Download or read book Improving Terrestrial Carbon Modeling written by Brett Raczka and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Terrestrial biosphere models can help identify physical processes that control carbon dynamics, including land-atmosphere CO2 fluxes, and have great potential to predict the terrestrial ecosystem response to changing climate. This dissertation evaluates ways to improve biosphere model performance by 1) evaluating short term (5 years) performance across a broad range of representation complexity, 2) identifying sources of parametric uncertainty for long term (~100 years) performance within a mechanistically detailed model (Ecosystem Demography) and 3) identifying observations that best constrain long term performance. Chapter 2 evaluates the performance of continental-scale carbon flux estimates from 17 models against carbon flux observations from 36 North American flux towers. On average the regional model runs overestimate the annual gross primary productivity (5%) and total respiration (15%), and significantly underestimate the annual net carbon uptake (64%) during the time period 2000-2005. Comparison with site-level simulations implicate choices specific to regional model simulations as contributors to the gross flux biases, but not the net carbon uptake bias. The models perform the best at simulating carbon exchange at deciduous broadleaf sites; likely because a number of models use prescribed phenology to simulate seasonal fluxes. In general, the models do not perform as well for crop, grass and evergreen sites in terms of bias, correlation and magnitude of variation. The regional models match the observations most closely in terms of seasonal correlation and seasonal magnitude of variation, but have very little skill at inter-annual correlation and minimal skill at inter-annual magnitude of variability. The comparison of site versus regional level model runs demonstrate that 1) the inter-annual correlation is higher for site-level model runs but the skill remains low, and 2) the underestimation of year-to-year variability for all fluxes is an inherent weakness of the models. The best performing regional models that do not use flux tower calibration are CLM-CN, CASA--GFEDv2 and SIB3. Two empirical models, calibrated with flux towers observations, EC-MOD and MOD17+, perform as well as the best process-based models. This suggests that 1) empirical, calibrated models can perform as well as complex, process-based models, and 2) combining process-based model structure with relevant constraining data could significantly improve model performance. Through a sensitivity analysis of the Ecosystem Demography model (version 2.1), Chapter 3 identifies quantum efficiency and leaf respiration rate parameters as the highest contributors to model uncertainty regardless of time frame (annual, decadal, centennial). This finding is sensitive to methodological choices within the meta-analysis process. Trait data provides relatively modest constraint upon the model simulation whereas integrative measurements of NEE and AGB provide strong constraints to the model and parameter uncertainty. Key actions for model improvement include 1) locating additional measurements related to quantum efficiency, leaf respiration rate and water fluxes (e.g. sap flux, soil moisture) and 2) implementing a more mechanistic representation of growth respiration within the model.
Download or read book Negative Emissions Technologies and Reliable Sequestration written by National Academies of Sciences, Engineering, and Medicine and published by National Academies Press. This book was released on 2019-04-08 with total page 511 pages. Available in PDF, EPUB and Kindle. Book excerpt: To achieve goals for climate and economic growth, "negative emissions technologies" (NETs) that remove and sequester carbon dioxide from the air will need to play a significant role in mitigating climate change. Unlike carbon capture and storage technologies that remove carbon dioxide emissions directly from large point sources such as coal power plants, NETs remove carbon dioxide directly from the atmosphere or enhance natural carbon sinks. Storing the carbon dioxide from NETs has the same impact on the atmosphere and climate as simultaneously preventing an equal amount of carbon dioxide from being emitted. Recent analyses found that deploying NETs may be less expensive and less disruptive than reducing some emissions, such as a substantial portion of agricultural and land-use emissions and some transportation emissions. In 2015, the National Academies published Climate Intervention: Carbon Dioxide Removal and Reliable Sequestration, which described and initially assessed NETs and sequestration technologies. This report acknowledged the relative paucity of research on NETs and recommended development of a research agenda that covers all aspects of NETs from fundamental science to full-scale deployment. To address this need, Negative Emissions Technologies and Reliable Sequestration: A Research Agenda assesses the benefits, risks, and "sustainable scale potential" for NETs and sequestration. This report also defines the essential components of a research and development program, including its estimated costs and potential impact.
Download or read book Climate Change and Terrestrial Ecosystem Modeling written by Gordon Bonan and published by Cambridge University Press. This book was released on 2019-02-21 with total page 459 pages. Available in PDF, EPUB and Kindle. Book excerpt: Provides an essential introduction to modeling terrestrial ecosystems in Earth system models for graduate students and researchers.
Download or read book Land Carbon Cycle Modeling written by Yiqi Luo and published by CRC Press. This book was released on 2022-08-18 with total page 602 pages. Available in PDF, EPUB and Kindle. Book excerpt: Carbon moves through the atmosphere, through the oceans, onto land, and into ecosystems. This cycling has a large effect on climate – changing geographic patterns of rainfall and the frequency of extreme weather – and is altered as the use of fossil fuels adds carbon to the cycle. The dynamics of this global carbon cycling are largely predicted over broad spatial scales and long periods of time by Earth system models. This book addresses the crucial question of how to assess, evaluate, and estimate the potential impact of the additional carbon to the land carbon cycle. The contributors describe a set of new approaches to land carbon cycle modeling for better exploring ecological questions regarding changes in carbon cycling; employing data assimilation techniques for model improvement; and doing real- or near-time ecological forecasting for decision support. This book strives to balance theoretical considerations, technical details, and applications of ecosystem modeling for research, assessment, and crucial decision making. Key Features Helps readers understand, implement, and criticize land carbon cycle models Offers a new theoretical framework to understand transient dynamics of land carbon cycle Describes a suite of modeling skills – matrix approach to represent land carbon, nitrogen, and phosphorus cycles; data assimilation and machine learning to improve parameterization; and workflow systems to facilitate ecological forecasting Introduces a new set of techniques, such as semi-analytic spin-up (SASU), unified diagnostic system with a 1-3-5 scheme, traceability analysis, and benchmark analysis, for model evaluation and improvement Related Titles Isabel Ferrera, ed. Climate Change and the Oceanic Carbon Cycle: Variables and Consequences (ISBN 978-1-774-63669-5) Lal, R. et al., eds. Soil Processes and the Carbon Cycle (ISBN 978-0-8493-7441-8) Windham-Myers, L., et al., eds. A Blue Carbon Primer: The State of Coastal Wetland Carbon Science, Practice and Policy (ISBN 978-0-367-89352-1)
Download or read book Terrestrial Carbon Observation written by Josef Cihlar and published by Food & Agriculture Org.. This book was released on 2002 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report summarises the discussions and recommendations of a workshop held in 2001, within the framework of the Terrestrial Carbon Observation (TCO) initiative. This workshop focused on the development of a systematic and collaborative approach to improving "in situ" or ground-based carbon data availability. The benefits of improved "in situ" terrestrial carbon observation will mean that countries can make more informed decisions related to the sustainable use and management of land resources.
Download or read book Modeling Terrestrial Carbon Cycle During the Last Glacial Maximum written by Dan Zhu and published by . This book was released on 2016 with total page 157 pages. Available in PDF, EPUB and Kindle. Book excerpt: During the repeated glacialinterglacialtransitions, there has been aconsistent and partly abrupt increase of nearly100 ppm in atmospheric CO2, indicating majorredistributions among the carbon reservoirs ofland, ocean and atmosphere. A comprehensiveexplanation of the carbon fluxes associatedwith the transitions is still missing, requiring abetter understanding of the potential carbonstock in terrestrial biosphere during the glacialperiod. In this thesis, I aimed to improve theunderstanding of terrestrial carbon stocks andcarbon cycle during the Last Glacial Maximum(LGM, about 21,000 years ago), through aseries of model developments to improve therepresentation of vegetation dynamics,permafrost soil carbon dynamics, andinteractions between large herbivores andvegetation in the ORCHIDEE-MICT landsurface model.For the first part, I improved theparameterization of vegetation dynamics inORCHIDEE-MICT for the northern mid- tohigh-latitude regions, which was evaluatedagainst present-day observation-based datasetsof land cover, gross primary production, andforest biomass. Significant improvements wereshown for the new model version in thedistribution of plant functional types (PFTs),including a more realistic simulation of thenorthern tree limit and of the distribution ofevergreen and deciduous conifers in the borealzone. The revised model was then applied tosimulate vegetation distribution during theLGM, showing a general agreement with thepoint-scale reconstructions based on pollen andplant macrofossil data.Among permafrost (perennially frozen) soils,the thick, ice-rich and organic-rich siltysediments called yedoma deposits hold largequantities of organic carbon, which areremnants of late-Pleistocene carbonaccumulated under glacial climates. In order tosimulate the buildup of the thick frozen carbonin yedoma deposits, I implemented asedimentation parameterization in the soilcarbon module of ORCHIDEE-MICT. Theinclusion of sedimentation allowed the modelto reproduce the vertical distribution of carbonobserved at the yedoma sites, leading toseveral-fold increase in total carbon. Simulatedpermafrost soil carbon stock during the LGMwas ~1550 PgC, among which 390~446 PgCwithin today's known yedoma region (1.3million km2). This result was still anunderestimation since the potentially largerarea of yedoma during the LGM than todaywas not yet taken into account.For the third part, in light of the growingevidence on the ecological impacts of largeanimals, and the potential role of megaherbivoresas a driving force that maintainedthe steppe ecosystems during the glacialperiods, I incorporated a dynamic grazingmodel in ORCHIDEE-MICT, based onphysiological equations for energy intake andexpenditure, reproduction rate, and mortalityrate for wild large grazers. The model showedreasonable results of today's grazer biomasscompared to empirical data in protected areas,and was able to produce an extensive biomewith a dominant vegetation of grass and asubstantial distribution of large grazers duringthe LGM. The effects of large grazers onvegetation and carbon cycle were discussed,including reducing tree cover, enhancinggrassland productivity, and increasing theturnover rate of vegetation living biomass.Lastly, I presented a preliminary estimation ofpotential LGM permafrost carbon stock, afteraccounting for the effects of large grazers, aswell as extrapolations for the spatial extent ofyedoma-like thick sediments based on climaticand topographic features that are similar to theknown yedoma region. Since these results werederived under LGM climate and constantsedimentation rate, a more realistic simulationwould need to consider transient climate duringthe last glacial period and sedimentation ratevariations in the next step.
Download or read book Land Use and the Carbon Cycle written by Daniel G. Brown and published by Cambridge University Press. This book was released on 2013-01-28 with total page 591 pages. Available in PDF, EPUB and Kindle. Book excerpt: Comprehensive exploration of how land use interacts with the atmosphere and carbon cycle, for advanced students, researchers and policy makers.
Download or read book Spatial Modeling of Carbon Pools and Fluxes of Terrestrial Ecosystems written by Abha Chhabra and published by LAP Lambert Academic Publishing. This book was released on 2012-03-01 with total page 204 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Carbon cycle holds center stage in many global change studies due to rising levels of atmospheric carbon dioxide and its role in influencing climate and determining food, fiber and wood supply for human use through plant productivity. Highly unusual variations in the global carbon balance over last few decades have prompted much research on the dynamics of carbon cycle. Terrestrial ecosystems play an important role in global carbon budgets. This book presents a detailed research study undertaken for improving our understanding of agroecosystem and forest carbon cycle in India. It includes a detailed assessment of past and ongoing landuse and landcover changes and their effects on agroecosystem carbon cycle in Indo-Gangetic plains and estimation of biomass, phytomass carbon and soil carbon pools, litterfall carbon flux, and long-term net carbon release in Indian forests at regional and national scales. The environmental, economic and societal importance of the carbon cycle has led to numerous research initiatives at national and international levels. This book is very useful and informative to researchers in the field of biogeochemical carbon cycle and global change studies.
Download or read book Evaluating and Improving Terrestrial Carbon Exchange in the NCAR CCM3 Land Surface Model written by Rui Gong and published by . This book was released on 1999 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Land Carbon Cycle Modeling written by Yiqi Luo and published by . This book was released on 2024 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Carbon moves through the atmosphere, through the oceans, onto land, and into ecosystems. This cycling has a large effect on climate - changing geographic patterns of rainfall and the frequency of extreme weather - and is altered as the use of fossil fuels adds carbon to the cycle. The dynamics of this global carbon cycling are largely predicted over broad spatial scales and long periods of time by Earth system models. This book addresses the crucial question of how to assess, evaluate, and estimate the potential impact of the additional carbon to the land carbon cycle. The contributors describe a set of new approaches to land carbon cycle modeling for better exploring ecological questions regarding changes in carbon cycling; employing data assimilation techniques for model improvement; doing real- or near-time ecological forecasting for decision support; and combining newly available machine learning techniques with process-based models to improve prediction of the land carbon cycle under climate change. This new edition includes seven new chapters: machine learning and its applications to carbon cycle research (five chapters); principles underlying carbon dioxide removal from the atmosphere, contemporary active research and management issues (one chapter); and community infrastructure for ecological forecasting (one chapter). Key Features Helps readers understand, implement, and criticize land carbon cycle models Offers a new theoretical framework to understand transient dynamics of the land carbon cycle Describes a suite of modeling skills - matrix approach to represent land carbon, nitrogen, and phosphorus cycles; data assimilation and machine learning to improve parameterization; and workflow systems to facilitate ecological forecasting Introduces a new set of techniques, such as semi-analytic spin-up (SASU), unified diagnostic system with a 1-3-5 scheme, traceability analysis, and benchmark analysis, and PROcess-guided machine learning and DAta-driven modeling (PRODA) for model evaluation and improvement Reorganized from the first edition with seven new chapters added Strives to balance theoretical considerations, technical details, and applications of ecosystem modeling for research, assessment, and crucial decision-making
Download or read book Vegetation and the Terrestrial Carbon Cycle written by David Beerling and published by Cambridge University Press. This book was released on 2001-10-18 with total page 432 pages. Available in PDF, EPUB and Kindle. Book excerpt: An analysis of the Earth's vegetations and carbon cycle in the past and predictions for the future.
Download or read book Terrestrial Carbon Observation written by Josef Cihlar and published by Food & Agriculture Org.. This book was released on 2002 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt: The term 'terrestrial carbon' refers to carbon contained in vegetation or soil stocks. The global carbon cycle plays an important role in sustaining agricultural productivity, biodiversity and forest ecosystems processes. This report identifies a framework for the systematic observation and assessment of carbon stocks on land and in the atmosphere, highlights a number of challenges that need to be addressed and outlines an approach to implement an initial observing system.
Download or read book Global Environmental Change written by National Research Council and published by National Academies Press. This book was released on 1999-09-14 with total page 621 pages. Available in PDF, EPUB and Kindle. Book excerpt: How can we understand and rise to the environmental challenges of global change? One clear answer is to understand the science of global change, not solely in terms of the processes that control changes in climate and the composition of the atmosphere, but in how ecosystems and human society interact with these changes. In the last two decades of the twentieth century, a number of such research effortsâ€"supported by computer and satellite technologyâ€"have been launched. Yet many opportunities for integration remain unexploited, and many fundamental questions remain about the earth's capacity to support a growing human population. This volume encourages a renewed commitment to understanding global change and sets a direction for research in the decade ahead. Through case studies the book explores what can be learned from the lessons of the past 20 years and what are the outstanding scientific questions. Highlights include: Research imperatives and strategies for investigators in the areas of atmospheric chemistry, climate, ecosystem studies, and human dimensions of global change. The context of climate change, including lessons to be gleaned from paleoclimatology. Human responses toâ€"and forcing ofâ€"projected global change. This book offers a comprehensive overview of global change research to date and provides a framework for answering urgent questions.
Download or read book Carbon and Nitrogen in the Terrestrial Environment written by R. Nieder and published by Springer Science & Business Media. This book was released on 2008-05-30 with total page 434 pages. Available in PDF, EPUB and Kindle. Book excerpt: Carbon and Nitrogen in the Terrestrial Environment is a comprehensive, interdisciplinary description of C and N fluxes between the atmosphere and the terrestrial biosphere; issues related to C and N management in different ecosystems and their implications for the environment and global climate change; and the approaches to mitigate emission of greenhouse gases. Drawing upon the most up-to-date books, journals, bulletins, reports, symposia proceedings and internet sources documenting interrelationships between different aspects of C and N cycling in the terrestrial environment, Carbon and Nitrogen in the Terrestrial Environment fills the gap left by most of the currently available books on C and N cycling. They either deal with a single element of an ecosystem, or are related to one or a few selected aspects like soil organic matter (SOM) and agricultural or forest management, emission of greenhouse gases, global climate change or modeling of SOM dynamics.
Download or read book A Macrosystems Approach Towards Improved Understanding of Interactions Between Forest Management Structure Function and Climate Change and Implications for the Terrestrial Carbon Cycle written by Bailey A. Murphy and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Forests constitute a significant global carbon sink that continues to expand in size, in addition to supporting a range of environmental, economic, and social co-benefits. Forests interact with the overlying atmosphere through exchanges of carbon, water, and energy, and because of the climatic relevance of these fluxes, processes related to terrestrial ecology and land use have a considerable impact on global climate. The comparatively large size of the forest carbon sink in combination with the complimentary climate feedbacks it provides give it significant potential as an avenue for climate mitigation through management practices designed to enhance carbon sequestration. However, anthropogenic management and shifting environmental conditions due to climate change modify forest structure and function, which fundamentally alters land-atmosphere exchanges and the resultant feedbacks with climate. Gaps remain in our understanding of how forest management, structure, function, and climate change interact across long timescales, and whether relationships are spatially dependent, particularly with regards to vulnerabilities of forest function to climate change. These knowledge gaps manifest as substantial uncertainty surrounding the future of the terrestrial carbon sink and other ecosystem services, and the viability of improved forest management as a climate mitigation strategy hinges on addressing these uncertainties. Here, we sought to address three overarching questions: 1) What is the mechanistic relationship between forest structure and function? 2) What is the primary driver of future shifts in forest function? And 3) How does management impact the stability of forest function in the face of climate change? Observational data from the Chequamegon Heterogeneous Ecosystem Energy-balance Study Enabled by a High-density Extensive Array of Detectors 2019 (CHEESEHEAD19) field campaign was used to construct simplified models of the mechanistic relationships between forest structure and function and evaluate spatial dependence. We found that the mechanistic relationship between forest structure and function is mediated by resource use efficiency, is dependent upon the spatial resolution used to calculate structural complexity metrics, and that structural metrics representing the degree of vertical heterogeneity are the most influential productivity drivers for heterogeneous temperate forests. Next, a process-based model was employed to simulate multi-decadal projections of vegetation demographics in response to management, using data from National Ecological Observatory Network (NEON) core terrestrial sites in two U.S. regions. Additionally, downscaled global climate model (GCM) output under two future radiative forcing scenarios (RCP4.5 and RCP8.5) was used to drive model meteorology, allowing for the approximation of vegetation responses to shifting climatic conditions, and facilitating understanding of how management might moderate those responses. With this approach, we showed that management is the strongest driver of future variability in forest function at the regional scale, but that at broader spatial scales gradients in future climate become critical. The narrow precedence of climate over management as a driver of forest function at the sub-continental scale suggests that their effects are likely not independent of one another. We also found that temporal stability is driven primarily by climate, while resilience is shaped by management, but that the impact of management on forest functional stability is regionally dependent and varies by management intensity and severity. These findings allow us to improve representation in ecosystem models of how structural complexity impacts light and water-sensitive processes, and ultimately productivity. Improved models enhance our capacity to accurately simulate forest responses to management, furthering our ability to assess climate mitigation strategies. Additionally, these findings highlight the regional dependency of the response of forest function to management and climate change, and caution that the same management approach is not necessarily viable everywhere, meaning that the durability of management related Nature-based Climate Solutions have to be assessed at the regional scale. This information can help forest managers evaluate trade offs between ecosystem goods and services, assess climate risks of applying management practices in different regions, and potentially identify specific components of ecosystem function to bolster through targeted management practices.
Download or read book Soil Carbon Storage written by Brajesh Singh and published by Academic Press. This book was released on 2018-04-12 with total page 341 pages. Available in PDF, EPUB and Kindle. Book excerpt: Soil Carbon Storage: Modulators, Mechanisms and Modeling takes a novel approach to the issue of soil carbon storage by considering soil C sequestration as a function of the interaction between biotic (e.g. microbes and plants) and abiotic (climate, soil types, management practices) modulators as a key driver of soil C. These modulators are central to C balance through their processing of C from both plant inputs and native soil organic matter. This book considers this concept in the light of state-of-the-art methodologies that elucidate these interactions and increase our understanding of a vitally important, but poorly characterized component of the global C cycle. The book provides soil scientists with a comprehensive, mechanistic, quantitative and predictive understanding of soil carbon storage. It presents a new framework that can be included in predictive models and management practices for better prediction and enhanced C storage in soils. - Identifies management practices to enhance storage of soil C under different agro-ecosystems, soil types and climatic conditions - Provides novel conceptual frameworks of biotic (especially microbial) and abiotic data to improve prediction of simulation model at plot to global scale - Advances the conceptual framework needed to support robust predictive models and sustainable land management practices
Download or read book Detecting a Terrestrial Biosphere Sink for Carbon Dioxide written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-08-16 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: There is considerable uncertainty as to whether interannual variability in climate and terrestrial ecosystem production is sufficient to explain observed variation in atmospheric carbon content over the past 20-30 years. In this paper, we investigated the response of net CO2 exchange in terrestrial ecosystems to interannual climate variability (1983 to 1988) using global satellite observations as drivers for the NASA-CASA (Carnegie-Ames-Stanford Approach) simulation model. This computer model of net ecosystem production (NEP) is calibrated for interannual simulations driven by monthly satellite vegetation index data (NDVI) from the NOAA Advanced Very High Resolution Radiometer (AVHRR) at 1 degree spatial resolution. Major results from NASA-CASA simulations suggest that from 1985 to 1988, the northern middle-latitude zone (between 30 and 60 degrees N) was the principal region driving progressive annual increases in global net primary production (NPP; i.e., the terrestrial biosphere sink for carbon). The average annual increase in NPP over this predominantly northern forest zone was on the order of +0.4 Pg (10 (exp 15) g) C per year. This increase resulted mainly from notable expansion of the growing season for plant carbon fixation toward the zonal latitude extremes, a pattern uniquely demonstrated in our regional visualization results. A net biosphere source flux of CO2 in 1983-1984, coinciding with an El Nino event, was followed by a major recovery of global NEP in 1985 which lasted through 1987 as a net carbon sink of between 0.4 and 2.6 Avg C per year. Analysis of model controls on NPP and soil heterotrophic CO2 fluxes (Rh) suggests that regional warming in northern forests can enhance ecosystem production significantly. In seasonally dry tropical zones, periodic drought and temperature drying effects may carry over with at least a two-year lag time to adversely impact ecosystem production. These yearly patterns in our model-predicted NEP are consistent in magnit...
