High Environmental Value Research Articles

Integrated use of biomarkers (acetylcholinesterase and antioxidant enzymes activities) in Mytilus galloprovincialis and Mullus barbatus in an Italian coastal marine area

The use of biomarkers to evaluate the biological effects of chemical pollutants in marine organisms represents a recent tool in the monitoring field responding to the need to detect and assess the effects of chemical contaminants on the biota. The aim of the present work was the field application of the integrated use of acetylcholinesterase (AChE) and antioxidant enzymes (catalase––CAT, glutathione peroxidase––GSH-Px), for detecting the possible exposure/effect induced by chemical pollutants in native marine organisms from a coastal marine area, represented by Salento Peninsula (Italy), that shows a coastline of high environmental value, but under constant urban pressure, including agriculture activities, widely diffused in the whole hinterland. Eight sampling stations were chosen: four not urbanized areas considered “uncontaminated” controls and four clearly exposed to anthropogenic impact. The bioindicator species studied were a sessile invertebrate, Mytilus galloprovincialis, and a benthic teleost fish, Mullus barbatus. AChE activity in M. galloprovincialis revealed significant differences among places; the minimum values observed (3.9±1.8 nmol min −1 mg −1) was about 50% reduced with respect to the maximum found (11.4±0.9 nmol min −1 mg −1). The reduction in AChE activity observed in two control stations could be explained by the leaching of pesticides into the sea from the agricultural lands. Moreover, the inhibition of AChE activity by heavy metals besides pesticides, can also explain the reduction of the enzymatic activity observed in an industrialized and harbour area. In M. galloprovincialis AChE activity showed a significant inverse correlation with catalase activity but not with glutathione peroxidase that did not significantly change in animals sampled from the eight stations. Also in M. barbatus AChE activity showed significant differences among places; it was inversely correlated with liver GSH-Px activity, but not with catalase activity, that did not show any significantly variation in animals sampled in the different stations. In conclusion, the integrated use of AChE and antioxidant enzymes (catalase or glutathione peroxidase) in M. galloprovincialis and M. barbatus, two species living in different compartment of marine coastal ecosystem, can find a useful application within the framework of marine coastal environment monitoring programs for detecting the possible exposure/effect induced by chemical pollutants, including pesticides, on living marine organisms.

Chemistry, Biology and Politics—The Case for Excellence in Environmental Assessment of Mining

From my perspective, the first part of this essay’s title encapsulates the essence of the environmental assessment of mining, namely the relationship between the chemistry of the aquatic environment (water quality), the organisms that live in the water, and the human interpretation/perception of the consequences of this interaction. In this essay I will refer to some specific examples from the tropical monsoonal region of Australia’s Northern Territory, a small part of which is shown in Figure 1. However, the issues I raise are generic to the mining industry and its relationship with chemistry professionals, regulators, and the community. Mining suffers from a number of perception issues in the public eye. The first of these often relates to location, since mining within or adjacent to areas of high conservation or environmental value is of concern to the community. The common perception is often one of mining as the despoiler, rather than of being potentially of net benefit to local communities and the Australian economy when it is appropriately carried out. A very potent image that regularly appears in the media is that of fish kills. If a mining operation is present in the general vicinity, the almost immediate reaction is to associate this event with the mine. However, in Northern Australia, especially in the rivers and wetlands of Kakadu National Park, large-scale mortality of fish is a regular natural occurrence and not a consequence of mining. Contrary to popular perception, the limnological environment in the northern wet–dry tropics presents one of the harshest of all freshwater habitats (Fig. 2). Rain falls for five to six months of the year—no rain for the rest—so the land alternates between flood and drought. Much limnological research on the topic of fish kills has been conducted across the floodplain environment over the past two decades. The data show that fish kills occur most David Jones is currently Principal Chemist and Manager of the Earth and Water Sciences group in Earth Water Life Sciences Pty Ltd (EWLS), a private consulting firm with an environmental science R&D focus, based in Darwin. Previously, he was a Principal Research Scientist at CSIRO, where he worked on elucidating bio-geochemical processes that control the release, subsequent transport and fate of inorganic contaminants from mining, electricity generating, and urban waste water sources. His current research interests lie in the multi-disciplinary application of the chemical, biological, and earth sciences to develop solutions for minimizing the environmental impact of mining, work over the past five years with EWLS focusing on the Ranger and Jabiluka uranium mines.

Ownership of Environmental Values and Opportunity Costs

Conservationists have recently used the concept of opportunity costs to calculate potential costs of conserving key sites with high environmental values. However, the validity of this approach can be questioned. The author briefly reviews property rights and decisionmaking on matters involving environmental values. Two examples are discussed: nature conservation, and the planting of genetically modified crops. The examples are considered in relation to existence values, citizens' preferences, problems associated with aggregating social preferences, and the observation that there are costs associated with exercising rights. The problems of the use of opportunity costs as a means of compensation for lost rights to environmental values are those of (1) who should determine the values; (2) whether payments should be made as compensation or as fines; and (3) who should receive the payments. These problems raise issues of equity, particularly as poor people often have claims to rights over areas with high environmental values. In conclusion, the roles of equity and sovereignty in the distribution of entitlements are emphasised and the difficulty of taking a policy decision to use market mechanisms for conserving biodiversity is discussed.

An analysis of externalities in agroforestry systems in the presence of land degradation

Agroforestry can help prevent land degradation while allowing continuing use of land to produce crops and livestock on a sustainable basis. Despite the recognition that trees may have a high environmental value at the local level and the attention agroforestry has received as a tool for sustainable agricultural development, there is a lack of formal economic analyses on the role of agroforestry; this need is addressed in this study. A general economic analysis of an agroforestry operation on land prone to degradation and in the presence of positive forest externalities is developed. A numerical application is presented, based on a biophysical model of a watershed. The model is used to assess the value of forest externalities and the marginal cost of land degradation. The potential cost of incentives required to achieve a given target level of land productivity is estimated. The technique illustrated in this paper could be used to provide cost estimates that would serve as a basis for initial negotiations between stakeholders in a watershed wishing to establish a common-property approach to land management.

The urban forestry programme in the heavily built-up milieu of Hong Kong

Urban forestry in Hong Kong is performed in exceptionally trying conditions due to the rampant occurrence of inherent physical and physiological constraints. The high-density development mode has resulted in cramped and poor-quality growing conditions both above and below the ground. The urban forest is unevenly scattered in a wide range of land uses with different canopy covers, species composition, tree dimensions and performance. Whilst overall tree number is limited, the floristic diversity is surprisingly high due to a combination of factors including a history of plant introduction, natural native diversity, and inheritance from pre-urbanization woodland and from former private gardens. Various participants and stakeholders play different roles in the urban forestry regime. Recent comprehensive studies of trees commissioned by the government at roadsides and urban parks provided valuable objective data and insight to design systematic and citywide management and planting plans. Trees dwelling in the peri- and intra-urban woodlands of high ecological and environmental values requires upgraded care and protection. The contribution of private developers in the urban greening programme needs to be encouraged with appropriate incentives, and be integrated into a comprehensive landscape plan.

Palaeohydrology, vegetation, and climate since the late Illinois Episode (∼130 ka) in south-central Illinois

Our interpretation of pollen and ostracode successions from four basins in south-central Illinois provides a new synthesis of palaeovegetation, palaeohydrology, and palaeoclimate for the period from the late Illinois Episode (about 130,000 years ago) to near the end of the Wisconsin Episode (about 25,000 years ago). Correlations of pollen biozones between Raymond, Pittsburg, and Bald Knob basins are the basis for identifying the late Illinois glacial, Sangamon interglacial, Wisconsin glacial, and Hudson interglacial episodes. Glacial episodes were identified primarily by the presence of Picea pollen and the ostracode Limnocythere friabilis, whereas interglacial episodes were identified by Quercus pollen and by the ostracodes Candona caudata and Heterocypris punctata. Within interglacial and glacial episodes, pollen and ostracode assemblages varied with changes in moisture balance. Local palaeohydrology was assessed primarily on the basis of environmental tolerance indices of ostracodes and the stable isotope (C,O) stratigraphy of ostracodal calcite. Regional moisture balance was assessed from multivariate analyses of the pollen successions. Three climatic regimes occurred during the Sangamon Episode. (1) One regime was characterised by precipitation exceeding evaporation that promoted basin overflow. This climate was inferred from the high percentages (generally >80%) of deciduous-forest pollen. Peaks in the abundance of Liquidambar and Fagus pollen indicate that winters may have been slightly warmer, and effective moisture slightly greater, than at present. (2) The second climatic regime was continental, similar to the present climate of Illinois in which precipitation is equal to or just less than evaporation. This climate is inferred from abundant Ambrosia pollen (40 to 60%) and abundant nektic (swimming) ostracode valves which suggest a shallow lake. These conditions probably developed in association with a ‘heat-low’ over the interior of North America during marine oxygen isotope stages 5e and 5c. Associated with the transition between the first two climates are fossils of the subtropical ostracode Heterocypris punctata and the giant tortoise Geochelone crassiscutata that suggest short periods in winter when polar low-pressure systems did not extend into Illinois as they do today. (3) The third climatic regime occurred during the transition from the Sangamon interglacial episode to the Wisconsin glacial episode. A severely continental climate is indicated by the heat-tolerant ostracode Pelocypris tuberculatum, variable δ 18O values of ostracode valves, and high environmental tolerance index values for the ostracode assemblages. The weedy Chenopodiaceae and Amaranthaceae families grew on exposed mudflats. The tree pollen associated with this type of climate included low percentages of Picea and Liquidambar, an assemblage that has no modern analogue. We suggest that this transitional climatic regime was associated with the large-scale changes in the climate system during marine oxygen isotope stage 4.

Ecological effects of fire fighting foams and retardants: a summary

Summary The use of fire fighting chemicals in Australia is increasing, yet few data are available to allow evaluation of their potential environmental effects on Australian ecosystems. These chemical retardants and foams are used extensively in natural areas with high environmental value, and there is a need to evaluate the effects of the fire compared with the effects of the fire retardant and suppressant chemicals. A summary of the data available suggests that there is significant potential for damage to terrestrial vegetation from fire retardants, and to aquatic ecosystems from fire fighting foams. There is a need to quantify the impacts of foams and retardants on native vegetation, and verify the effects of foams on aquatic organisms. There is great potential for the use of foams for prescribed burning operations, as well as wildfire suppression, but its widespread use should be minimised until its potential ecological impacts can be assessed. Existing guidelines for handling foam in the field should be strictly enforced.

Towards and Integrated Sustainable Development Management Strategy for Torres Strait

Lying between mainland Australia and Papua New Guinea, Torres Strait is a region of high environmental value faced by a plethora of environmental management issues. Although the environment is protected to some extent by the Torres Strait Treaty, the situation is complicated by the desire of the traditional inhabitants for political and economic autonomy and by the involvement of three levels of government, two sovereign nations and a wide range of sectoral interests in environmental management. The failure to extend the moratorium on mining exploration and exploitation of the seabed may act as a catalyst for the development of an integrated and sustainable approach to environmental management in the region. Nevertheless, there are significant constraints which may prevent this. These include the politicisation of environmental issues, lack of effective environmental management at the local level and pressure for the exploitation of natural resources.

Current understanding of white and red pine physiology

For significant and predictable improvements in productivity of red and white pine forests, an increased understanding of the physiological processes in these species is essential. Relatively little physiological research has focused on these two species over the last two decades. However, with renewed interest in these species now for their high social, environmental and economic value this situation is changing. This paper describes past efforts at understanding red and white pine physiology, as well as discussing recent achievements. In addition, new results obtained by the authors through the use of Biotronic growth units are described in more detail to emphasize the high adaptability of white pine seedlings in response to nutrient stress through changes in carbon distribution, nutrient uptake and utilization.The ultimate practical output of much forestry research is often models predicting tree and forest growth. However, models which are based solely on empirical growth measurement data will not provide the understanding that is necessary for sustainable management; thus, increased research on physiological processes will continue to be required in future. Long-term detailed field studies that consider environmental and silvicultural influences at the organ and whole tree level are required to ensure that future models have high explanatory value. Key words: white pine, red pine, tree physiology, photosynthesis, seedling nutrition, silviculture

Development of Mediterranean agriculture: An ecological approach

Environmental conditions in Mediterranean Europe impose restrictions on the development of modern agrarian practice. Traditional Mediterranean agriculture generated landscapes of high environmental value, permitting the cultivation of a wide variety of crops with a sustained production, but with mean yields inferior to those of Atlantic Europe. In recent times the evolution of Mediterranean agriculture has followed a dual process of a more intensive production in more fertile lands and marginalization and abandonment of the least productive lands. Both tendencies have been exacerbated by the introduction of CAP mechanisms, resulting in environmental deterioration. The new set-aside and extensification policies increase the uncertainty concerning environmental quality in the Mediterranean area. It is therefore recommended to set up specific policies for each individual area, taking into consideration the particular ecological characteristics and development of the Mediterranean region, thereby safe-guarding the conservation of its interesting agrarian landscapes.