Considerations for Manufacturing Bio-Based Plastic Products

One engine that drives the United States’ economic growth is an ever-increasing demand for manufactured products, both at home and abroad. This increase has created a major concern for the environment in terms of disposing used goods and ensuring that these products are safe. As environmental concerns grow, however, renewable resources are gaining increasing attention, especially as industrial ecology and product biodegradability gain importance. Added to this, biological materials are increasingly being utilized to replace traditional materials in manufacturing. To aid both educators as well as researchers, this paper examines several considerations that are essential for manufacturing plastic products that contain biomaterials. These include the selection of materials, the selection of manufacturing processes, manufacturing costs, and the quality of final products. Additionally, several standard methods that are commonly used for the determination of mechanical and physical properties are compiled; thus this paper should be a useful resource for both educators and researchers. The trends discussed here and their implications are critical for those involved in manufacturing, because contrary to conventional wisdom, simultaneously meeting the material production needs of our society, as well as that of the environment are not mutually-exclusive.     

Rapid amino acid cycling in arctic and antarctic soils

Amino acids constitute one of the largest inputs of organic nitrogen (N) to most polar soils and have been hypothesized to be important in regulating vegetational succession and productivity in Arctic ecosystems. Our understanding of amino acid cycling in these soils, however, is poor. The aim of this study was to investigate the size and rate of turnover of the amino acid pool in a range of Arctic and Antarctic soils. Our results indicate that in polar soils with either high or low ornithogenic inputs the amino acid pool is small in comparison to the inorganic N pool (NO^–₃ and NH⁺₄). The free amino acid pool constituted only a small proportion of the total dissolved organic nitrogen (DON) pool in these soils. Here we show that these low concentrations may be due to rapid use by the soil microbial community in both Arctic and Antarctic soils. The turnover of the amino acid pool in soil was extremely rapid, with a half-life ranging from 2 to 24 h, indicating that this N pool can be turned over many hundred times each summer when polar soils are frequently unfrozen. The implications of amino acids in N cycling and plant and microbial nutrition are discussed.     

Impact of Land Use on Soluble Organic Nitrogen in Soil

Although it has been hypothesized that soluble organic nitrogen (SON) plays a central role in regulating productivity in some terrestrial ecosystems, the factors controlling the size of the SON pool in soil remain poorly understood. Therefore our principal aim in this work was to assess the impact of seven different land use systems (rough and managed grassland, deciduous and coniferous woodland, heathland, wetland and tilled land) on the size of the SON and inorganic N (NO ₃ ^– , NH ₄ ⁺ ) pools in the surface soil layer (0–15 cm). After extraction with deionised water, we found that in most cases the size of the water extractable organic N (WEON) pool was similar in size to the inorganic N pool. In contrast, the KCl extractable organic N (KClEON) pool constituted the dominant form of soluble N in soils under all land uses, perhaps indicating that significant amounts were held on the soil exchange phase. In contrast to inorganic N, which varied significantly with land use, the size of the KClEON and WEON pool was similar for all land uses with the exception of KClEON in tilled land, where significantly lower amounts were observed. We conclude that SON constitutes an important soil N pool in a broad range of land uses, and that its role in microbial N assimilation, plant nutrition and ecosystem responses to atmospheric N deposition warrants further attention. SAFRD, University of Newcastle, Newcastle-upon-Tyne, NE1 7RU, U.K.     

An assessment of Mississippi's nonindustrial private forest landowners knowledge of forestry BMP's

This study examined the knowledge levels of Mississippi Non Industrial Private Forest (NIPF) landowners. Data were collected by passing out surveys to participants in Best Management Practices (BMP) educational programs held in conjunction with County Forestry Association (CFA) meetings across Mississippi. Ten CFA's participated in this study. Educational program participants were asked to fill out a survey with several demographic and BMP questions prior to the educational program. Results show that BMP program participants owned an average of 113 hectares, whereas the average Mississippi NIPF landowner owns 20 hectares. Responses to BMP related questions show that Mississippi NIPF landowners have a low level of knowledge concerning BMP's. This situation is likely similar to other states in the Southeastern United States. It can be assumed that county forestry association members are more active and informed about managing their forest land. Therefore, these results may overestimate the BMP knowledge level all landowners in Mississippi.Improved educational programs for NIPF landowners, along with better communication between foresters, loggers, and NIPF landowners are needed if BMP's are to be implemented effectively in Mississippi and across the southern region.     

Building a place-responsive society through inclusive local projects and networks

This paper presents the story of a project undertaken by researchers who are active participants in the national Australian debate over place and belonging. It arose from the desire to ground this debate, which brings issues of ecological sustainability, reconciliation and multiculturalism together, in more localised action aimed at building a 'place-responsive society'. The project was carried out as a case study in a region that combines part of the Sydney metropolitan area and the separate 'city' of the Blue Mountains, and involved a consultative committee and then a regional forum of conservationists, environmental educators and community workers. The researchers explored existing place-oriented initiatives in the region and developed practical projects for the future, most notably a proposal for 'totemic species' work within schools involving local Aboriginal people. The research demonstrated, more than anything else, that indigenous Australian approaches to 'place awareness' and nature conservation remain highly relevant in contemporary Australia. It also showed that bioregional awareness and the notion of place responsiveness can add value to more traditional approaches to nature conservation and environmental education. There are opportunities to galvanise local action that can integrate community and environmental work and revitalise professional practice in both areas, but the effort involves working constantly with difference and conflict.     

Spatial prioritization of revegetation sites for dryland salinity management: an analytical framework using GIS

To address the limited application of analytical and modelling techniques in prioritizing revegetation sites for dryland salinity (saline land) management, a case study of the Hodgson Creek catchment in Queensland, Australia, was conducted. An analytical framework was developed, incorporating the use of spatial datasets (Landsat 7 image, DEM, soil map, and salinity map), which were processed using digital image processing techniques and a geographic information system (GIS). Revegetation sites were mapped and their priority determined based on recharge area, land use/cover and sub‐catchment salinity. The analytical framework presented here enhances the systematic use of land information, widens the scope for scenario testing, and improves the testing of alternative revegetation options. The spatial patterns of revegetation sites could provide an additional set of information relevant in the design of revegetation strategies.     

Rapid amino acid cycling in arctic and antarctic soils

Amino acids constitute one of the largest inputs of organic nitrogen (N) to most polar soils and have been hypothesized to be important in regulating vegetational succession and productivity in Arctic ecosystems. Our understanding of amino acid cycling in these soils, however, is poor. The aim of this study was to investigate the size and rate of turnover of the amino acid pool in a range of Arctic and Antarctic soils. Our results indicate that in polar soils with either high or low ornithogenic inputs the amino acid pool is small in comparison to the inorganic N pool (NO^? ₃ and NH⁺ ₄). The free amino acid pool constituted only a small proportion of the total dissolved organic nitrogen (DON) pool in these soils. Here we show that these low concentrations may be due to rapid use by the soil microbial community in both Arctic and Antarctic soils. The turnover of the amino acid pool in soil was extremely rapid, with a half-life ranging from 2 to 24 h, indicating that this N pool can be turned over many hundred times each summer when polar soils are frequently unfrozen. The implications of amino acids in N cycling and plant and microbial nutrition are discussed.