Planting History and Propagule Pressure as Predictors of Invasion by Woody Species in a Temperate Region

Abstract:  We studied 28 alien tree species currently planted for forestry purposes in the Czech Republic to determine the probability of their escape from cultivation and naturalization. Indicators of propagule pressure (number of administrative units in which a species is planted and total planting area) and time of introduction into cultivation were used as explanatory variables in multiple regression models. Fourteen species escaped from cultivation, and 39% of the variance was explained by the number of planting units and the time of introduction, the latter being more important. Species introduced early had a higher probability of escape than those introduced later, with more than 95% probability of escape for those introduced before 1801 and <5% for those introduced after 1892. Probability of naturalization was more difficult to predict, and eight species were misclassified. A model omitting two species with the largest influence on the model yielded similar predictors of naturalization as did the probability of escape. Both phases of invasion therefore appear to be driven by planting and introduction history in a similar way. Our results demonstrate the importance of forestry for recruitment of invasive trees. Six alien forestry trees, classified as invasive in the Czech Republic, are currently reported in nature reserves. In addition, forestry authorities want to increase the diversity of alien species and planting area in the country.     

Water supply,waste assimilation,and low-flow issues facing the Southeast Piedmont Interstate-85 urban archipelago

Rapidly growing cities along the Interstate-85 corridor from Atlanta, GA, to Raleigh, NC, rely on small rivers for water supply and waste assimilation. These rivers share commonalities including water supply stress during droughts, seasonally low flows for wastewater dilution, increasing drought and precipitation extremes, downstream eutrophication issues, and high regional aquatic diversity. Further challenges include rapid growth; sprawl that exacerbates water quality and infrastructure issues; water infrastructure that spans numerous counties and municipalities; and large numbers of septic systems. Holistic multi-jurisdiction cooperative water resource planning along with policy and infrastructure modifications is necessary to adapt to population growth and climate. We propose six actions to improve water infrastructure resilience: increase water-use efficiency by municipal, industrial, agricultural, and thermoelectric power sectors; adopt indirect potable reuse or closed loop systems; allow for water sharing during droughts but regulate inter-basin transfers to protect aquatic ecosystems; increase nutrient recovery and reduce discharges of carbon and nutrients in effluents; employ green infrastructure and better stormwater management to reduce nonpoint pollutant loadings and mitigate urban heat island effects; and apply the CRIDA framework to incorporate climate and hydrologic uncertainty into water planning.     

Determinants of National Fire Plan Fuels Treatment Expenditures: A Revealed Preference Analysis for Northern New Mexico

The accumulation of fire fuels in forests throughout the world contributes significantly to the severity of wildfires. To combat the threat of wildfire, especially in the wildland-urban interface (WUI), US federal land management agencies have implemented a number of forest restoration and wildfire risk reduction programs. In the spirit of revealed preference analyses, the objective of this study is to investigate the pattern and determinants of National Fire Plan (NFP) expenditures for fuel reduction treatments in northern New Mexico (USA). Estimation results from a set of Generalized Estimating Equations models are mixed with respect to risk reduction hypotheses, and also raise issues regarding how risk reduction should be defined for a region characterized by both pockets of urban sprawl into the WUI and large areas of chronic rural poverty. Program preferences for project funding under the federal Collaborative Forest Restoration Program in New Mexico are shown to be distinctly different (e.g., exhibiting greater concern for social equity) than for other NFP-funded projects.     

山西关帝山神尾沟植物群落物种多样性与环境关系的研究I．丰富度、均匀度和物种多样性指数

以89个植物群落调查样地数据为基础,运用8个多样性指数对山西关帝山神尾沟物种多样性与环境之间的关系进行了分析.（1）群落总的表现为多样性和均匀度随海拔升高而下降,丰富度从1700m下降到2400m后开始升高;（2）群落不同层次表现为乔木层和灌木层多样性、丰富度和均匀度随海拔升高而下降,草本多样性和均匀度表现为上升趋势,丰富度下降到1900m后开始上升;（3）乔灌草三者多样性和丰富度指数值以及变化幅度都表现为草本层>灌木层>乔木层,三者均匀度相差不大;（4）群落不同坡向表现为阳坡多样性和丰富度都大于阴坡,均匀度相差不大.图6参7     

Modeling to Evaluate Contribution of Oil and Gas Emissions to Air Pollution

Oil and gas production in the Western United States has increased considerably over the past 10 years. While many of the still limited oil and gas impact assessments have focused on potential human health impacts, the typically remote locations of production in the Intermountain West suggests that the impacts of oil and gas production on national parks and wilderness areas (Class I and II areas) could also be important. To evaluate this, we utilize the Comprehensive Air quality Model with Extensions (CAMx) with a year-long modeling episode representing the best available representation of 2011 meteorology and emissions for the Western United States. The model inputs for the 2011 episodes were generated as part of the Three State Air Quality Study (3SAQS). The study includes a detailed assessment of oil and gas (O&G) emissions in Western States. The year-long modeling episode was run both with and without emissions from O&G production. The difference between these two runs provides an estimate of the contribution of the O&G production to air quality. These data were used to assess the contribution of O&G to the 8 hour average ozone concentrations, daily and annual fine particulate concentrations, annual nitrogen deposition totals and visibility in the modeling domain. We present the results for the Class I and II areas in the Western United States. Modeling results suggest that emissions from O&G activity are having a negative impact on air quality and ecosystem health in our National Parks and Class I areas.

Implications: In this research, we use a modeling framework developed for oil and gas evaluation in the western United States to determine the modeled impacts of emissions associated with oil and gas production on air pollution metrics. We show that oil and gas production may have a significant negative impact on air quality and ecosystem health in some national parks and other Class I areas in the western United States. Our findings are of particular interest to federal land managers as well as regulators in states heavy in oil and gas production as they consider control strategies to reduce the impact of development.     

Regional Transport and Urban Contributions to Fine Particle Concentrations in Southeastern Canada

Abstract

The impact of various atmospheric transport directions on ambient fine particle (PM_2.5) concentrations at several sites in southeastern Canada was estimated (for May-September) using back-trajectory analysis. Three-day back trajectories (four per day) were paired with 6-hr average PM_2.5 mass concentrations measured using tapered element oscillating microbalances (TEOM). PM_2.5 concentrations at rural locations in the region were affected by nonlocal sources originating in both Canada and the United States. Comparison of sites revealed that, on average, the local contribution to total PM_2.5 in the greater Toronto area (GTA) is approximately 30–35%. At each location, average PM_2.5 concentrations under south/southwesterly flow conditions were 2–4 times higher than under the corresponding northerly flow conditions. The chemical composition of both urban and rural PM_2.5 was determined during two separate 2-week spring/summer measurement campaigns. Components identified included SO₄ ^2?, NO₃ ^?, NH₄+, black carbon and organic carbon (OC), and trace elements. Higher particle mass at the urban Toronto site was composed of a higher proportion of all components. However, black carbon, NO₃ ^?, NaCl, and trace elements were found to be the most enriched over the rural/regional background levels.     

Aerosols and associated precipitation patterns in Atlanta

The role of aerosol concentrations on summer precipitation was examined in Atlanta, Georgia for the period 2003–2004. Each day of the week was examined to ascertain their aerosol concentrations. Thursday had the highest median 2.5 μm particulate matter (PM 2.5) concentrations at two of three Environmental Protection Agency stations. Monday and Thursday had the largest area of significantly different precipitation when compared to other days of the week. All but the southeast quadrant of the metropolitan area had a significant difference in precipitation on high versus low aerosol days. High aerosol days had greater instability (higher average convective available potential energy and lower convective inhibition), and a slightly more shallow mixing layer when compared to low aerosol days. Most of metropolitan Atlanta had higher precipitation amounts on high aerosol days and was significantly different from low aerosol days.     

与有机食品相关联的消费者行为的决定因素

对于消费者来说,在他们决定购买或消费有机食品(主要为新鲜的有机食品)时,哪些因素会影响他们的购物决定?学者们对这一问题的研究已经很多了.研究的结果均表明:人们的态度和实际的行为之间有一些矛盾,对于有机食品,人们往往态度上是积极的但是常常却不购买它们.这一矛盾主要源于消费者并不把"有机生产"当作一项重要的采购标准,另外,有机食品在口味及贮藏限期(食品的两种非常重要的品质)上也并不比常规的食品具有优越性.此外,有机食品在价格上被认为比常规食品明显偏贵也是一个重要的因素.根据两个瑞典实例研究发现,人们对有机食品的态度及行为与其健康收益具有非常紧密的关系,并且超过了其正面的环境影响.一个新的欧盟项目将对新鲜的以及加工的有机食品的影响进行调查,并且还将对八个欧盟国家的人们在选择有机食品时,道德、伦理及情感因素所产生的影响进行调查.     

密克罗尼西亚联邦科斯雷岛上的人口迁徙、市场及红树林资源利用

密克罗尼西亚联邦(FSM)的科斯雷岛是易发生经济活动聚集的岛屿经济的典型.家庭平均人口多,可居住土地面积小,经济活动有限,家庭依赖自然资源作为燃料和食物的程度高.我们分析了经济活动聚集--及其通过贸易和人口迁徙得到缓和--是如何影响红树林资源利用的.对1996年和2000年的家庭调查进行比较的结果表明,尽管美国援助和公营部门就业机会的减少,家庭对红树林资源的平均消费并未增加,人口迁徙和汇款收入使得人们可能通过购买进口燃料和建筑材料来取代红树林木材.尽管人们的偏爱发生了变化,重点转向对进口品的消费,人口增长以及美国经济援助的进一步减少将可能造成对红树林和高地木材的总需求上升.此外,持续的移民出境现象,可能会加速锯缘青蟹向岛外科斯雷人居住地的出口.