A MATHEMATICAL MODEL FOR DEVELOPING ETHNO-BIOLOGICALLY DIVERSE TROPICAL FORESTS

This paper presents a dynamic optimal control model describing the benefits and costs associated with the development of tropical forests rich in plant and animal species and folk knowledge. The model is a framework to assess how various market and institutional incentives might influence both deforestation and the collection of "ethno-biological information."Resource /Energy Economics and Policy,

MARINE RESERVES FOR FISHERIES MANAGEMENT

Conventional methods of regulating commercial fisheries restrict catch by limiting either the quantity or efficiency of fishing effort, or by putting direct limits on catch. These regulatory practices are neither feasible nor desirable for many fisheries, and have failed to conserve fishery stocks in other fisheries. Marine reserves may be an effective alternative management strategy for some fisheries. Here we develop a dynamic model of marine reserves applicable to inshore fisheries. In contrast to previous models of reserves, the model is fully dynamic and provides information on both equilibrium conditions and the path to equilibrium. A simulation model based on red snapper data from the Gulf of Mexico is presented. The simulation results suggest that marine reserves can sustain or increase yields for moderate to heavily fished fisheries but will probably not improve yields for lightly fished fisheries.Resource /Energy Economics and Policy,

Armillaria in Massachusetts Forests: Ecology, Species Distribution, and Population Structure, with an Emphasis on Mixed Oak Forests

The ecology, species distribution, and population structure of Armillaria was investigated in the forests of Massachusetts. From 64 plots at 16 sites, 640 isolates of Armillaria were collected from six forest types (northern hardwoods, mixed oak, pitch pine, white pine, white pine/mixed oak, and eastern hemlock). Armillaria gallica proved to be the most abundant species, making up 316/640 (52%) of all isolations. This was followed by A. solidipes (219/640; 34%), A. mellea (46/640; 7%), A. calvescens (36/640; 6%), A. gemina (16/640; 3%), and A. sinapina (7/640; 1%). Armillaria gallica was routinely encountered causing significant decay of the lower bole on living hardwood hosts, especially oaks. The population structure of 153 isolates of A. gallica collected from mixed oak forests was investigated using amplified fragment length polymorphisms (AFLPs). From a total sampling area of 4.51 ha, 38 AFLP genotypes were discovered, yielding a figure of eight genets per hectare with the average A. gallica genet occupying 0.13 ha. When the effects of hydrolyzable tannins on in vitro growth were compared between A. calvescens and A. gallica, it was A. gallica that appeared better at oxidizing and metabolizing commercial tannins (tannic acid and gallic acid) along with black oak root bark extracts. This was determined through measurements of colony area and dry biomass, and suggests that A. gallica may be a better adapted pathogen of oak. In order to more accurately distinguish between isolates of A. calvescens and A. gallica, a three-gene phylogeny was reconstructed, using partial sequences of the elongation factor 1-alpha (tef1), RNA polymerase II (rpb2) and nuclear large subunit (nLSU) genes. After comparing 12 isolates each of A. calvescens and A. gallica that originated from across northeastern North America, only the tef1 gene could accurately distinguish these two species. Five single nucleotide polymorphisms were present between the two species and maximum likelihood and maximum parsimony methods grouped A. calvescens and A. gallica into monophyletic clades

We want our view and eat it too

2011 Spring.Includes bibliographical references.How do we amuse ourselves in America's most beautiful places? The relationship that many Americans have with the natural world is one of awkwardness and detachment that is manifested in the way we vacation in and tour around National Parks and other naturally beautiful places. Culturally instilled perceptions of place and a frantic pace to see it all keep many circulating around the edges of the natural world rather than experiencing it in more intimate ways. Many have a distanced appreciation for a beautiful natural landscape, especially those iconic views that are recognizable from ubiquitous travel brochures, postcards, posters, books, and calendars. They inspire awe and appreciation, but we soon shoot our photograph and quickly move to the next panorama so the view becomes a film, flashing by frame by frame through our vehicle's windows. Kitschy tourist stops, amusement parks, golf courses, shopping centers, restaurants, or funky little coffee shops and pubs bring urban pleasures and comforts to our experience of the natural world. Our behavior exposes several underlying tensions that exist in our individual and collective psyches: the tensions between conservation and consumption, observation and immersion, and the natural and artificial. My intention is to visually investigate these tensions by exploring the roads we build, the parks we set aside, the objects we place within the natural landscape, and the activities in which we participate, often pushing these into the realm of the ridiculous in order to raise questions about what we might do if we could. As a society we simultaneously want a world filled with beautiful landscapes and a comfortable lifestyle. However, our current way of life demands a high rate of natural resource consumption that destroys precious ecosystems, which by association destroys the beautiful view. We want the best of both worlds; we want our view and to eat it too. My work is aimed at visually exploring this paradox and the tension that exists when a society tries to reconcile competing desires

An engineering approach to the use of expert systems technology in avionics applications

The concept of using a knowledge compiler to transform the knowledge base and inference mechanism of an expert system into a conventional program is presented. The need to accommodate real-time systems requirements in applications such as embedded avionics is outlined. Expert systems and a brief comparison of expert systems and conventional programs are reviewed. Avionics applications of expert systems are discussed before the discussions of applying the proposed concept to example systems using forward and backward chaining

Preservation On Island: How Historic Preservation Can Promote the Vitality of Maine's Island Communities

This thesis seeks to explore how historic preservation can contribute to the vitality of Maine's 15 year-round island communities. On one level, this means determining how existing preservation planning tools—such as tax incentives—can protect the islands' historic resources while also providing financial benefit to island residents. On a deeper level I hope to demonstrate that the island communities survive in large part because people are willing to forego certain modern conveniences in order to live in a community that has a compelling and unique sense of place. It is my argument that preserving this sense of place is largely the province of the historic preservation discipline, and is fundamentally important if the islands are to remain vital communities. The first chapter introduces the general significance of Maine's island communities and lays out the planning issues that are most likely to confront preservation efforts on the islands. The second chapter outlines the most common preservation planning tools that are available in the State of Maine and briefly describes how these tools can be applied to Maine's island communities. The chapter has been organized according to who is most likely to implement the tool: legal actions at the federal, state, and local levels; then actions available to private and non-profit entities. The remaining chapters explore how historic preservation can be implemented on three of the 15 remaining year-round island communities. These case studies are presented in geographical order, beginning from the south: Chebeague in bustling Casco Bay; Vinalhaven at the mouth of Penobscot Bay; and remote Frenchboro on the outer edge of Maine's archipelago. The discussion of each island includes a brief summary of the community's history—especially as it relates to the development of the island—and outlines the significant historic contexts and associated building types that characterize the island's built environment. A summary of the preservation planning issues unique to the community is then presented, followed by an exploration of existing historic preservation efforts and suggestions for future work. Each case study ends with a summary of recommended actions for the local community and invested third parties