Download or read book Assessing the Impacts of Land Use Change and Ecological Restoration on CH4 and CO2 Fluxes in the Sacramento San Joaquin Delta California written by Sara Helen Knox and published by . This book was released on 2016 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Sacramento-San Joaquin Delta in California was drained for agriculture and human settlement circa 1850, resulting in extreme rates of soil subsidence and CO2 emissions due to peat oxidation. As a result of this prolonged ecosystem carbon imbalance where ecosystem respiration exceeded primary productivity, much of the land surface in the Delta now lies 5 to 8 m below sea level. To help reverse subsidence and convert Delta ecosystems from net carbon sources to carbon sinks, land managers have begun converting drained agricultural lands back to flooded ecosystems including wetlands and irrigated rice paddies. However, this comes at the cost of increased CH4 emissions, a much more potent greenhouse gas than CO2. To evaluate the impacts of drained to flooded land-use change on the biosphere-atmosphere exchange of CO2 and CH4 in the Delta, I conducted a full year of simultaneous eddy covariance measurements at two conventional drained agricultural peatlands (a pasture and a corn field) and three flooded land-use types (a rice paddy and two restored wetlands). This research showed that the drained sites were large CO2 and greenhouse gas (GHG) sources. However, this study also found that converting drained agricultural peat soils to flooded rice paddies or wetlands can help reduce or reverse soil subsidence and reduce GHG emissions, despite the potential for considerably higher CH4 emissions. In particular, wetlands offer the greatest potential for reversing subsidence since both restored wetlands were large net carbon sinks. Since natural and managed ecosystems can exhibit large year-to-year variation in CO2 and CH4 exchange, I analyzed 6.5 years of measurements from the irrigated rice paddy to investigate the factors affecting CH4 fluxes across diel to interannual timescales and quantify interannual variability in CO2 and CH4 budgets. Using wavelet analysis, I found that photosynthesis induced the diel pattern in CH4 flux, but soil temperature influenced its amplitude. At the seasonal scale, linear and neural network models indicated that photosynthesis and water levels were the dominant factors regulating daily average CH4 fluxes. However, across years, much of the variability in annual and growing season CH4 sums was driven by soil temperature. Soil temperature also strongly influenced ecosystem respiration, resulting in large interannual variability in the net carbon budget at the paddy. This study emphasizes the need for long-term, continuous measurements particularly under changing climatic conditions. With a growing interest in including wetlands in carbon markets worldwide due to their ability to accumulate large amounts of carbon, there is a need for models that can accurately and cheaply predict wetland CO2 and CH4 fluxes. In the final chapter of this dissertation, I combined eddy covariance CO2 fluxes measurements, flux footprint analysis, and near-surface (i.e. digital cameras) or satellite remote sensing data to investigate the potential of using the light use efficiency approach to accurately and cost-effectively model photosynthesis in wetland systems. Through this analysis, I showed that digital camera and Landsat imagery can be used to model carbon uptake in wetlands, providing inexpensive means of monitoring carbon cycling in these environments that can be used in carbon markets. By measuring trace gas exchange across multiple sites for multiple years, this dissertation provides new and important insights on the impacts of land use change in the Delta, improves our understanding of factors influencing CO2 and CH4 fluxes from agricultural and restored wetlands across diel to interannual timescales, and presents cost-effective and accurate ways of estimating photosynthesis in restored wetlands by combining flux measurements with near-surface and satellite remote sensing. This work helps bridge understanding between biometeorology, biogeochemistry and climate policy, and provides valuable information to help inform management decisions regarding carbon and water management of the Delta.

Download or read book Wetland Carbon and Environmental Management written by Ken W. Krauss and published by John Wiley & Sons. This book was released on 2021-11-23 with total page 484 pages. Available in PDF, EPUB and Kindle. Book excerpt: Explores how the management of wetlands can influence carbon storage and fluxes. Wetlands are vital natural assets, including their ability to take-up atmospheric carbon and restrict subsequent carbon loss to facilitate long-term storage. They can be deliberately managed to provide a natural solution to mitigate climate change, as well as to help offset direct losses of wetlands from various land-use changes and natural drivers. Wetland Carbon and Environmental Management presents a collection of wetland research studies from around the world to demonstrate how environmental management can improve carbon sequestration while enhancing wetland health and function. Volume highlights include: Overview of carbon storage in the landscape Introduction to wetland management practices Comparisons of natural, managed, and converted wetlands Impact of wetland management on carbon storage or loss Techniques for scientific assessment of wetland carbon processes Case studies covering tropical, coastal, inland, and northern wetlands Primer for carbon offset trading programs and how wetlands might contribute The American Geophysical Union promotes discovery in Earth and space science for the benefit of humanity.Its publications disseminate scientific knowledge and provide resources for researchers, students, and professionals.

Download or read book Observing Modeling and Understanding Processes in Natural and Managed Peatlands written by Michel Bechtold and published by Frontiers Media SA. This book was released on 2022-05-25 with total page 234 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Subsidence and Carbon Fluxes in the Sacramento San Joaquin Delta California written by and published by . This book was released on 1994 with total page 2 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Effect of Agricultural Land Use Changes on Greenhouse Gas Emissions and Carbon Dynamics in Drained Peat Soils in the San Joaquin Delta CA written by Yacov Assa and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: AbstractGreenhouse Gas Emissions (GHG) from two cropping systems on Twitchell Island was monitored spring 2010 to spring 2012. The island is one of 57 manmade Islands located in the San Joaquin-Sacramento Delta in California (herein the "Delta"). The cropping systems under study were field corn and Delta rice. The project was set to study the effects of the cropping system on GHG emissions and soil organic carbon (SOC). Carbon Dioxide (CO2), Methane (CH4) and Nitrous Oxide (N2O) emissions measurement was done every one to three weeks during spring 2010-2012. Crop final biomass and total carbon (C) was measured for residue and C input estimation each year. In addition, the effect of crop residue levels on GHG emissions and C dynamics was studied over one year in each system during 2010-2011. The main objective of this study was to test the hypothesis that conversion of subsided agricultural peat land from the current corn system to Delta rice would reduce overall GHG emissions, mainly CO2 and N2O. It was hypothesized that the increase in CH4 emissions due to the flooding conditions would be insignificant relative to total reduction in CO2 emissions.The Delta rice CH4 cumulative emissions differed between the two years of study (212 and 39 kg CH4 C/ha for the 2010-2011 and 2011-2012 year, respectively). The reduction in 2011-2012 vs. 2010-2011 CH4 emissions was likely due to the placement of rice residue 20-30cm below soil surface when the field was moldboard plowed in spring 2011 and the shorter flooding period during the 2011 rice growing season (108 vs. 82 days in 2010 and 2011, respectively). In an experiment to determine the effects of various levels of rice residue on CO2 and CH4 emissions, CH4 emissions from plots receiving rice residues averaged as much as 3 times higher than plots with no residue, while CO2 emissions were not affected. During both years, a significant percentage of the CH4was emitted during the winter field drain in preparation for spring planting (63% and 53% in 2010-2011 and 2011-2012 respectively). Total CO2 emissions in the rice system averaged slightly lower during 2010-2011 than in 2011-2012 (8044kg CO2 C vs. 9860kg CO2 -C/ha), respectively with over 70% of the emissions occurring when the field was not flooded. These figures are likely an overestimation, as they do not take into account the diurnal temperature fluctuation where soil respiration is lower at night. Total N2O emissions were higher in the rice system during 2010-2011 than 2011-2012 (11 kg N2O-N/ha and 6 kg N2O-N/ha in 2010-2011 and 2011-2012 respectively). All GHG emissions were related to flooding regime and soil water status, and were highest after the winter drain and during the period of field operations to summer flood for rice growing.In the corn system, total CO2 emissions were similar in 2011-2012 and 2010-2011 (8845 and 8405 kg CO2-C/ha respectively) with about 60% of it occurring during the corn growing period. N2O emissions averaged higher in the 2nd year of the study (8.9 vs. 12.6 kg N2O-N/ha in the 2010-2011 and 2011-2012 periods, respectively). N2O emissions from the corn system were also affected by soil water status, and were highest in the spring during a period of drop in water table levels. Residue level did not affect CO2 or N2O emissions in the cornfield. Total estimated residue carbon input from both systems was similar in 2011 (circa 5 metric tons C/ha) but was higher in the corn system in 2010 (circa 5 and 9 metric tons C /ha in the rice and corn systems respectively). In 2011 the corn residue was baled and removed, which left an estimated 1 ton C/ha from residue input. Both systems are a net source of GHG. A significant portion of the rice GHG emissions occurred during the fallow period and when the rice was planted but not flooded (i.e. pre-flood and drain process). In the corn system, GHG emissions occurred during the summer (CO2) and spring (N2O). Rice total GHG emissions (in CO2 equivalents) were higher in 2010-2011 but not significantly different in 2011-2012 than the corn system. Although the rice did not significantly reduce CO2emissions, while increasing CH4, it offers a system with more room for management improvements for GHG and subsidence mitigation. N2O emissions consisted of 50% to 75% of the annual GWP in CO2 equivalents in the two years (excluding CO2 emissions) in the rice system. A management practice that reduces N2O emissions would greatly reduce the total GHG. Lengthening the period the field is flooded in the winter, and shortening the drainage periods can significantly reduce N2O and CO2 emissions. But the possible increase in CH4emissions should be considered. Also, summer mid-season drain is likely reduce CH4 emissions during the summer flooding period and possibly during the fall drainage. The shortening of the drainage period can be achieved by actively pumping water out of the drainage ditches instead of letting the water percolate down, although the energy cost and effect on drain water DOC content should be considered. Improving agronomic management practices, such as variety selection for higher yield and lower days to harvest would shorten the period for CH4 emissions during the summer. Lastly, better crop establishment would improve crop uniformity, which again would lead to shorter time to harvest and guaranty higher yields.

Download or read book Climate and Land Use Change Effects on Ecological Resources in Three Watersheds a Synthesis Report written by United States Government Environmental Protection Agency and published by CreateSpace. This book was released on 2012-12-23 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt: During the early 2000s, the Environmental Protection Agency's (EPA's) Office of Research and Development, Global Change Research Program, supported three watershed assessments to evaluate different approaches and tools for understanding and managing climate and land-use change impacts on watershed ecological resources. Watershed assessments were conducted for (1) several small rivers in southern Maryland, (2) Arizona's San Pedro River, and (3) California's Sacramento River. In this report, we comparatively analyze the three case-study approaches in order to develop recommendations that may be useful as guidance to others conducting similar assessments. Key insights gained from these studies include: 1. Prioritize locations for studies to maximize decision support. 2. Target selection of stakeholders, establish credibility of underlying methods and models, and incorporate incentives for mutually beneficial results. 3. Provide essential climate science capabilities and tools to project teams. 4. Develop model linkages at the onset, carry out assessment activities at multiple scales, and require explicit uncertainty analysis of results. The watershed assessment case studies described in this report yield richness of detail in terms of methods and results, as well as inform more generally on best practices for conducting future watershed assessments. However these were pioneering studies addressing difficult and complex problems. Future assessments will continue to refine the understanding of how to maximize decision support, including providing necessary keystone capabilities and tools to effectively estimate climate change vulnerabilities, developing and supporting successful stakeholder processes, and characterizing uncertainty and scaling or transferring results to increase their relevance.

Download or read book Sacramento San Joaquin Delta Feasibility Report and Water Resource Study written by and published by . This book was released on 1982 with total page 656 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Sacramento San Joaquin Delta California written by United States. Army. Corps of Engineers. Sacramento District and published by . This book was released on 1982 with total page 754 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book CALFED Bay Delta Program Programmatic EIS Long Term Comprehensive Plan to Restore Ecosystem Health and Improve Water Management San Francisco Bay Sacramento San Joaquin River Bay Delta D Dsum Program Goals and Objectives Dapp1 No Action Alternative written by and published by . This book was released on 2000 with total page 532 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Drainage return Surface water Withdrawal and Land use Data for the Sacramento San Joaquin Delta with Emphasis on Twitchell Island California written by William E. Templin and published by . This book was released on 1997 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Sacramento San Joaquin Delta Wildlife Habitat Protection Restoration Plan written by California. Department of Fish and Game and published by . This book was released on 1980 with total page 356 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Ecosystem Restoration Program Plan Ecological attributes of the San Francisco Bay Delta Watershed written by CALFED Bay-Delta Program and published by . This book was released on 2000 with total page 604 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Peatlands and Climate Change written by Maria Strack and published by . This book was released on 2008 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt: The International Peat Society IPS established a joint IPS Working Group on Peatlands and Climate Change in the end of the year 2005. The Working Group's task was to compile information into a summary of available knowledge to help the IPS and other actors to understand the role of peatlands and peat within the current context of global climate change.

Download or read book Comparing Futures for the Sacramento San Joaquin Delta written by Jay Lund and published by Univ of California Press. This book was released on 2010-02-02 with total page 257 pages. Available in PDF, EPUB and Kindle. Book excerpt: An ecosystem in freefall, a shrinking water supply for cities and agriculture, an antiquated network of failure-prone levees—this is the Sacramento-San Joaquin Delta, the major hub of California's water system. Written by a team of independent water experts, this analysis of the latest data evaluates proposed solutions to the Delta's myriad problems. Through in-depth economic and ecological analysis, the authors find that the current policy of channeling water exports through the Delta is not sustainable for any interest. Employing a peripheral canal-conveying water around the Delta instead of through it—as part of a larger habitat and water management plan appears to be the best strategy to maintain both a high-quality water supply and at the same time improve conditions for native fish and wildlife. This important assessment includes integrated analysis of long term ecosystem and water management options and demonstrates how issues such as climate change and sustainability will shape the future. Published in cooperation with the Public Policy Institute of California

Download or read book Restoring the Environment written by CALFED Bay-Delta Program. Ecosystem Restoration Program and published by . This book was released on 1999 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Report on Land Use Patterns in the Sacramento San Joaquin Delta written by Tom Hawkins and published by . This book was released on 1993 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Towards Climate responsible Peatlands Management written by Riccardo Biancalani and published by Mitigation of Climate Change i. This book was released on 2014 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The aim of this guidebook is to support the reduction of GHG emissions from managed peatlands and present guidance for responsible management practices that can maintain peatlands ecosystem services while sustaining and improving local livelihoods. This guidebook also provides an overview of the present knowledge on peatlands, including their geographic distribution, ecological characteristics and socio-economic importance.