Potentialities,problems, policies and progress in modelling sustainable development: A dynamic,hierarchical approach

This paper discusses some of the potentials, problems, policies and progress in modelling sustainable development. After briefly describing ten approaches to modelling sustainable development, some of the methodological problems still to be resolved are addressed. It is then suggested that policies to promote sustainable development should operate at six different spatial levels connecting global, multinational, national, regional, local and individual. Attempting to model sustainable development in such a hierarchical manner is exceedingly difficult. One way of modelling sustainable development is to develop the concept of a sustainable corridor, combining ecological, economic and equity considerations in a hierarchical fashion and through space-time. A preliminary dynamic, hierarchical model is described connecting global and national patterns of development. Using global and national data for Scotland, the calibrated model, running under the business-as-usual scenario, shows that current development paths are unsustainable. It is shown that, by implementing a judicious choice of policies, a sustainable corridor for a global and a national system can be achieved. The ways in which this preliminary model can be developed to connect all six hierarchical levels are discussed.     

Is Scotland sustainable? A the series of indicators of sustainable development

Seven measures of sustainable development for Scotland are examined for the period 1980-1993. These measures are green net national product, genuine savings, ecological footprint, environmental space, human appropriation of net primary production, the index of sustainable economic welfare and the genuine progress indicator. Very different messages concerning sustainable development in Scotland emerge from these measures.     

Rural southeast Texas air quality measurements during the 2006 Texas Air Quality Study

The authors conducted air quality measurements of the criteria pollutants carbon monoxide, nitrogen oxides, and ozone together with meteorological measurements at a park site southeast of College Station, TX, during the 2006 Texas Air Quality Study II (TexAQS). Ozone, a primary focus of the measurements, was above 80 ppb during 3 days and above 75 ppb during additional 8 days in summer 2006, suggestive of possible violations of the ozone National Ambient Air Quality Standard (NAAQS) in this area. In concordance with other air quality measurements during the TexAQS II, elevated ozone mixing ratios coincided with northerly flows during days after cold front passages. Ozone background during these days was as high as 80 ppb, whereas southerly air flows generally provided for an ozone background lower than 40 ppb. Back trajectory analysis shows that local ozone mixing ratios can also be strongly affected by the Houston urban pollution plume, leading to late afternoon ozone increases of as high as 50 ppb above background under favorable transport conditions. The trajectory analysis also shows that ozone background increases steadily the longer a southern air mass resides over Texas after entering from the Gulf of Mexico. In light of these and other TexAQS findings, it appears that ozone air quality is affected throughout east Texas by both long-range and regional ozone transport, and that improvements therefore will require at least a regionally oriented instead of the current locally oriented ozone precursor reduction policies.     

Mathematical Methods for Spatially Cohesive Reserve Design

The problem of designing spatially cohesive nature reserve systems that meet biodiversity objectives is formulated as a nonlinear integer programming problem. The multiobjective function minimises a combination of boundary length, area and failed representation of the biological attributes we are trying to conserve. The task is to reserve a subset of sites that best meet this objective. We use data on the distribution of habitats in the Northern Territory, Australia, to show how simulated annealing and a greedy heuristic algorithm can be used to generate good solutions to such large reserve design problems, and to compare the effectiveness of these methods.     

Airborne particulate-associated polyaromatic hydrocarbons,n-alkanes,elemental and organic carbon in three European cities

Total suspended particulate (TSP) samples were collected weekly over a period of one year at four European sites during 1995/6. Two sites were in London-a Central London site (CL, St Paul's Cathedral) and a suburban North London site (NL, Bounds Green); the other two sites were in Porto, Portugal and Vienna, Austria. TSP was collected using a low volume sampler. Organic carbon (OC) and elemental carbon (EC) concentrations were measured using a thermal-optical carbon analyser. Parallel samplers collected TSP for subsequent GC-MS analysis of thirty-nine combustion-associated organic compounds; 16 polyaromatic hydrocarbons (PAHs) and 23 n-alkanes. OC and EC correlate well at all sites (r2 = 0.39-0.65), although the London inter-site correlations were low, suggesting that local sources of OC and EC have a significant influence on local concentrations. Concentrations do not vary widely across the four urban sites, despite the significant differences in urban characteristics. Seasonal patterns of OC:EC ratios were similar at the London and Vienna sites, with highest ratios in autumn and winter, and annual mean OC:EC ratios were identical at these sites. The Carbon Preference Index (CPI) indicated vehicle emissions to have a stronger influence over particulate concentrations at the Vienna and central London sites; there was a stronger biogenic signature in north London and Porto. In addition, two PAH compounds (pyrene and fluoranthene) previously associated with diesel exhaust, were correlated with OC and EC concentrations at the London and Vienna sites.     

Direct and indirect effects of ammonia, ammonium and nitrate on phosphatase activity and carbon fluxes from decomposing litter in peatland

Here we investigate the response of soils and litter to 5 years of experimental additions of ammonium (NH₄), nitrate (NO₃), and ammonia (NH₃) to an ombrotrophic peatland. We test the importance of direct (via soil) and indirect (via litter) effects on phosphatase activity and efflux of CO₂. We also determined how species representing different functional types responded to the nitrogen treatments. Our results demonstrate that additions of NO₃, NH₄ and NH₃ all stimulated phosphatase activity but the effects were dependent on species of litter and mechanism (direct or indirect). Deposition of NH₃ had no effect on efflux of CO₂ from Calluna vulgaris litter, despite it showing signs of stress in the field, whereas both NO₃ and NH₄ reduced CO₂ fluxes. Our results show that the collective impacts on peatlands of the three principal forms of nitrogen in atmospheric deposition are a result of differential effects and mechanisms on individual components.     

Relative kinetic measurements of rate coefficients for the gas-phase reactions of Cl atoms and OH radicals with a series of methyl alkyl esters

Relative kinetic studies have been performed on the reactions of Cl atoms with a series of methyl alkyl esters in a 405-liter borosilicate glass chamber at (298 ± 3) K and one atmosphere of synthetic air using in situ FTIR spectroscopy to monitor the reactants. Rate coefficients (in units of cm³ molecule^?1 s^?1) were determined for the following compounds: methyl acetate (2.48 ± 0.58) × 10^?12; methyl propanoate (1.68 ± 0.36) × 10^?11; methyl butanoate (4.77 ± 0.87) × 10^?11; methyl pentanoate (7.84 ± 1.15) × 10^?11; methyl hexanoate (1.09 ± 0.31) × 10^?10; methyl heptanoate (1.56 ± 0.37) × 10^?10; methyl cyclohexane carboxylate (3.32 ± 0.76) × 10^?10; methyl-2-methyl butanoate (9.41 ± 1.39) × 10^?11.In addition rate coefficients (in units of 10^?11 cm³ molecule^?1 s^?1) have been obtained for the reactions of OH radicals with the following compounds: methyl butanoate (3.55 ± 0.71), methyl pentanoate (5.41 ± 1.08), and methyl-2-methyl butanoate (4.08 ± 0.82).Using the kinetic rate data tropospheric lifetimes for the methyl alkyl esters with respect to their reactions with OH, and Cl have been estimated for typical ambient air concentrations of these oxidants.     

Habitat Conditions and Correlations of Sediment Quality Triad Indicators in Delaware Bay

This paper summarizes sampling results from NOAA's National Status and Trends (NS&T) Program for marine environmental quality in Delaware Bay. A stratified-random design was used to determine the spatial extent of sediment contamination and toxicity in Delaware Bay from offshore stations in the coastal zone, the lower estuary, the upper estuary, the fresh/salt mixing zone, and tidal fresh areas. Sediment samples were taken for chemical analyses of major classes of environmental contaminants, a suite of toxicity bioassays, and benthic macrofaunal community assessment to identify patterns of resident species. The tidal-fresh areas and portions of the mixing zone of the study area were heavily contaminated. Contaminant concentrations were frequently above the 90th percentile of EMAP Virginian Province levels. PAHs in the sediment were higher than previously documented, with a major component of PAHs being pyrogenic in origin. Bioassay results were highly variable. Toxicity and contaminant levels were correlated when aggregated into indices, but were only marginally correlated with benthic community impacts. High and low abundance stations were found in all zones. Most of the tidal fresh stations were dominated by pollution tolerant species. Species diversity and abundance were generally lowest in the fresh/salt mixing zone.     

Biomonitoring with Gammarus pulex at the Meuse (NL), Aller (GER) and Rhine (F) rivers with the online Multispecies Freshwater Biomonitor

Biological early warning systems represent a set of tools that may be able to respond to certain chemical monitoring requirements of recent European legislation, the Water Framework Directive (WFD2000/60/EC), that aims to improve and protect water quality across Europe. In situ biomonitoring was performed along the rivers Meuse (NL), Aller (GER) and Rhine (F) within the frame of the European Union-funded Project SWIFT-WFD. Gammarus pulex was used as a test organism during the evaluation of the Multispecies Freshwater Biomonitor(R) (MFB), an online biomonitor to quantitatively record different behaviour patterns of animals. At the river Meuse G. pulex reacted to pulse exposure of either a mixture of trace metals or of several organic xenobiotics, by showing up to 20% decreased locomotory activity (already at the 1st pulse) and increased mortality (at 2nd or 3rd pulse only). G. pulex deployed within the MFB system were observed to survive well at the monitoring station on the Aller (100%) and monitoring did not result in the measurement of chemical irregularities. In contrast, deployment at the monitoring station on the Rhine river demonstrated that the test organism was able to detect chemical irregularities by up to 20% decreased locomotory activity in the animals. The MFB proved to be an alert system for water quality monitoring at sensitive sites and sites with accidental pollution.     

Efficient thinning regimes for Eucalyptus fastigata: Multi-objective stand-level optimisation using the island model genetic algorithm

A stand-level optimisation problem formulated to determine a set of efficient thinning regimes satisfying two objectives, i.e. value production for sawlog harvesting and volume production for a pulpwood market, was demonstrated for a Eucalyptus fastigata trial in Kaingaroa Forest, New Zealand. Genetic algorithms were used to estimate the set of efficient thinning regimes (i.e. regimes that occur when it is not possible to increase the achievement of one objective without reducing another) known as a Pareto frontier. Each thinning regime specified a unique combination of initial planting density; frequency, timing and intensity of thinning; final crop number; and rotation length. Specifications for the “best” regime in the Pareto set (i.e. the one that satisfied a balanced trade-off between value and volume production) were similar to those recommended through professional judgment based on pooled long-term field observations from different eucalypt species grown throughout New Zealand. The advantage of Pareto optimality was the ability of not only identifying a unique thinning regime, but equally efficient regimes each providing a different combination of value and volume production. Research on this approach has the potential of being applied to other forest sites, providing there is sufficient re-measurement data to reflect stand growth dynamics.