The pattern of metal deposition to a woodland ecosystem as revealed by bryophyte analysis

The concentrations and enrichment factor data for 7 metals has been investigated in samples of Hypnum cupressiforme obtained from various parts of a woodland located to the south east of London and immediately adjacent to the M 25 motorway. Despite the rural location of the woodland, metal level and enrichment factor data suggest a moderate degree of contamination. Application of analysis of variance to the data indicates individual metal levels at woodland edges are significantly different from adjacent internal sites, suggesting enhanced deposition at these edges. The fact that this significance pattern is not repeated at all edges indicates a directional influence on levels. Correlation coefficient data indicates metal/metal associations and allows some speculation about the major pathways by which metals are atmospherically transported to and deposited in the woodland.     

Multi-scale Atmospheric Dispersion Modelling by Use of Adaptive Gridding Techniques

An accurate prediction of the transport-reaction behaviour of atmospheric chemical species is required to fully understand the impact on the environment of pollution emissions. Elevated levels of secondary pollutants such as ozone in the lower atmosphere can be harmful to the health of both plants and animals, and can cause damage to property present in the urban environment. Detailed models of pollution mechanisms must therefore be developed through comparisons with field measurements to aid the selection of effective abatement policies. Such models must satisfy accuracy requirements both in terms of the number of species represented, and the spatial resolution of species profiles. Computational expense often compels current models to sacrifice detail in one of these areas. This paper attempts to address the latter point by presenting an atmospheric transport-reaction modelling strategy based upon a finite volume discretisation of the atmospheric dispersion equation. The source terms within this equation are provided by an appropriate reduced chemical scheme modelling the major species in the boundary layer. Reaction and transport discretisations are solved efficiently via a splitting technique applied at the level of the non-linear equations. The solution grid is generated using time dependant adaptive techniques, which provide a finer grid around regions of high spatial error in order to adequately resolve species concentration profiles. The techniques discussed are applied in two dimensions employing emissions from both point and area sources. Preliminary results show that the application of adaptive gridding techniques to atmospheric dynamics modelling can provide more accurately resolved species concentration profiles, accompanied by a reduced CPU time invested in solution. Such a model will provide the basis for high resolution studies of the multiple scale interactions between spatially inhomogeneous source patterns in urban and regional environments.     

Land classification and ecosystem classification

Earth, the ecosphere, is a unified functional ecosystem. Ecological land classification (ELC) and regionalization divides and categorizes this unity into similar and dissimilar pieces-sectoral ecosystems - at various scales, in the interests of admiration and understanding. The recognition of land/water ecosystems in a hierarchy of sizes provides a rational base for the many-scaled problems of protection and careful exploitation in the fields of agriculture, forestry, wildlife and recreation. In forested terrain the protection of biodiversity, old growth forests, watersheds and wildlife habitat depends on spatial-temporal planning of forestry operations to maintain a preferred mosaic structure of local ecosystems within each ecological region. Without ecological understanding and a good ELC, this is impossible. Conceiving the world as comprising nested land/water ecosystems that are the source of life, elevates the role of Earth-as-context, an antidote to destructive anthropocentrism.     

Multi-scale spatial structure of heavy metals in agricultural soils in Beijing

To effectively investigate the spatial variability of heavy metals in soil, produce a higher quality spatial distribution map, and identify the potential pollution sources of heavy metals, geostatistics was employed to evaluate the effect of scale on spatial variability of heavy metals in Beijing agricultural soils. The results revealed that spatial variability of Cr, Ni, Zn, and Hg was dependent on scale. Validation of the optimality of theoretical semivariance and comparative analysis of the estimation accuracy demonstrated that the multi-scale nested model can reveal the spatial structure of heavy metals effectively and improve the estimation accuracy better than the single-scale method, thereby enabling production a higher quality spatial interpolation map. Thus, the multi-scale kriging nested model is a useful tool for revealing spatial variability of heavy metals in soils, while the spatial distribution maps allow the identification of hot spots with high concentrations of heavy metals.     

An argument for ecosystem level monitoring

One objective of environmental monitoring programs is documentation of qualitative and quantitative environmental changes in response to external stresses, including chemical contamination. Chemical contaminant, biological, and ecological measurements have been used as environmental monitors. Contaminant monitoring allows estimation of exposures; biological and ecological monitoring allow estimation of uptake and effects.Measurements of ecosystem homeostasis such as nutrient cycling processes have been shown to be good ecosystem level monitors. The rate of dissolved nutrient loss from ecosystems has been conclusively shown to increase as a function of chemical contamination until a new equilibrium is reached, the pollutant input has become negligible, or until nutrient pools have been depleted. Consequently, nutrient pools in environmental strata and in biota are altered and eventually depleted by chemical stress.The use of nutrient cycling to determine sensitive responses to and long-term changes for chemical contamination is an essential monitoring strategy for environmental management and compliance purposes. Measurements of export (rapid response) and pools (long-term consequences) are within current technology, are cost-effective, and allow rapid implementation of remedial measures or environmental controls.Paper presented at a Symposium held on 20–21 April 1982, in Edmonton, Alberta, Canada.     

Multi-scale landscape factors influencing stream water quality in the state of Oregon

Enterococci bacteria are used to indicate the presence of human and/or animal fecal materials in surface water. In addition to human influences on the quality of surface water, a cattle grazing is a widespread and persistent ecological stressor in the Western United States. Cattle may affect surface water quality directly by depositing nutrients and bacteria, and indirectly by damaging stream banks or removing vegetation cover, which may lead to increased sediment loads. This study used the State of Oregon surface water data to determine the likelihood of animal pathogen presence using enterococci and analyzed the spatial distribution and relationship of biotic (enterococci) and abiotic (nitrogen and phosphorous) surface water constituents to landscape metrics and others (e.g. human use, percent riparian cover, natural covers, grazing, etc.). We used a grazing potential index (GPI) based on proximity to water, land ownership and forage availability. Mean and variability of GPI, forage availability, stream density and length, and landscape metrics were related to enterococci and many forms of nitrogen and phosphorous in standard and logistic regression models. The GPI did not have a significant role in the models, but forage related variables had significant contribution. Urban land use within stream reach was the main driving factor when exceeding the threshold (> or =35 cfu/100 ml), agriculture was the driving force in elevating enterococci in sites where enterococci concentration was <35 cfu/100 ml. Landscape metrics related to amount of agriculture, wetlands and urban all contributed to increasing nutrients in surface water but at different scales. The probability of having sites with concentrations of enterococci above the threshold was much lower in areas of natural land cover and much higher in areas with higher urban land use within 60 m of stream. A 1% increase in natural land cover was associated with a 12% decrease in the predicted odds of having a site exceeding the threshold. Opposite to natural land cover, a one unit change in each of manmade barren and urban land use led to an increase of the likelihood of exceeding the threshold by 73%, and 11%, respectively. Change in urban land use had a higher influence on the likelihood of a site exceeding the threshold than that of natural land cover.     

Lake ecosystem responses to rapid climate change

In this paper, we examine the consequences of rapid climate change on lake ecosystems in terms of two main effects: variability effects and magnitude effects. How these factors influence life history selection is considered by focusing upon body size as a quantifiable and strong correlate of life history variation (Pianka 1970, McNab 1980, Charnov 1991). We then consider the relationship between the concept of biological diversity and the diversity of life history strategies in the context of rapid climate change.     

Water quality indices as indicators of ecosystem change

The operational management of water quality requires a methodology that can provide precise information on cycles and trends in water quality in an objective and reproducible manner. Such information can be provided by the adoption of a water quality indexing system. The continuous scale afforded by a water quality index allows changes in river water quality to be highlighted. At the same time the sub-division of this scale into a series of water quality and water use categories provides an easy means of relating information to government and public.The development of four independent water quality indices (WQIs) is outlined. These have been applied to data for a number of UK river reaches. The results of these applications indicate the utility of these indices in the classification of water quality and the monitoring of ecosystem change.     

Choices of ecosystem capital without discounting and prices

In the last decade, neo-classical economists have used the Consumption-Growth Based Utility (CGBU) framework to suggestan appropriate discount rate for eco-system capital. The CGBU framework, being based on the simplicity and single-valued nature of man-made capital, is subject to many limitations. Three general limitations of the framework, irrespective of its use for man-made capital or ecosystem capital, paradox of consumption growth, expectations' insensitive utility specification, and insensitivity to the nature of returns, arediscussed. With respect to its use for ecosystem capital, the framework has two limitations: ecosystems cannot be commoditizedand ecosystem capital satisfies differentiated needs, and, hence, gross substitution between different components of ecosystem capital or between ecosystem capital and man-made capital is not possible. Therefore, the rate of discount for ecosystem capital suggested on the basis of the framework is arbitrary. In the context of international security, choices ofecosystem capital are similar to the choices of military decisions. Similar to military decisions, ecosystem choices should be made without discounting and prices. The neo-classicalframework does not have appropriate tools for such decision analyses, and other streams of economics, specifically post-Keynesian economics, may assist decision- makers in analysing ecosystem choices without prices and discounting.     

Exploring spatial change and gravity center movement for ecosystem services value using a spatially explicit ecosystem services value index and gravity model

Spatially explicit ecosystem services valuation and change is a newly developing area of research in the field of ecology. Using the Beijing region as a study area, the authors have developed a spatially explicit ecosystem services value index and implemented this to quantify and spatially differentiate ecosystem services value at 1-km grid resolution. A gravity model was developed to trace spatial change in the total ecosystem services value of the Beijing study area from a holistic point of view. Study results show that the total value of ecosystem services for the study area decreased by 19.75% during the period 1996?C2006 (3,226.2739 US$ × 10⁶ in 1996, 2,589.0321 US$ × 10⁶ in 2006). However, 27.63% of the total area of the Beijing study area increased in ecosystem services value. Spatial differences in ecosystem services values for both 1996 and 2006 are very clear. The center of gravity of total ecosystem services value for the study area moved 32.28 km northwestward over the 10 years due to intensive human intervention taking place in southeast Beijing. The authors suggest that policy-makers should pay greater attention to ecological protection under conditions of rapid socio-economic development and increase the area of green belt in the southeastern part of Beijing.     

Long‐term variability of a stochastic forced pelagic ecosystem model

The long‐term natural variability of a pelagic ecosystem model is investigated using a simple numerical model which consists of six state variables: two nutrients, two phytoplankton species, detritus and benthos. For the investigation of natural variability the model is forced with first and second order autoregressive processes and noise. The interannual variability of the system with respect to phytoplankton mortality is investigated in different runs which are integrated over 300 years.     

Recovery assessment of a refined-oil impacted and fire ravaged mangrove ecosystem

An assessment of the diversity and abundance of macrobenthic community in a refined-oil (petrol) impacted and fire-ravaged mangrove ecosystem within the vicinity of a marine receipt terminal facility (Atlas Cove) serving as a distribution and pump station for refined products was carried out. The mangrove ecosystem was subjected to massive petrol spillage from a leaking pipeline and eventual fire outbreak. Following rehabilitation activities, a recovery assessment of the impacted ecosystem was carried out. The field surveys revealed that the petrol leakage and fire outbreak resulted in a near complete destruction of the mangrove ecosystem around the Atlas Cove depot, with macrobenthic species diversity index ranging between 0−0.4, compared to 0.78−0.87 in the control stations. The dominant early arrivals or colonizers of the impacted stations areas were Clibanarius africanus and Callinectes amnicola. Early signs of recovery of the impacted area were observed within about two and a half (2 1/2) to three (3) months, based on diversity and abundance indices respectively. The period of early signs of recovery also coincide with an observed reduction in the total hydrocarbon content (THC) levels in the sediment collected from the impacted stations by about nine folds from 3.67 mg/kg to 0.42 mg/kg within 3 months. Despite the apparent signs of recovery, the need for long-term monitoring of the impacted stations was discussed.     

Residue levels of organochlorine pesticides in some ecosystem components of Manzala Lake

To evaluate the organochlorine pesticide (OCP) contamination of Manzala Lake, its ecosystem was investigated during the winter season (December to March). The studied ecosystem components were water, sediment, aquatic weeds, and fishes in four locations. The samples were analyzed by gas chromatography with electron capture detector. Pollutant levels of total OCPs showed significantly high levels in the water areas of Round road (46.253 ng/ml), Port-Said Damietta road (19.301 ng/ml), followed by Bughas El-Rasoah (5.539 ng/ml), then Ashtoum El Gamel (natural reserve area now) (0.289 ng/ml). Organochlorines were detected in sediment only in Round road (3.359 μg/kg) and Port-Said Damietta road (0.171 μg/kg) by significant order while they were undetectable in Ashtoum El Gamel and Bughas El-Rasoah. Total OCPs in aquatic weeds ranged between 0.194 μg/kg in Port-Said Damietta and 0.026 μg/kg in Ashtoum El Gamel. While OCPs were 0.160 and 0.153 μg/kg in Round road and Bughas El-Rasoah, respectively. Concerning fish muscles OCPs were significantly higher in the Round road area (0.397 μg/kg) followed by the Port-Said Damietta road (0.258 μg/kg), and finally, Ashtoum El Gamel samples (0.126 μg/kg). The results revealed the direct relation for the accumulation of OCPs between studied ecosystem parameters at the Manzala Lake during the winter season. Results also demonstrated that fish samples collected from the Manzala Lake in the studied areas were contaminated with levels of organochlorines, not higher than the maximum permissible level recorded by FAO/WHO, and that the public is not at risk with fish consumption.     

Impact of degradation on nitrogen transformation in a forest ecosystem of India

A study was performed selecting one protected forest and an adjacent degraded forest ecosystem to quantify the impact of forest degradation on soil inorganic nitrogen, fine root production, nitrification, N-mineralization and microbial biomass N. There were marked seasonal variations of all the parameters in the upper 0–10 and lower 10–20 cm depths. The seasonal trend of net nitrification and net N-mineralization was reverse of that for inorganic nitrogen and microbial biomass N. Net nitrification, net N-mineralization and fine root biomass values were highest in both forests during rainy season. On contrary, inorganic nitrogen and microbial biomass N were highest during summer season. There was a marked impact of forest degradation on inorganic nitrogen, fine root production nitrification, N-mineralization and microbial biomass observed. Soil properties also varied with soil depth. Fine root biomass, nitrification, N-mineralization and microbial biomass N decreased significantly in higher soil depth. Degradation causes decline in mean seasonal fine root biomass in upper layer and in lower depth by 37% and 27%, respectively. The mean seasonal net nitrification and N-mineralization in upper depth decreased by 42% and 37%, respectively and in lower depth by 42.21% and 39% respectively. Similarly microbial biomass N also decreased by 31.16% in upper layer 33.19% in lower layer.     

Impact of urbanization on natural ecosystem service values: a comparative study

With rapid population growth and rural to-urban migration in many Chinese cities, a large amount of natural lands have been converted to urban and agricultural lands recently. During this process of land conversion, economic development and quality of life improvement are considered as major goals, and their influences on ecological systems have often been neglected. The degradation of natural ecological systems due to land use change, however, has become severe,and may require immediate attentions from urban planners and local governments. Taking HaDaQi industrial corridor, Heilongjiang Province, China,as a case study area, this paper examined the trend of land use changes during 1990–2005, and quantified their influences on natural eco system service values. In particular, this study applied two major valuation methods, and examined whether different valuation methods generate significantly different results. Analysis of results suggests that human dominated land uses (e.g., urban and agriculture)have expanded rapidly at the cost of natural lands (e.g., wetlands and forest). Due to these land use changes, the total ecosystem service value decreased 29% (2.26% annually) from 1990 to 2005 when the first method was applied, and this rate is estimated to be 15.7% (1.13% annually)with the second approach. Moreover, the annual rate of ecosystem service value decline during 2000–2005 is about four times higher than that in 1990–2000 with both methods, suggesting much more severe ecosystem degradation during 2000–2005.     

Modelling vegetation greenness responses to climate variability in a Mediterranean terrestrial ecosystem

Accurate knowledge of the quality and environmental impact of the highway runoff in Pear River Delta, South China is required to assess this important non-point pollution source. This paper presents the quality characterization and environmental impact assessment of rainfall runoff from highways in urban and rural area of Guangzhou, the largest city of Pear River Delta over 1 year’s investigation. Multiple regression and Pearson correlation analysis were used to determine influence of the rainfall characteristics on water quality and correlations among the constituents in highway runoff. The results and analysis indicates that the runoff water is nearly neutral with low biodegradability. Oil and grease (O&G), suspended solids (SS) and heavy metals are the dominant pollutants in contrast to the low level of nutrient constituents in runoff. Quality of highway runoff at rural site is better than that of at urban site for most constituents. Depth and antecedent dry period are the main rainfall factors influencing quality of highway runoff. The correlation patterns among constituents in highway runoff at urban site are consistent with their dominant phases in water. Strong correlations (r ≥ 0.80) are found among chemical oxygen demand (COD), total phosphorus, Cu and Zn as well as conductivity, nitrate nitrogen and total nitrogen. O&G, COD, SS and Pb in highway runoff at urban site substantially exceed their concentrations in receiving water of Pear River. The soil directly discharged by highway runoff at rural site has contaminated seriously by heavy metals in surface layer accompanying with pH conversion from original acidic to alkaline at present.