Agroforestry and grass buffer effects on water quality on grazed pasture watersheds

Paper presented at the 11th North American Agroforesty Conference, which was held May 31-June 3, 2009 in Columbia, Missouri.In Gold, M.A. and M.M. Hall, eds. Agroforestry Comes of Age: Putting Science into Practice. Proceedings, 11th North American Agroforestry Conference, Columbia, Mo., May 31-June 3, 2009.Conservation practices including agroforestry and grass buffers are believed to reduce non point source pollution (NPSP) from grazed pasture watersheds. Agroforestry, a land management practice that intersperses agricultural crops with trees, recently received increased attention in the temperate zone due to its environmental and economic benefits. However, studies are limited that examined buffer effects on water quality on grazed pasture watersheds. Six small watersheds, two with agroforestry buffers, two with grass buffers, and two control watershdeds were used to test the hypothesis that agroforestry and grass buffers reduce NPSP from grazed pasture watersheds. Vegetation in grass buffer and pasture areas include red clover (Trifolium pretense L.) and lespedeza (Kummerowia stipulacea Maxim.) planted into fescue (Festuca arundinacea Schreb.). Eastern cottonwood trees (Populus deltoids Bortr. ex Marsh.) were planted into fescue in agroforestry buffers. Soils at the site are mostly Menfro silt loam (fine-silty, mixed, superactive, mesic Typic Hapludalfs). Watersheds were instrumented with two-foot H flumes, water samplers, and flow measuring devices in 2001. Composite water samples were analyzed for sediment, and total nitrogen after each runoff event to compare treatment differences. Watersheds with agroforerstry and grass buffers had significantly lower runoff volumes as compared to the control watersheds. The loss of sediment, and total nitrogen were smaller for the buffer watersheds. The results of the study suggest that establishment of groforestry and grass buffers help reduce NPSP pollution from grazed pasture watersheds. It is anticipated as trees grow and roots occupy more soil volume, the reduction in N in runoff should increase on the agroforestry watershed.Ranjith P. Udawatta (1, 2), Harold E. Garrett (2), and Robert L. Kallenbach (3) ; 1. Department of Soil, Environmental and Atmospheric Sciences. 2. Center for Agroforestry. 3. Department of Plant Sciences, University of Missouri, Columbia, MO 65211.Includes bibliographical references

Agroforestry interactions and soil water use in watersheds under corn-soybean management

Paper presented at the 11th North American Agroforesty Conference, which was held May 31-June 3, 2009 in Columbia, Missouri.In Gold, M.A. and M.M. Hall, eds. Agroforestry Comes of Age: Putting Science into Practice. Proceedings, 11th North American Agroforestry Conference, Columbia, Mo., May 31-June 3, 2009.Agroforestry and grass buffer practices reduce non point source pollution from corn-soybean watersheds, yet little is known about the processes and mechanisms involved. The objective of this study was to compare the soil water dynamics in crop, grass, and agroforestry areas throughout the growing season to understand soil water use and recharge differences among the treatments. The study was conducted on two corn (Zea mays L.)-soybean (Glycine max (L.) Merr.) rotational watersheds with grass and agroforestry buffers at the Greenley Research Center, Knox County, MO. Campbell soil moisture sensors were installed in crop, grass, and agroforestry areas with six replications at 5, 10, 20, and 40 cm depths to record volumetric soil water content at 10 minute intervals for 2004 through 2007. Initial soil moisture was lower in tree and grass buffer areas than crop areas probably due to water use by the permanent vegetation before crops were established. The differences were larger for shallower depths as compared to the 40 cm depth. The trend continued throughout the growing season. Weekly soil moisture content was significantly higher in the crop treatment as compared to the buffer treatments. During rain events water content increased in all depths and treatments and the differences in water content among treatments diminished. At the end of the growing season, soil water content increased when water use was low and as the profile recharged by rain events. The results of the study suggest that establishment of grass and agroforestry buffers help reduce non point source pollution from row crop agriculture by using additional water that would have otherwise have been lost in runoff carrying sediments, nutrients, and pesticides.Ranjith P. Udawatta (1,2), Stephen H. Anderson (1), Peter P. Motavalli (1), and Harold E. Garrett (2) ; 1. Department of Soil, Environmental and Atmospheric Sciences. 2. Center for Agroforestry, and University of Missouri, Columbia, MO 65211.Includes bibliographical references

Controlling swine odor with windbreaks

Paper presented at the 11th North American Agroforesty Conference, which was held May 31-June 3, 2009 in Columbia, Missouri.In Gold, M.A. and M.M. Hall, eds. Agroforestry Comes of Age: Putting Science into Practice. Proceedings, 11th North American Agroforestry Conference, Columbia, Mo., May 31-June 3, 2009.Emissions of malodor from swine facilities are an increasing environmental concern for the swine producers and nearby local communities. Use of natural windbreaks for odor abatement is recent and the science in support of using windbreaks for this purpose is limited. To provide sound science to the study of windbreaks and odor control, the University of Missouri Center for Agroforestry initiated a study in 2007 to evaluate the effects of windbreaks on transport of odors. A 3-row windbreak configuration was implemented consisting of pitch-loblolly pine (Pinus rigida_P. taeda), a conifer, on the inside row closest to the farrowing house; red maple (Acer rubrum) alternating with pin oak (Quercus palustris) a deciduous hardwood species that retains many of its leaves throughout much of the winter, as the middle row and; Viburnum 'Allegheny' (Viburnum rhytidophyllum X V. lantana), a semi-evergreen shrub that quickly reaches heights of 10 to 15 feet, as the outside row. Before the windbreak takes effect, air samples are being taken at varying distances from the facility (up to a mile radius) to monitor the baseline background concentrations of odorous gasses including ammonia (NH3), hydrogen sulfide (H2S), major volatile organic compounds (VOCs) and particulates. The spatial distribution and temporal variation in concentrations of these malodorous compounds have been characterized and mapped. This baseline information will be used for evaluating the impact of the windbreak on odor concentrations and movement over time.Chung-Ho Lin (1), Dusty D. Walter (1), Harold E. Garrett (1) and Robert N. Lerch (2). 1. Center for Agroforestry, University of Missouri, Columbia, MO 65211. 2. U.S. Department of Agriculture-Agricultural Research Service, Cropping Systems and Water Quality Research Unit, Columbia, Missouri 65211.Includes bibliographical references

Do insect outbreaks reduce the severity of subsequent forest fires?

Understanding the causes and consequences of rapid environmental change is an essential scientific frontier, particularly given the threat of climate- and land use-induced changes in disturbance regimes. In western North America, recent widespread insect outbreaks and wildfires have sparked acute concerns about potential insect-fire interactions. Although previous research shows that insect activity typically does not increase wildfire likelihood, key uncertainties remain regarding insect effects on wildfire severity (i.e., ecological impact). Recent assessments indicate that outbreak severity and burn severity are not strongly associated, but these studies have been limited to specific insect or fire events. Here, we present a regional census of large wildfire severity following outbreaks of two prevalent bark beetle and defoliator species, mountain pine beetle (Dendroctonus ponderosae) and western spruce budworm (Choristoneura freemani), across the US Pacific Northwest. We first quantify insect effects on burn severity with spatial modeling at the fire event scale and then evaluate how these effects vary across the full population of insect-fire events (n = 81 spanning 1987-2011). In contrast to common assumptions of positive feedbacks, we find that insects generally reduce the severity of subsequent wildfires. Specific effects vary with insect type and timing, but both insects decrease the abundance of live vegetation susceptible to wildfire at multiple time lags. By dampening subsequent burn severity, native insects could buffer rather than exacerbate fire regime changes expected due to land use and climate change. In light of these findings, we recommend a precautionary approach when designing and implementing forest management policies intended to reduce wildfire hazard and increase resilience to global change

Do insect outbreaks reduce the severity of subsequent forest fires?

Understanding the causes and consequences of rapid environmental change is an essential scientific frontier, particularly given the threat of climate-and land use-induced changes in disturbance regimes. In western North America, recent widespread insect outbreaks and wildfires have sparked acute concerns about potential insect-fire interactions. Although previous research shows that insect activity typically does not increase wildfire likelihood, key uncertainties remain regarding insect effects on wildfire severity (i.e., ecological impact). Recent assessments indicate that outbreak severity and burn severity are not strongly associated, but these studies have been limited to specific insect or fire events. Here, we present a regional census of large wildfire severity following outbreaks of two prevalent bark beetle and defoliator species, mountain pine beetle (Dendroctonus ponderosae) and western spruce budworm (Choristoneura freemani), across the US Pacific Northwest. Wefirst quantify insect effects on burn severity with spatial modeling at the fire event scale and then evaluate how these effects vary across the full population of insect-fire events (n = 81 spanning 1987-2011). In contrast to common assumptions of positive feedbacks, we find that insects generally reduce the severity of subsequent wildfires. Specific effects vary with insect type and timing, but both insects decrease the abundance of live vegetation susceptible to wildfire at multiple time lags. By dampening subsequent burn severity, native insects could buffer rather than exacerbate fire regime changes expected due to land use and climate change. In light of these findings, we recommend a precautionary approach when designing and implementing forest management policies intended to reduce wildfire hazard and increase resilience to global change.Keywords: fire ecology, remote sensing, regime change, forest health, defoliator, bark beetle, disturbance interaction

Does wildfire likelihood increase following insect outbreaks in conifer forests?

Although there is acute concern that insect‐caused tree mortality increases the likelihood or severity of subsequent wildfire, previous studies have been mixed, with findings typically based on stand‐scale simulations or individual events. This study investigates landscape‐ and regional‐scale wildfire likelihood following outbreaks of the two most prevalent native insect pests in the US Pacific Northwest (PNW): mountain pine beetle (MPB; Dendroctonus ponderosae) and western spruce budworm (WSB; Choristoneura freemani). We leverage seamless census data across numerous insect and fire events to (1) summarize the interannual dynamics of insects (1970–2012) and wildfires (1984–2012) across forested ecoregions of the PNW; (2) identify potential linked disturbance interactions with an empirical wildfire likelihood index; (3) quantify this insect‐fire likelihood across different insect agents, time lags, ecoregions, and fire sizes. All three disturbance agents have occurred primarily in the drier, interior conifer forests east of the Cascade Range. In general, WSB extent exceeds MPB extent, which in turn exceeds wildfire extent, and each disturbance typically affects less than 2% annually of a given ecoregion. In recent decades across the PNW, wildfire likelihood does not consistently increase or decrease following insect outbreaks. There is evidence, however, of linked interactions that vary across insect agent (MPB, WSB), space (ecoregion), and time (interval since insect onset). Specifically, in most cases following MPB activity, fire likelihood is neither higher nor lower than in non‐MPB‐affected forests. In contrast, fire likelihood is lower following WSB activity across multiple ecoregions and time lags. In addition, insect‐fire likelihood is not consistently associated with interannual fire extent, suggesting that other factors (e.g., climate) control the disproportionately large fire years accounting for regional fire dynamics. Thus, although both bark beetles and defoliators alter fuels and associated fire potential, the windows of opportunity for increased or decreased fire likelihood are too narrow—or the phenomena themselves too rare—for a consistent signal to emerge across PNW conifer forests. These findings suggest that strategic plans should recognize (1) the relative rarity of insect‐fire interactions and (2) the potential ecosystem restoration benefits of native insect outbreaks, when they do occur

Does wildfire likelihood increase following insect outbreaks in conifer forests?

Although there is acute concern that insect-caused tree mortality increases the likelihood or severity of subsequent wildfire, previous studies have been mixed, with findings typically based on stand-scale simulations or individual events. This study investigates landscape- and regional-scale wildfire likelihood following outbreaks of the two most prevalent native insect pests in the US Pacific Northwest (PNW): mountain pine beetle (MPB; Dendroctonus ponderosae) and western spruce budworm (WSB; Choristoneura freemani). We leverage seamless census data across numerous insect and fire events to (1) summarize the interannual dynamics of insects (1970–2012) and wildfires (1984–2012) across forested ecoregions of the PNW; (2) identify potential linked disturbance interactions with an empirical wildfire likelihood index; (3) quantify this insect-fire likelihood across different insect agents, time lags, ecoregions, and fire sizes. All three disturbance agents have occurred primarily in the drier, interior conifer forests east of the Cascade Range. In general, WSB extent exceeds MPB extent, which in turn exceeds wildfire extent, and each disturbance typically affects less than 2% annually of a given ecoregion. In recent decades across the PNW, wildfire likelihood does not consistently increase or decrease following insect outbreaks. There is evidence, however, of linked interactions that vary across insect agent (MPB, WSB), space (ecoregion), and time (interval since insect onset). Specifically, in most cases following MPB activity, fire likelihood is neither higher nor lower than in non-MPB-affected forests. In contrast, fire likelihood is lower following WSB activity across multiple ecoregions and time lags. In addition, insect-fire likelihood is not consistently associated with interannual fire extent, suggesting that other factors (e.g., climate) control the disproportionately large fire years accounting for regional fire dynamics. Thus, although both bark beetles and defoliators alter fuels and associated fire potential, the windows of opportunity for increased or decreased fire likelihood are too narrow—or the phenomena themselves too rare—for a consistent signal to emerge across PNW conifer forests. These findings suggest that strategic plans should recognize (1) the relative rarity of insect-fire interactions and (2) the potential ecosystem restoration benefits of native insect outbreaks, when they do occur

Does wildfire likelihood increase following insect outbreaks in conifer forests?

Although there is acute concern that insect‐caused tree mortality increases the likelihood or severity of subsequent wildfire, previous studies have been mixed, with findings typically based on stand‐scale simulations or individual events. This study investigates landscape‐ and regional‐scale wildfire likelihood following outbreaks of the two most prevalent native insect pests in the US Pacific Northwest (PNW): mountain pine beetle (MPB; Dendroctonus ponderosae) and western spruce budworm (WSB; Choristoneura freemani). We leverage seamless census data across numerous insect and fire events to (1) summarize the interannual dynamics of insects (1970–2012) and wildfires (1984–2012) across forested ecoregions of the PNW; (2) identify potential linked disturbance interactions with an empirical wildfire likelihood index; (3) quantify this insect‐fire likelihood across different insect agents, time lags, ecoregions, and fire sizes. All three disturbance agents have occurred primarily in the drier, interior conifer forests east of the Cascade Range. In general, WSB extent exceeds MPB extent, which in turn exceeds wildfire extent, and each disturbance typically affects less than 2% annually of a given ecoregion. In recent decades across the PNW, wildfire likelihood does not consistently increase or decrease following insect outbreaks. There is evidence, however, of linked interactions that vary across insect agent (MPB, WSB), space (ecoregion), and time (interval since insect onset). Specifically, in most cases following MPB activity, fire likelihood is neither higher nor lower than in non‐MPB‐affected forests. In contrast, fire likelihood is lower following WSB activity across multiple ecoregions and time lags. In addition, insect‐fire likelihood is not consistently associated with interannual fire extent, suggesting that other factors (e.g., climate) control the disproportionately large fire years accounting for regional fire dynamics. Thus, although both bark beetles and defoliators alter fuels and associated fire potential, the windows of opportunity for increased or decreased fire likelihood are too narrow—or the phenomena themselves too rare—for a consistent signal to emerge across PNW conifer forests. These findings suggest that strategic plans should recognize (1) the relative rarity of insect‐fire interactions and (2) the potential ecosystem restoration benefits of native insect outbreaks, when they do occur

Modelling the dynamics of support for a right-wing populist party: the case of UKIP

ABSTRACT: Similar to a number of other right-wing populist parties in Europe, Great Britain's United Kingdom Independence Party (UKIP) has experienced increased public support in recent years. Using aggregate data from monthly national surveys conducted between April 2004 and April 2014, time series analyses demonstrate that the dynamics of UKIP support were influenced by a combination of spatial and valence issues. A spatial issue, Euroscepticism, was fundamental, with UKIP support moving in dynamic equilibrium with changing public attitudes towards EU membership. In addition, widespread anti-immigration sentiment and dissatisfaction with the performance of the Conservative–Liberal Democrat coalition government combined with the “oxygen of publicity” to propel UKIP's surge. The political context after the 2010 general election helped as well by enabling UKIP to benefit from valence considerations. Many voters continued to doubt the competence of the major opposition party, Labour, while the Liberal Democrats were part of the government and, hence, unavailable as a protest vehicle. Since many of the forces driving UKIP support are beyond its control, the party's prospects are highly uncertain

LSST Science Book, Version 2.0

A survey that can cover the sky in optical bands over wide fields to faint magnitudes with a fast cadence will enable many of the exciting science opportunities of the next decade. The Large Synoptic Survey Telescope (LSST) will have an effective aperture of 6.7 meters and an imaging camera with field of view of 9.6 deg^2, and will be devoted to a ten-year imaging survey over 20,000 deg^2 south of +15 deg. Each pointing will be imaged 2000 times with fifteen second exposures in six broad bands from 0.35 to 1.1 microns, to a total point-source depth of r~27.5. The LSST Science Book describes the basic parameters of the LSST hardware, software, and observing plans. The book discusses educational and outreach opportunities, then goes on to describe a broad range of science that LSST will revolutionize: mapping the inner and outer Solar System, stellar populations in the Milky Way and nearby galaxies, the structure of the Milky Way disk and halo and other objects in the Local Volume, transient and variable objects both at low and high redshift, and the properties of normal and active galaxies at low and high redshift. It then turns to far-field cosmological topics, exploring properties of supernovae to z~1, strong and weak lensing, the large-scale distribution of galaxies and baryon oscillations, and how these different probes may be combined to constrain cosmological models and the physics of dark energy.Comment: 596 pages. Also available at full resolution at http://www.lsst.org/lsst/sciboo