Robust optimization evaluation of reliance on locally produced foods

While local food production may be beneficial in terms of developing the local economy and reducing greenhouse gases from transportation, sustainability strategies focused on local food production may generate their own risks due to yield variability. We have developed a robust optimization (RO) model to determine the minimum amount of land (cropland and pasture) required to grow food items that would satisfy a local population’s (accounting for gender and age) calorie and nutrient needs. This model has been applied to Boone County, Missouri, which has a population of approximately 170,000. Boone County is 1790 km², with 16% of the land defined as cropland and 30% defined as pasture. The model includes 27 nutrients from 17 potential foods that could be produced: six fruits and vegetables, five grains and six animal-sourced foods. Yield estimates are based on the predominate methods of agriculture in the USA. We first run our model assuming no variability, using the midpoint yield estimates. Then, to quantify uncertainty in yield for different food types, we use historical yield data over 10 years to estimate this variability and run our RO model under these variability estimates. We compare the two model results to illustrate the impact of data uncertainty on meeting sustainable local food for communities. Solutions suggest that nutrition needs can be met for the Boone County population within the land area defined.     

Accelerated carbonation of different size fractions of bottom ash from RDF incineration

This paper investigates the effects of accelerated carbonation on the characteristics of bottom ash from refuse derived fuel (RDF) incineration, in terms of CO₂ uptake, heavy metal leaching and mineralogy of different particle size fractions. Accelerated aqueous carbonation batch experiments were performed to assess the influence of operating parameters (temperature, CO₂ pressure and L/S ratio) on reaction kinetics. Pressure was found to be the most relevant parameter affecting the carbonation yield. This was also found to be largely dependent on the specific BA fraction treated, with CO₂ uptakes ranging from ～4% for the coarse fractions to ～14% for the finest one. Carbonation affected both the mineralogical characteristics of bottom ash, with the appearance of neo-formation minerals, and the leaching behaviour of the material, which was found to be mainly related to the change upon carbonation in the natural pH of the ash.     

A review of municipal solid waste composition and quantities in Poland

A review of results of the research involving the quantitative and composition analyses of household waste conducted in Poland in recent years is presented in this paper. For these analyses various methodologies have been employed, as there is not one obligatory methodology how to characterise municipal solid waste. The results of the research in large Polish cities indicate great variability, which is difficult to be reasonably explained. This situation is affected by a number of factors, such as various methods and places for sample collection, various methods for tests, fractional character of most of the studies (studies carried out only in some periods during a year). Consequently, it is neither possible to measurably compare their results, nor to generalise them. Hence, within this article only individual data for large cities is provided. It is therefore necessary to standardise methodology for such analyses in Europe, taking into account local variability (such as different housing patterns, climate and waste collection schemes) to allow comparison of results.Reported yearly household waste generation in Polish cities varies from 238 to 309 kg per inhabitant. Biodegradable waste is a strongly dominated fraction in household waste from Polish cities, followed by paper/cardboard and plastics. Historical data shows that waste composition has undergone profound changes, the most significant being an increase of the share of plastics and decrease of fine fraction. The presented data indicates that waste composition strongly depends on the type of housing and its heating system. In the new multi-family buildings with central heating the share of paper and plastics is higher than in old houses with individual heating. In the latter ones the share of fine fraction is higher.     

Flexible reproductive strategies in tropical and temperate Sepioteuthis squids

A major difficulty confronting the determination of cephalopod reproductive life history is assessing over what portion of the life span an individual is reproductively mature and actively depositing eggs. This paper assesses the potential of the tropical Sepioteuthis lessoniana and two genetic types of the temperate Sepioteuthis australis, to spawn multiple batches of eggs at discrete times throughout the adult life span. This is achieved by histological examination of the ovarian gametogenic cycle and detailed morphological assessments of the reproductive system, in conjunction with other biological information. The genetic type of S. australis found at the northern limits of its Australian distribution showed evidence of a high correlation between body size and quantity of mature eggs, suggesting that eggs may be accumulating to be laid in a single batch. Although maturation was also a size-related process in S. lessoniana and Tasmanian S. australis, oviduct size was not correlated with body weight in mature females, which is indicative of multiple spawning. Further supporting evidence includes relatively low gonadosomatic indices, the heavier weight of the ovary relative to the oviduct, and the feeding activity of mature animals. Mature S. lessoniana and S. australis individuals were present at each location over very wide age and size ranges. In Tasmanian waters, there were distinct seasonal differences in the reproductive biology of S. australis. Summer-caught individuals had much higher gonadosomatic indices and may have been laying larger batches of eggs compared with winter-caught individuals. Summer-caught females also showed a negative correlation between egg size and egg number within the oviduct, suggesting that some individuals were producing fewer, larger eggs and others many smaller eggs. Evidence suggests that considerable flexibility is inherent in the reproductive strategy of both S. lessoniana and S. australis. Received: 11 May 2000 / Accepted: 12 September 2000     

State Intervention to Protect Endangered Species: Why History and Bad Luck Matter

Abstract: Illegal exploitation threatens the survival of many species, and anti-poaching legislation ("protection on paper") does not protect species. State enforcement is needed to support and supplement the formal status of endangered species, but state enforcement can be a source of instability leading to the demise of species if ad hoc rules are followed blindly. We demonstrate this with a model of poaching, wildlife, and government wildlife enforcement, but our findings apply more generally. Crucial assumptions of the dynamic model are that both poaching and enforcement effort increase or decrease whenever poaching effort and enforcement are relatively profitable or unprofitable activities, respectively. We found that multiple steady states may characterize the system's equilibrium. Depending on initial populations, the initial extent of state involvement, and random events, animal populations may be severely depleted or unexpectedly built up during transition phases. Our findings highlight the importance of history and luck in protecting endangered species.     

Inexact fuzzy-stochastic constraint-softened programming – A case study for waste management

In this study, an inexact fuzzy-stochastic constraint-softened programming method is developed for municipal solid waste (MSW) management under uncertainty. The developed method can deal with multiple uncertainties presented in terms of fuzzy sets, interval values and random variables. Moreover, a number of violation levels for the system constraints are allowed. This is realized through introduction of violation variables to soften system constraints, such that the model’s decision space can be expanded under demanding conditions. This can help generate a range of decision alternatives under various conditions, allowing in-depth analyses of tradeoffs among economic objective, satisfaction degree, and constraint-violation risk. The developed method is applied to a case study of planning a MSW management system. The uncertain and dynamic information can be incorporated within a multi-layer scenario tree; revised decisions are permitted in each time period based on the realized values of uncertain events. Solutions associated with different satisfaction degree levels have been generated, corresponding to different constraint-violation risks. They are useful for supporting decisions of waste flow allocation and system-capacity expansion within a multistage context.     

Reuse of Stormwater for Watering Gardens and Plants Using Green Gully: A New Stormwater Quality Improvement Device (SQID)

This paper introduces a new stormwater quality improvement device, called the "Green Gully" that collects, purifies, and reuses stormwater throughout an automated system. The working principal of the Green Gully is divided into two parts. Firstly, diverting stormwater from roadways to the diverter channel by filtering litter and secondly, watering the gardens and roadside plants with the stormwater that is collected from diverter channel. Stormwater treatment is an important step before reusing the water for gardening purpose. Different treatment levels (primary, secondary, and tertiary) are applied depending on the application to make water suitable for long-term storage and watering purposes. In this study, stormwater samples from three sites of Rockhampton City have been tested and analyzed to determine the quality of water for reuse. The parameters tested were electrical conductivity, pH, salinity, concentration of oil and grease, total suspended solid, turbidity, alkalinity, sodium, and chloride. The results of on-site stormwater quality tests are compared with the Australian and New Zealand Environment Conservation Council (ANZECC) standards and quality data available in the literature for each parameter suitable for irrigating roadside plants and gardening. Although, the results of this study is comparable with the literature data, a significantly different quality data are found compared to ANZECC standards. However, the samples collected for this study gave a basic understanding of stormwater quality issues for potential inflows to the Green Gully. Further study is recommended in order to establish mathematical link between raw stormwater quality and water quality required for gardening and irrigating roadside plants and for adopting required level of treatment facility with Green Gully for purifying and reusing water through an automated network system.     

Editorial: Statistical ecology and forest biometry

Environmental and Ecological Statistics -     

Fluoride accumulation in pasture forages and soils following long-term applications of phosphorus fertilisers.

Ingestion of soils with high fluoride (F) concentration may cause chronic fluorosis in grazing animals. Analysis of New Zealand pasture soils with long-term phosphorus (P) fertilisation histories showed that total surface soil (0-75 mm depth) F concentration increased up to 217-454 mg kg-1 with P fertiliser application. One-third to two-thirds of F applied in fertilisers resides in the top 75 mm soil depth. Pasture forage accumulation of F was low, and therefore, F intake by grazing animals through pasture consumption is expected to be much lower than F intake by soil ingestion. Ten annual applications of single superphosphate (30 and 60 kg P ha-1 year-1) to a Pallic Soil (Aeric Fragiaqualf) significantly increased total F and labile F (0.01 M CaCl2 extract) concentrations to 200 and 120 mm depths, respectively, of the 300 mm depth investigated. The mobility of F in the soil profile was similar to two other elements, P and cadmium derived from the fertiliser.