institute for Environmental Studies, Tsukuba, 305-0053, Japan
| | - Guo-Yu Lan
- Rubber Research Institute, Chinese Academy of Tropical Agricultural Sciences, Danzhou, 571737, China
| | - Chuang Yang
- Rubber Research Institute, Chinese Academy of Tropical Agricultural Sciences, Danzhou, 571737, China
| | - Zhong-Liang Tao
- Rubber Research Institute, Chinese Academy of Tropical Agricultural Sciences, Danzhou, 571737, China
| | - Bang-Qian Chen
- Rubber Research Institute, Chinese Academy of Tropical Agricultural Sciences, Danzhou, 571737, China
| | - Yao-Hua Tian
- Yunnan Institute of Tropical Crops, Jinghong, 666100, China
| | - Liang Song
- Key Lab of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, 666303, China
| | - Muhammad Tahir Jatoi
- Ecology Program, Institute for Tropical Agriculture and Forestry, Hainan University, Haikou, 570228, China
- Rubber Research Institute, Chinese Academy of Tropical Agricultural Sciences, Danzhou, 571737, China
| | - Jun-Fu Zhao
- Ecology Program, Institute for Tropical Agriculture and Forestry, Hainan University, Haikou, 570228, China
| | - Lian-Yan Yang
- Ecology Program, Institute for Tropical Agriculture and Forestry, Hainan University, Haikou, 570228, China
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17
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Yi K, Dragoni D, Phillips RP, Roman DT, Novick KA. Dynamics of stem water uptake among isohydric and anisohydric species experiencing a severe drought. TREE PHYSIOLOGY 2017; 37:1379-1392. [PMID: 28062727 DOI: 10.1093/treephys/tpw126] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2016] [Accepted: 12/22/2016] [Indexed: 06/06/2023]
Abstract
Predicting the impact of drought on forest ecosystem processes requires an understanding of trees' species-specific responses to drought, especially in the Eastern USA, where species composition is highly dynamic due to historical changes in land use and fire regime. Here, we adapted a framework that classifies trees' water-use strategy along the spectrum of isohydric to anisohydric behavior to determine the responses of three canopy-dominant species to drought. We used a collection of leaf-level gas exchange, tree-level sap flux and stand-level eddy covariance data collected in south-central Indiana from 2011 to 2013, which included an unusually severe drought in the summer of 2012. Our goal was to assess how patterns in the radial profile of sap flux and reliance on hydraulic capacitance differed among species of contrasting water-use strategies. In isohydric species, which included sugar maple (Acer saccharum Marsh.) and tulip poplar (Liriodendron tulipifera L.), we found that the sap flux in the outer xylem experienced dramatic declines during drought, but sap flux at inner xylem was buffered from reductions in water availability. In contrast, for anisohydric oak species (Quercus alba L. and Quercus rubra L.), we observed relatively smaller variations in sap flux during drought in both inner and outer xylem, and higher nighttime refilling when compared with isohydric species. This reliance on nocturnal refilling, which occurred coincident with a decoupling between leaf- and tree-level water-use dynamics, suggests that anisohydric species may benefit from a reliance on hydraulic capacitance to mitigate the risk of hydraulic failure associated with maintaining high transpiration rates during drought. In the case of both isohydric and anisohydric species, our work demonstrates that failure to account for shifts in the radial profile of sap flux during drought could introduce substantial bias in estimates of tree water use during both drought and non-drought periods.
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Affiliation(s)
- Koong Yi
- School of Public and Environmental Affairs, Indiana University Bloomington, 1315 East Tenth Street, Bloomington, IN 47405, USA
| | - Danilo Dragoni
- Department of Geography, Indiana University Bloomington, 701 East Kirkwood Avenue, Bloomington, IN 47405, USA
| | - Richard P Phillips
- Department of Biology, Indiana University Bloomington, 1001 East Third Street, Bloomington, IN 47405, USA
| | - D Tyler Roman
- US Department of Agriculture Forest Service, Northern Research Station, 1831 Highway 169 East , Grand Rapids, MN 55744, USA
| | - Kimberly A Novick
- School of Public and Environmental Affairs, Indiana University Bloomington, 1315 East Tenth Street, Bloomington, IN 47405, USA
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18
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Campioli M, Malhi Y, Vicca S, Luyssaert S, Papale D, Peñuelas J, Reichstein M, Migliavacca M, Arain MA, Janssens IA. Evaluating the convergence between eddy-covariance and biometric methods for assessing carbon budgets of forests. Nat Commun 2016; 7:13717. [PMID: 27966534 PMCID: PMC5171944 DOI: 10.1038/ncomms13717] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2015] [Accepted: 10/27/2016] [Indexed: 11/13/2022] Open
Abstract
The eddy-covariance (EC) micro-meteorological technique and the ecology-based biometric methods (BM) are the primary methodologies to quantify CO2 exchange between terrestrial ecosystems and the atmosphere (net ecosystem production, NEP) and its two components, ecosystem respiration and gross primary production. Here we show that EC and BM provide different estimates of NEP, but comparable ecosystem respiration and gross primary production for forest ecosystems globally. Discrepancies between methods are not related to environmental or stand variables, but are consistently more pronounced for boreal forests where carbon fluxes are smaller. BM estimates are prone to underestimation of net primary production and overestimation of leaf respiration. EC biases are not apparent across sites, suggesting the effectiveness of standard post-processing procedures. Our results increase confidence in EC, show in which conditions EC and BM estimates can be integrated, and which methodological aspects can improve the convergence between EC and BM.
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Affiliation(s)
- M. Campioli
- Centre of Excellence PLECO (Plant and Vegetation Ecology), Department of Biology, University of Antwerp, 2610 Wilrijk, Belgium
| | - Y. Malhi
- Environmental Change Institute, School of Geography and the Environment, University of Oxford, Oxford OX1 3QY, UK
| | - S. Vicca
- Centre of Excellence PLECO (Plant and Vegetation Ecology), Department of Biology, University of Antwerp, 2610 Wilrijk, Belgium
| | - S. Luyssaert
- LSCE CEA-CNRS-UVSQ, Orme des Merisiers, F-91191 Gif-sur-Yvette, France
| | - D. Papale
- DIBAF, University of Tuscia, 01100 Viterbo, Italy
- Euro-Mediterranean Center on Climate Change, CMCC, 73100 Lecce, Italy
| | - J. Peñuelas
- CSIC, Global Ecology Unit, CREAF-CEAB-CSIC-UAB, Cerdanyola del Vallès, 08193 Barcelona, Catalonia, Spain
- CREAF, Cerdanyola del Vallès, 08193 Barcelona, Catalonia, Spain
| | - M. Reichstein
- Max Planck Institute for Biogeochemistry, 07745 Jena, Germany
| | - M. Migliavacca
- Max Planck Institute for Biogeochemistry, 07745 Jena, Germany
| | - M. A. Arain
- School of Geography & Earth Sciences, McMaster University, Hamilton, Ontario, Canada L8S 4K1
| | - I. A. Janssens
- Centre of Excellence PLECO (Plant and Vegetation Ecology), Department of Biology, University of Antwerp, 2610 Wilrijk, Belgium
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19
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Novick KA, Oishi AC, Miniat CF. Cold air drainage flows subsidize montane valley ecosystem productivity. GLOBAL CHANGE BIOLOGY 2016; 22:4014-4027. [PMID: 27081931 DOI: 10.1111/gcb.13320] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2015] [Accepted: 03/28/2016] [Indexed: 06/05/2023]
Abstract
In mountainous areas, cold air drainage from high to low elevations has pronounced effects on local temperature, which is a critical driver of many ecosystem processes, including carbon uptake and storage. Here, we leverage new approaches for interpreting ecosystem carbon flux observations in complex terrain to quantify the links between macro-climate condition, drainage flows, local microclimate, and ecosystem carbon cycling in a southern Appalachian valley. Data from multiple long-running climate stations and multiple eddy covariance flux towers are combined with simple models for ecosystem carbon fluxes. We show that cold air drainage into the valley suppresses local temperature by several degrees at night and for several hours before and after sunset, leading to reductions in growing season respiration on the order of ~8%. As a result, we estimate that drainage flows increase growing season and annual net carbon uptake in the valley by >10% and >15%, respectively, via effects on microclimate that are not be adequately represented in regional- and global-scale terrestrial ecosystem models. Analyses driven by chamber-based estimates of soil and plant respiration reveal cold air drainage effects on ecosystem respiration are dominated by reductions to the respiration of aboveground biomass. We further show that cold air drainage proceeds more readily when cloud cover and humidity are low, resulting in the greatest enhancements to net carbon uptake in the valley under clear, cloud-free (i.e., drought-like) conditions. This is a counterintuitive result that is neither observed nor predicted outside of the valley, where nocturnal temperature and respiration increase during dry periods. This result should motivate efforts to explore how topographic flows may buffer eco-physiological processes from macroscale climate change.
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Affiliation(s)
- Kimberly A Novick
- School of Public and Environmental Affairs, Indiana University - Bloomington, 702 N. Walnut Grove Avenue, Bloomington, IN, 47405, USA
| | - A Christopher Oishi
- USDA Forest Service - Southern Research Station, Coweeta Hydrologic Laboratory, 3160 Coweeta Lab Road, Otto, NC, 28763, USA
| | - Chelcy Ford Miniat
- USDA Forest Service - Southern Research Station, Coweeta Hydrologic Laboratory, 3160 Coweeta Lab Road, Otto, NC, 28763, USA
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20
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Manoli G, Domec JC, Novick K, Oishi AC, Noormets A, Marani M, Katul G. Soil-plant-atmosphere conditions regulating convective cloud formation above southeastern US pine plantations. GLOBAL CHANGE BIOLOGY 2016; 22:2238-2254. [PMID: 26762609 DOI: 10.1111/gcb.13221] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Accepted: 12/09/2015] [Indexed: 06/05/2023]
Abstract
Loblolly pine trees (Pinus taeda L.) occupy more than 20% of the forested area in the southern United States, represent more than 50% of the standing pine volume in this region, and remove from the atmosphere about 500 g C m-2 per year through net ecosystem exchange. Hence, their significance as a major regional carbon sink can hardly be disputed. What is disputed is whether the proliferation of young plantations replacing old forest in the southern United States will alter key aspects of the hydrologic cycle, including convective rainfall, which is the focus of the present work. Ecosystem fluxes of sensible (Hs) and latent heat (LE) and large-scale, slowly evolving free atmospheric temperature and water vapor content are known to be first-order controls on the formation of convective clouds in the atmospheric boundary layer. These controlling processes are here described by a zero-order analytical model aimed at assessing how plantations of different ages may regulate the persistence and transition of the atmospheric system between cloudy and cloudless conditions. Using the analytical model together with field observations, the roles of ecosystem Hs and LE on convective cloud formation are explored relative to the entrainment of heat and moisture from the free atmosphere. Our results demonstrate that cloudy-cloudless regimes at the land surface are regulated by a nonlinear relation between the Bowen ratio Bo=Hs/LE and root-zone soil water content, suggesting that young/mature pines ecosystems have the ability to recirculate available water (through rainfall predisposition mechanisms). Such nonlinearity was not detected in a much older pine stand, suggesting a higher tolerance to drought but a limited control on boundary layer dynamics. These results enable the generation of hypotheses about the impacts on convective cloud formation driven by afforestation/deforestation and groundwater depletion projected to increase following increased human population in the southeastern United States.
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Affiliation(s)
- Gabriele Manoli
- Nicholas School of the Environment, Duke University, Durham, NC, 27708, USA
| | - Jean-Christophe Domec
- Nicholas School of the Environment, Duke University, Durham, NC, 27708, USA
- Department of Forestry and Environmental Resources, North Carolina State University, Raleigh, NC, 27607, USA
| | - Kimberly Novick
- School of Public and Environment Affairs, Indiana University, Bloomington, IN, 47405, USA
| | | | - Asko Noormets
- Department of Forestry and Environmental Resources, North Carolina State University, Raleigh, NC, 27607, USA
| | - Marco Marani
- Nicholas School of the Environment, Duke University, Durham, NC, 27708, USA
| | - Gabriel Katul
- Nicholas School of the Environment, Duke University, Durham, NC, 27708, USA
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Novick KA, Miniat CF, Vose JM. Drought limitations to leaf-level gas exchange: results from a model linking stomatal optimization and cohesion-tension theory. PLANT, CELL & ENVIRONMENT 2016; 39:583-96. [PMID: 26466749 DOI: 10.1111/pce.12657] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2014] [Accepted: 09/14/2015] [Indexed: 05/23/2023]
Abstract
We merge concepts from stomatal optimization theory and cohesion-tension theory to examine the dynamics of three mechanisms that are potentially limiting to leaf-level gas exchange in trees during drought: (1) a 'demand limitation' driven by an assumption of optimal stomatal functioning; (2) 'hydraulic limitation' of water movement from the roots to the leaves; and (3) 'non-stomatal' limitations imposed by declining leaf water status within the leaf. Model results suggest that species-specific 'economics' of stomatal behaviour may play an important role in differentiating species along the continuum of isohydric to anisohydric behaviour; specifically, we show that non-stomatal and demand limitations may reduce stomatal conductance and increase leaf water potential, promoting wide safety margins characteristic of isohydric species. We used model results to develop a diagnostic framework to identify the most likely limiting mechanism to stomatal functioning during drought and showed that many of those features were commonly observed in field observations of tree water use dynamics. Direct comparisons of modelled and measured stomatal conductance further indicated that non-stomatal and demand limitations reproduced observed patterns of tree water use well for an isohydric species but that a hydraulic limitation likely applies in the case of an anisohydric species.
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Affiliation(s)
- Kimberly A Novick
- School of Public and Environmental Affairs, Indiana University, Bloomington, IN, 47405, USA
| | - Chelcy F Miniat
- USDA Forest Service, Coweeta Hydrologic Laboratory, Otto, NC, 28734, USA
| | - James M Vose
- USDA Forest Service - Southern Research Station - Center for Integrated Forest Science. North Carolina State University, Department of Forestry and Environmental Resources, Raleigh, NC, 27695-8008, USA
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