ArticleLiterature Review

Effects of Air Pollution on Ecosystems and Biological Diversity in the Eastern United States

Authors:
• 39.92
• Biodiversity Research Institute, Portland, Maine, United States
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Abstract

Conservation organizations have most often focused on land-use change, climate change, and invasive species as prime threats to biodiversity conservation. Although air pollution is an acknowledged widespread problem, it is rarely considered in conservation planning or management. In this synthesis, the state of scientific knowledge on the effects of air pollution on plants and animals in the Northeastern and Mid-Atlantic regions of the United States is summarized. Four air pollutants (sulfur, nitrogen, ozone, and mercury) and eight ecosystem types ranging from estuaries to alpine tundra are considered. Effects of air pollution were identified, with varying levels of certainty, in all the ecosystem types examined. None of these ecosystem types is free of the impacts of air pollution, and most are affected by multiple pollutants. In aquatic ecosystems, effects of acidity, nitrogen, and mercury on organisms and biogeochemical processes are well documented. Air pollution causes or contributes to acidification of lakes, eutrophication of estuaries and coastal waters, and mercury bioaccumulation in aquatic food webs. In terrestrial ecosystems, the effects of air pollution on biogeochemical cycling are also very well documented, but the effects on most organisms and the interaction of

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... High levels of pollutant mixtures containing B[a]P have resulted in symptoms such as breathing problems, asthma-like symptoms, and lung function abnormalities, eye irritation, nausea, vomiting, diarrhoea and confusion [21]. It was also investigated specific effects of B[a]P on the origin and development of asthma bronchiole, due to the impact of air pollution in critically polluted industrial clusters, Angul-Talcher area [22,23]. ...
... Effects of air pollutants on living organism will not only be limited to the human and animal health but also include the status of whole environment [23,24]. Studies on the relationship between air pollution and reducing species diversity clearly show the detrimental effects of environmental contaminants on the extinction of animals and plants species [24,25]. ...
... Talcher power station measured average hourly levels of SO2, NO2 and PM2.5. Environmental monitoring studies reported that the levels of B[a]P tend to be higher in Talcher area than in Angul area [23]. Whereas concentration of B[a]P in air levels found to be 0.2-19.3 ...
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Industrial growth has been a national issue with leading risk factor towards human health and the environment. The major air pollutants including particle pollution has different toxicological impacts on animals and human health. Polycyclic aromatic hydrocarbon (PAHs) present in particle is known to induce significant respiratory, reproductive and neuropsychiatric complications. To investigate the effect of major particle pollutants, sources of emission, and their impact on human health and to check the toxicological/pathological impact of particulate matter (PM) containing Benzo[a]pyrene like toxicants on increasing rate of respiratory and reproductive diseases. The percentage of different trace element in the atmosphere was measured by monitoring air quality index through high volume sampling method and Atomic Absorption Spectroscopy in Angul-Talcher areas. Effect of intratracheal and intraperitonial administration of B[a]P during PND 28 were examined on adult male Wistar rats after 15 days and 30 days of post exposure. Chest X-ray reports of human (Aged 20-60) were collected for acute respiratory diseases, asthma, conjunctivitis and bronchitis. Study showed monthly variation in the elemental content of the flyash samples including B[a]P. Histopathology of lungs and testis showed morphological changes in B[a]P treated rats as compared to the control. Similarly chest X-ray report showed different respiratory symptoms in human residing near Angul-Talcher industrial areas. The indices for PM are above the standard and mostly at dangerous level in TTPS. Thermal emissions are important in causing respiratory and other diseases. The present findings may contribute to building up evidences for environmental exposure and health effects in man and animals.
... Biodiversity has declined globally as a result of anthropogenic environmental perturbations, including changes in land-use diversity in a variety of ecosystems (Gilliam 2006(Gilliam 2014bLovett et al. 2009). The Athabasca oil sands region (AOSR) is the largest oil sands mining area in the world (Alberta Government 2013). ...
... There is no direct evidence of S deposition effect on plant diversity; however, indirect effects of excess S on plant growth and species diversity include cation leaching, soil acidification, and Al toxicity (Lovett et al. 2009). Large areas in the AOSR have been reported to have S deposition in excess of critical loads (Whitfield et al. 2010b), although deposition rates are low compared with many other sites, including eastern North America (Vet et al. 2005;World Meteorological Organization 2004), the western and central parts of Europe (Vanguelova et al. 2007), and eastern Asia (Fujii et al. 2008). ...
... The S-meditated decreases in % cover, evenness, and species diversity in the shrub layer support our third hypothesis, and likely arose from decreased cation concentrations, such as Ca 2+ and K + , in the forest floor. Sulfur deposition rarely affects plant growth or species composition directly, but does so through increasing cation leaching and soil acidification (Lovett et al. 2009). Chronic S deposition has been reported to accelerate leaching loss of base cations as they accompany SO 4 2− leaching (Bouwman et al. 2002). ...
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... Increases in fossil fuel combustion emit a large amount NO x and SO 2 to the atmosphere, and nitrogen (N) and sulfur (S) compounds formed in the atmosphere eventually return to the surrounding areas as N and S deposition, which can cause base cation leaching, nutrient imbalance and soil acidification (Fenn et al., 1998;Lovett et al., 2009), threatening forests surrounding the emission source. The Athabasca oil sands region in northern Alberta, Canada, is the world's largest oil sands reservoir and oil sands mining and upgrading related activities emit approximately 300 and 250-300 Mg day −1 for NO x and SO 2 , respectively, since the mid-2000s (Hazewinkel et al., 2008;The Royal Society of Canada, 2010). ...
... Chronic N deposition can change understory plant species composition by increasing soil N availability and base cation leaching (Fenn et al., 1998;Gilliam, 2006Gilliam, , 2014aJung et al., 2017;Lovett et al., 2009). Increases in soil N availability increase the abundance of nitrophilous species (Gilliam, 2014a;Hruška et al., 2012). ...
... Increases in soil N availability increase the abundance of nitrophilous species (Gilliam, 2014a;Hruška et al., 2012). High concentrations of N deposition increase base cation leaching and aluminum (Al) mobility and toxicity in the soil (Lovett et al., 2009), which in turn can decrease the cover of plant species that require high base cation supply and other species sensitive to acid stress (Lu et al., 2010(Lu et al., , 2014. Many studies have evaluated the effect of excess N deposition on understory communities in temperate forest ecosystems with inconsistent results (Gilliam, 2006(Gilliam, , 2014bHurd et al., 1998;Rainey et al., 1999;Thomas et al., 1999), depending on soil N availability, duration of experimental N addition and amount of N added (Bobbink et al., 2010). ...
Article
Oil sands mining activities in northern Alberta, Canada emit large amounts of nitrogen (N) and sulfur (S) oxides to the atmosphere, increasing N and S deposition. We studied the long-term (2006–2016) effect of elevated concentrations of simulated N and S deposition on soil properties and understory species composition in a mixedwood boreal forest in a two (0 and 30 kg N ha⁻¹ year⁻¹, as ammonium nitrate) × two (0 and 30 kg S ha⁻¹ year⁻¹, as sodium sulfate) factorial experiment. Soil (forest floor and 0–15 cm mineral soil) and understory vegetation samples were collected and the cover of understory vegetation was determined in August 2016. Eleven years of N deposition increased (p =.045) total N concentration and decreased (p <.10 unless otherwise indicated) carbon to N ratio by 11 and 7%, respectively, in the forest floor. Sulfur deposition decreased (p =.045) exchangeable calcium concentration by 36% in the mineral soil. Species evenness (by 7%) and the overall diversity (by 7%) were decreased and community composition was changed (p =.008) in the herb stratum by N but not by S deposition, due to species-specific responses to N deposition. However, elevated concentrations of N and S deposition did not change species diversity and composition in the shrub stratum. Decreased foliar phosphorus and potassium concentrations and increased N to phosphorus ratio in some species indicate a potential risk of nutrient imbalance by N deposition. Reducing N emission to minimize its negative effect on boreal forest ecosystems should be a priority in emissions management in the oil sands.
... Another issue affecting forest health is air pollution, which can generate significant pressure onto these terrestrial ecosystems due to the presence of various anthropic pollutants, the most important of whichand probably the most widely studiedis tropospheric ozone (O 3 ) (representative for large scale vegetation injuries) (Ashmore, 2005;Bytnerowicz et al., 2007;Wittig et al., 2009). However, nitrogen and sulphur are two other representative global pollutants that, through excessive acid deposition (NO x and SO 2 ), have generated major soil acidification and tree productivity decline in many temperate and boreal forests (Lovett et al., 2009;Lu et al., 2014). At the same time, it appears terrestrial acidification is also a notable threat for the health of tropical forests (Azevedo et al., 2013;Lu et al., 2014). ...
... Thus, in many forest areas, the beneficial effect of low rates of N deposition (which is known to stimulate forest productivity) was annulled, as will be presented at length in the biogeochemical change section. Other examples include mercury (Lovett et al., 2009) and certain dangerous radionuclides (like radiocesium) transferred to forest biomass during nuclear tests (Prăvălie, 2014) or the major nuclear accidents in Chernobyl and Fukushima (Thiry et al., 2009;Koarashi et al., 2016;Teramage et al., 2016;Prăvălie and Bandoc, 2018). However, the harmful effects are mainly regional and affect people and animals (through food webs and other pathways), rather than forest ecosystems. ...
Article
Forests are among the most important terrestrial ecological systems in terms of the multitude of ecosystem functions and services they provide. These biotic systems are vital not only for ensuring the wellbeing of human society and for preserving global biodiversity, but also for regulating the climate system, decarbonizing the atmosphere via carbon sequestration (in biomass or underlying soil carbon pools) and evaporative cooling processes that mitigate climate warming. However, forest ecosystems are currently being subjected to a wide range of natural and anthropic disturbances that pose a real threat not only to forest health and the various benefits forests provide for human society, but also to the overall functioning of the global system. This paper is a review that aims to analyse, in a brief and holistic manner, the main perturbations Earth forest ecosystems are currently facing, both the obvious (e.g. deforestation) and discrete/silent ones (e.g. defaunation) that have generally not yet been tackled strictly as ecological forest issues in the international scientific literature. At the same time, the paper aims to highlight the possible effects generated by forest perturbations in the global warming process, through carbon fluxes and biogeophysical feedbacks between these terrestrial systems and the atmosphere. Upon analysis of a vast scientific bibliography, it was found there currently are 12 major forest disturbances that can be grouped into three categories based on the prevalence of triggering causes, i.e. climatic (phenological shifts, range shifts, die-off events, insect infestations), anthropic (deforestation, fragmentation, air pollution) and mixed (defaunation, fires, composition shifts, net primary productivity shifts, biogeochemical shifts) perturbations. These ecological issues, which occur frequently, intensely and on large spatial scales, are able to significantly disrupt forest productivity and therefore strongly erode the forests'capacity to stabilize the climate system. All identified disturbances can amplify global warming in various ways, including by means of many positive feedback mechanisms in the case of climatic perturbations. Finally, this review paper proposes five major anthropogenic strategies to fight this multidimensional forest crisis – mitigate, adapt, repair, protect and research actions, which, if implemented rapidly, efficiently and on a large scale via international policies, can successfully stabilize these terrestrial ecosystems and, implicitly, the climate system in the 21st century.
... Airborne particulate matters (PM) with organic and inorganic compounds are the noticeable factors of air pollution emitted primarily from the soil, fuel combustion, and industrial activities (de Paula et al. 2015). PM possibly contain toxic elements that can be transferred by natural processes to the hydrosphere and biota, traveling more distances from the main source (Lovett et al. 2009). Origin of PM is not only an anthropogenic activity but also a natural phenomenon such as dust storms in the deserts and dried bed of rivers, ponds, or lakes (Ferreira-Baptista and De Miguel 2005;Nikoonahad et al. 2017;Rai 2013). ...
... There are many mechanical methods for monitoring and purification of air pollutants especially metal elements, which include fabric filtration, electrofiltration, and scrubbing. These techniques require high technology, highly skilled experts, and high cost (Kulkarni et al. 2011). Plants have shown good potential for reception of gaseous and particulate pollutants (Teiri et al. 2018). ...
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In the northwest of Iran, the dust of salty and toxic metals possibly caused due to drying Urmia Lake is threatening the health of surrounding communities. This study aimed to employ leaves of local deciduous trees for biomonitoring of toxic elements and to evaluate air pollution tolerance of the trees for greenbelt application. Sampling from leaves of four dominant tree species including Vitis vinifera, Juglans regia, Ulmus umbraculifera, and Popolus alba was carried out from gardens in two radial distances (5 and 10 km) around the Urmia Lake accounting for 16 sites. The concentration of metals in the leaves were extracted according to method USEPA method 3050B and measured by ICP AES technique. According to the levels of air pollution tolerance index (APTI), Popolus alba showed to be more sensitive to air pollution and can be applied for biomonitoring. The ranks of heavy metals and sodium concentrations in the leaves gained in the order of Na > Zn > Cu > Ni > Pb > As > Cd. The mean enrichment factor for the elements was calculated from 1 to 3, suggesting minor enrichment for them. As, Pb, and Na with similar spatial distribution were dominantly observed in northwest and center-east of the Urmia Lake. Potential ecological risk (PER) index showed a moderate risk in 6% of sampling zones, where Cd and As were identified as responsible pollutants. Principle component and correlation analysis between the elements depicted human sources such as industrial activity and road traffic for Cd, Cu, Ni, Pb, and Zn, whereas As and Na were most likely originated from the aerosols of Urmia Lake. Our findings showed that Popolus alba can be applied as a local biomonitor and Vitis vinifera with moderate tolerance can be used as a good air pollutant sink in greenbelt development around the drying Urmia Lake in the northwest of Iran.
... . L'ozone a également un effet néfaste sur la végétation en réduisant la photosynthèse induisant une baisse de la productivité des écosystèmes naturels et des rendements agricoles (Chen et al., 2009, Lovett et al., 2009. De plus, l'ozone contribue à l'accroissement de l'effet de serre en absorbant en partie la chaleur rayonnée par les sols (Garrec, 2000). ...
... During the last decade, a growing occurrence of tropospheric ozone episodes, as well as an increase in background tropospheric ozone concentrations was observed in Europe and at many places of the northern hemisphere (Oltmans et al., 2006). Tropospheric ozone pollution constitutes a major environmental preoccupation because of the strong oxidant properties of this molecule, which is known to cause damages to animals and vegetation (Chen et al., 2009, Lovett et al., 2009), but also health damages (McConnell et al., 2002, Mudway andKelly, 2004). In this frame, precise air quality simulations and forecasts are needed to improve our capacity to inform populations, to protect human health and the natural environment, and to design strategies to reduce the pollution levels. ...
Thesis
Les composés organiques volatils biogènes (COVb), majoritairement émis par la végétation, favorisent la pollution à l'ozone en présence d'oxydes d'azote (NOx). En région PACA, les formations arbustives méditerranéennes (ou matorrals) occupent une grande surface et sont fortement émettrices de COVb. Cependant, elles étaient mal décrites dans le modèle CHIMERE qui sert à la prédiction de la pollution à l'ozone. L'objectif de ce travail a été d'améliorer leur prise en compte en s'intéressant aux principaux paramètres de la modélisation des émissions de COVb : la répartition des espèces, leurs biomasses foliaires et leurs facteurs d'émission. D'abord, la composition floristique des matorrals a été étudiée in-situ, afin d'établir une typologie basée sur les espèces dominantes qui a servi de référence pour cartographier les matorrals par classifications supervisées d'images satellites. Ensuite, des méthodes non destructives d'estimation de la biomasse foliaire ont été mises au point afin d'obtenir les estimations ponctuelles nécessaires à la réalisation de cartes de variabilité spatiale de la biomasse foliaire des principales espèces. Par ailleurs, à partir d'une synthèse bibliographique et de mesures in-situ des émissions de COVb, il a été possible d'améliorer les facteurs d'émission des principales espèces arbustives, mais également de montrer que la saison et le type de substrat influencent les émissions de monoterpènes de Cistus monspeliensis, une espèce arbustive très répandue en région méditerranéenne. Enfin, nous avons testé l'influence de données affinées pour les matorrals, pour la prévision des émissions de COVb et de la pollution à l'ozone avec le modèle CHIMERE. Les améliorations apportées induisent une augmentation des émissions de COVb (+6 à +10%), qui se répercute sur la production d'ozone (+2 à +8%). L'utilisation d'une formation type par département semble donner des résultats similaires à ceux qui sont obtenus en prenant en compte une variation kilométrique des matorrals. La présence de NOx étant indispensable pour la production d'ozone, la variation de la concentration d'ozone est donc essentiellement observée dans la zone Berre-Aix-Marseille.
... Other studies have showed that hydrological disturbance affected nutrient availability because nitrates were readily leached from oxidized soil during drain- age 14 . Anthropogenic nutrient inputs to the biosphere from fertilizers and atmospheric pollutants now exceed natural sources and enhance plant invasion 15 . There is also evidence that invasive species may access forms of nutrients that neighbouring (native) species are not using, including amino 16 . ...
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Abstract Rumex confertus is an alien invasive perennial plant that has increased its range rapidly within central Europe in the last 100 years. This study examined the effects of a commercial fertilizer on the competition between the invasive Rumex confertus and two non-invasive native species R. acetosa or R. conglomeratus in terms of morphological and physiological traits and relative yield. All three Rumex species were grown in the open field with two levels of nutrient availability in field plots. Competition and fertilizer had significant effects on height, relative growth rate (RGR), specific leaf area (SLA) as well as shoot and root biomass of all three species. The fertilized plants had high macronutrient and nitrate contents in leaf tissue. Relative yield of R. confertus was
... While numerous studies have focused on the provision of ecosystem services, relatively little attention has been directed toward the disaggregation of benefits in terms of the institutional aspects of unequal social allocation of the supply of ecosystem services (Daw et al., 2011). Furthermore, while there are studies on the effects of hazardous air pollutants on biodiversity and ecosystem services (Grantz et al., 2003;Lovett et al., 2009), due to methodological or empirical challenges for integrated analyses, few of these have addressed the EJ implications of economic development-driven spatial disparities in ecosystem services and economic disservices (Marshall and Gonzalez-Meler, 2016). The research presented in this paper addresses that knowledge gap. ...
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Inequality in access to ecosystem services is inextricably linked with environmental justice in socially heterogeneous urban settings. Historically, San Antonio has been the gateway to Mexico and is strategically located along the North American Free Trade Agreement (NAFTA) corridor. It is also characterized by some of the most distinct residential segregation among U.S. cities. However, little is understood about the ways in which historically institutionalized residential segregation initiated by the Home Owners’ Loan Corporation (HOLC) and NAFTA have affected socio-ecological outcomes. Here, this paper presents a novel empirical study of racial residential segregation. The study utilizes quantitative and spatially explicit estimates of regulating ecosystem services and biodiversity, and links the supply of ecosystem services to the distribution of human well-being within a heterogeneous social-ecological system. Specifically, the paper employed 1930s HOLC redlining maps and applied the ceteris paribus approach for racial concentrations to reflect a historical legacy and path dependence by institutional inertia. The results point to the social-ecological divide in that Hispanic and African American minorities derive fewer ecosystem benefits and face greater health risks and socio-economic disadvantages (p<0.01). Notably, NAFTA corridor-related health risks are the most significant for the Hispanic population (p<0.01). These patterns are likely to persist and may be amplified by 2050 (adjusted R2=0.646). The findings highlight that institutional transformations are essential for the greater social-ecological equity in the San Antonio region under NAFTA and, potentially, new United States-Mexico-Canada Agreement. Additionally, by assessing the EJ implications of spatially heterogeneous distribution of ecosystem services supply, the paper provides methodology that enhances science-based planning and better environmental decisionmaking to avoid or mitigate social-ecological divides in rapidly urbanizing regions both in the U.S. and around the world.
... Excessive air pollution has resulted in acidification of lakes, eutrophication of local water bodies and coastal waters, and accumulation of mercury in aquatic food webs. 2 Nature-based solutions (NBS) including green infrastructure methods like trees, grasslands, green roofs, and urban farms are being increasingly used for improving air quality through direct interception of particles from the atmosphere on the leaf surface. 3,4 Several studies have highlighted the benefits of using urban forests in cities 5 and trees for the removal of significant amount of pollutants from the atmosphere. ...
Article
Despite wide adoption of pollution control technologies, industrial facilities emit about half the criteria air pollutants in the US and contribute to poor air quality in many regions. Vegetation such as trees, shrubs, and grasses also have the capacity to directly remove air pollution. This work assesses the role of vegetation, particularly trees, in mitigating air emissions near point sources at nearly 20,000 sites across the US. Additional mitigation capacity due to ecological restoration to the average local vegetation is also determined. Comparing emissions with the average uptake capacity at each site indicates that currently most sites in the southeastern part of the US have enough vegetation cover to offset most emissions while industrial facilities, particularly those in the western part of the country can benefit the most from restoration. A relatively large fraction of sites in the Mining, Quarrying and Oil & Gas Extraction, Transportation and Warehousing, and Management of Companies and Enterprises sectors have enough current or restored capacity to mitigate their emissions. Land around facilities in the Finance and Insurance, Real Estate, and Retail and Leasing sectors lacks much capacity. Such results encourage further work toward sustainable engineering by seeking synergies between industrial and ecological systems.
... These toxic compounds may deposit into the aquatic systems and may bio-magnify in the aquatic organisms at the top of the trophic levels. Most of the ecosystems are exposed to multiple air pollutants simultaneously and various species differ in sensitivity to air pollution and its biogeochemical consequences, and this differential sensitivity implies that air pollution will shift the species' composition or will lead to outright loss of sensitive species of various ecosystems (Lovett et al., 2009). ...
Chapter
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Air pollution is a growing concern from social, economic and ecological dimensions of society. This chapter focuses on air pollution effects on the environment and on the economy. Several energy-utilizing anthropogenic activities emit large amounts of toxic gases and particulate matter into the environment. Through several atmospheric processes these pollutants create very critical environmental problems such as acid rain, eutrophication, and global climate change. Acid rain has variety of environmental impacts due to the presence of nitrogen and sulfur in it. It affects nutrient leaching from soil, trees, fish and wildlife, along with building materials adversely. Different ranges of pH may affect a variety of species in the aquatic ecosystem. Haze is one of the significant factors and a result of air pollution, especially in the megacities. Haze is responsible for the visibility degradation in both developed and developing countries. Apart from visibility reduction, it also creates cloud formation by forming cloud condensation nuclei (CCN). The emission from thermal power plants and vehicles also contributes a large amount of nitrogen oxides entering the aquatic ecosystem, which ultimately causes eutrophication in lakes. The depletion of stratospheric ozone allows harmful solar radiation to reach the Earth’s surface, which causes a variety of diseases in plants, animals and human beings. In contrast to stratospheric ozone, ground level ozone has harmful effects on the living creatures due to its toxic nature. Ground level ozone can have adverse impacts on human health even at very low levels in the atmosphere. The global climate change is also linked to the increasing level of air pollutants, especially Greenhouse Gases (GHGs). Due to the increasing anthropogenic activities necessary to fulfil today’s energy requirements, a large amount of GHGs are emitted into the atmosphere and are causing the rise in global annual temperature by several fold. This chapter tries to understand how air pollution is affecting the global economic growth and environment. Pollution may cause direct pressure on economies through increased numbers of deaths due to respiratory disorders or cardiovascular diseases, installation of pollution-control technologies to reduce the deaths, management of degraded ecosystems and carving out conservation strategies for pollution threatened species. It can also affect economic growth indirectly by increasing morbidities, reducing labour working days and reducing productivity. World Health Organization (WHO, 2016a) reported that 12.6 million deaths per year were found linked with environmental pollution. Out of these, 11.6% of deaths are directly linked to air pollution, from indoor and outdoor sources. Another report of the World Health Organization (WHO, 2016b) estimated the expected additional deaths at approximately 250,000 per year from 2030 to 2050 due to malnutrition, malaria, diarrhoea and heat stress. The direct damage cost due to health issues is estimated to be between US$2–4 billion/year by 2030. Therefore it is crucial to understand that air pollution not only affects ecological systems but also economic systems. Thus, this chapter shows the demand for more research in the area of air pollution and its impact on the economy and environment for successful policymaking. ... Pollution of air and water also affect the balance of the ecosystem and largely affect the biodiversity of the land. Acidification of lakes and soils, eutrophication of waters and bioaccumulation of metals/heavy metals in food web and plethora of other problems occur due to pollution (Lovett et al. 2009). Pollutants such as polyaromatic hydrocarbon (PAHs) and PCBs from effluent discharge and oil spills which when released in water bodies affect biology of that system. ... Article Full-text available Since last century or so anthropogenic activities have intensely metamorphosed the earth’s ecosystem and resulted into major environmental changes. Widespread interference of human related activities have resulted in major problems including environmental pollution, land degradation, global warming/climate change, paucity of potable water supply and biodiversity loss. These issues have directly affected the quality and sustainability of the ecosystems. In addition, these activities have resulted in loss of habitats resulting in mass extinction of species which in itself is a matter of great concern. Studies and data clearly show that if present trends continue the conditions are expected to worsen in the coming time and human civilization itself will be in trouble. To minimize this crisis, possible green solutions like use of microbes and biotechnological tools are gaining importance and need further attention in order to lessen or remediate the harmful effects of anthropogenic activities thus ensuring environmental sustainability. ... Another set of studies attempts to assess the human-related influence on biodiversity and ecosystems (Lovett et al., 2009;Stevens et al., 2004;Phelps, 2012), which services provide significant benefits to human welfare with some estimates exceeding global GDP (OECD, 2012;Costanza et al., 1997). In contrast to the climate change assessment studies, while ecosystem impacts can in overall be even more important to human's welfare changes, it is much harder to measure the impacts in a conventional manner and design monetary metrics for further comparisons. ... Data Full-text available ... Health effects due to air pollution are a big concern for the World Health Organization [3]. But, air pollution does not only cause toxicological effects on human health, it has also significantly degraded the environment in the last years [4,5]. In this review, the contribution of various waste management methods, wastewater treatment plants, refining and desalination plants in polluting the atmosphere are studied. ... ... Ozone (O 3 ) is a reactive oxidant considered a hazard to human health (WHO, 2013), as well as a greenhouse gas (IPCC, 2007) that affects sensitive vegetation and ecosystems (Lovett et al., 2006). Evidence is acknowledged that, even at low concentrations, O 3 produces short-term effects on mortality and respiratory morbidity, experienced in many cities in Europe (WHO, 2003). ... Article Full-text available Classification models to forecast exceedance of the ozone (O3) threshold established by European legislation are rare in literature, as is the focus on background O3, with higher concentrations at city outskirts. This study evaluated the performance of nine classifiers to forecast this threshold exceedance by background O3. Models used five large hourly background O3 data sets (2006–2015), and included temporal features describing the O3 formation dynamic. Bagging and stacking ensembles of such classifiers and their cost of learning were also evaluated. C5.0 and nnet classifiers achieved the best forecasting performance, even at imbalanced learning. Bagging ensembles outperformed stacking approaches, although with little accuracy improvement as compared to classifiers. The cost of learning evidenced similar performance results from reduced fractions of original data sets. The use of these models to forecast background O3 threshold exceedances are encouraged due to the performances obtained and to their easy reproducibility. ... 4: Environmental impacts: Increasing environmental and water pollution of the city. Isfahan has been set above the standard levels (KhoshAkhlagh, 1999), which causes disturbance to the urban ecosystem and, consequently, decreases citizens' quality of life ( Lovett et al., 2009). ... ... Notwithstanding, any damage to the most important and ubiquitous ingredient of environment, that is, water, therefore literally can be conceived as a serious self-inflicted body blow for us. 3 Perhaps, that is how Mother Nature restores the balance. Unfortunately, this very balance of the nature has now moved into uncharted waters by our ever increasing lifestyle and subsequent industrial progress. ... Article Full-text available We report herein the development of a unique low-molecular-weight gelator-induced technique for environmental remediation. The motive of this work is wastewater purification using a gel-based toxic heavy metal sequestration. The essence of this technique was to bring two different functionalities, one capable of multiple coordination and another with gel-forming ability, arranged in tandem within a single ligand molecule. Naturally, the success of the approach depends on whether the two tandem-arrayed functionalities are indeed working in tandem. Our results show that the ligand molecule is an excellent example of concomitant hydrogelator and metallogelator. The most interesting aspects of this study involve the toxic metal sequestration of Pb, Cd, and Hg which was further studied in detail with spectroscopic, microscopic, and diffraction techniques. We also report here a rare property of pure organic hydrogel-to-metallogel transformation which could open up a new avenue on wastewater purification. In essence, the hydrogels can be envisaged as a unique class of metal-free zeolite analogue for environmental remediation not by just absorbance but through absorbance cum coordination, which are further corroborated by the inductively coupled plasma-optical emission spectroscopy results. ... Airborne particulate matter (PM) with organic and inorganic compounds are the noticeable factors of air pollution emitted primarily from soil, fuel combustion and industrial activities [3,4]. PM may possibly contain toxic elements that can be transferred by natural processes to the hydrosphere and biota, traveling more distances from the main source [5]. Origin of PM is not only related to anthropogenic activity, but also natural phenomena such as dust storm in the deserts, and dried bed of rivers, ponds or lakes [6][7][8]. ... Article Full-text available In northwest of Iran, airborne particulate matter originated from drying Urmia Lake is threaten the health of surrounding communities due to salt particles and heavy metals. This study aimed to use leave of local trees for biomonitoring of toxic metals and to evaluate tolerance of the trees against air pollution due to greenbelt development. Leaf samples were taken from four dominant tree species including Vitis vinifera, Juglans regia, Ulmus umbraculifera and Popolus alba in two radial distances (5 and 10 km) around the Urmia Lake in 32 sampling sites. The concentration of Cd, Pb, Ni, As, Cu, Zn and Na in the leaves were extracted according to method 3050B defined by United States Environmental Protection Agency (USEPA) and analyzed by ICP-AES technique. According to the levels of air pollution tolerance index (APTI), Popolus. alba was classified as more sensitive and Vitis. vinifera as moderately tolerant. The accumulation/existence of metals in the leaves can be arranged as follows: Na > Zn > Cu > Ni > Pb > As > Cd. Our findings showed that Popolus. alba can be applied as a local biomonitor and Vitis. vinifera can be used as a good sink of air pollutants for greenbelt development around the drying Urmia Lake. •The results show that APTI is a suitable index for selection of tree species as biomonitor and green belt development.•Determination of metal concentration level in local tree leaves is suggested as a good tool for mapping of airborne metal.•The local trees can be suitable for development of greenbelt in order to improve air quality, and also for biomonitoring of air pollution. ... • human-related influence on biodiversity and ecosystems (Lovett et al., 2009;Stevens et al., 2004; Phelps, 2012); • planetary boundaries estimates ( Rockstrom et al., 2009;Steffen et al., 2015). ... Presentation Full-text available Presentation explores consequences of the global fossil-fuel subsidies reform and air pollution taxation. It also provides assessment of the health and environmental co-benefits of such policies. ... Our framework can additionally incorporate ecosystem changes that result from pollution-type drivers. For example, the emission of substances like sulfur, nitrogen, ozone and mercury into the atmosphere may significantly affect several ecosystem processes and change species composition, even at sub lethal concentrations (Lovett et al., 2009). In our framework, these effects can be represented as the replacement of a highly productive ecosystem for a less productive one. ... Article Full-text available Life Cycle Assessment (LCA) is a tool to quantitatively assess the environmental impacts associated to a product's life cycle. Since its conception, LCA has improved considerably in sophistication and scope. Yet efforts to incorporate ecosystem services (ES) are still at an early stage. We present a novel framework for assessing ES in LCA that integrates models from adjacent fields and partitions the required modeling steps into different phases of LCA. Physical models are first used to determine how physical units of ecosystems are transformed by industrial processes; ES models are then used to determine the losses or gains of ES per ecosystem unit, and economic valuation is used to normalize and weigh the total ES losses/gains. We demonstrate the framework for a case study on water extraction by the mining industry in Chile and compare ES losses that result from the transformation of wetland and coastal ecosystems respectively. The proposed framework advances current efforts to assess ES beyond land use impacts in LCA by presenting a coherent approach to deal with spatial and temporal variability of ES production and by incorporating socioeconomic aspects of ES use. It also facilitates the coupling of LCA with other ES databases currently being developed. ... Heavy 51 metals are mostly emitted by agricultural, industrial and transport activities ( Gaudry et al., 2008) 52 and can be accumulated in human organism, leading to disease and mortality ( Ghio et al., 2012). 53 They also have a deleterious impact on biodiversity, biogeochemical processes and ecosystem 54 services ( Lovett et al., 2009;Meyer et al., 2012). Moss biomonitoring of air pollution uses 55 organisms living under a wide range of environmental conditions, which can affect the heavy metal 56 content in mosses ( Dołegowska and Migaszewski, 2015). ... Article Full-text available Several studies suggest that potential competition exists between marine cations and heavy metals for binding sites on the cell wall of mosses. This competition would impact the heavy metal concentration measured in mosses by biomonitoring programs, which may underestimate air pollution by heavy metals in a coastal environment. In the present study, we aim to identify possible mechanisms affecting lead uptake by mosses in a coastal environment, specifically, the competition between lead (Pb2+) and sodium (Na+) for binding sites in Hypnum cupressiforme (Hc). We also compared the response of continental and coastal Hc populations to Pb2+ exposure by immersing the moss samples in artificial solutions that comprised six experimental treatments and subsequently locating and quantifying Pb2+ and Na+ using the sequential elution technique and X-ray microanalyses with a scanning electron microscope. We demonstrated that high concentrations of Pb2+ prevented Na+ from binding to the cell wall. We also examined the effect of the salt acclimation of Hc on Pb2+ and Na+ accumulation. Coastal Hc populations accumulated more Na and less Pb than continental Hc populations in all treatments. Moreover, our results showed treatment effects on the intra/extracellular distribution of Na+, as well as site. This feedback on the influence of salt stress tolerance on Pb2+ uptake by mosses requires further study and can be investigated for other heavy metals, leading to a better use of mosses as biomonitoring tools. ... Acidification of lakes resulting from acid pollution has caused adverse impacts to fish and other aquatic communities across the eastern United States, especially in the Adirondack region (Lovett et al., 2009, Driscoll et al., 2001. Although these impacts are well-known, many of the most sensitive species are small native cyprinids that are not typically targeted by recreational anglers. ... ... Another set of studies attempts to assess the human-related influence on biodiversity and ecosystems (Lovett et al., 2009;Stevens et al., 2004;Phelps, 2012), which services provide significant benefits to human welfare with some estimates exceeding global GDP (OECD, 2012;Costanza et al., 1997). A separate sub stream of this field of studies can be associated with planetary boundaries concept (Rockstrom et al, 2009;Steffen et al, 2015). ... ... Most developing nations have been influenced by atmospheric pollution, in terms of human health [1], climate change [2] and loss of biodiversity [3]. With urban transport development, trafficderived pollutants become an increasing problem [4], [5], [6] and have been linked to respiratory and cardiovascular disease, birth and developmental defects, cancer and so on. ... ... Less work has been done to identify the effect of air pollution on whole ecosystems but Lovett et al (2009) studied the impact of fur pollutants, sulfur, nitrogen, ozone, and mercury in eight North American ecosystems and concluded that: "Effects of air pollution were identified, with varying levels of certainty, in all the ecosystem types examined. None of these ecosystem types is free of the impacts of air pollution, and most are affected by multiple pollutants." ... Article Full-text available The Covid-19 pandemic has resulted in disruption of work and other social activities of so many people. Some were forced to stay at home and many decided to stay at home for fear of being infected with the virus. This phenomenon brought different reactions and even mental stress to many people. However, there were people who turned this kind of tragedy into creative work. This paper discusses the experiences and insights of known plant lovers in Digos City, Davao del Sur Philippines. Digos City is one of the heavily affected places during the series of earthquakes that jolted Davao del Sur last year. While people are still recovering, COVID-19 added an additional burden to the residents. In this paper, we argue that their decision to focus on gardening was not only to fight boredom and to divert their attention during lockdown but this was their way of maintaining their well-being by participating in the on-going work of creation and recreation and to rise from the tragedy. We further arguethat it might be good that this creative work will go beyond home gardening and beyond pots and slowly extend to creative work for environmental protection and preservation through more active engagements into reforestation activities. ... Research about the effects of air pollution in the environment and in birds, however, has focused mostly on terrestrial and aquatic habitats (reviewed in Lovett et al., 2009), and on on-the-ground specimens (reviewed in Sanderfoot & Holloway, 2017), research is needed to evaluate its effects on airspace habitat use (Diehl, Peterson, Bolus, & Johnson, 2017) and bird behaviour aloft (but see Li et al., 2016). ... Article 1.Urban areas affect terrestrial ecological processes and local weather, but we know little about their effect on aerial ecological processes. 2.Here, we identify urban from non‐urban areas based on the intensity of artificial light at night (ALAN) in the landscape, and, along with weather covariates, evaluate the effect of urbanization on flight altitudes of nocturnally migrating birds. 3.Birds are attracted to ALAN, hence we predicted that altitudes would be lower over urban than over non‐urban areas. However, other factors associated with urbanization may also affect flight altitudes. For example, surface temperature and terrain roughness are higher in urban areas, increasing air turbulence, height of the boundary layer, and affecting local winds. 4.We used data from nine weather surveillance radars in the eastern US to estimate altitudes at five quantiles of the vertical distribution of birds migrating at night over urban and non‐urban areas during five consecutive spring and autumn migration seasons. We fit generalized linear mixed models by season for each of the five quantiles of bird flight altitude and their differences between urban and non‐urban areas. 5.After controlling for other environmental variables and contrary to our prediction, we found that birds generally fly higher over urban areas compared to rural areas in spring, and marginally higher at the mid layers of the vertical distribution in autumn. We also identified a small interaction effect between urbanization and crosswind speed, and between urbanization and surface air temperature, on flight altitudes. We also found that the difference in flight altitudes of nocturnally migrating birds between urban and non‐urban areas varied among radars and seasons, but were consistently higher over urban areas throughout the years sampled. 6.Our results suggest that the effects of urbanization on wildlife extend into the aerosphere, and are complex, stressing the need of understanding the influence of anthropogenic factors on airspace habitat. This article is protected by copyright. All rights reserved. ... No matter what their impact is, pollution affects every species on this planet. Wildlife is prone to suffer the same symptoms and diseases suffered by humans (Lovett et al., 2009). Global warming is changing some ecosystems faster than the capability of animals and plants to adapt, leading to possible extinction of a huge number of species (Andrady, Aucamp, & Austin, 2016). ... Article Background As a result of human socioeconomic activity, industrial wastes have increased distressingly. Plastic pollution is globally distributed across the world due to its properties of buoyancy and durability. A big health hazard is the sorption of toxicants to plastic while traveling through the environment. Two broad classes of plastic‐related chemicals are of critical concern for human health—bisphenols and phthalates. Bisphenol A (BPA) is an endocrine‐disruptor compound (EDC) with estrogenic activity. It is used in the production of materials that are used daily. The endocrine modulating activity of BPA and its effects on reproductive health has been widely studied. BPA also has effects on the immune system; however, they are poorly investigated and the available data are inconclusive. Phthalates are also EDCs used as plasticizers in a wide array of daily‐use products. Since these compounds are not covalently bound to the plastic matrix, they easily leach out from it, leading to high human exposure. These compounds exert several cell effects through modulating different endocrine pathways, such as estrogen, androgen, peroxisome proliferator‐activated receptor gamma, and arylhydrocarbon receptor pathways. The exposure to both classes of plastic derivatives during critical periods has detrimental effects on human health. Methods In this review, we have compiled the most important of their perinatal effects on the function of the immune system and their relationship to the development of different types of cancer. Results/Conclusion The administration of bisphenols and phthalates during critical stages of development affects important immune system components, and the immune function; which might be related to the development of different diseases including cancer. ... This is a consequence already presented of reducing the use of mineral nitrogen fertilizers for the basic crop (Lovett et al. 2009). ... Chapter The sustainable approach to reducing pesticide pollution by using mycoremediation methods also aims to monitor and give equal importance to all ecological categories of organisms installed on degraded lands with maximum risk, because only a specific diversity in the ecosystem can guarantee its stability, its chances of evolution, and implicitly the ecoprotective functions for which it is installed. Toxic substances are sometimes needed to eradicate a particularly serious infestation or disease, but these toxic substances should be used as a last resort after using all bioremediation methods including mycoremediation methods. Recovery of appropriate biological processes is vital. ... Acid deposition to sensitive landscapes can affect fish and other biotic communities in freshwater ecosystems (Lovett et al., 2009). Surface water acidification is characterized by elevated concentrations of strong acid anions (SO 4 2− , NO 3 − ), low pH and ANC, and mobilization of calcium and inorganic monomeric aluminum (Al i ), which can impair the health of resident fish populations and their communities (Baldigo et al., 2007(Baldigo et al., , 2019a. ... Article Full-text available The present-day acid-base chemistry of surface waters can be directly linked to contemporary observations of acid deposition; however, pre-industrial conditions are key to predicting the potential future recovery of stream ecosystems under decreasing loads of atmospheric sulfur (S) and nitrogen (N) deposition. The integrated biogeochemical model PnET-BGC was applied to 25 forest watersheds that represent a range of acid sensitivity in the Adirondack region of New York, USA to simulate the response of streams to past and future changes in atmospheric S and N deposition, and calculate the target loads of acidity for protecting and restoring stream water quality and ecosystem health. Using measured data, the model was calibrated and applied to simulate soil and stream chemistry at all study sites. Model hindcasts indicate that historically stream water chemistry in the Adirondacks was variable, but inherently sensitive to acid deposition. The median model-simulated acid neutralizing capacity (ANC) of the streams was projected to be 55 μeq L-1 before the advent of anthropogenic acid deposition (~1850), decreasing to minimum values of 10 μeq L-1 around the year 2000. The median simulated ANC increased to 13 μeq L-1 by 2015 in response to decreases in acid deposition that have occurred over recent decades. Model projections suggest that simultaneous decreases in sulfate, nitrate and ammonium deposition are more effective in restoring stream ANC than individual decreases in sulfur or nitrogen deposition. However, the increases in stream ANC per unit equivalent decrease in S deposition is greater compared to decreases in N deposition. Using empirical algorithms, fish community density and biomass are projected to increase under several deposition-control scenarios that coincide with increases in stream ANC. Model projections suggest that even under the most aggressive deposition-reduction scenarios, stream chemistry and fisheries will not fully recover from historical acidification by 2200. ... The environmental impact caused by human activities, such as urbanization, negatively affects biodiversity (McKinney 2008) due to modification of natural systems brought about by the transformation or loss of their original structural composition (Vitousek et al. 1997). Biodiversity loss in urban settlements is primarily caused by the reduction, isolation, and low connectivity of green areas, as well as by the scarcity of nourishment (Fattorini 2011) and other factors such as chemical and noise pollution (Lovett et al. 2009, Proppe et al. 2013. In urban areas, the least perturbed habitats and soils are found primarily in peripheral zones (McDonnell and Pickett 1990); however, there are other sectors within cities such as parks, freshwater sources, or abandoned terrains that can turn into habitats or refugia for the surviving populations. ... Article Full-text available We report an inventory of the superfamily Scarabaeoidea present at the campus of the University of Sucre, Sincelejo, Colombia. Specimens were captured between the months of May and June 2016. A total of 510 specimens were collected belonging to 3 families, 8 subfamilies, 27 genera, and 34 species. The subfamilies presenting the greatest diversity were Scarabaeinae and Dynastinae. For the first time the following 8 species were recorded for Sucre Department: Anomala valida Burmeister, 1844, Liogenys quadridens (Fabricius, 1798), Megasoma elephas (Fabri-cius, 1775), Omorgus suberosus (Fabricius, 1775), Phileurus didymus (Linnaeus, 1758), Phileurus valgus (Olivier, 1789), Phyllo phaga menetriesi (Blanchard, 1850), and Xenopelidnota anomala (Burmeister, 1844). We highlight the importance of green zones within urban areas as possible faunistic refugia for different taxonomic groups, especially for the beetles of the superfamily Scarabaeoidea. ... However, gaps in the impacts of air pollution on the environment exist and may underestimate the effects of air pollutants on the environment. Lovett et al. (2009) recommended that air quality impacts that are known to occur in the Northeast region be considered in any long-term environmental conservation strategy. ... ... However, gaps in the impacts of air pollution on the environment exist and may underestimate the effects of air pollutants on the environment. Lovett et al. (2009) recommended that air quality impacts that are known to occur in the Northeast region be considered in any long-term environmental conservation strategy. ... ... Reduced photosynthesis and visible damage such as chlorosis, lesions, and abscission are preludes to growth inhibition and to the mortality of the more sensitive plants, leading to the alteration of the vegetation structure [16][17][18]26,27,32,[36][37][38][39]. In addition, vegetation is influenced by changes in reproductive capacity due to air pollution and acid rain [40][41][42][43], and by interactions with plant diseases and insects [44][45][46][47]. ... Article Full-text available This study was carried out to clarify the vegetation decline due to air pollutants emitted in the process of industrial activities and the passive restoration of the vegetation due to socioeconomic changes after economic growth. To achieve this goal, we investigated the spatial distribution of vegetation, differences in species composition and diversity among vegetation types different in damage degree, vegetation dynamics, the age structure and annual ring growth of two dominant plant species, and the landscape change that occurred in this area over the last 50 years. Plant communities tended to be spatially distributed in the order of grassland, shrubland (dominated by Styrax japonicus Siebold and Zucc. community), and forests (dominated by Pinus thunbergii Parl. and Pinus densiflora Siebold and Zucc. communities), with increasing distance from the pollution source. The result of stand ordination based on vegetation data reflected the trend of such a spatial distribution. Species richness evaluated based on the species rank dominance curve was the highest in shrubland and the lowest in grassland; species richness in forests was intermediate. The size class distribution of woody plant species in four plant communities composing three vegetation types showed the possibility of them being replaced by forest in the late successional stage. However, the density of successor trees was relatively low, whereas the density of shrubby plants, which are resilient to air pollution, was very high. The age class distribution of a dominant species forming shrubland and pine forest showed that most of them were recruited after industrialization in this area. The period when young individuals in both vegetation types were recruited corresponded to the period when the annual ring growth of the pine trees that survived air pollution was reduced. An analysis of the landscape change in this area indicated that coniferous forest and agricultural field decreased greatly, whereas industrial area, residential area, mixed forest, and broadleaved forest showed increasing trends since construction of the industrial complex. As a result, the decrease in coniferous forest is usually due to vegetation decline and partially to succession, as the pine trees dominating the forest are not only sensitive to air pollution but are also shade-intolerant. The increase in mixed and broadleaved forests reflects vegetation decline or succession. Vegetation decline progressed for about 30 years after the construction of the industrial complex; it has begun to be restored passively since then, although the change has been slow. These results are in line with the environmental Kuznets curve hypothesis that environmental degradation increases in the early stages of economic growth to a certain point, and, after a turning point, economic development leads to environmental improvements—thus, there is an inverted U-shaped relationship between economic growth and environmental degradation. ... The toxic gases released by industries and other sources have a significant impact on humans and other life on the earth [1][2][3][4]. H2S is a poisonous gas, and as per the American Conference of Government Industrial ... Conference Paper Full-text available ... Climate change and atmospheric nitrogen (N) deposition represent two components of contemporary global change which are both considered as important, but unequal, challenges to biodiversity issues GBO-3, 2010). While scientists have mostly focused on climate change as the prime threat to biodiversity conservation (Hannah et al., 2002), air pollution, an acknowledged widespread problem, is increasingly considered in nature planning or management (Lovett et al., 2009) and nowadays recognized for its importance in conservation issues and ecosystem health Phoenix et al., 2006;. Historic climatic warming is now well documented (Moberg et al., 2005;Osborn & Briffa, 2006) and it is projected that the increase of the global mean surface temperature will rise from 1.8 at present to 4.0°C over the next 100 years, mainly due to the CO 2 enrichment of the atmosphere by fossil fuel use (IPCC, 2007). ... ... Therefore, air pollution has the capacity to destroy the economy of a place and cause loss of valuable resources yielding billions of monies annually. Damages caused by air pollution could make people's productive energy to drop due to associated ailments (Gary et al., 2009;Ghorani-Azam et al., Loomis et al., 2014;Mahendra and Vaibhav, 2013;Mellouki et al., 2016;World Bank, 2016). From the preceding literature, it has become obvious that several cities are affected by poor air quality. ... Article Full-text available The present investigation was carried out on the characterization of Air Quality Index (AQI) of Port Harcourt Tropical Littoral City in Nigeria. This study used Testo 350XL Gas Analyzer (NOx and CO) and 5 in 1 multi-function laser sensor BRV8 (PM10 and PM2.5. detectors) for air quality measurements. The field data were converted into AQI values. The Geographic Positioning System (GPS) was used to establish the sample locations. Findings showed that Carbon Oxide (CO) at 32.7% contributed the greatest threat to life and PM2.5 (15%) had the least harmful effect. In a population of 3,235,840 only 8.8% persons had good and satisfactory AQI. The unhealthy and unsatisfactory category of 2,951,655 people accounted for 91.2% in the AQI classification with expected respiratory symptoms. The very unhealthy AQI classification was found in areas of Aba Express Road, Mile One, Rumuola, Artillery, Garrison and Woji respectively. The good and satisfactory AQI category was located at the fringes of the Air Port. The result showed that AQI in the morning differed significantly from that of the evening. Therefore, the people and authorities should mitigate environmental pollution in Port Harcourt City of Nigeria. ... The mobilization of aluminum (Al) cations from surrounding soils into surface waters via atmospheric acid deposition can negatively impact the biodiversity and functioning of aquatic ecosystems (Horne and Dunson, 1995;Lovett et al., 2009). Generally, in teleost fishes, Al toxicity in moderately acidic water (pH 5-6) is caused by Al's precipitation and polymerization, resulting in Al deposition on the gill surface. ... Article Full-text available Exposure to environmental contaminants may lead to allostatic load. A situation when the costs of coping with chronic or repeated stress affects long-term survival, reproductive output and, ultimately, ecosystem health. By being a central mediator of behavioral and endocrinal stress responses the brain serotonergic (5-HTergic) system plays a key role in allostatic processes. In this study we explored if sublethal effects of Al in acidified water was reflected in changes in 5-HT neurochemistry and the endocrinal stress response in a unique land-locked salmon from Lake Bygelandsfjorden in southern Norway. Fish were exposed to acidified (pH 5.5) water with different concentrations of Al for five to six days. After this, effects on plasma cortisol levels and telencephalic 5-HT neurochemistry were investigated before and after a standardized acute stress test. In addition, gill Al deposition was investigated to quantify the physiological impact of increasing Al concentrations. Before the stress test, there was a positive dose response relationship between Al concentrations, gill Al deposition, serotonergic turnover rate and plasma cortisol. However, in confinement stressed fish, exposure to the highest Al concentrations (148 μg l-l) resulted in decreased cortisol values compared to fish exposed lower Al concentrations (74, 94 and 124 μg l-l). This suggests that fish exposed to the highest Al concentration were unable to mount a proper cortisol response to the confinement and demonstrates that neuroendocrine indicators of allostatic can reveal sublethal effects of acidification and, potentially, environmental impacts of other factors. ... Efluentes industriais sem tratamento adequado podem apresentar concentrações elevadas de elementos potencialmente tóxicos, podendo representar uma fonte potencial de contaminação, entretanto, também podem ser provenientes de processos naturais que se relacionam às anomalias geoquímicas das rochas (FARIAS et al., 2007;GUEDES, et al., 2005). Apesar de alguns serem essenciais aos seres vivos, como magnésio, ferro e zinco, ainda que em baixas concentrações, em altas concentrações podem ser tóxicos (LOVETT et al., 2009;ZHONG et al., 2016;YANG et al., 2016;OLLSON et al., 2017). Metais como mercúrio, chumbo e cádmio, geralmente apresentam elevada toxicidade à biota aquática (BITTAR, 2008 ... ... Less work has been done to identify the effect of air pollution on whole ecosystems but Lovett et al (2009) studied the impact of fur pollutants, sulfur, nitrogen, ozone, and mercury in eight North American ecosystems and concluded that: "Effects of air pollution were identified, with varying levels of certainty, in all the ecosystem types examined. None of these ecosystem types is free of the impacts of air pollution, and most are affected by multiple pollutants." ... Article Full-text available Air pollution causes millions of deaths globally every year. The cause is largely, but not solely, from fossil fuel combustion in the electricity generation and transport sectors as well as various agricultural and waste management practices. This pollution in the form of ground level ozone, particulate matter and acidic gases such as nitrogen oxides and sulfur dioxide causes respiratory, cardiovascular and neurological problems in humans. These health concerns tend to have a greater impact on more vulnerable sectors of societies, including street vendors, agricultural workers and school children. There is a growing body of evidence that the pollution has equally devastating impacts on other organisms including plants, which may harm whole ecosystems. As humans are integral to rather than independent of nature, then this will have further reciprocal effects on us. A survey of people in rural central Thailand indicates that people are largely unaware of the main causes of and, to some extent ambivalent of, the risks associated with air pollution. An absence of policy to address this through mechanisms such as taxation akin to tobacco, alcohol or the UK 2017 sugar tax and compulsory environmental education programmes could be viewed as evidence of moral blindness. In light of some events of the Covid-19 pandemic, the importance of developing united policies to cope with worldwide air pollution is never been more apparent. There is good news in that data on local air quality is becoming increasing available in user friendly apps, which creates an opportunity to develop participatory education programmes that could emphasise personal responsibility, to address both the twin pandemics of air pollution and environmental moral blindness. Keywords: Air pollution, Global Burden of Disease, Moral Blindness, SDGs, Participatory Education ... Apart from the issue of the direct health effects (of NO2 or of the mixture it signifies), nitrogen oxide also plays an important role in atmospheric chemistry [26,27] and in ecosystems [28,29]. Therefore, there are many valid reasons for reducing NOX emissions that must be kept in mind. ... Article Full-text available In epidemiological studies, both spatial and temporal variations in nitrogen dioxide (NO2) are a robust predictor of health risks. Compared to particulate matter, the experimental evidence for harmful effects at typical ambient concentrations is less extensive and not as clear for NO2. In the wake of the “Diesel emission scandal—Dieselgate”, the scientific basis of current limit values for ambient NO2 concentrations was attacked by industry lobbyists. It was argued that associations between NO2 levels and medical endpoints were not causal, as NO2 in older studies served as a proxy for aggressive particulate matter from incineration processes. With the introduction of particle filters in diesel cars, NO2 would have lost its meaning as a health indicator. Austria has a high percentage of diesel-powered cars (56%). If, indeed, associations between NO2 concentrations and health risks in previous studies were only due to older engines without a particle filter, we should expect a reduction in effect estimates over time as an increasing number of diesel cars on the roads were outfitted with particle filters. In previous time series studies from Vienna over shorter time intervals, we have demonstrated distributed lag effects over days up to two weeks and previous day effects of NO2 on total mortality. In a simplified model, we now assess the effect estimates for moving 5-year periods from the beginning of NO2 monitoring in Vienna (1987) until the year 2018 of same and previous day NO2 on total daily mortality. Contrary to industry claims of a spurious, no longer valid indicator function of NO2, effect estimates remained fairly stable, indicating an increase in total mortality of previous day NO2 by 0.52% (95% CI: 0.35–0.7%) per 10 µg/m3 change in NO2 concentration. Article Increased availability of monomeric aluminum (Al(3+)) in forest soils is an important adverse effect of acidic deposition that reduces root growth and inhibits nutrient uptake. There is evidence that Al(3+) exposure interferes with NO3(-) uptake. If true for overstory trees, the reduction in stand demand for NO3(-) could increase NO3(-) discharge in stream water. These effects may also differ between species that tolerate different levels of soil acidity. To examine these ideas, we measured changes in relative uptake of NO3(-) and NH4(+) by six tree species in situ under increased soil Al(3+) using a (15)N-labeling technique, and measured soluble soil Al levels in a separate whole-watershed acidification experiment in the Fernow Experimental Forest (WV). When exposed to added Al(3+), the proportion of inorganic N acquired as NO3(-) dropped 14% across species, but we did not detect a reduction in overall N uptake, nor did tree species differ in this response. In the long-term acidification experiment, we found that soluble soil Al was mostly in the free Al(3+) form, and the concentration of Al(3+) was ~65 μM higher (~250%) in the mineral soil of the acidified watershed vs. an untreated watershed. Thus, increased levels of soil Al(3+) under acidic deposition cause a reduction in uptake of NO3(-) by mature trees. When our (15)N uptake results were applied to the watershed acidification experiment, they suggest that increased Al(3+) exposure could reduce tree uptake of NO3(-) by 7.73 kg N ha(-1) year(-1), and thus increase watershed NO3(-) discharge. Article Full-text available La contaminación atmosférica tiene un fuerte impacto en la salud de las personas, así como afecta de forma importante los aspectos económicos de las sociedades humanas, sin dejar a un lado la alteración que está provocando en el clima del planeta y sus ecosistemas. Article Environmental influences like acidification promote stress at the ecosystem level that manifests as reduction in metabolic and biogeochemical efficiency. Headwater streams along a chronic acidity gradient were assessed to explore how stress alters microbial abundance and activity and their influence on ecosystem structure and function. Streams draining deciduous forests were investigated during autumn when channels were filled by leaf litter. Whole-system measures of respiration were coupled to estimates of fungal biomass in leaf biofilms to generate an ecosystem-level measure of metabolic efficiency (qCO2E, g CO2–C g C⁻¹ d⁻¹). Stable isotope releases of nitrate nitrogen (¹⁵N–NO3) were performed to address nitrate uptake ($${\text{U}}_{{{\text{NO}}_{ 3} }}$$) across streams. Fungal stocks decreased across five streams as pH declined (6.98–5.34). Whole-system respiration decreased fivefold with increasing acidity, while qCO2E did not respond consistently to acidification, but was correlated with stream temperature. Across streams, concentrations of nitrogen (N) were low and $${\text{U}}_{{{\text{NO}}_{ 3} }}$$ related to nutrient availability and not to stream acidity. Results illustrate that acidification alters ecosystem processes through influences on microbial abundance and metabolic activity, while scarce N availability and low $${\text{U}}_{{{\text{NO}}_{ 3} }}$$ characterized biogeochemical behavior during autumnal periods of maximal detrital stocks. Article We investigated whether the trophic ecology of an apex predator is influenced by ecosystem-level nutrient depletion. The feeding behavior and nutrient assimilation of a terrestrial salamander, Eastern Red-backed Salamander (Plethodon cinereus (Green, 1818)), was surveyed along a gradient of forest biogeochemistry. Recent studies have documented populations of these salamanders in forests with low-pH soils that were long thought to be fatal. One mechanism that may enable P. cinereus to tolerate acid-impaired habitats is its generalist life history. We sampled diet, invertebrate prey abundance, and tissue composition of P. cinereus from sites that range in calcium availability and soil pH in northern forests of North America. We found that P. cinereus consistently exhibited a generalist feeding strategy, having diverse diets closely representing resource availability. Prey abundances were unrelated to the biogeochemical gradient (excluding gastropods), indicating relatively intact food webs. Although P. cinereus at the two most acid-impaired sites consumed more prey, overall trophic strategies were consistent across the gradient. Salamander tissue composition was unrelated to variation in forest biogeochemistry, although manganese levels were elevated in the most acid-impaired forests. We suggest that a generalist feeding strategy, combined with diverse and compositionally stable food webs, facilitates tolerance by this abundant predator of the challenges imposed by acid-impaired habitats. Chapter In the previous section we outlined an argument connecting unsustainable development to human social and ecological justice. In doing so, we provided summaries of several studies whose results support the notion that unsustainable development is differentially distributed across nations, that this differential in unsustainable development is related to the structure of global capitalism and results from the organization of the treadmill of production, and that the organizational structure of capitalism promotes unequal ecological exchange and ecological exploitation in ways that impair the ability of less-developed nations to access and control their own ecological resources. In short, drawing on prior literature, that these conditions, connected to the organization of the capitalist world system, cause social and ecological (in)justice to be unevenly distributed, and have particularly adverse consequences for less-developed nations with respect to equity issues related to access to and the use of ecological resources. Preprint Full-text available We have developed an integrated tool of assessment that can be used for evaluating the public health costs caused by the concentrations of fine particulate matter (PM2.5) in ambient air. The model can be used in assessing the impacts of various alternative air quality abatement measures, policies and strategies. The model has been applied for the evaluation of the costs of the domestic emissions that influence the concentrations of PM2.5 in Finland in 2015. The model includes the impacts on human health; however, it does not address the impacts on climate change or the state of the environment. First, the national Finnish emissions were evaluated using the Finnish Regional Emission Scenarios model (FRES) on a resolution of 250 × 250 m² for the whole of Finland. Second, the atmospheric dispersion was analyzed by using the chemical transport model SILAM and the source-receptor matrices contained in the FRES model. Third, the health impacts were assessed by combining the spatially resolved concentration and population datasets, and by analyzing the impacts for various health outcomes. Fourth, the economic impacts for the health outcomes were evaluated. The model can be used to evaluate the costs of the health damages for various emission source categories, for a unit of emissions of PM2.5. It was found that economically the most effective measures would be the reduction of the emissions in urban areas of (i) road transport, (ii) non-road vehicles and machinery, and (iii) residential wood combustion. The reduction of the precursor emissions of PM2.5 was clearly less effective, compared with reducing directly the emissions of PM2.5. We have also designed a user-friendly web-based tool of assessment that is available open access. Article Dust pollution is expected to be a significant pollution in the urban forests, especially in semiarid environments. The purpose of this study was to evaluate the effects of soil dust on the morphological, physiological and biochemical traits of seedlings of Fraxinus rotundifolia Mill., Morus alba L., Celtis caucasica Willd. and Melia azedarach L. These species are widely grown in Iran’s urban areas, particularly in semiarid regions. The seedlings were dusted at four concentrations, 0, 300, 750 and 1500 μg m⁻³, once a week for 10 weeks in four plastic chambers, placed in a completely randomized design with four repetitions. Dust accumulation was greatest at the 750 and 1500 μg m⁻³ levels in the following order: M. alba > C. caucasica > F. rotundifolia > M. azedarach. In all species, dust decreased the leaf area, stem diameter, height, leaf, shoot, root and total biomass but increased the root–shoot ratio. Photosynthesis, transpiration, stomatal conductance, mesophyll conductance, leaf extract pH, Fv/Fm and t1/2 decreased, while leaf temperature and water use efficiency increased. Likewise, chlorophyll a, chlorophyll b, carotenoid and total chlorophyll content were diminished. M. alba has the highest soil dust accumulation potential but the lowest decrease in the properties studied. C. caucasica has a high-dust accumulation potential, but it was highly affected by dust treatment. M. azedarach and F. rotundifolia did not accumulate much dust. We conclude that among the four tree species, M. alba is the most suitable species for the urban forests of semiarid zones where dust pollution is high and dust reduction desired. Article Understanding how urban air quality depends on urban form can have important implications for improving urban air quality by optimizing urban planning and management policies. This study employed the spatial autoregressive model to explore the effect of urban form on urban air quality in 288 prefecture-level cities in China. Information on the air quality (AQI) and six criteria pollutants (PM2.5, PM10, CO, SO2, NO2, O3) were obtained from the hourly observation data of 1333 in-situ air monitoring stations throughout 2015. Urban form is characterized by five metrics, including urban size, shape, sprawl, fragmentation and traffic accessibility, and it is calculated based on land cover data. Results show that urban shape complexity and population density have a significant negative impact on urban air quality. Large city size is strongly related to comparatively poor air quality for cities in Southern China and only shows a slight association with emissions in Northern China. In general, lower-sized, scattered, polycentric cities provide better air quality in China. It is suggested that higher air quality and fewer pollutant emissions can be achieved through urban form planning and management po- licies, which aim to restrict the blind expansion of urban land and encourage moderately scattered, polycentric urban development. Article Full-text available Despite the well-established links between air pollution and human health, vegetation, and aquatic ecosystems, less attention has been paid to the potential impact of reactive atmospheric gases and aerosols on avian species. In this literature review, we summarize findings published since 1950 regarding avian responses to air pollution and discuss knowledge gaps that could be addressed in future studies. We find consistent evidence for adverse health impacts on birds attributable to exposure to gas-phase and particulate air pollutants, including carbon monoxide (CO), ozone (O3), sulfur dioxide (SO2), smoke, and heavy metals, as well as mixtures of urban and industrial emissions. Avian responses to air pollution include respiratory distress and illness, increased detoxification effort, elevated stress levels, immunosuppression, behavioral changes, and impaired reproductive success. Exposure to air pollution may furthermore reduce population density, species diversity, and species richness in bird communities. Literature Review Article Full-text available The common loon (Gavia immer) is a high-trophic-level, long-lived, obligate piscivore at risk from elevated levels of Hg through biomagnification and bioaccumulation. From 1991 to 1996 feather and blood samples from adult loons were collected between June and September in five regions of North America: Alaska, northwestern US, Upper Great Lakes, New England, and the Canadian Maritimes. Concentrations of Hg in adults ranged from 2.8 to 36.7 {micro}g/g in feathers and from 0.12 to 7.80 {micro}g/g in whole blood. Blood Hg concentrations in 3 to 6-week-old juveniles ranged from 0.03 to 0.78 {micro}g/g. To better interpret exposure data, relationships between blood and feather Hg concentrations were examined among age and sex classes. Blood and feather Hg correlated strongest in areas with the highest blood Hg levels, indicating a possible carryover of breeding season Hg that is depurated during winter remigial molt. Mean blood and feather Hg concentrations in males were significantly higher than concentrations in females for each region. The mean blood Hg concentration in adults was 10 times higher than that in juveniles, and feather Hg concentrations significantly increased over 1 to 4-year periods in recaptured individuals. Geographic stratification indicates a significant increasing regional trend in adult and juvenile blood Hg concentrations from west to east. This gradient resembles US Environmental Protection Agency-modeled predictions of total anthropogenic Hg deposition across the US. This gradient is clearest across regions. Within-region blood Hg concentrations in adults and juveniles across nine sites of one region, the Upper Great Lakes, were less influenced by variations in geographic Hg deposition than by hydrology and lake chemistry. Loons breeding on low-pH lakes in the Upper Great Lakes and in all lake types of northeastern North America are most at risk from Hg. Article Full-text available Few wetland studies from temperate North America have related either spe- cies richness or plant community composition to any direct measure of nutrient availability, or examined changes in species composition following experimental nutrient additions. Studies of wetlands in western Europe and of other terrestrial ecosystems in North America frequently show that nutrient enrichment leads to changes in species composition, declines in overall plant species diversity, and loss of rare and uncommon species. We therefore used an extensive literature survey and analysis of data on plant species composition, species richness, productivity or standing crop, and C:N:P stoichiometry in plant tissues and surface soils to draw conclusions about the nature of nutrient limitation in temperate North American bogs, fens, marshes, and swamps, and to infer their potential response to nutrient enrichment. We searched all major bibliographic data bases for studies containing such data (through March 1998) and added relevant data from our own ongoing research. We analyzed plant and soil data sets by wetland type and by wetland soil type, and the plant data set also by growth form. Existing studies appear to confirm common generalizations: (1) plant community type changes across broad nutrient gradients; (2) species richness declines as various indicators of nutrient availability increase beyond some threshold; and (3) rare and uncommon species are almost always associated with species-rich communities. However, (1) these general- izations do not always hold within community types; (2) for many community types, the threshold beyond which richness declines has not been established, and high or low diversity may occur below that threshold; and (3) the failure of many studies to include bryophytes precludes drawing strong conclusions about nutrient availability and diversity in peatlands. Marshes had significantly lower mean nitrogen : phosphorus (N:P) ratios in live tissue than other wetland types (bogs, fens, and swamps), which did not differ significantly from each other. Mean N:P ratios in live tissues were significantly higher in peatlands than in mineral-soil wetlands. Nitrogen : phosporus ratios in litter did not differ significantly between peatlands and mineral-soil wetlands but were higher than in live tissues. Among growth forms, the highest mean N:P ratios in live tissues occurred in bryophytes, and the lowest in vascular herbaceous species. Only bryophyte live tissues differed significantly from other growth forms; litter N:P ratios were not significantly different among growth forms. Average N:P ratios in surface soils were lower in marshes and swamps than in bogs and fens. Wetlands on mineral soils had lower average N:P ratios than wetlands on peat soils. Average surface soil N:P ratios rose sharply at high soil organic-matter contents ($90%) and were generally greater than 16 at organic-matter concentrations above 20%. In combination, plant tissue and surface soil N:P ratios suggest that a large proportion of North American wetlands are either P limited or co-limited by N and P, especially those occurring on organic soils. Only marshes have N:P ratios in both live tissues and surface soils that consistently indicate N limitation, although soils data suggest that the majority of swamps are also N limited. Vascular herbaceous species appear to be N limited, but no pattern is apparent among other growth forms. Inferences drawn from N:P stoichiometry need to be verified by examining ecosystem response to experimental fertilization. High variances in plant and soil N:P ratios suggest that understanding nutrient limitation at both the community and individual-species level may be necessary to predict changes in species composition and richness with nutrient enrichment.
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This recently-initiated research represents a multi-disciplinary and multi-institutional effort to extrapolate research, monitoring, and modeling results, including physical, chemical, and biological findings, from intensively-studied lakes to the regional population of acid-sensitive Adirondack lakes. Extrapolation will be based on the statistical frame of EPA's Environmental Monitoring and Assessment Program (EMAP) and intensively-studied sites were drawn from RPI's Adirondack Effects Assessment Program (AEAP) and EPA's Adirondack Long-term Monitoring Project (ALTM). A total of 68 watersheds will be included in this effort, which has involved field sampling during summer, 2003 to develop a statistically-representative soils database and will involve model projections using the MAGIC and PnET-BGC models to classify lakes according to their sensitivity to change in S and/or N deposition. The results of this research will allow fuller utilization of data from on-going chemical and biological monitoring and process-level studies by providing a mechanism for regionalization of findings and developing/refining relationships among watershed characteristics, chemical change, and biological responses to changing levels of acid deposition. This project is important for the management of the ecosystems in New York that are most responsive to changes in acid deposition. Results of this project will determine the portions of the Adirondack region where acidified lakes will recover, and by how much, in response to varying levels of future deposition. It will also identify portions of the region and types of watersheds in which recovery is unlikely. It will provide critical information for determining which areas require the most intensive research or remediation efforts.
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We hypothesized that much of the variability in dissolved inorganic nitrogen (DIN) loss from forested catchments can be explained by land use history and interannual climatic variation, and that these factors determine the degree to which N deposition results in increased storage of C in forests. We used an existing model of C, N, and water balances in forest ecosystems in conjunction with long-term climate and N leaching loss data from several northern hardwood forest ecosystems to predict the effects of land use, climate variability and N deposition on C storage and N cycling and loss. Six sites from the White Mountains of New Hampshire with very different land use histories and annual stream DIN losses were used. The only model parameter that varied between sites was land use or disturbance history. Each site was simulated using both mean climate data for each year and actual time series climate data. Vegetation removal resulted in a period of increased DIN leaching, followed by losses below those in control stands for both measured and simulated data. One site with an extreme fire event over 170 years ago still showed reduced N losses in both modeled and measured data. Significant interannual variation in DIN loss is evident in the field data. Model predictions using actual climate time series data captured much of this variation. This high interannual variability along with the slow rate of change in DIN loss predicted by PnET-CN using mean climate throughout the simulations suggests that statistically significant increases in DIN leaching losses due to long-term increases in N deposition will not be detectable for several decades, given current rates of N deposition. N deposition increased C storage in all simulations, but the quantity stored was about 50% that predicted by another published model. This difference results from differences in the efficiency with which added N is retained in the ecosystem. The previous model used an 80% retention value, while retention was closer to 50% over most of the time period examined here.
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Two plots in a red pine stand at the Harvard Forest, Massachusetts, have been fertilized for 7 yr with 5 g·m-2·yr-1 or 15 g·m-2·yr-1 of N and compared to an unfertilized control to study the effects of chronic N additions on nutrient cycling, plants, and soil. Movement of added N into soils and plant biomass was tracked using additions of an 15N label to the 5 g·m-2·yr-1 and control plots for two of these years. We present data on changes in the understory plant community of these plots. We measured aboveground biomass, density, N and other elemental concentrations, and 15N tracer recoveries to catalogue the effects of the N additions on this community. Nitrogen contents increased while biomass and nutrient cation concentrations decreased in some species. Percent recoveries of 15N tracers were small but detectable. The natural abundances of 15N also increased in a fertilized treatment without tracer additions. Though this forest has not yet reached N saturation by some definitions, it is possible that the understory is already saturated with N. Understory species may be useful indicators for N saturation through their increasing N content, decreasing nutrient concentrations, and increasing δ15N in tissues.
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This review focuses on mercury (Hg) inputs and outputs in temperate and boreal terrestrial systems. It covers deposition via throughfall and litterfall, whose sum (ca. 38 μg m-2 a-1) is greater than that via precipitation (ca. 10 μg m-2 a-1). Outputs considered include volatilization, soil sequestration, and streamflow. The former is highly uncertain, but the mean rate (11 ng m-2 h-1) over a growing season is equivalent to about 32 μg m-2 a-1. Modern rates of soil sequestration (ca. 5 μg m-2 a-1) and streamflow fluxes (ca. 2 μg m-2 a-1) balance the annual budget. The majority of the uncertainty in the budget is related to volatilization. Nonetheless, a large fraction of atmospheric Hg is likely a product of continuing deposition and volatilization. Watershed characteristics related to streamflow fluxes of both Hg and methylmercury (MeHg) are discussed. Both runoff concentration and flux of Hg are weakly and inversely related to watershed size. Dissolved organic carbon (DOC) and particulates are important carriers of Hg; watershed activities that affect either affect Hg flux. Runoff flux of MeHg is skewed with about 80% of observations less than 0.15 μg m-2 a-1. Although there is no pattern of MeHg flux with watershed size, there is a strong positive relationship between flux and wetland area. Wetlands are a site of MeHg production and their presence increases water residence time; both increase MeHg flux. Concentrations of MeHg in streamflow from watersheds with wetlands are near the current water quality criterion, and effective control measures in those watersheds appear problematic.
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This investigation is part of the Temporally Integrated Monitoring of Ecosystems ((TIME) project, an effort to meet the difficult challenge of monitoring surface water quality in the northeastern United States for signs of change in response to the Clean Air Act Amendments of 1990. The overall objective of the study was to develop a unified scheme for classifying lakes in the northeast into relatively homogeneous groups and improve the likelihood of detecting water quality trends in the region. The study approach involved combining the best elements of several procedures recently used for defining regional subpopulations of lakes; these were termed the hydrogeochemical model (HM), geographical model (GM), and multivariate statistical model (MSM). Lake and watershed data from the U.S. Environmental Protection Agency Eastern Lake Survey (ELS) were used to evaluate the classification methods and their modifications. After preliminary comparisons were made of the three classification schemes, it was concluded that the resulting subpopulations indicated that there was meaningful similarity among methods but that the significant dissimilarity reflected distinctive attributes of each classification method. These differences were deemed important; accordingly, integration of the methods entailed efforts to preserve parts of each. This was accomplished by assigning each lake of the ELS data set into a lake cluster that had been defined by jointly applying the HM and GM methods. Subsequently, the jointly classified clusters were aggregated by coupling an application of the MSM (cluster analysis) with subjective judgment regarding termination of the process of cluster formation. This integration of procedures gave rise to nine subpopulations that separated mainly on the basis of hydrogeochemical factors, though geographic influences also were evident in the results. The integrated classification procedure provided an explicit method involving the combination of several kinds of data to yield lake subpopulations. Although the process of integrating this information may stand alone as a useful exercise, the results obtained from the integrated classification model exhibited less dispersion than those formed by the parent procedures. This is an important consideration when subpopulation homogeneity is wanted as a means to improve trend detection. From the view of statistical efficiency, therefore, the integrated procedure may be considered to be more optimal than the parent schemes. When the complexity of the integrated approach is considered, however, we conclude that the next most precise classification scheme, the HM approach, may be preferred over the integrated classification for use in the design of an actual monitoring program.
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Current levels of anthropogenic mercury (Hg) in the environment can cause harm to humans and wildlife. Well-documented negative effects on birds are described, but there is presently limited information for passerine exposure to mercury. Some investigations have used insect-eating birds as potential bioindicators of mercury exposure. However, our understanding of methlymercury (MeHg) availability to birds in coastal wetlands, tidal systems that may be especially conducive to Hg methylation, remains poor. Two species of sharp-tailed sparrow breed in coastal wetlands in eastern North America and are suitable candidate indicators for contaminants in these habitats. We measured blood Hg from breeding Saltmarsh (Ammodramus caudacutus) and Nelson’s (Ammodramus nelsoni) sharp-tailed sparrows in five Maine salt marshes to determine if these species could be used to assess the extent of MeHg availability in salt marshes. Blood Hg for both species differed among the five marshes with concordance between species and site such that marshes with high MeHg levels were the same for both species. Blood Hg levels were 1.7 times higher in Saltmarsh sharp-tailed sparrows than in Nelson’s and exceeded Hg levels from passerines in known MeHg-contaminated lakes. This research is the first to show that insectivorous passerines breeding in salt marshes are accumulating MeHg.
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Humans have altered global nitrogen cycling such that more atmospheric N2 is being converted (fixed') into biologically reactive forms by anthropogenic activities than by all natural processes combined. In particular, nitrogen oxides emitted during fuel combustion and ammonia volatilized as a result of intensive agriculture have increased atmospheric nitrogen inputs (mostly NO3 and NH4) to temperate forests in the Northern Hemisphere. Because tree growth in northern temperate regions is typically nitrogen-limited, increased nitrogen deposition could have the effect of attenuating rising atmospheric CO2 by stimulating the accumulation of forest biomass. Forest inventories indicate that the carbon contents of northern forests have increased concurrently with nitrogen deposition since the 1950s. In addition, variations in atmospheric CO2 indicate a globally significant carbon sink in northern mid-latitude forest regions. It is unclear, however, whether elevated nitrogen deposition or other factors are the primary cause of carbon sequestration in northern forests. Here we use evidence from 15N-tracer studies in nine forests to show that elevated nitrogen deposition is unlikely to be a major contributor to the putative CO2 sink in forested northern temperature regions.
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Reported in this paper are foliar chemistry, tree growth (above- and below-ground), soil chemistry, nitrogen cycling (net mineralization and nitrification) and soil $\mathrm{N}_2\mathrm{O}$ flux responses to the first 6 yr of chronic nitrogen amendments at the Harvard Forest (Massachusetts, USA). A 70-yr-old red pine (Pinus resinosa Ait.) stand and a 50-yr-old mixed hardwood stand received control, low nitrogen (50 kg$\cdot$ ha$^{-1}\cdot$ yr$^{-1})$, high nitrogen (150 kg$\cdot$ ha$^{-1}\cdot$ yr$^{-1})$, and low nitrogen plus sulfur treatments, with additions occurring in six equal doses over the growing season as NH$_4$NO$_3$ and Na$_2$SO$_4$. Foliar N concentrations increased up to 25% in the hardwood stand and 67% in the pines, and there was no apparent decrease of N retranslocation due to fertilization. Wood production increased in the hardwood stand in response to fertilization but decreased in the pine stand. Fine-root nitrogen concentrations increased with N additions, and fine roots were a significant sink for added nitrogen. Nitrate leaching losses increased continuously over the 6-yr period in the treated pine stands but remained insignificant in the hardwoods. Annual net N mineralization increased substantially in response to treatments in both stands but declined in the pine high-N plot by the end of year six. Net nitrification increased from 17% of net mineralization in 1988 to 51% in 1993 for the pine high-N plot. Only a slight increase in net nitrification was measured in the hardwood stand, and only in 1993. Extractable $\mathrm{NH}_4$ was consistently higher in treated plots than in controls in both stands, where extractable $\mathrm{NO}_3$ was higher than controls only in the treated pine plots. Soil extracts yielded
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In this chapter we have suggested that the relationship between acid deposition research and ecosystem science has been synergistic, and that both have benefited. Not only did ecosystem science help to initiate and contribute to acid deposition research, but significant advances have been made in the discipline of ecosystem science over the past few decades as a result of studying acid deposition and its effects. It was through the study of ecosystems that the regional extent of air pollution and its potential ramifications were first brought to the attention of the scientific community as well as to the public. The national and international attention resulted in a high degree of public interest and substantial funding. The ecosystem research, synergism among disciplines and among scientists, and the research process itself yielded important benefits for the discipline of ecosystem science. These benefits fall into three categories of success: (1) scientific, including advances in our knowledge about the structure and function of ecosystems; (2) infrastructure, which concerns development of new physical, informational, and human resources for the field; and (3) experience on the public stage, which involves the discipline’s first tentative steps toward achieving effective science about complex issues in the public spotlight.
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Fertilizing Tsuga canadensis with N stimulated population growth of Adelges tsugae in a forest plantation in Connecticut. Fertilized hemlocks had five times more adelgids, had inferior color, and produced 25% less new growth than unfertilized trees after a single adelgid generation. -from Author
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The article reports on a study that compared the biological effects of a fish removal experiment in a non-acidified lake with changes reported from acidified waters. After the fish removal in the experimental lake a development similar to that in acidified waters occurred. Disappearance of fish means that a large-size selective predator is replaced by small-size selective predators such as corixids, Chaoborus larvae and other aquatic insects susceptible to fish predation and thus kept at low densities when fish are present. Absence of fish, together with the shift to invertebrate-dominated predator-prey systems, implies structural changes in both species composition and size composition among zooplankton and phytoplankton. Pyrrophytes become more abundant among primary producers, and among the grazers there is a change towards larger species. Species diversity in the plankton community as a whole is reduced. Refs.
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Spatial patterns of atmospheric deposition across the northeastern United States were evaluated and summarized in a simple model as a function of elevation and geographic position within the region. For wet deposition, 3-11 yr of annual concentration data for the major ions in precipitation were obtained from the National Atmospheric Deposition Program/National Trend Network (NADP/NTN) for 26 sites within the region. Concentration trends were evaluated by regression of annual mean concentrations against latitude and longitude. For nitrate, sulfate, and ammonium concentrations, a more than twofold linear decrease occurs from western New York and Pennsylvania to eastern Maine. These trends were combined with regional and elevational trends of precipitation amount, obtained from 30-yr records of annual precipitation at >300 weather stations, to provide long-term patterns of wet deposition. Regional trends of dry deposition of N and S compounds were determined using 2-3 yr of particle and gas concentration data collected by the National Dry Deposition Network (NDDN) and several other sources, in combination with estimates of deposition velocities. Contrary to wet deposition trends, the dominant air concentration trends were steep decreases from south to north, creating regional decreases in total deposition (wet + dry) from the southwest to the northeast. This contrast between wet and dry deposition trends suggests that within the northeast the two deposition forms are received in different proportions from different source areas, wet deposited materials primarily from areas to the west and dry deposited materials primarily from urban areas along the southern edge of the region. The equations generated describing spatial patterns of wet and dry deposition within the region were entered into a geographic information system (GIS) containing a digital elevation model (DEM) in order to develop spatially explicit predictions of atmospheric deposition for the region.
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Three species of Sphagnum (S. magellanicum, S. flexuosum and S. rubellum) were exposed to an artificial ozone regime in open-top chambers. Exposure levels consisted of a modified twice ambient (2X) treatment and a charcoal-filtered treatment. Additionally, an open plot treatment was established. The total ozone exposures during the experimental period were 80, 40 and 0.4 ppm in the 2X, open plot and charcoal-filtered treatments, respectively. Ozone level, temperature, humidity, light intensity and NOx level were constantly monitored during the experimental period. After ten weeks of exposure the growth (length and dry weight), photosynthesis and chlorophyll content were measured. The study showed that ozone exposure had a significant influence on growth in length, photosynthesis and chlorophyll content. There were also significantdifferences in reaction to ozone among species. Differences in light intensity, humidity, temperature and ozone level between open plots and charcoal-filtered chambers revealed differences in growth in length, biomass, photosynthesis and chlorophyll content between plants in open plots and plants in charcoal-filtered chambers.
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This field manipulation study tested the effect of weekly pulses of solutions of NH4NO3 and (NH4)2SO4 salts on the evolution of CH4 and N2O from peatland soils. Methane and nitrous oxide emission from a nutrient-poor fen in northern Minnesota USA was measured over a full growing season from plots receiving weekly additions of NH4NO3 or (NH4)2SO4. At this relatively pristine site, natural additions of N and S in precipitation occur at 8 and 5 kg ha−1 y−1, respectively. Nine weekly additions of the dissolved salts were made to increase this to a total deposition of 31 kg N ha−1 y−1 on the NH4NO3-amended plots and 30 and 29 kg ha−1 y−1 of N and S, respectively, in the (NH4)2SO4-amended plots. Methane flux was measured weekly from treatment and control plots and all data comparisons are made on plots measured on the same day. After the onset of the treatments, and over the course of the growing season, CH4 emission from the (NH4)2SO4-amended plots averaged 163 mg CH4 m−2 d−1, significantly lower than the same-day control plot mean of 259 mg CH4 m−2 d−1 (repeated measures ANOVA). Total CH4 flux from (NH4)2SO4 treatment plots was one third lower than from control plots, at 11.7 and 17.1 g CH4 m−2, respectively. Methane emission from the NH4NO3-amended plots (mean of 256 mg CH4 m−2 d−1) was not significantly different from that of controls measured on the same day (mean of 225 mg CH4 m−2 d−1). Total CH4 flux from NH4NO3 treatment plots and same-day controls was 16.9 and 15.1 g CH4 m−2, respectively. In general, stable, relatively warm and wet periods followed by environmental triggers' such as rainfall or changes in water table or atmospheric pressure, which produced a CH4 `pulse' in the other plots, produced no observable peak in CH4 emission from the (NH4)2SO4-amended plots. Nitrous oxide emission from all of the plots was below the detection limit over the course of the experiment.
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The Episodic Response Project (ERP) was an interdisciplinary study designed to address uncertainties about the occurrence, nature, and biological effects of episodic acidification of streams in the northeastern United States. The ERP research consisted of intensive studies of the chemistry and biological effects of episodes in 13 streams draining forested watersheds in the three study regions: the Northern Appalachian region of Pennsylvania and the Catskill and Adirondack Mountains of New York. Wet deposition was measured in each of the three study regions. Using automated instruments and samplers, discharge and chemistry of each stream was monitored intensively from fall 1988 through spring 1990. Biological studies focused on brook trout and native forage fish. Experimental approaches included in situ bioassays, radio transmitter studies of fish movement, and fish population studies. This paper provides an overview of the ERP, describes the methodology used in hydrologic and water chemistry components of the study, and summarizes the characteristics of the study sites, including the climatic and deposition conditions during the ERP and the general chemical characteristics of the study streams.
Article
Sediment cores were collected from eight remote lakes in the Adirondack region of New York in the summer of 1998. The cores were sectioned, dated by 210Pb, and analyzed for the concentration of total mercury (HgT) by cold vapor atomic fluorescence spectroscopy. Using sediment accumulation rates, the HgT fluxes were calculated to produce core Hg profiles on an historical timescale. All Adirondack lakes showed an increase in HgT flux beginning in the period from 1850 to 1900. While one lake exhibited a maximum sediment Hg flux in 1881, the remainder had a maximum sediment Hg flux occurring in the period from 1973 to 1990. The ratio of maximum sediment Hg flux to values evident before Hg increases was 5.2. Seven of the eight lakes have shown decreasing fluxes from maximum values in recent years. The decreases ranged from 12% to 71%, with an average of 32%. The Hg flux ratio has decreased by 42% to 3.0 for the most recent sediments. The modern and preindustrial fluxes are positively correlated to the watershed area to lake surface area ratio. This indicates that the watershed surrounding a lake provides a significant contribution to the overall mercury flux to a lake. These profiles were compared to sediment profiles from cores for the same eight lakes collected around 1982. There are many similarities between the two sets of cores even though the new cores were taken 15 years later and at different locations in the lake. The average flux ratio of the most recent sediments has decreased by 14% between the 1982 cores and the 1998 cores, providing additional evidence of recent declines in lake sediment mercury fluxes.
Article
Woods and Panther lakes in the Adirondack Mountains of New York respond differently to the same acidic deposition. A mathematical model study has shown that lake water becomes acidic when hydrologic conditions force precipitation to flow to the lakes as surface flow or as lateral flow through the shallow organic soil horizon. Hydrographic data, capacity of flow through inorganic soil horizons, runoff recession curves, and groundwater level fluctuations of Woods and Panther lake basins provide independent evidence to support the thesis that the acidic state of a lake depends on the paths the tributary water takes as it passes thorough the terrestrial system. It is concluded thot Panther Lake is more alkaline than Woods Lake, because a larger proportion of the precipitation falling on the basin passes through deeper mineral soil horizons.
Article
A gradient of atmospheric nitrogen deposition exists across the northeastern United States due to the concentration of urban and industrial sources of nitrogen oxides in the southern and western parts of the region. We examined possible effects of N deposition on N cycling in forests by measuring potential net mineralization and nitrification of soils under single-species plots of sugar maple and American beech along this gradient. The total atmospheric deposition of nitrogen was estimated to range from 11.1 kg N.ha(-1).yr(-1) at a site in southern New York to 4.2 kg N.ha(-1).yr(-1) at a site in western Maine. Although potential net mineralization and nitrification rates were extremely variable, highly significant positive correlations were observed between N deposition and mineralization and nitrification rates in organic horizons in maple plots, but not in beech plots. The correlation between deposition and N cycling variables was weaker in mineral horizons than in organic horizons for maple plots, and no significant correlations between these variables were found for beech mineral horizons. Many beech soils showed no net nitrification even under the higher deposition conditions. Percentage nitrogen (%N) of the organic horizons increased with increasing deposition in sugar maple, but not in beech plots. In organic horizons of both species, mineralization and nitrification increased with increasing %N, although the slopes of the increases were steeper for maple than for beech. Nitrogen deposition, mean annual temperature, and mean annual precipitation were intercorrelated across the sites of this study, but the data indicate that the observed patterns of N mineralization in maple plots resulted from the N deposition gradient rather than the climate gradient. These results suggest that the two species respond differently to N accumulation from atmospheric deposition. Species differences in the responses of forests to N deposition should be considered in both the prediction of forest response and the management of forest composition which could affect that response.
Article
Nitrogen cycling was studied during the first 2 yr of spray irrigation of vegetation by treated wastewater in Falmouth (Cape Cod), Massachusetts. We attempted to take advantage of an unexpected natural 15N enrichment during wastewater treatment to trace the fate of wastewater N following irrigation. Wastewater N was enriched by 6-20‰ relative to soil and by 13-25‰ relative to vegetation. We were able to estimate retention of wastewater N by soil using a mass balance of 15N. However, under conditions of N saturation δ15N values for plants were lower than expected, possibly due to discrimination against 15N during uptake of NH4+ and NO3- by plant roots. This is a potential weakness of trying to use low-level natural 15N enrichment in a tracer study. This problem is not likely to occur in N-limited ecosystems, or at high levels of isotopic enrichment. Three different ecosystem types were irrigated: a successional pitch pine woodland 26 yr in age; a mixed oak-pitch pine forest >70 yr in age; and cleared areas revegetated with grasses and old-field weeds. Areas near the spray heads were overloaded with N at deposition rates of 370-480 kg · ha-1 · yr-1. Pine woods and grass areas rapidly became N saturated; soil pore water NO3- levels reached 800 μmol/L in irrigation in year 1 and 1400 μmol/L in year 2. In contrast, soil pore water NO3- levels in the oak forest did not consistently exceed 100 μmol/L until late in year 2. Soil was a major sink for wastewater N in year 1, but in year 2 soil N retention fell to near zero, and N leaching losses greatly increased. At the onset of N saturation, irrigated forests were invaded by weedy species including Phytolacca americana, Polygonum convolvulus, and Solanum dulcamera, later followed by Celastrus orbiculatus and Lonicera tartarica.
Article
Atmospheric deposition to montane ecosystems is higher than to adjacent lowlands. However, because of the heterogeneity of mountainous landscapes, rates of deposition are likely to vary considerably across major landscape features. Estimates of total atmospheric deposition for montane areas in the United States are wide ranging and usually based on models that do not take into account landscape heterogeneity. Thus, little is known about the spatial variability of atmospheric deposition to these high-elevation ecosystems. We identified four landscape features that are likely to control patterns and rates of atmospheric deposition in mountainous terrain, including (1) forest edges or gaps, (2) elevation, (3) aspect, and (4) vegetation type, and we measured patterns of atmospheric deposition across them in the Catskill Mountains of New York State. We measured lead amount in the forest floor as an index of atmospheric deposition, used these data to estimate relative deposition to the Hunter Mountain massif, and with a geographic information system (GIS) database, scaled up atmospheric deposition estimates to the Hunter Mountain landscape. Area-weighted mean deposition to the region above 1000 m thigh-elevation) was 13-43% greater than to a nearby, low-elevation site, depending upon how edges were defined. In addition, we identified "hotspots" of deposition, such as high-elevation, coniferous forest edge zones, where atmospheric deposition of pollutants and nutrients was 300% greater (44 kg N . ha(-1).yr(-1) and 46 kg S.ha(-1).yr(-1)) than to low-elevation forests (11.1 kg N.ha(-1).yr(-1) and 11.6 kg S.ha(-1).yr(-1)). Our data suggest that estimates of atmospheric deposition to mountainous terrain that do not include landscape heterogeneity may be inadequate. Furthermore, current models of atmospheric deposition cannot predict "hotspot" regions of extremely high deposition. Landscape features such as forest edges, elevation, aspect, and vegetation type should be considered in future modeling efforts.
Article
Atmospheric nitrogen deposition has been hypothesized as one of the causal factors in the decline of ectomycorrhizal fungal (EMF) sporocarps. We assessed the effects of N deposition on EMF of forests dominated by white spruce (Picea glauca (Moench) Voss) over a short, steep N deposition gradient in Alaska, USA. The study area had received high NH3 inputs from an industrial ammonia production facility for almost 30 yr. Current N inputs varied 20-fold over the gradient. High N inputs have increased soil N availability, which has led to decreased soil pH and base cation availability; increased foliar N and decreased foliar P, Mg, and K; increased tree growth; and replacement of mosses by grasses. At the six lowest N sites, 144 species were encountered, whereas only 14 species were encountered at the six highest N sites. With increasing mineral N availability in the organic horizon, there were declines in both total species richness (1994 and 1995) and total sporocarp abundance (1994 only). Correlation analysis identified two groups of taxa that responded differently to the N inputs. One group ("nitrophobic" taxa: Cortinarius, Russula, Tricholoma, Lactarius, Hebeloma) declined in species richness or abundance with increasing organic horizon mineral N. In the second group ("nitrophilic". taxa: Lactarius theiogalus, Laccaria, Paxillus involutus, and Hygrophorus olivaceoalbus), sporocarp abundance was either not correlated or slightly positively correlated with organic horizon N availability. Redundancy analysis identified two axes of environmental variation that explained 62% and 7% of the variation in the EMF community and clearly distinguished the two groups of taxa. The environmental variables included in the final model were mineral soil base cations, organic horizon mineral N, and organic horizon net mineralization. These results support the hypothesis that long-term N inputs alone may lead to loss of EMF sporocarp diversity and indicate that EMF should be considered in the establishment of critical loads of N.
Article
Some natural ecosystems near industrialized and agricultural areas receive atmospheric nitrogen inputs that are an order of magnitude greater than those presumed for preindustrial times. Because nitrogen (N) often limits microbial growth on dead vegetation, increased N input can be expected to affect the ecosystem process of decomposition. We found that extracellular enzyme responses of a forest-floor microbial community to chronically applied aqueous NH4NO3 can explain both increased and decreased litter decomposition rates caused by added N. Microbes responded to N by increasing cellulase activity in decaying leaf litter of flowering dogwood, red maple, and red oak, but in high-lignin oak litter, the activity of lignin-degrading phenol oxidase declined substantially. We believe this is the first report to reduced ligninolytic enzyme activity caused by chronic N addition in an ecosystem. This result provides evidence that ligninolytic enzyme suppression can be an important mechanism explaining decreased decay rates of plant matter seen in this and other N-addition experiments. Since lignin and cellulose are the two most abundant organic resources on earth, these altered enzyme responses signal that atmospheric N deposition may be affecting the global carbon cycle by influencing the activities of microbes and their carbon-acquiring enzymes - especially the unique ligninolytic enzymes produced by white-rot fungi - over broad geographic areas.
Article
The impacts of airborne pollutants have been studied in only a few groups of soil animals, notably protozoans, nematodes, potworms, earthworms, mites, and collembolans. Pollutants in the form of acid depositions, which contain SO42-, NOx,H+, heavy metals, and some organic compounds, are not homogeneously distributed on the landscape. Deposition patterns depend mainly on landscape configuration and plant cover. Airborne pollutants affect soil animals both directly and indirectly. Direct toxic effects are associated with uptake of free acidic water from the environment by some soil animals and with consumption of polluted food by others. Indirect effects are mediated primarily through disappearance or reduction of the food resources (microflora and microfauna) of soil animals, changes in organic matter content, and modification of microclimate. In the field, changes in competition among species are probably important factors that influence the soil animal community structure as well as the reactions of individual species to soil acidification or liming. The overall effect is a depauperation of soil with an attendant reduction in the rate of organic matter decomposition. We have provided five hypotheses, using soil fauna as indicators, to allow for quick evaluation of environmental changes caused by airborne pollutants.
Article
The influence of N pulses in the form of experimental additions of HNO3 at two times ambient and (NH4)(2)SO4 at two and four times ambient on the herbaceous and woody understory plants in three Adirondack Mountain hardwood forests was evaluated. Addition of (NH4)(2)SO4 decreased cover of dominant herbs and woody seedlings at Woods Lake, a site in the western Adirondacks. Tissue N concentrations of combined herbs and ferns at Woods Lake increased with addition of NH4+ at both levels (9% at two times ambient; 13% at four times ambient) and increased with all three N treatments at Huntington Forest, a central Adirondack site (14% with NO3- and NH4+ at two times ambient; 22% with NH4+ at four times ambient). Seedlings of American beech (Fagus grandifolia Ehrh.) increased foliar N concentration 7-8% with addition of NH4+ treatments at Huntington Forest, but did nor respond to N addition at Woods Lake and Pancake Hall Creek, a western Adirondack site. In general, greatest plant nutrient response to N addition occurred at Huntington Forest, where atmospheric inputs of N are lower than at Woods Lake and Pancake Hall Creek.
Article
Although ozone is generally accepted to be an important phytotoxic air pollutant, little is known of its effects on natural and semi-natural vegetation. In this study two bryophyte species, Sphagnum recurvum P. Beauv. and Polytrichum commune Hedw., were exposed to long-term chronic ozone concentrations, i.e. 70–80 ppb (nl 1−1), for 6–9 wk in summer conditions (mean 15°C) and in winter conditions (mean 6.4°C) in open-top chambers (OTC), in the field, and at 15°C and 5°C in controlled-environment chambers, under laboratory conditions. Fumigation with ozone caused a significant reduction in the growth of treated plants in comparison with that of control plants. However, there were differences between species. S. recurvum was more affected than P. commune. In the controlled-environment chambers growth of S. recurvum was reduced under both winter and summer conditions by 21 and 15%, respectively. In the OTCs, S. recurvum growth was reduced (by 17%) only under summer conditions. P. commune growth was only significantly reduced following ozone exposure in the OTCs under winter conditions. Here the growth reduction was by 22%. Net CO2 assimilation of the two species was also significantly reduced by ozone exposure but only in the OTCs under winter conditions. Net CO2 assimilation of S. recurvum and P. commune was reduced by 60 and 80%, respectively. The ratio of variable to maximal fluorescence (Fv/Fm ratio) was the least affected of the parameters measured. Only for P. commune fumigated in the OTCs under winter conditions was the Fv/Fm ratio significantly reduced (by 4.4%). Bryophytes, by the very nature of their morphology and physiology are, perhaps, more likely to be susceptible to ozone pollution than higher plants; these results are discussed in relation to their possible ecological significance.
Article
Lakes across the Northern Hemisphere have experienced enhanced atmospheric deposition of anthropogenically derived Hg for over 100 years. In the present study, we quantified Hg fluxes to the sediments of ten small drainage lakes across Vermont and New Hampshire, USA, for the period ∼1800 to present. Dates were established by 210Pb. Total Hg (HgT) fluxes to sediments ranged from 5 to 17μgm−2yr−1 during pre-industrial times, and from 21 to 83μgm−2yr−1 presently. Present-day HgT fluxes are between 2.1 to 6.9 times greater than pre-1850 fluxes. Current-day direct atmospheric Hg deposition to the study region was estimated at 21μgm−2yr−1, which agrees well with measured HgT deposition, when re-evasion of Hg is accounted for. Our data suggest that Hg fluxes to lake sediments have declined in recent decades, owing to reductions in atmospheric Hg deposition to the lake surface. Watershed export of atmospherically deposited Hg remains elevated relative to present-day deposition rates, which contributes to the impression that Hg retention by watershed soils has declined.
Article
Mercury levels in the aquatic environment of North America have been increasing, raising the possibility that this highly toxic heavy metal might alter fish populations. Previous investigations have demonstrated toxic effects of mercury on teleost reproduction, but these findings were observed following unrealistically high exposures. In this study, we used concentrations frequently observed in North American lakes to investigate the effects of dietary methylmercury on growth, gonadal development, and plasma cortisol levels in juvenile walleye (Stizostedion vitreum). For a period of 6 months, two groups of walleye were reared on untainted catfish fillets, while two test groups were fed fillets injected with methylmercury, one group receiving 0.1 μg Hg g−1 food (low-mercury diet) and the other receiving 1.0 μg Hg g−1 food (high-mercury diet). After the exposure period, fish fed the low- and high-mercury diets had mean body burdens of 0.254 ± 0.015 μg Hg g−1 and 2.37 ± 0.09 μg Hg g−1, respectively. Dietary mercury significantly impaired both growth and gonadal development in males, which was apparent as reduced fish length, weight, and gonadosomatic index. Testicular atrophy was observed in fish fed the mercury-tainted fillets, but was nonexistent in control animals. Mercury also suppressed plasma cortisol in juveniles (sexes combined). The findings of this study suggest that dietary methylmercury, at levels currently found in the aquatic environment, might reduce juvenile survival by impairing growth and immune function. Furthermore, these results suggest that methylmercury might also affect reproductive potential of teleosts by impairing testicular development in young.
Article
Three generations of mallard ducks (Anas platyrhynchos) were fed either a control diet or a diet containing 0.5 ppm mercury in the form of methylmercury. The levels of mercury in adult tissues and eggs remained about the same over 3 generations. The methylmercury diet had no effect on adult weights or weight changes during the reproductive season. Females fed a diet containing 0.5 ppm mercury laid a greater percentage of their eggs outside their nestboxes than did controls, and also laid fewer eggs and produced fewer ducklings. Methylmercury in the diet appeared to result in a small amount of eggshell thinning. Ducklings from parents fed methylmercury were less responsive than controls to tape-recorded maternal calls, but were hyper-responsive to a frightening stimulus in avoidance tests; there were no significant differences in locomotor acitivity in an open-field test.
Article
The fundamental principles of atmospheric chemistry are examined in a textbook for graduate science students. Topics addressed include the bulk composition, structure, and dynamics of the atmosphere; photochemical processes and elementary reactions; the chemistry of the stratosphere; tropospheric chemistry and the methane oxidation cycle; and ozone in the troposphere. Consideration is given to volatile hydrocarbons and halocarbons, the atmospheric aerosol, the chemistry of clouds and precipitation, nitrogen compounds in the troposphere, sulfur compounds in the atmosphere, the geochemistry of CO2, and atmospheric evolution. Diagrams, graphs, and tables of numerical data are provided.
Article
Our base case estimate indicates that approximately 25% of the anthropogenic nitrogen loading to the Bay originates as atmospheric nitrate deposition, which arises almost entirely from anthropogenic emissions of nitrogen oxides. A sensitivity analysis was also performed indicating a range of 20% to 30% for the contribution of atmospheric nitrate. Atmospheric ammonium deposition contributes another 14% of the total. We conclude that atmospheric sources of nitrogen, particularly nitrogen oxides emissions, should be considered in management strategies aimed at reducing nitrogen loading of coastal waters. -from Authors
Article
Chronic nitrogen deposition may affect the long-term survival of plant pop- ulations. The northern pitcher plant, Sarracenia purpurea, is a model system for forecasting extinction risk in the face of increasing nitrogen deposition. Uptake of N occurs directly from pitcher leaves, which fill with rainwater and prey, and accumulate nutrients. We monitored the demography of two populations of S. purpurea in ombrotrophic bogs of northern New England (USA) and described population growth with a four-stage matrix model. Growth, survivorship, and reproduction were in close balance, and the model pre- dicted population growth rates close to zero, with long doubling times. In a life-table response experiment, we manipulated in situ concentrations of nitrogen and phosphorus in pitcher plant leaves. At high levels of N and high N:P ratios, population growth rates were significantly depressed. Using local N-deposition records, we forecast different N-deposition scenarios and built a nonstationary population growth model, in which a different transition matrix at each time step reflected the current deposition regime. Autocorrelation in the time series of N deposition rates generated periodic increases in population size superimposed on long-term trends of exponential decline. For a 1% annual increase in N deposition rates, this model predicted a substantial risk of extinction at 100 yr (0.38-0.70), with an estimated population survival time of 160-180 yr. Although slow-growing populations of Sarracenia can buffer substantial environmental change, chronic increases in N deposition rate threaten population persistence.
Book
The book is the first comprehensive, integrated synthesis of available information on the current and potential effects of acidic deposition on lakes and streams in geographic regions of the United States having significant numbers of low-alkalinity surface waters. It presents and evaluates data for entire regions and is national in scope. The authors have collected the results of diverse studies of aquatic ecosystems. The authors stress the current status of water chemistry and the processes important in controlling water chemistry. Authors of case study chapters have characterized these processes on a regional basis by using, assessing, and comparing high-quality data sets. A major conclusion demonstrated by these regional comparisons is that there is substantial diversity among regions with respect to the nature of surface waters and the processes affecting them. The most important contributions of the book are the descriptions of intra- and inter-regional variations in surface water chemistry and its controlling factors, and the assessment of the significance of these variations to our understanding of the acidic deposition phenomenon and its implications for public policy decisions.
Article
Understanding the factors regulating the concentrations of basic cations in soils and surface waters is critical if rates of recovery are to be predicted in response to decreases in acidic deposition. Using a dynamic simulation model (PnET-BGC), we evaluated the extent to which atmospheric deposition of strong acids and associated leaching by strong anions, atmospheric deposition of basic cations through changes in emissions of particulate matter, and historical forest cutting have influenced soil pools of exchangeable basic cations and the acid-base status of stream water at the Hubbard Brook Experimental Forest (HBEF) in New Hampshire. Historical deposition of basic cations was reconstructed from regression relationships with particulate matter emissions. Simulation results indicate that the combination of these factors has resulted in changes in the percent soil base saturation, and stream pH and acid neutralizing capacity (ANC) from pre-industrial estimates of ~20%, ~6.3 and ~45 µeq L-1, respectively, to current values of ~10%, ~5.0 and ~-5 µeq L-1, respectively. These current values fall within the critical thresholds at which forest vegetation and aquatic biotic are at risk from soil and surface water acidification due to acidic deposition. While the deposition of strong acid anions had the largest impact on the acid-base status of soil and stream water, the reduction in deposition of basic cations associated with reductions in particulate emissions was estimated to have contributed about 27% of the depletion in soil Ca2+ exchange pool and 15% of the decreases in stream water concentrations of basic cations. Decline in stream water concentrations of basic cation occurred under both increasing and decreasing exchangeable pools, depending on the process controlling the acid base status of the ecosystem. Model calculations suggest that historical forest cutting has resulted in only slight decreases in soil pools of exchangeable basic cations, and has had a limited effect on stream ANC over the long-term.
Article
Recent studies have found that "pristine" peatlands have high peat and pore water methylmercury (MeHg) concentrations and that peatlands may act as large sources of MeHg to the downstream aquatic system, depending upon the degree of hydrologie connectivity and catchment physiography. Sulphate-reducing bacteria have been implicated as principal methylators of inorganic mercury in many environments with previous research focused primarily on mercury methylation in aquatic sediments. Experiments in a poor fen in the Experimental Lakes Area, northwestern Ontario, Canada, demonstrated that the in situ addition of sulphate to peat and peat pore water resulted in a significant increase in pore water MeHg concentrations. As peatlands cover a large area of the Northern Hemisphere, this finding has potentially far ranging implications for the global mercury cycle, particularly in areas impacted by anthropogenically derived sulphate where the methylmercury fraction of total mercury species may be much larger than in nonimpacted environments.
Article
The calcium/aluminum (Ca/Al) molar ratio of the soil solution provides a valuable measurement endpoint or ecological indicator for identification of approximate thresholds beyond which the risk of forest damage from Al stress and nutrient imbalances increases. The Ca/Al ratio can also be used as an indicator to assess forest ecosystem changes over time in response to acidic deposition, forest harvesting, or other processes contributing to acid soil infertility. Based on a critical review of literature on Al stress, we estimate that there is a 50:50 risk of adverse impacts on tree growth or nutrition when the soil solution Ca/Al ratio is as low as 1.0, a 75% risk when the soil solution ratio is as low as 0.5, and nearly a 100% risk when the soil solution Ca/Al molar ratio is as low as 0.2. The Ca/Al ratio of the soil solution can be corroborated with other complementary indices.
Article
The impact of residential and agricultural development as the cause of water pollution on aquatic macrophyte communities in the New Jersey Pine Barrens was examined by comparison with unpolluted communities. The only major physical and chemical differences between stream types were greatly elevated pH values and NO3− concentrations at the polluted sites. A total of 59 aquatic macrophyte species were identified during the study. Slightly more species (41) occurred at the polluted sites than at the unpolluted sites (38). Twenty-two species were confined to polluted sites and 19 to unpolluted sites. Classification of all species as either typical or not typical Pine Barrens species revealed that the primary effect of pollution was the replacement of a distinctive Pine Barrens flora (e.g. Carex walteriana, Eleocharis olivacea, E. tuberculosa, Eriocaulon compressum, and Utricularia fibrosa) with one containing many marginal or non-indigenous species common to wetlands throughout the Eastern US (e.g. Callitriche heterophylla, Galium tinctorium, and Polygonum punctatum).
Article
Acidic deposition and its effects on aquatic ecosystems have been major scientific and public policy issues in the United States since the early 1970s. The high level of concern arises primarily from the potential for wide-scale and long-term changes in water chemistry and the resulting loss of aquatic biota, especially fish. Considerable research has been performed and hundreds of scientific papers and several major books and reports have been written on the subject. We now have a good understanding of the nature and extent of at least wet acidic deposition, and we know that current low pH values for wetfall are caused primarily by sulfur and nitrogen oxide emissions from combustion of fossil fuels. From numerous surveys and studies, including the U.S. Environmental Protection Agency’s (EPA) National Surface Water Survey (NSWS), we have learned much about the current status of low-alkalinity surface waters in many regions of the country, and the extent to which water chemistry has been affected by acidic deposition. However, the many and diverse studies completed by state and federal agencies, universities, and other organizations and individuals have not been thoroughly analyzed and integrated on a regional or national scale.