Adding value to ecological risk assessment with population modeling

Current measures used to estimate the risks of toxic chemicals are not relevant to the goals of the environmental protection process, and thus ecological risk assessment (ERA) is not used as extensively as it should be as a basis for cost-effective management of environmental resources. Appropriate population models can provide a powerful basis for expressing ecological risks that better inform the environmental management process and thus that are more likely to be used by managers. Here we provide at least five reasons why population modeling should play an important role in bridging the gap between what we measure and what we want to protect. We then describe six actions needed for its implementation into management-relevant ERA.

Sizing reserves within a landscape: the roles of villagers' reactions and the ecological-socioeconomic setting

Traditionally, siting and sizing decisions for parks and reserves reflected ecological characteristics but typically failed to consider ecological costs created from displaced resource collection, welfare costs on nearby rural people, and enforcement costs. Using a spatial game-theoretic model that incorporates the interaction of socioeconomic and ecological settings, we show how incorporating more recent mandates that include rural welfare and surrounding landscapes can result in very different optimal sizing decisions. The model informs our discussion of recent forest management in Tanzania, reserve sizing and siting decisions, estimating reserve effectiveness, and determining patterns of avoided forest degradation in Reduced Emissions from Deforestation and Forest Degradation programs.

The relationship between European Community agricultural Structural Policies and their implementation and agricultural succession and inheritance within Member States

This paper presents an overview of the European Union involvement in agricultural restructuring. By way of introduction it looks at the processes of farm replication operating in Europe and the forces behind them. It then considers the wider application of EU measures in each Member State and how they interrelate with the national property laws and social customs. In conclusion the paper appraises the restructuring policies by examining the balance between legitimising the concentration of property rights amongst a minority and the fragmentation of estates between the majority.

Retirement and succession on the family farm

For farmers, the decision as to when to retire is probably one of the hardest that they will have to face during their working lives. The business of farming brings special circumstances which means that retirement is more often a process than a definitive action. This paper seeks firstly to clarify those special circumstances, and then, by means of flow charts, to identify the key decisions which must be faced if the retirement is to be successful. The practise of handing on the farmland and the other business assets to the next generation are regarded as separate but interrelated stages in the process of retirement, both having legal, financial and human consequences which are considered. By way of conclusion, the parameters for a successful retirement are considered, both from the standpoint of the retirer and of the successor.

Succession to farm tenancies: future imperfect?

Until the law was amended in 1984, the tenants of agricultural holdings enjoyed security of tenure for life, plus the prospect of two family successions to their tenancies, virtually guaranteeing a tenant- farming family at least three generations occupation of a holding. The orthodox view has been that any transfers of interests that took place before the passing of the Act which introduced the scheme in 1976 would not count towards the inherent 'totting-up' process. The 1993 High Court judgement in Saunders v Ralph has raised serious questions as to the validity of that assertion. This paper seeks to identify the key legal provisions involved and to highlight the problems that may result from the case.

On the edge: Southern Levantine Epipalaeolithic–Neolithic chronological succession

The broad picture of the cultural and chronological succession from the Epipalaeolithic to the Neolithic in the southern Levant is generally well understood. However, at a more detailed, local level, many questions remain unanswered. In this paper we examine the archaeological record of cultural developments in southern Jordan and the Negev. Focusing on a series of 14C dates from the early occupation of the PPNA site of WF16, we provide a critical review of dating evidence for the region. This review suggests that while the 14C chronology is ambiguous and problematic there is good evidence for a local historical development from the Harifian variant of the Natufian to the early PPNA, well to the south of any core Mediterranean woodland zone. This stresses the importance of considering developments at local scales of analysis, and that the Neolithic transition occurred within a framework of many interacting sub-regional provinces.

The monitoring of ecological quality and the classification of standing waters in temperate regions: a review and proposal based on a worked scheme for British waters

This paper reviews the ways that quality can be assessed in standing waters, a subject that has hitherto attracted little attention but which is now a legal requirement in Europe. It describes a scheme for the assessment and monitoring of water and ecological quality in standing waters greater than about I ha in area in England & Wales although it is generally relevant to North-west Europe. Thirteen hydrological, chemical and biological variables are used to characterise the standing water body in any current sampling. These are lake volume, maximum depth, onductivity, Secchi disc transparency, pH, total alkalinity, calcium ion concentration, total N concentration,winter total oxidised inorganic nitrogen (effectively nitrate) concentration, total P concentration, potential maximum chlorophyll a concentration, a score based on the nature of the submerged and emergent plant community, and the presence or absence of a fish community. Inter alia these variables are key indicators of the state of eutrophication, acidification, salinisation and infilling of a water body.

Community-based climate change adaptation strategies for integrated prawn-fish-rice farming in Bangladesh to promote social-ecological resilience

Farming freshwater prawns with fish in rice fields is widespread in coastal regions of southwest Bangladesh because of favourable resources and ecological conditions. This article provides an overview of an ecosystem-based approach to integrated prawn-fish-rice farming in southwest Bangladesh. The practice of prawn and fish farming in rice fields is a form of integrated aquaculture-agriculture, which provides a wide range of social, economic and environmental benefits. Integrated prawn-fish-rice farming plays an important role in the economy of Bangladesh, earning foreign exchange and increasing food production. However, this unique farming system in coastal Bangladesh is particularly vulnerable to climatechange. We suggest that community-based adaptation strategies must be developed to cope with the challenges. We propose that integrated prawn-fish-rice farming could be relocated from the coastal region to less vulnerable upland areas, but caution that this will require appropriate adaptation strategies and an enabling institutional environment.

Ecological intensification: harnessing ecosystem services for food security

Rising demands for agricultural products will increase pressure to further intensify crop production, while negative environmental impacts have to be minimized. Ecological intensification entails the environmentally friendly replacement of anthropogenic inputs and/or enhancement of crop productivity, by including regulating and supporting ecosystem services management in agricultural practices. Effective ecological intensification requires an understanding of the relations between land use at different scales and the community composition of ecosystem service-providing organisms above and below ground, and the flow, stability, contribution to yield, and management costs of the multiple services delivered by these organisms. Research efforts and investments are particularly needed to reduce existing yield gaps by integrating context-appropriate bundles of ecosystem services into crop production systems.

A complex system perspective on the emergence and spread of infectious diseases: integrating economic and ecological aspects

The emergence and spread of infectious diseases reflects the interaction of ecological and economic factors within an adaptive complex system. We review studies that address the role of economic factors in the emergence and spread of infectious diseases and identify three broad themes. First, the process of macro-economic growth leads to environmental encroaching, which is related to the emergence of infectious diseases. Second, there are a number of mutually reinforcing processes associated with the emergence/spread of infectious diseases. For example, the emergence and spread of infectious diseases can cause significant economic damages, which in turn may create the conditions for further disease spread. Also, the existence of a mutually reinforcing relationship between global trade and macroeconomic growth amplifies the emergence/spread of infectious diseases. Third, microeconomic approaches to infectious disease point to the adaptivity of human behavior, which simultaneously shapes the course of epidemics and responds to it. Most of the applied research has been focused on the first two aspects, and to a lesser extent on the third aspect. With respect to the latter, there is a lack of empirical research aimed at characterizing the behavioral component following a disease outbreak. Future research should seek to fill this gap and develop hierarchical econometric models capable of integrating both macro and micro-economic processes into disease ecology.