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Urban Trees as Sinks for Soot: Deposition of Atmospheric Elemental Carbon to Oak Canopies and Litterfall Flux to Soil

Description: Elemental carbon (EC), a product of incomplete combustion of fossil fuels and biomass, contributes to climate warming and poor air quality. In urban areas, diesel fuel trucks are the main source of EC emissions from mobile sources. After emission, EC is deposited to receptor surfaces via two main pathways: precipitation (wet deposition) and directly as particles (dry deposition). Urban trees may play an important role in removing EC from the atmosphere by intercepting and delivering it directly to the soil. The goal of this research was to quantify the magnitude of EC retention in leaf waxes (in-wax EC) and EC fluxes to the soil via leaf litterfall in the City of Denton, Texas. Denton is a rapidly growing urban location in the Dallas-Fort Worth metropolitan area. A foliar extraction technique was used to determine EC retention in leaf waxes. Foliar samples were collected monthly, from April through July, from pairs of Quercus stellata (post oak, n=10) and Quercus virginiana (live oak, n = 10) trees. Samples were rinsed with water and chloroform in a two-step process to determine EC retained in leaf waxes. A Sunset OC/EC aerosol analyzer was utilized to analyze the EC content of extracts filtered onto quartz-fiber filters. From April through July, leaf litter was collected bi-weekly under 35 trees (20 post oak, 15 live oak), and oven dried to determine dry weight. EC retained by tree canopies was estimated by multiplying in-wax EC by canopy leaf area index, while EC flux to soil was estimated by multiplying in-wax EC by leaf litterfall mass. This study shows that through retention of EC in leaf waxes, urban tree canopies represent important short-term sinks for soot in urban areas.
Date: May 2018
Creator: Rindy, Jenna
Partner: UNT Libraries

Western Spruce Budworm Effects on Throughfall C, N, and P Fluxes in a Central Washington Forest

Description: Western spruce budworm (Choristoneura occidentalis) outbreaks periodically disturb Western US conifer forests by defoliating canopies, which could alter the quantity and chemistry of throughfall delivered to the forest floor. Our objectives were to: i) quantify throughfall water, carbon (C), nitrogen (N), and phosphorus (P) fluxes under budworm-impacted canopies, and ii) examine the influence of herbivore intensity on flux magnitudes. In June 2015, we installed throughfall collectors in two watersheds experiencing high and background levels of herbivory. In each watershed, four plots, each with three throughfall collectors, were established (n=24) collectors), and two bulk rainfall collectors were installed in areas without canopy cover. Throughfall and rainfall were collected from late June to early November 2015. Samples were analyzed for dissolved organic carbon (DOC), ammonium (NH4-N), and soluble reactive phosphorus (SRP). Over the sampling period, throughfall fluxes ranged 8.57 to 47.59 kg/ha for DOC, 0.004-0.011 kg/ha for NH4-N, and 007 - 0.29 kg/ha for SRP. Percent throughfall was slightly, but not significantly, higher in the high (48%) compared to the background watershed (42%). There were no differences in solute concentrations among the watersheds. Net throughfall fluxes, the sum of canopy uptake and leaching and dry/fog deposition, differed significantly for NH4-N by herbivory level and through time for NH4-N and DOC but not SRP. Over time, net NH4-N throughfall fluxes showed a clear transition from net uptake of NH4-N to net leaching of NH4-N in the high herbivory watershed. There was also a clearn NH4-N pulse in the high herbivory watershed after the first, but not subsequent, rainfall events. In this N-limited forest, altered throughfall N may affect soil nutrient cycling and downstream water quality.
Date: December 2016
Creator: Bailey, Jennifer Meghan
Partner: UNT Libraries

Structure, Composition, and Regeneration of Cross Timbers Forest Fragments in Different Land Use Contexts

Description: Throughout its current range, the Cross Timbers forest ecosystem is vulnerable to land-use change. In this study, we examined the surrounding land use matrix on the vegetation structure, composition and regeneration of six Cross Timbers forest fragments in Denton County, Texas (north of the Dallas-Fort Worth metroplex). Two fragments adjacent to agricultural land, two to residential neighborhoods, and two formally protected forest sites were selected. In summer 2015, five 100 m2 plots were randomly established in each fragment at least 200 meters from the edge. In each plot, all live and dead trees ≥ 3 cm diameter were identified and their height and diameter at breast height (DBH at 1.3 m aboveground) measured. Evidence of dumping (presence of trash) was recorded as an index of human frequentation. Differences in vegetation structure among the forest fragments were found. Most notably, fragments adjacent to agriculture contained 25% to 50% fewer trees per hectare than all other sites (Kruskal-Wallis, p < 0.02), especially trees <10 cm DBH. However, residential fragments had fewer trees that were ≥15 cm DBH compared to the other fragments, indicating that these are the youngest of the forest patches surveyed. Trash was observed in 60% of plots surveyed at residential forest sites, showing high levels of human frequentation compared to the protected and agricultural forest sites. Agricultural sites contained the lowest number of recorded tree species and were most similar to each other, sharing 91% of species. These findings indicate that surrounding land use affects forest structure and composition, consequently affecting valuable ecosystem services including wildlife habitat, aesthetics and recreation.
Date: May 2015
Creator: Dunn, Ingrid
Partner: UNT Libraries

QUANTIFYING FOREST ABOVEGROUND CARBON POOLS AND FLUXES USING MULTI-TEMPORAL LIDAR A report on field monitoring, remote sensing MMV, GIS integration, and modeling results for forestry field validation test to quantify aboveground tree biomass and carbon

Description: Sound policy recommendations relating to the role of forest management in mitigating atmospheric carbon dioxide (CO{sub 2}) depend upon establishing accurate methodologies for quantifying forest carbon pools for large tracts of land that can be dynamically updated over time. Light Detection and Ranging (LiDAR) remote sensing is a promising technology for achieving accurate estimates of aboveground biomass and thereby carbon pools; however, not much is known about the accuracy of estimating biomass change and carbon flux from repeat LiDAR acquisitions containing different data sampling characteristics. In this study, discrete return airborne LiDAR data was collected in 2003 and 2009 across {approx}20,000 hectares (ha) of an actively managed, mixed conifer forest landscape in northern Idaho, USA. Forest inventory plots, established via a random stratified sampling design, were established and sampled in 2003 and 2009. The Random Forest machine learning algorithm was used to establish statistical relationships between inventory data and forest structural metrics derived from the LiDAR acquisitions. Aboveground biomass maps were created for the study area based on statistical relationships developed at the plot level. Over this 6-year period, we found that the mean increase in biomass due to forest growth across the non-harvested portions of the study area was 4.8 metric ton/hectare (Mg/ha). In these non-harvested areas, we found a significant difference in biomass increase among forest successional stages, with a higher biomass increase in mature and old forest compared to stand initiation and young forest. Approximately 20% of the landscape had been disturbed by harvest activities during the six-year time period, representing a biomass loss of &gt;70 Mg/ha in these areas. During the study period, these harvest activities outweighed growth at the landscape scale, resulting in an overall loss in aboveground carbon at this site. The 30-fold increase in sampling density between the 2003 and 2009 did not ...
Date: April 1, 2012
Creator: Spangler, Lee; Vierling, Lee A.; Stand, Eva K.; Hudak, Andrew T.; Eitel, Jan U.H. & Martinuzzi, Sebastian
Partner: UNT Libraries Government Documents Department

A Low Carbon Development Guide for Local Government Actions in China

Description: Local level actions are crucial for achieving energy-saving and greenhouse gas emission reduction targets. Yet it is challenging to implement new policies and actions due to a lack of information, funding, and capacity. This is particularly the case in developing countries such as China. Even though national energy intensity and carbon intensity targets have been set, most local governments do not have the knowledge regarding actions to achieve the targets, the cost-effectiveness of policies, the possible impact of policies, or how to design and implement a climate action plan. This paper describes a guidebook that was developed to motivate and provide local governments in China with information to create an action plan to tackle climate change and increase energy efficiency. It provides a simple step-by-step description of how action plans can be established and essential elements to be included - from preparing a GHG emission inventory to implementation of the plan. The guidebook also provides a comprehensive list of successful policies and best practices found internationally and in China to encourage low carbon development in industry, buildings, transportation, electric power generation, agriculture and forestry. This paper also presents indicators that can be used to define low-carbon development, as well as to evaluate the effectiveness of actions taken at an aggregated (city) level, and at a sectoral or end use level. The guidebook can also be used for low carbon development by local governments in other developing countries.
Date: May 1, 2011
Creator: Zheng, Nina; Zhou, Nan; Price, Lynn & Ohshita, Stephanie
Partner: UNT Libraries Government Documents Department

Emissions Scenarios, Costs, and Implementation Considerations of REDD Programs

Description: Greenhouse gas emissions from the forestry sector are estimated to be 8.4 GtCO2-eq./year or about 17percent of the global emissions. We estimate that the cost forreducing deforestation is low in Africa and several times higher in Latin America and Southeast Asia. These cost estimates are sensitive to the uncertainties of how muchunsustainable high-revenue logging occurs, little understood transaction and program implementation costs, and barriers to implementation including governance issues. Due to lack of capacity in the affected countries, achieving reduction or avoidance of carbon emissions will require extensive REDD-plus programs. Preliminary REDD-plus Readiness cost estimates and program descriptions for Indonesia, Democratic Republic of the Congo, Ghana, Guyana and Mexico show that roughly one-third of potential REDD-plus mitigation benefits might come from avoided deforestation and the rest from avoided forest degradation and other REDD-plus activities.
Date: April 11, 2011
Creator: Sathaye, Jayant; Andrasko, Ken & Chan, Peter
Partner: UNT Libraries Government Documents Department

Phylogeny and comparative genome analysis of a Basidiomycete fungi

Description: Fungi of the phylum Basidiomycota, make up some 37percent of the described fungi, and are important from the perspectives of forestry, agriculture, medicine, and bioenergy. This diverse phylum includes the mushrooms, wood rots, plant pathogenic rusts and smuts, and some human pathogens. To better understand these important fungi, we have undertaken a comparative genomic analysis of the Basidiomycetes with available sequenced genomes. We report a phylogeny that sheds light on previously unclear evolutionary relationships among the Basidiomycetes. We also define a `core proteome? based on protein families conserved in all Basidiomycetes. We identify key expansions and contractions in protein families that may be responsible for the degradation of plant biomass such as cellulose, hemicellulose, and lignin. Finally, we speculate as to the genomic changes that drove such expansions and contractions.
Date: March 14, 2011
Creator: Riley, Robert W.; Salamov, Asaf; Grigoriev, Igor & Hibbett, David
Partner: UNT Libraries Government Documents Department

2010 Forest Carbon Workgroup: Final Report

Description: This document provides a detailed report and recommendations of the 2010 Forest Carbon Work group to the Director of the Department of Ecology and the Commissioner of Public Lands. The recommendations relate to the critical role Washington’s forest lands will play in addressing the challenge of climate change; appropriate responses to pressure for conversion of working forest lands to non-forest uses; and the role of ecosystem service markets, including carbon offset markets, and other incentive systems in bringing about desired results. The 2010 Work group included some members of a similar 2008 Work group and built on the results of that 2008 effort. The report appendix contains purpose statements by each participating interest, explaining its rationale for participation. In light of the 2010 Work group emphasis, this document focused on three topics: Forest carbon considerations in avoiding forest land use conversion; incentives to reward forest landowners for providing ecosystem services, including carbon storage and improvement of forest health; and features of forest carbon offset protocols and registries that are appropriate for use by forest offset project developers in Washington State.
Date: January 2011
Creator: Partridge, Craig; Boese, Jerry & Bernath, Stephen
Partner: UNT Libraries

Climate change and forests in India: note from the guest editors

Description: Forestry is one of the most important sectors in the context of climate change. It lies at the center-stage of global mitigation and adaptation efforts. Yet, it is one of the least understood sectors, especially in tropical zones, which constitute a significant portion of the global forests. Recently, there has been a growing interest in forests in addressing global climate change. The IPCC Assessment Report 4 (2007) Chapters related to forests have highlighted the limited number of studies on the impact of climate change on forests at the regional, national and sub-national level, while policy makers need information at these scales. Further, implication of projected climate change on mitigation potential of forest sector is only briefly mentioned in the IPCC report, with limited literature to support the conclusions. India is one among the top ten nations in the world in terms of forest cover. It is also sixth among the tropical countries in terms of forested area. As IPCC Assessment Report 5 work is about to be initiated soon, studies on the impact of climate change on forests as well as the mitigation potential of the forest sector, particularly at regional and national level, will be of great interest to the scientific and policy community. In order to conserve the carbon stored in forests and to reduce CO2 emissions from the forest sector, the Reduced Emissions from Deforestation and Degradation (REDD) mechanism is now being finalized under the UNFCCC. In this context, climate change itself may affect the mitigation potential significantly, and it is important to understand how vulnerable the forest carbon stock (biomass and soil) in the tropics is to the projected climate change. In fact, there is a need to study the impact of climate change on forests for all the major forested countries
Date: December 23, 2010
Creator: Ravindtranath, N.H. & Aaheim, Asbjporn
Partner: UNT Libraries Government Documents Department

Woody energy crops in the southeastern United States: Two centuries of practitioner experience.

Description: Forest industry experts were consulted on the potential for hardwood tree species to serve as feedstock for bioenergy in the southeastern United States. Hardwoods are of interest for bioenergy because of desirable physical qualities, genetic research advances, and growth potential. Yet little data is available regarding potential productivity and costs. This paper describes required operations and provides a realistic estimate of the costs of producing bioenergy feedstock based on commercial experiences. Forestry practitioners reported that high productivity rates in southeastern hardwood plantations are confined to narrow site conditions or require costly inputs. Eastern cottonwood and American sycamore grow quickly on rich bottomlands, but are also prone to pests and disease. Sweetgum is frost hardy, has few pest or disease problems, and grows across a broad range of sites, yet growth rates are relatively low. Eucalypts require fewer inputs than do other species and offer high potential productivity but are limited by frost to the lower Coastal Plain and Florida. Further research is required to study naturally regenerated hardwood biomass resources. Loblolly pine has robust site requirements, growth rates rivaling hardwoods, and lower costs of production. More time and investment in silviculture, selection, and breeding will be needed to develop hardwoods as competitive biofuel feedstock species. Because of existing stands and fully developed operations, the forestry community considers loblolly pine to be a prime candidate for plantation bioenergy in the Southeast.
Date: July 1, 2010
Creator: Kline, Keith, L. & Coleman, Mark, D.
Partner: UNT Libraries Government Documents Department

U.S. Climate Action Report 2010

Description: The Fifth U.S. Climate Action Report presents a detailed outline of the actions the U.S. is taking to address climate change, contains updated projections on U.S. greenhouse gas emissions, and underscores the United States commitment to address climate change.
Date: June 2010
Creator: U.S. Department of State
Partner: UNT Libraries

Our Planet, December 2009

Description: Magazine of the United Nations Environment Programme discussing worldwide environmental policies and other concerns. This issue is devoted to the 2009 United Nations Climate Change Conference, know as the Copenhagen Summit, which sought an international agreement on climate change mitigation.
Date: December 2009
Creator: United Nations Environment Programme
Partner: UNT Libraries

Estimates of Carbon Mitigation Potential from Agricultural and Forestry Activities

Description: Numerous theoretical and empirical studies estimate the greenhouse gas (GHG) mitigation potential of farm and forestry activities, and suggest that the potential for carbon uptake in agricultural soils and forest lands is much greater than current rates. Following a discussion of the estimated current emissions and carbon sequestration by the agricultural and forestry sectors, this report presents a brief overview of the available estimates from USDA and EPA carbon mitigation studies, and then discusses some of the limitations of the available data and modeling results. This report is organized into four parts, including a brief overview of the agriculture and forestry sectors within the broader climate change debate, as well as various data and information on potential for carbon storage and mitigation from farming and forestry activities.
Date: June 19, 2009
Creator: Johnson, Renée; Gorte, Ross W.; Yacobucci, Brent D. & Schnepf, Randy
Partner: UNT Libraries Government Documents Department

Our Planet, May 2009

Description: Magazine of the United Nations Environment Programme discussing worldwide environmental policies and other concerns. This issue is devoted to examples of grass roots actions that result in positive changes around the world.
Date: May 2009
Creator: United Nations Environment Programme
Partner: UNT Libraries

Estimates of Carbon Mitigation Potential from Agricultural and Forestry Activities

Description: This report presents a brief overview of the available estimates from U.S. Department of Agriculture (USDA) and U.S. Environmental Protection Agency (EPA) carbon mitigation studies, and then discusses some of the limitations of the available data and modeling results. It includes informationa bout estimated current emissions and sequestration, estimated addtional potential sequestration, limitations of mitigation potential estimates, and considerations for Congress.
Date: February 20, 2009
Creator: Johnson, Renee; Gorte, Ross W.; Yacobucci, Brent D. & Schnepf, Randy
Partner: UNT Libraries Government Documents Department

Estimates of Carbon Mitigation Potential from Agricultural and Forestry Activities

Description: The report is organized into three parts. The first provides a brief overview of the role of the agriculture and forestry sectors within the broader climate change debate, describing available estimates of current GHG emissions and carbon sequestration in the farm and forestry sectors. The second describes available data and information on the potential for carbon storage (tonnage) by type of farming and forestry activity, and presents available estimates of the carbon sequestration potential in these sectors. The final part discusses some of the limitations of available estimates of GHG mitigation potential in the agriculture and forestry sectors, focusing on recent policy and market changes and other types of modeling uncertainties that could limit the accuracy of available mitigation projections.
Date: February 20, 2009
Creator: Johnson, Renee; Gorte, Ross W.; Yacobucci, Brent D. & Schnepf, Randy
Partner: UNT Libraries Government Documents Department