Jon D. Erickson

Linking Ecology and Economics for Ecosystem Management

Abstract This article outlines an approach, based on ecosystem services, for assessing the trade-offs inherent in managing humans embedded in ecological systems. Evaluating these trade-offs requires an understanding of the biophysical magnitudes of the changes in ecosystem services that result from human actions, and of the impact of these changes on human welfare. We summarize the state of the art of ecosystem services–based management and the information needs for applying it. Three case studies of Long Term Ecological Research (LTER) sites—coastal, urban, and agricultural—illustrate the usefulness, information needs, quantification possibilities, and methods for this approach. One example of the application of this approach, with rigorously established service changes and valuations taken from the literature, is used to illustrate the potential for full economic valuation of several agricultural landscape management options, including managing for water quality, biodiversity, and crop productivity.

A “One Health” Approach to Address Emerging Zoonoses: The HALI Project in Tanzania

Jonna Mazet and colleagues describe their work in the Tanzania-based HALI Project, which adopts the “One Health” approach to address emerging zoonoses and that recognizes the interconnectedness of human, animal, and environmental health.

Solar power and climate change policy in developing countries

Solar energy is one option for reducing future greenhouse gas emissions. Offsetting 50% of all future growth in thermal electricity generation by photovoltaics (PVs) would reduce annual global carbon dioxide emission from projected increased levels by 10% in 20 years and 32% in 50 years. Several projects are under way worldwide to demonstrate the feasibility of PV systems. This paper examines the economic competitiveness of PV systems and concludes that even after including externality costs, without significant technological breakthroughs, the economics of PV applications are unlikely to allow for an unsubsidized, widespread adoption of this technology in the near future. Further, if the goal of PV transfer programmes is to limit future greenhouse gas emissions, there are larger and cheaper opportunities available in industrialized countries to achieve reductions. Alternative measures for ensuring a market for photovoltaics, hence providing manufacturers with opportunities to improve the current technology, include mandating that utilities install a certain quantity of solar technologies by a certain date. Finally, moving towards a renewable energy future that includes PV systems requires a sustained R&D programme that will lead to improvements in panel and other system efficiencies.

Cross-Linking of IgE-Receptor complexes at the cell surface: A fluorescence method for studying the binding of monovalent and bivalent haptens to IgE

We have developed a method for use in investigating factors controlling the binding and cross-linking by bivalent haptens of immunoglobulin E (IgE) bound to receptors on rat basophilic leukemia (RBL) cells. This method employs monoclonal anti-2,4-dinitrophenyl (DNP) IgE that is labeled with fluorescein-5-isothiocyanate (FITC), and it measures FITC quenching that accompanies DNP occupation of the antibody combining sites in a titration experiment. The validity of this approach is demonstrated using the monovalent hapten DNP-L-lysine. The affinity constant for this ligand obtained by the FITC quenching method is compared with those obtained with previously established methods: equilibrium dialysis and quenching of endogenous tryptophan for IgE in solution and [3H]-DNP-L-lysine binding to IgE on cells. The FITC quenching method has been used to carry out a detailed study of the binding of monovalent DNP-aminocapryol-L-tyrosine (DCT) and bivalent (DCT)2-cystine to FITC-IgE and its Fab fragments in solution. Intrinsic (K) and cross-linking (Kx) affinity constants are obtained by analyzing the binding curves in terms of simple equilibrium equations. With these DCT haptens the ability of this method to assess hapten binding and cross-linking of IgE bound to receptors on RBL cells is shown.

Cross-linking of IgE-receptor complexes at the cell surface: synthesis and characterization of a long bivalent hapten that is capable of triggering mast cells and rat basophilic leukemia cells.

The ability of a series of bivalent haptens to bind and cross-link immunoglobulin E (IgE) in solution and on the surface of cells was examined. Several short (less than 30 A) dinitrophenyl (DNP) haptens were found to bind tightly to and cross-link a monoclonal anti-DNP IgE in solution, but these failed to trigger substantial release of 3H-serotonin from sensitized rat basophilic leukemia (RBL) cells or rat peritoneal mast cells. A longer bivalent hapten, approximately 50 A in length, consisting of two DNP-aminocaproyl-L-tyrosine (DCT) groups coupled to the alpha-amino groups of L-cystine was synthesized and characterized. This bivalent hapten [(DCT)2-cystine], binds very tightly to the same monoclonal anti-DNP IgE in solution and cross-links these antibodies to form higher mol. wt aggregates as judged by gel filtration and binding studies. It also stimulates degranulation of both RBL and mast cells sensitized with two different monoclonal anti-DNP IgE antibodies, with the mast cells exhibiting generally greater responsiveness to this ligand. The (DCT)2-cystine bivalent hapten appears to have the structural features necessary for carrying out detailed binding studies with receptor-bound IgE on the cell surface.

INCORPORATING CATASTROPHES INTO INTEGRATED ASSESSMENT: SCIENCE, IMPACTS, AND ADAPTATION

Incorporating potential catastrophic consequences into integrated assessment models of climate change has been a top priority of policymakers and modelers alike. We review the current state of scientific understanding regarding three frequently mentioned geophysical catastrophes, with a view toward their implications for integrated assessment modeling. This review finds inadequacies in widespread model assumptions regarding the nature of catastrophes themselves and climate change impacts more generally. The possibility of greatly postponed consequences from near- and medium-term actions suggests that standard discounting practices are inappropriate for the analysis of climate catastrophe. Careful consideration of paleoclimate and geophysical modeling evidence regarding the possibility of changes in ocean circulation suggests a reframing of the source of climate change damages in economic models, placing changes in climate predictability, rather than gradual changes in mean values, at the focus of economic damage assessments. The implications of decreases in predictability for the modeling of adaptation are further discussed.

New perspectives in ecosystem services science as instruments to understand environmental securities

As societal demand for food, water and other life-sustaining resources grows, the science of ecosystem services (ES) is seen as a promising tool to improve our understanding, and ultimately the management, of increasingly uncertain supplies of critical goods provided or supported by natural ecosystems. This promise, however, is tempered by a relatively primitive understanding of the complex systems supporting ES, which as a result are often quantified as static resources rather than as the dynamic expression of human–natural systems. This article attempts to pinpoint the minimum level of detail that ES science needs to achieve in order to usefully inform the debate on environmental securities, and discusses both the state of the art and recent methodological developments in ES in this light. We briefly review the field of ES accounting methods and list some desiderata that we deem necessary, reachable and relevant to address environmental securities through an improved science of ES. We then discuss a methodological innovation that, while only addressing these needs partially, can improve our understanding of ES dynamics in data-scarce situations. The methodology is illustrated and discussed through an application related to water security in the semi-arid landscape of the Great Ruaha river of Tanzania.

Interaction of IgE with Its High-Affinity Receptor

Structural interactions between IgE and its high-affinity receptor have been investigated with the methods of fluorescence resonance energy transfer and genetic engineering. The results indicate that IgE has a bent conformation when bound to receptor on the cell surface and that the site of interaction is contained in the C epsilon 2 and C epsilon 3 domains; the C-terminal domain, C epsilon 4, is not required for binding. Cross-linking of IgE-receptor complexes is required for signal transduction across the plasma membrane. Binding studies with defined bivalent ligands indicate that structural and/or kinetic features determine the functional effectiveness of the cross-linked states.

Photovoltaic technology: Markets, economics, and rural development

Abstract Photovoltaic (PV) electricity has been widely supported as a remote energy source for developing countries. In response, the production and shipment of PV modules in developed nations has steadily increased through the past decade, often marketed through the auspices of technology transfer and financed by international development aid. This paper investigates the motives, economics, and development implications of PVs in rural electrification, drawing on field research in the Dominican Republic. The implications of subsidizing a PV market rather than investing in further PV research and development are explored.

Urban Metabolism and Payment for Ecosystem Services: History and Policy Analysis of the New York City Water Supply

The interaction of urban cores and their rural hinterlands is considered from an ecological–economic perspective. The concept of ‘urban metabolism’ motivates discussion of urban dependence on geographic regions outside their borders for both sources of inputs and as waste sinks. The U.S. Environmental Protection Agencys 1989 Surface-Water Treatment Rule forces cities to consider the ecosystem services preserved by appropriate land-use management inside suburban and rural watersheds used for urban water supplies. A case study of New York City and its water supply from the Catskill–Delaware watershed system is used to explore these themes. Compensation from the city to watershed communities may be an effective way to motivate protection of those ecosystem functions. Both direct payments and investment in economic development projects consistent with water quality goals are reviewed as policy instruments.