Atmospheric pollution in an urban environment by tree bark biomonitoring - part II: Sr, Nd and Pb isotopic tracing

The harmful effect of manmade particles on natural processes and human health is documented by a large number of studies showing a positive correlation between particulate matter (PM) concentration and health effects. Diminution of this health risk necessitates among others the precise knowledge of the particle sources, their physical and chemical properties and their dissemination in the environment. Pb isotope ratios have been successfully used during the past decades as tracers of anthropogenic Pb disseminated in the biosphere. Here we show that tree bark biomonitoring with lead (Pb), strontium (Sr) and neodymium (Nd) isotope ratios as tracers allow a thorough analysis of the impacts of industrial and other anthropogenic emissions on the urban environment. This is the first comprehensive multi-isotope tracer study of atmospheric pollution in an urban environment allowing to identify and to integrate the different plume paths of emissions in a digital map system. This innovative approach might become an important tool for environmental management and policy-making processes dealing especially with risks and surveillance of air quality in the urban environment.     

Mercury in Tree Swallow Food, Eggs, Bodies, and Feathers at Acadia National Park, Maine, and an EPA Superfund Site, Ayer, Massachusetts

We monitored nest boxes during 1997–1999 at Acadia National Park, Mt. Desert Island, ME and at an old-field site in Orono, ME to determine mercury (Hg) uptake in tree swallow (Tachycineta bicolor) eggs, tissues, and food boluses. Also, in 1998–1999 we monitored nest boxes at Grove Pond and Plow Shop Pond at a U.S. Environmental Protection Agency Superfund site in Ayer, MA. We recorded breeding success at all locations. On average among locations, total mercury (THg) biomagnified 2 to 4-fold from food to eggs and 9 to 18-fold from food to feathers. These are minimum values because the proportion of transferable methyl mercury (MeHg) of the THg in insects varies (i.e., 35%–95% of THg) in food boluses. THg was highest in food boluses at Aunt Betty Pond at Acadia, whereas THg in eggs was highest at the Superfund site. A few eggs from nests at each of these locations exceeded the threshold (i.e., 800–1,000 ng/g, wet wt.) of embryotoxicity established for Hg. Hatching success was 88.9% to 100% among locations, but five eggs failed to hatch from 4 of the 11 clutches in which an egg exceeded this threshold. MeHg in feathers was highest in tree swallows at Aunt Betty Pond and the concentration of THg in bodies was related to the concentration in feathers. Transfer of an average of 80%–92% of the Hg in bodies to feathers may have enhanced nestling survival. Residues of Hg in tissues of tree swallows in the Northeast seem higher than those of the Midwest.     

Stakeholder perceptions and practices regarding Prosopis (mesquite) invasions and management in South Africa

Invasive alien trees impact the environment and human livelihoods. The human dimensions of such invasions are less well understood than the ecological aspects, and this is hindering the development of effective management strategies. Semi-structured interviews were undertaken to investigate the knowledge and perceptions of Prosopis between different stakeholder groups. Chi-squared tests, Welch ANOVAs, and Principle Component Analyses were run. Factors such as land tenure and proximity to invasions were especially important for explaining differences in perceptions and practices relating to Prosopis among different stakeholder groups. Most respondents were aware of Prosopis and considered it to be invasive (i.e., spreading). Costs associated with Prosopis were perceived to exceed benefits, and most stakeholders wanted to see a reduction in the abundance of Prosopis stands. The mean total cost for the management of Prosopis was US$ 1914 year⁻¹ per farm, where costs ranged from under US$ 10 to over UD$ 500 per ha based on invasion densities and objectives for control. The findings highlight the need for more effective management interventions.     

我国苏南地区香樟树皮赋存的二英类污染特征及来源

为分析长江下游经济高速发展区的POPs污染特征,于2012年8月在苏南地区典型城市10个采样点采集香樟树皮,应用高分辨气相色谱-高分辨质谱(HRGC-HRMS)联用技术对二英(PCDD/Fs)浓度水平进行监测,同时采用主成分分析(PCA)法探讨其可能来源. 结果表明:苏南地区香樟树皮中二英的毒性当量(I-TEQ)浓度(以干质量计,下同)为5.6～12.2 pg/g,平均值为7.2 pg/g;4～8氯代二英同族体质量分数(以干质量计)范围为418～938 pg/g,平均值为635 pg/g. 由于二英在大气中的长距离迁移潜力较强,在研究的苏南地区区域尺度上,其含量在城市中心区和对照区之间的差异性并不明显;苏南地区香樟树皮二英质量分数及毒性当量浓度均高于国外报道的背景区及典型城市中树皮的水平. 对比典型二英排放源及树皮中二英特征谱图,可推断苏南地区香樟树皮中二英可能主要来源于危险(医疗)废物焚烧、机动车尾气排放和工业燃烧源.      

二龙山水库上游小流域生态环境综合治理示范区研究

介绍了二龙山上游小流域中小梨树沟的生态环境综合治理情况,在现有治理成果的基础上,提出了该生态示范区更全面的治理规划(包括土地利用规划和治理措施规划),并且总结了治理措施的实施成果,在此基础上对示范区的综合治理进行了评价.      

Tree plantations for restoration of degraded lands and greening of India: a case study of tree growers' cooperatives

India has over 100 m ha (million hectares) of village common lands. De jure, these lands are owned by the state but, de facto, they are used in common by villagers. Most of the village commons are degraded and denuded and are almost nonproductive. Several attempts have been made in the recent past to restore them through planting of trees by governmental and non-governmental organizations. Tree Growers' Co-operative Societies (TGCS), as an organisational innovation of relatively recent origin, have proved to be more cost-effective than other forms of organisations engaged in greening the village commons in India. This paper attempts to assess the financial viability of tree plantations carried out by three selected TGCS and to distil lessons of their experience useful for policy purposes. The study revealed that plantations founded by the sample TGCS were financially viable, and that the plantations had transformed the desolate village commons into 'green wealth'. The authors conclude that the TGCS have a high potential as an instrument for promoting the afforestation of India's degraded village common lands and thereby improving village economy and the quality of the environment.     

Sm-Gly-VB6对Pb-Cd胁迫下五种树木若干生理生化指标的影响

采用叶圆片法研究了模拟 Pb- Cd胁迫污染对 5种树木若干生理生化指标的影响。结果表明 ,Pb- Cd胁迫 ( Pb70 0 m g·L-1 ,Cd2 0 m g/ L)使 5种树木的叶绿素含量、质膜透性、过氧化氢酶活性、叶片内 Pb和 Cd的富集量均产生明显变化。经 Sm- G ly-VB6处理的 5种树木 ,上述各项指标的变幅明显减小 ,说明 Sm- G ly- VB6对重金属伤害植物有一定的缓解作用     

Polycyclic aromatic hydrocarbons in leaf cuticles and inner tissues of six species of trees in urban Beijing

Leaf samples of six tree species were collected along urban roadsides and a campus site in Beijing for measurement of polycyclic aromatic hydrocarbons (PAHs). PAHs in leaves were attributed to two fractions, leaf cuticles and inner leaf tissues, using sequential extraction. Total concentrations of 16 PAHs in the cuticles and the inner tissues were 69.3+/-64.6 microg g(-1) (d.w.) and 1.07+/-0.2 microg g(-1) (d.w.) at roadside and 57.5+/-52.6 microg g(-1) and 0.716+/-0.2 microg g(-1) on campus, respectively. The lipid-normalized inner tissue PAHs varied from 5.8 microg g(-1) to 15.0 microg g(-1). Similarities in PAH spectra between leaf cuticles and airborne particles and between the inner tissues and gaseous phase imply that airborne particulates and gaseous PAHs are likely the sources of PAHs for cuticles and the inner tissues, respectively. Difficulty in migration of heavier PAHs into inner tissues could be another reason.     

Assessing the suitability of Norway spruce wood as an environmental archive for sulphur

The aim of this study was to assess the suitability of Norway spruces (Picea abies L. Karst.) as an environmental archive for sulphur. For this purpose spruce trees were sampled in two distinct regions of Switzerland: the Alps and the Swiss Plateau, which differ significantly with respect to S immission. Wood samples were measured using two methods: LASER Ablation high resolution inductively coupled plasma mass spectrometry (LA-HR-ICP-MS) and inductively coupled plasma optical emission spectrometry (ICP-OES) after acid digestion. Independently corroborated by previous measurements of sulphur in peat bogs, the rise and fall of sulphur dioxide pollution in Switzerland appears to be reflected in spruce wood sulphur content. While the wood sulphur content profile of trees sampled in the Alps is relatively flat, the profiles of trees located on the Swiss Plateau display a characteristic sulphur peak. This corresponds to air pollution data in the different regions and indicates that the trees reacted on the changing S supply and recorded a pollution signal in the wood.     

Mercury and other element exposure to tree swallows (Tachycineta bicolor) nesting on Lostwood National Wildlife Refuge, North Dakota

Elevated mercury concentrations in water were reported in the prairie wetlands at Lostwood National Wildlife Refuge, ND. In order to determine whether wildlife associated with these wetlands was exposed to and then accumulated higher mercury concentrations than wildlife living near more permanent wetlands (e.g. lakes), tree swallow (Tachycineta bicolor) eggs and nestlings were collected from nests near seasonal wetlands, semi-permanent wetlands, and lakes. Mercury concentrations in eggs collected near seasonal wetlands were higher than those collected near semi-permanent wetlands or lakes. In contrast, mercury concentrations in nestling livers did not differ among wetland types. Mercury and other element concentrations in tree swallow eggs and nestlings collected from all wetlands were low. As suspected from these low concentrations, mercury concentrations in sample eggs were not a significant factor explaining the hatching success of the remaining eggs in each clutch.