TL;DR: In this article, a series of fireplace source tests was conducted on six fuel wood species found in the Southern United States to determine fine particulate emission factors for total mass, ionic and elemental species, elemental and organic carbon, and over 250 individual organic compounds.
Abstract: The fireplace combustion of wood is a significant and largely unregulated source of fine particle pollution in the United States. Source apportionment techniques that use particulate organic compounds as tracers have been successful in determining the contribution of wood smoke to ambient fine particle levels in specific areas in California. To apply these techniques to the rest of the United States, the differences in emissions profiles between different wood smoke sources and fuel types should be resolved. To this end, a series of fireplace source tests was conducted on six fuel wood species found in the Southern United States to determine fine particulate emission factors for total mass, ionic and elemental species, elemental and organic carbon, and over 250 individual organic compounds. The wood species tested, chosen for their high abundance and availability in the Southern U.S. region, were yellow poplar, white ash, sweetgum, mockernut hickory, loblolly pine, and slash pine. The differences in the emissions of compounds such as substituted phenols and resin acids help to distinguish between the smoke from hardwood and softwood combustion. Levoglucosan, a cellulose pyrolysis product which may serve as a tracer for wood smoke in general, was quantified in the emissions from all the wood species burned. The furofuran lignan, yangambin, which was emitted in significant quantities from yellow poplar combustion and not detected in any of the other North American wood smokes, is a potential species-specific molecular tracer which may be useful in qualitatively identifying particulate emissions from a specific geographical area where yellow poplar is being burned.
TL;DR: The hypothesis that, compared with open pastures, silvopastures contain more C in deeper soil layers under similar ecological settings, possibly as a consequence of a major input to soil organic matter from decomposition of dead tree-roots is supported.
Abstract: Compared with open (treeless) pasture systems, silvopastoral agroforestry systems that integrate trees into pasture production systems are likely to enhance soil carbon (C) sequestration in deeper soil layers. To test this hypothesis, total soil C contents at six soil depths (0-5, 5-15, 15-30, 30-50, 50-75, and 75-125 cm) were determined in silvopastoral systems with slash pine (Pinus elliottii) + bahiagrass (Paspalum notatum) and an adjacent open pasture (OP) with bahiagrass at four sites, representing Spodosols and Ultisols, in Florida. Soil samples from each layer were fractionated into three classes (250-2000, 53-250, and <53 microm), and the C contents in each were determined. Averaged across four sites and all depths, the total soil organic carbon (SOC) content was higher by 33% in silvopastures near trees (SP-T) and by 28% in the alleys between tree rows (SP-A) than in adjacent open pastures. It was higher by 39% in SP-A and 20% in SP-T than in open pastures in the largest fraction size (250-2000 microm) and by 12.3 and 18.8%, respectively, in the intermediate size fraction (53-250 microm). The highest SOC increase (up to 45 kg m(-2)) in whole soil of silvopasture compared with OP was at the 75- to 125-cm depth at the Spodosol sites. The results support the hypothesis that, compared with open pastures, silvopastures contain more C in deeper soil layers under similar ecological settings, possibly as a consequence of a major input to soil organic matter from decomposition of dead tree-roots.
TL;DR: After four growing seasons, annual fertilization and complete weed control produced similar levels of response, increasing aboveground biomass 700% for loblolly pine and 300% for slash pine, as a consequence of accelerated stand development.
Abstract: (...) After four growing seasons, annual fertilization and complete weed control produced similar levels of response, increasing aboveground biomass 700% for loblolly pine and 300% for slash pine. The combined treatment improved total dry matter production 1600% (from 1.9 to 32.2 Mg ha −1 ) for loblolly pine and 450% (from 4.3 to 23.6 Mg ha −1 ) for slash pine. Equally large treatment-associated increases (up to 1210%) in all-sided leaf area index were measured. Cultural treatments increased the proportional allocations of dry matter to stem wood, stem bark, and branches for both species, a consequence of accelerated stand development. (...)
TL;DR: In this article, the authors measured fluxes of N2O, CH4 and CO2 from control and urea-nitrogen fertilized soils of a mature slash pine (Pinuselliottii var. elliotti Englem.) plantation in Alachua County, Florida.
Abstract: We measured fluxes of N2O, CH4 and CO2 from control and urea-nitrogen fertilized soils of a mature slash pine (Pinuselliottii var. elliottii Englem.) plantation in Alachua County, Florida. The fert...
TL;DR: Introduction and Historical Background Plan of Procedure: Forests of the longleaf-slash pine belt and natural or artificial non-forested areas.
Abstract: Introduction and Historical Background Plan of Procedure I. Forests of the longleaf-slash pine belt 1. Longleaf pine forest 2. Longleaf-scrub oak forest 3. Slash pine forest 4. "Scrub" forest II. Coastal plain and bottomland hardwood forests 5. Bottomland and Mississippi Delta hardwood forests 6. Coastal plain scrub oak forests 7. Southeastern hammocks 8. Pocosins III. Coastal plain swamp forests 9. Cypress swamps 10. Southern white cedar swamps IV. Upland forests 11. Upland mixed pine and oak forests 12. Upland red cedar-hardwood forest 13. Upland scrub oak forest 14. Upland oak-hickory forest V. Natural or artificial non-forested areas 15. Southeastern prairies 16. Southeastern coastal and swamp marshes 17. Southeastern grass-sedge bogs or "savannahs" 18. Southeastern pastures Summary Literature Cited