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Browsing Gund Institute for Ecological Economics by Title

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  • Manukyan, N.; Eppstein, M. J.; Rizzo, D. M. (IEEE TRANSACTIONS ON NEURAL NETWORKS ON LEARNING SYSTEMS, 2012
      A self-organizing map (SOM) is a self-organized projection of high-dimensional data onto a typically 2-dimensional (2-D) feature map, wherein vector similarity is implicitly translated into topological closeness in the 2-D projection. However, when there are more neurons than input patterns, it can be challenging to interpret the results, due to diffuse cluster boundaries and limitations of current methods for displaying interneuron distances. In this brief, we introduce a new cluster reinforcement (CR) phase for sparsely-matched SOMs. The CR phase amplifies within-cluster similarity in an unsupervised, datadriven manner. Discontinuities in the resulting map correspond to between-cluster distances and are stored in a boundary (B) matrix. We describe a new hierarchical visualization of cluster boundaries displayed directly on feature maps, which requires no further clustering beyond what was implicitly accomplished during self-organization in SOM training. We use a synthetic benchmark problem and previously published microbial community profile data to demonstrate the benefits of the proposed methods.
  • Moeliono, M.; Wollenberg, E.; Limberg, G.; eds (Earthscan Publications, London, UK.London, UK, 2009
  • Ferreira, D.; Suslick, S.; Farley, J.; Costanza, R.; Krivov, S. (Energy Policy, 2004
      The main objective of this paper is to deepen the discussion regarding the application of financial assurance instruments, bonds, in the upstream oil sector. This paper will also attempt to explain the current choice of instruments within the sector. The concepts of environmental damages and internalization of environmental and regulatory costs will be briefly explored. Bonding mechanisms are presently being adopted by several governments with the objective of guaranteeing the availability of funds for end-of-leasing operations. Regulators are mainly concerned with the prospect of inheriting liabilities from lessees. Several forms of bonding instruments currently available were identified and a new instrument classification was proposed. Ten commonly used instruments were selected and analyzed under the perspective of both regulators and industry (surety, paid-in and periodic-payment collateral accounts, letters of credit, self-guaran tees, investment grade securities, real estate collaterals, insurance policies, pools, and special funds). A multiattribute value function model was then proposed to examine current instrument preferences. Preliminary simulations confirm the current scenario where regulators are likely to require surety bonds, letters of credit, and periodic payment collateral account tools. (C) 2003 Elsevier Science Ltd. All rights reserved.
  • Macedo, M. N.; DeFries, R. S.; Morton, D. C.; Stickler, C. M.; Galford, G. L.; Shimabukuro, Y. E. (Proceedings of the National Academy of Sciences of the United States of America, 2012
      From 2006 to 2010, deforestation in the Amazon frontier state of Mato Grosso decreased to 30% of its historical average (1996-2005) whereas agricultural production reached an all-time high. This study combines satellite data with government deforestation and production statistics to assess land-use transitions and potential market and policy drivers associated with these trends. In the forested region of the state, increased soy production from 2001 to 2005 was entirely due to cropland expansion into previously cleared pasture areas (74%) or forests (26%). From 2006 to 2010, 78% of production increases were due to expansion (22% to yield increases), with 91% on previously cleared land. Cropland expansion fell from 10 to 2% of deforestation between the two periods, with pasture expansion accounting for most remaining deforestation. Declining deforestation coincided with a collapse of commodity markets and implementation of policy measures to reduce deforestation. Soybean profitability has since increased to pre-2006 levels whereas deforestation continued to decline, suggesting that antideforestation measures may have influenced the agricultural sector. We found little evidence of direct leakage of soy expansion into cerrado in Mato Grosso during the late 2000s, although indirect land-use changes and leakage to more distant regions are possible. This study provides evidence that reduced deforestation and increased agricultural production can occur simultaneously in tropical forest frontiers, provided that land is available and policies promote the efficient use of already-cleared lands (intensification) while restricting deforestation. It remains uncertain whether government- and industry-led policies can contain deforestation if future market conditions favor another boom in agricultural expansion.
  • Fisher, B.; Turner, R. K.; Morling, P. (Ecological Economics, 2009
      The concept of ecosystems services has become an important model for linking the functioning of ecosystems to human welfare. Understanding this link is critical for a wide-range of decision-making contexts. While there have been several attempts to come up with a classification scheme for ecosystem services, there has not been an agreed upon, meaningful and consistent definition for ecosystem services. In this paper we offer a definition of ecosystem services that is likely to be operational for ecosystem service research and several classification schemes. We argue that any attempt at classifying ecosystem services should be based on both the characteristics of the ecosystems of interest and a decision context for which the concept of ecosystem services is being mobilized. Because of this there is not one classification scheme that will be adequate for the many contexts in which ecosystem service research may be utilized. We discuss several examples of how classification schemes will be a function of both ecosystem and ecosystem service characteristics and the decision-making context. (C) 2008 Elsevier B.V. All rights reserved.
  • Kleijn, D.; Winfree, R.; Bartomeus, I.; Carvalheiro, L. G.; Henry, M.; Isaacs, R.; Klein, A. M.; Kremen, C.; M'Gonigle, L. K.; Rader, R.; Ricketts, T. H.; Williams, N. M.; Adamson, N. L.; Ascher, J. S.; Baldi, A.; Batary, P.; Benjamin, F.; Biesmeijer, J. C.; Blitzer, E. J.; Bommarco, R.; Brand, M. R.; Bretagnolle, V.; Button, L.; Cariveau, D. P.; Chifflet, R.; Colville, J. F.; Danforth, B. N.; Elle, E.; Garratt, M. P. D.; Herzog, F.; Holzschuh, A.; Howlett, B. G.; Jauker, F.; Jha, S.; Knop, E.; Krewenka, K. M.; Le Feon, V.; Mandelik, Y.; May, E. A.; Park, M. G.; Pisanty, G.; Reemer, M.; Riedinger, V.; Rollin, O.; Rundlof, M.; Sardinas, H. S.; Scheper, J.; Sciligo, A. R.; Smith, H. G.; Steffan-Dewenter, I.; Thorp, R.; Tscharntke, T.; Verhulst, J.; Viana, B. F.; Vaissiere, B. E.; Veldtman, R.; Westphal, C.; Potts, S. G. (Nature CommunicationsNat. Commun., 2015
      There is compelling evidence that more diverse ecosystems deliver greater benefits to people, and these ecosystem services have become a key argument for biodiversity conservation. However, it is unclear how much biodiversity is needed to deliver ecosystem services in a cost- effective way. Here we show that, while the contribution of wild bees to crop production is significant, service delivery is restricted to a limited subset of all known bee species. Across crops, years and biogeographical regions, crop-visiting wild bee communities are dominated by a small number of common species, and threatened species are rarely observed on crops. Dominant crop pollinators persist under agricultural expansion and many are easily enhanced by simple conservation measures, suggesting that cost- effective management strategies to promote crop pollination should target a different set of species than management strategies to promote threatened bees. Conserving the biological diversity of bees therefore requires more than just ecosystem-service-based arguments.
  • Kemkes, R. J.; Farley, J.; Koliba, C. J. (Ecological Economics, 2010
      There are several policy tools available for the provision of ecosystem services. The economic characteristics of the ecosystem service being provided, such as rivalry and excludability, along with the spatial scale at which benefits accrue can help determine the appropriate policy approach. In this paper we provide a brief introduction to ecosystem services and discuss the policy tools available for providing them along with the dimensions, political feasibility and appropriateness of each tool. Throughout the paper we focus primarily on payments as a mechanism for ecosystem service provision. We present a framework for determining the characteristics of an ecosystem service and when payments are a viable policy tool option based on the characteristics. Additionally, we provide examples of when payments do not provide a socially desirable level of ecosystem benefits. We conclude with a summary of policy recommendations, specifically desirable property rights and payment types based on the particular classification of an ecosystem service. We also discuss the advantages of creating monopsony power to reduce transaction costs, delineating and bundling ecosystem services and utilizing existing intermediaries. (C) 2009 Elsevier B.V. All rights reserved.
  • Xu, Y. Y.; Schroth, A. W.; Rizzo, D. M. (Limnology and Oceanography-MethodsLimnol. Oceanogr. Meth., 2015
      Over the past 30+ years, researchers and water resource managers have often relied on a set of regression-based equations to describe the relationships between secchi depth (SD), chlorophyll (Chl) and total phosphorous (TP) and quantitatively assess lake trophic status after Carlson (1977). Here, we develop a revised framework for eutrophication assessment that incorporates recent statistical advances in ecology and leverages the increasing availability of lake-specific datasets in the 21st Century. Long-term (1992-2012) water quality data from Lake Champlain (LC) are used to revisit and revise classic equations of tropic state indices (TSIChl/TP). The upper boundaries of SD-ln(Chl) and ln(Chl)-ln(TP) distributions within this dataset fit well with quantile regression (99th, QR) to generate LC-specific TSIChl/TP equations. Our results illustrate that Carlson (1977)'s original TSIChl/TP equations overestimate the trophic status of LC relative to LC-specific equations, and highlight the power of the QR-derived TSIChl/TP metric. We combine TSISD and TSIChl into one metric to indicate pseudoeutrophication and pseudomesotrophication of oligotrophic waters as well as pseudoeutrophication of mesotrophic waters to identify waters threatened by potential trophic shift. Additionally, TSIChl and TSITP were coupled as a complimentary dual metric to indicate potential risks of excessive phosphorus loading to oligotrophic and mesotrophic waters. With these dual metric schemes, we performed cluster analysis of 15 locations to spatially assess trophic status and phosphorous risks across LC. This study describes a relatively simple and robust approach for lake-specific status assessment, the structure of which can be broadly utilized within monitoring and research communities.
  • Seguino, Stephanie (The Review of Black Political EconomyRev Black Polit EconSpringer-Verlag, Dordrecht, Netherlands., 2012
  • Roman, J. (Proceedings of the Royal Society B-Biological Sciences, 2006
      Most invasion histories include an estimated arrival time, followed by range expansion. Yet, such linear progression may not tell the entire story. The European green crab (Carcinus maenas) was first recorded in the US in 1817, followed by an episodic expansion of range to the north. Its population has recently exploded in the Canadian Maritimes. Although it has been suggested that this northern expansion is the result of warming sea temperatures or cold-water adaptation, Canadian populations have higher genetic diversity than southern populations, indicating that multiple introductions have occurred in the Maritimes since the 1980s. These new genetic lineages, probably from the northern end of the green crab's native range in Europe, persist in areas that were once thought to be too cold for the original southern invasion front. It is well established that ballast water can contain a wide array of nonindigenous species. Ballast discharge can also deliver genetic variation on a level comparable to that of native populations. Such gene flow not only increases the likelihood of persistence of invasive species, but it can also rapidly expand the range of long-established nonindigenous species.
  • Koliba, C.; Zia, A. (Administrative Theory & Praxis, 2009
      The legitimacy of democratic governments hinges on the capacity of public institutions and their elected and appointed leaders to successfully fulfill their sovereign obligations. Dating back to Alexander Hamilton’s insistence on creating the Department of Treasury, these sovereign obligations have presumably been extended into matters pertaining to the health of the national economy. Since the Great Depression, national economic policies have been designed and implemented with regularity. These policies have ranged from large scale public works projects of the New Deal, to the creation of economic regulation subsystems during the post WWII era, , to the de-regulation and privatization movements of the re-reinventing governments era.. Economic policies have often been framed in terms of certain philosophies, political ideologies and governance theories that run the gamut from Keynesian, Neo-classical, Real Business Cycle, and New Public Management conceptions of government and market relationships. We argue that this recent history needs to be taken into consideration as questions about the implications of the economic crisis for the democratic legitimacy of governments are raised. We conclude that the current economic crisis is leading to the repudiation of certain assumptions concerning markets, democracies, and the role of government. However, we assert that, any critique of neo-classical economic and market theory needs to be grounded in certain assumptions regarding governance and the “polycentric” governance networks that have emerged over the course of the past forty years. We suggest that as a result of an increasing reliance on indirect and third party governance structures (Salamon, 2002), the roles and responsibilities of democratic governments in addressing pressing public problems have been drastically altered. We argue that the question of democratic legitimacy has shifted focus from being a matter solely relevant to governments to being an attribute of governance processes (Cleveland, 1973; Frederickson, 1999). Grounded in a now three decades-old body of literature that views governances processes as unfolding in inter-organizational policy or governance networks (Heclo, 1978; Rhodes, 1997; Milward and Provan, 199-; Agronoff and McGuire, 2003; Sorenson and Torfing, 2008), we suggest that the question of how and to what extent the legitimacy of the public sector thrives or suffers depends on the capabilities of government actors to reassert their capacity to regulate regulatory subsystems, including both market and non-market transactions, to effectively manage contracts, and infuse governance processes with sufficient “democratic anchorage” (Sorensen and Torfing, 2005).
  • Franklin, J. F.; Spies, T. A.; Van Pelt, R.; Carey, A. B.; Thornburgh, D. A.; Berg, D. R.; Lindenmayer, D. B.; Harmon, M. E.; Keeton, W. S.; Shaw, D. C.; Bible, K.; Chen, J. Q. (Forest Ecology and Management, 2002
      Forest managers need a comprehensive scientific understanding of natural stand development processes when designing silvicultural systems that integrate ecological and economic objectives, including a better appreciation of the nature of disturbance regimes and the biological legacies, such as live trees, snags, and logs, that they leave behind. Most conceptual forest development models do not incorporate current knowledge of the: (1) complexity of structures (including spatial patterns) and developmental processes; (2) duration of development in long-lived forests; (3) complex spatial patterns of stands that develop in later stages of seres; and particularly (4) the role of disturbances in creating structural legacies that become key elements of the post-disturbance stands, We elaborate on existing models for stand structural development using natural stand development of the Douglas-fir-western hemlock sere in the Pacific Northwest as our primary example; most of the principles are broadly applicable while some processes (e.g. role of epicormic branches) are related to specific species. We discuss the use of principles from disturbance ecology and natural stand development to create silvicultural approaches that are more aligned with natural processes. Such approaches provide for a greater abundance of standing dead and down wood and large old trees, perhaps reducing short-term commercial productivity but ultimately enhancing wildlife habitat, biodiversity, and ecosystem function, including soil protection and nutrient retention. (C) 2002 Elsevier Science B.V All rights reserved.
  • Allen, Elizabeth; Kruger, Chad; Leung, Fok-Yan; Stephens, JennieC (Journal of Environmental Studies and SciencesJ Environ Stud SciSpringer US, New Haven, CT., 2013
  • Sheil, Douglas; Basuki, Imam; German, Laura; Kuyper, Thomas W.; Limberg, Godwin; Puri, Rajindra K.; Sellato, Bernard; van Noordwijk, Meine; Wollenberg, Eva (Forests, 2012
  • Ricketts, T. H.; Daily, G. C.; Ehrlich, P. R. (Biological Conservation, 2002
      Indicator taxa are often proposed as efficient ways of identifying conservation priorities, but the correlation between putative indicators and other taxa has not been adequately tested. We examined whether a popular indicator taxon. the butterflies, could provide a useful surrogate measure of diversity in a closely related but relatively poorly known group, the moths, at a local scale relevant to many conservation decisions (10(0)-10(1) km(2)). We sampled butterflies and moths at 19 sites representing the three major terrestrial habitats in sub-alpine Colorado: meadows. aspen forests, and conifer forests. We found no correlation between moth and butterfly diversity across the 19 sites, using any of five different diversity measures. Correlations across only meadow sites (to test for correlation within a single, species-rich habitat) were also not significant. Butterflies were restricted largely to meadows, where their host plants occur and thermal environment is favorable. In contrast, all three habitats contained substantial moth diversity, and several moth species were restricted to each habitat. These findings suggest that (1) butterflies are unlikely to be useful indicators of moth diversity at a local scale; (2) phylogenetic relatedness is not a reliable criterion for selecting appropriate indicator taxa, and (3) a habitat-based approach would more effectively conserve moth diversity in this landscape and may be preferable in many situations where indicator taxa relationships are untested. (C) 2001 Elsevier Science Ltd. All rights reserved.
  • Seguino, Stephanie; Floro, Maria Sagrario (International Review of Applied Economics, 2003
  • Ellis, A. M.; Myers, S. S.; Ricketts, T. H. (PloS One, 2015
      Despite suggestions that animal pollinators are crucial for human nutritional health, no studies have actually tested this claim. Here, we combined data on crop pollination requirements, food nutrient densities, and actual human diets to predict the effects of pollinator losses on the risk of nutrient deficiency. In four developing countries and across five nutrients, we found that 0 to 56% of populations would become newly at risk if pollinators were removed. Increases in risk were most pronounced for vitamin A in populations with moderate levels of total nutrient intake. Overall, the effects of pollinator decline varied widely among populations and nutrients. We conclude that the importance of pollinators to human nutrition depends critically on the composition of local diets, and cannot be reliably predicted from global commodity analyses. We identify conditions under which severe health effects of pollinator loss are most likely to occur.
  • Keeton, W. S.; Franklin, J. F. (Ecological Monographs, 2005
      Biological legacies left by natural disturbances provide ecological functions throughout forest stand development, but their influences on processes of ecological succession are not completely understood. We investigated the successional role of one type of biological legacy: remnant old-growth trees persisting in mature Pseudotsuga menziesii (Douglas-fir) forests in the U.S. Pacific Northwest. We tested the hypothesis that remnant old-growth Tsuga heterophylla (western hemlock) and Thuja plicata (western red cedar) trees enhance the reestablishment of shade-tolerant conifers by increasing the availability of seed. Reestablishment of shade-tolerant conifers is a key process in late-successional forest development because it leads to vertical differentiation of the canopy and eventual codominance of shade-tolerant species. Two study areas were selected in the southern Washington Cascade Range, USA. Both had an unfragmented, mature forest cover that was regenerated naturally following wildfire. Twelve study sites were selected, including sites with and without remnant T. plicata and T. heterophylla. Overstory structure and composition, microsite variables, and conifer regeneration were systematically sampled using nested belt transects and quadrats. Sites with remnant T. heterophylla and T plicata had significantly higher densities of conspecific seedlings. Multivariate analyses showed remnant T. heterophylla and T. plicata presence and density to be the strongest predictors of seedling densities, although the basal area of mature conspecific trees, relative density, aspect, stand age, and microsite characteristics were important secondary predictors. Microsite variations explained regeneration patchiness. Seedling densities were strongly correlated with proximity to remnant trees, exhibiting a negative exponential decline with distance. Shade-tolerant conifers are likely to reestablish faster at sites with remnant seed trees, but canopy. disturbances are probably necessary for subsequent height growth. Remnant shade-tolerant conifers are an important biological legacy and seed source influencing rates of ecological succession in mature P. menziesii stands. Successional and stand development models should explicitly incorporate this dynamic.
  • Harrison, D. M.; Noordewier, T. G.; Yavas, A. (2004
      Conventional wisdom in the mortgage industry holds that loan-to-value (LTV) ratios are positively correlated with mortgage default rates. However, not all empirical studies of mortgage loan performance support this view. This paper offers a theoretical signaling model of why the correlation between LTV ratios and default risk is contingent upon the default costs of the borrower. Specifically, the model proposes that when default costs are high there exists a separating equilibrium in which risky borrowers will self-select into lower LTV loans to reduce the probability of facing a costly default, while safe borrowers will self-select into higher LTV loans as a signal of their enhanced creditworthiness. This adverse selection process gives rise to the possibility of higher default probabilities for lower LTV loans. Conversely, when default costs are low the conventional result, in which risky borrowers select higher LTV loans than safe borrowers, is obtained. Empirical results, based on a sample of 859 single-family residential mortgage loans drawn from the portfolio of a national mortgage lender, are consistent with the separating equilibria predicted by the model.

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