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  TB208: Biological Water Quality Standards to Achieve Biological Condition Goals in Maine Rivers and Streams: Science and Policy

  Susan P. Davies, Francis Drummond, David L. Courtemanch, Leonidas Tsomides, and Thomas J. Danielson

  This publication describes the philosophy, history, methodology, and management applications of numeric biological criteria in water quality standards in Maine. The presentation describes the decision-making process used by the Maine Department of Environmental Protection (MDEP) for assessing attainment of aquatic life uses in water quality standards using benthic macroinvertebrates in Maine streams and rivers including eight case studies of management applications and the improved environmental outcomes that have resulted. The MDEP, University of Maine, and business and nonprofit stakeholders participated in the development and testing of Maine’s numeric biological criteria. This publication further discusses the broader relevance of numeric biological criteria in water quality management at both the state and federal levels and considers parallels and differences between Maine’s biological criteria and other biological assessment methods in the United States and the European Union.

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  TB207: A Manual for Remote Sensing of Maine Lake Clarity

  Ian M. McCullough, Cynthia S. Loftin, and Steven A. Sader

  The purpose of this manual is to support use of satellite-based remote sensing for statewide lake water-quality monitoring in Maine. The authors describe step-by-step methods that combine Landsat and MODIS satellite data with field-collected Secchi disk data for statewide assessment of lake water clarity. Landsat can be simul­taneously used to assess more than Maine 1,000 lakes ≥ 8 ha, whereas MODIS can be used to assess a maximum of 364 lakes ≥ 100 ha (250-m image resolution) or 83 lakes ≥ 400 ha (500-m image resolution). Although the methods were specifically developed for Maine, other states or non-Maine agen­cies may find these methods as useful starting points in developing their own protocols for regional remote lake monitoring.

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  TB206: Biodiversity of the Schoodic Peninsula: Results of the Insect and Arachnid Bioblitzes at the Schoodic District of Acadia National Park, Maine

  Donald S. Chandler, David Manski, Charlene Donahue, and Andrei Alyokhin

  Bioblitzes have become a popular approach to involve scientists and the public in studying biodiversity. They reinforce the idea that natural areas are resources of scientific and educational value and are a way of engaging the public in experiencing the natural world. A bioblitz is typically conducted over a 24-hour period in a targeted area, with the goal of documenting the presence of as many species as possible. Scientists and “weekend naturalists,” along with other individuals who enjoy being in the field, are asked to attend bioblitzes as volunteers to help in finding and identifying as many species as possible. The formal goal of the bioblitzes at Acadia National Park was to once annually collect, sort, and identify as many species of arthropods of a chosen group as possible, within a 24-hour period. Collecting was geographically limited to the Schoodic District of the park, starting in 2004 and continuing to the present. A wide variety of collecting methods was used during the various bioblitzes.

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  TB205: Cost of Supplemental Irrigation for Potato Production in Maine

  David Silver, Ermias Afeworki, and George K. Criner

  This report presents estimated irrigation costs for potato production in Maine. The variability of the weather in Maine (particularly precipitation) has a large influence on crop yields and overall farm profitability. The use of supplemental irrigation on high-value agricultural crops can improve the economic situation of farmers who use this equipment efficiently. Costs considered in this report include capital costs (equipment, interest, water development (pond construction, permitting, engineering), and operating and maintenance costs (labor, power, repair).

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  TB204: Organic Milk Production in Maine: Attributes, Costs, and Returns

  Amelia L. Cook, Patrick S. Heacock, George K. Criner, and Lisa A. Bragg

  This report summarizes attributes, costs, and returns for organic dairy farms in Maine that responded to the 2008 dairy cost of production survey. This survey and analysis was conducted by the University of Maine in cooperation with the Maine Milk Commission. This publication reports on data collected over the 2007 production year. Analysis and discussion of the data revolve around four categories. The first category averages all 30 organic farms to create a statewide group. The authors then broke these 30 farms into three size groups (small, medium, and large) based on the number of cows on each farm. There were nine small farms with an average of 30 cows on each farm, 10 medium farms with an average of 55 cows each, and 11 large farms with about an average of 100 cows each. The analysis presented here discusses characteristics of the three size groups, along with the statewide group.

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  TB201: Comparison of the Efficacy of Sodium Acid Sulfate and Citric Acid Treatments in Reducing Acrylamide Formation in French Fries

  Byungchul Kim, L. Brian Perkins, Beth Calder, and Lawrence A. LeBlanc

  Two acidulant food additives, sodium acid sulfate (SAS) and citric acid, were investigated for their effectiveness in reducing acrylamide formation in french fries. Acrylamide concentration was determined by gas chromatography-mass spectrometry (GC-MS) after cleanup of french fry extracts by passage through a C-18 column and derivitization by bromination. At a frying temperature of 180°C, both acidulants appeared ineffective, possibly due to the rapid rate of acrylamide formation, which surpassed the capacity of the acidulants to protonate acrylamide intermediates. At the lowest frying temperature tested (160°C), 3% SAS and 3% citric acid significantly (P < 0.05) inhibited acrylamide formation as compared to the control. However, 3% SAS appeared to inhibit acrylamide formation more effectively than citric acid at 160°C, as well as at frying temperatures of 170 and 180°C. Our results indicate that acrylamide formation during frying can be reduced by treatment of potatoes with 3% SAS or citric acid, but SAS, a stronger acid with a lower pKa, is the more effective acidulant.

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  TB202: Composition and Biomass of Forest Floor Vegetation in Experimentally Acidified Paired Watersheds at the Bear Brook Watershed in Maine

  Peter Kenlan, G. B. Wiersma, A. S. White, and I. J. Fernandez

  The percentage cover (abundance), frequency of occurrence, biomass, species richness, and species diversity of understory herbs was measured on a paired watershed ecosystem in eastern Maine, USA. This paired watershed site (Bear Brook Watershed in Maine, BBWM) has had the West Bear Brook Watershed treated bi-monthly with granular ammonium sulfate at a rate of 28.8 kg S ha-1 yr-1 and 25.2 kg N ha-1 yr-1 since 1989. East Bear Brook Watershed serves as the reference site. More than 100 plots were randomly located across the two watersheds. The data suggest that there is generally a lower frequency of occurrence of understory plants on the treated watershed. In addition there was a significant difference in species richness with the treated watershed (West Bear) being lower than the reference watershed (East Bear). Biomass measures generally followed this same trend although there were not significant differences detected. These differences reflect treatment effects in light of biogeochemical changes shown to be occurring in other studies due to treatments.

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  TB203: Recent Advances in the Biology and Genetics of Lowbush Blueberry

  Daniel J. Bell, Lisa J. Rowland, John Smagula, and Frank Drummond

  For lowbush blueberries, this publication presents an in-depth look at the biology and genetics of lowbush blueberry. The authors provide details on its genetic composition and the outline the usefulness of various biochemical, genomic, and other markers in studying the plants genetic structure. The authors also provide an overview of the plant’s economic value to Maine, nutritional value, and its life history.

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  TB197: Forest Biomass Estimates in Maine:Statewide, County, and Spatial

  Kenneth M. Laustsen

  In Maine, statewide biomass estimates have increased from 752 million dry tons in 1982 to 980 million dry tons in a 2003 estimate. These estimates are produced using Forest Inventory & Analysis (FIA) data collected during Maine’s periodic and now annualized inventory design. The Maine Forest Service began tracking and reporting on wood flows of biomass in 1986. For the last 20 years (1986–2005) the total annual harvesting of all products has ranged between 6 and 7 million cords, extracted from a standing inventory that is currently estimated to be 277 million cords. The objectives of this current study were (1) to document historic estimates of forest biomass; (2) to outline the current estimation process; and (3) to estimate availability of various forest- and tree-based biomass components at a variety of scales. This analysis uses a variety of data including previously published reports, current Maine Forest Service wood processor reports, and the latest USDA Forest Service Forest Inventory and Analysis (FIA) data.

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  TB198: Economic Analysis of Organic Pest Management Strategies for Lowbush Blueberries Using Enterprise Budgeting

  Andrew C. Files, David Yarborough, and Frank Drummond

  Enterprise budgets were developed for the 12 different pest management treatments of a large-plot organic blueberry transitions project in Maine, covering two prune/harvest cycles (2004–2005 and 2006–2007). Regression analysis of the plot-level yield results for the aggregate of the two prune/harvest cycles indicated that burning fields as compared to mow­ing fields significantly increased blueberry yields over the aggregate of two prune/harvest cycles. Similarly, adding 1,000 lbs of sulfur before the first prune/harvest cycle significantly increased blueberry yields over the aggregate of two prune/harvest cycles as compared to no addition of sulfur. The addition of fertilizer had no significant impact on blueberry yields.

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  TB199: Ant–Homopteran Relationships: Relevance to an Ant Invasion in Maine

  Katherine E. McPhee, Eleanor Groden, and Francis A. Drummond

  The richness and diversity of native ant species on Mt. Desert Island, Maine, have been reduced in areas infested with Myrica rubra (European red ant). In general, the success of invasive ant species has been attributed to interference and exploitative competition coupled with the ants’ opportunistic diets. In field experiments on Mount Desert Island, Maine, M. rubra discovered and recruited to baits faster than native ants. This study also showed that M. rubra displaced most native ant species from food resources (Garnas 2005). This, together with M. rubra’s aggressive defense of invaded territories, has led to fewer native ants in infested areas. The purpose of this literature review is to investigate ant–homopteran relationships and discuss the possibility of homopterans indirectly aiding ant invasions.

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  TB200: Carbon and Nutrients in Maine Forest Soils

  Ivan J. Fernandez

  Recent public concerns surrounding climate change and greenhouse gas emissions have resulted in a lively debate about approaches to fossil fuel offsets and carbon (C) sequestration in forests. The forest community sees opportunities for the intensification of the use of forests for markets ranging from forest products, such as fuel or fuel feedstock, to a range of new bioproducts. This report provides initial insights from an ongoing effort to synthesize forest soils data for Maine. The specific objectives presented here were (1) to develop descriptive statistics for C and measures of available forms of the essential nutrients N, P, and Ca in Maine forest soils; (2) to evaluate the ecological stoichiometry of forest soil C relative to available N, P, and Ca; and (3) to highlight information needs to address the simultaneous goals of forest use, C sequestration, and forest sustainability.

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  TB196: Temperature, Soil Moisture, and Streamflow at the Bear Brook Watershed in Maine (BBWM)

  Ivan J. Fernandez, Joseph E. Karem, Stephen A. Norton, and Lindsey E. Rustad

  The Bear Brook Watershed in Maine is a whole-ecosystem chemical manipulation initiated in 1987 to study the effects of acid deposition on forests and surface waters. The focus of this research was to understand the biogeochemical response of watersheds with emphasis on chemistry and hydrology. In 2001 a program was initiated to provide more detailed measurements of temperature and moisture to examine critical linkages amongst chemical, biological, and physical processes that ultimately work together to define ecosystem function. The purpose of this publication is to provide data from the initial phase of soil temperature, air temperature, and soil moisture measurements at the site. In addition, the authors have incorporated aspects of relevant precipitation and streamflow characteristics available for the full project period.

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  TB192: The Use of Glyphosate Herbicides in Managed Forest Ecosystems and Their Effects on Non-target Organisms with Particular Reference to Ants as Bioindicators

  Kerry F.L. Guiseppe, Francis A. Drummond, Constance Stubbs, and Stephen Woods

  This publication reviews and synthesizes the results of many research studies designed to elucidate the ecological effects of the herbicide glyphosate used in forested landscapes. We have not intended our review to be an exhaustive review of all published studies (both laboratory and field investigations) concerned with faunal and floral glyphosate interactions and the environmental fate of glyphosate. We particularly focused on studies that had relevance to north temperate forest ecosystems and selected published investigations to incorporate into our review that cover a wide range of faunal and floral taxa that might be exposed to herbicides during applications.

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  TB193: The Cost of Producing Milk in Maine: Results from the 2005 Dairy Cost of Production Survey

  Lisa A. Bragg and Timothy J. Dalton

  This report summarizes the results of the 2005 Dairy Cost of Production survey implemented by The University of Maine and the Maine Milk Commission. This study summarizes data collected over the 2004 production year. Funding for this report was provided by the Maine Milk Commission. Analysis and discussion of the data in this report centers on an industry-wide group and three smaller sets called clusters. Cluster analysis attempts to identify groups of farms from within the sample of survey respondents that have relatively homogenous characteristics.

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  TB194: Hemisgrapsus sanguineus (Asian Shore Crab) as Predator of Juvenile Homarus americanus (American Lobster)

  Anna Demeo and John G. Riley

  Hemigrapsus sanguineus, commonly known as the Asian shore crab, was first discovered on the east coast of the United States in New Jersey in 1988. The spread of this invasive crab has been rapid, and it is now abundant along a large portion of the mid-Atlantic and southern New England coast. Further, an invasion of H. sanguineus into New Hampshire and southern Maine is in its preliminary stages. The introduction of this crab to North America could potentially affect a variety of native species. Numerous studies have examined the predation of H. sanguineus on blue mussels, snails, and other bivalves. In this study, we consider the predation of H. sanguineus on juvenile Homarus americanus(American lobster). We conducted laboratory experiments to investigate whether H. sanguineus can and will consume juvenile H. americanus. These trials affirmed that invasive crabs do prey on lobsters even when the crabs were provided other food alternatives and the lobsters were given shelter. Further research is necessary to evaluate if there exists a real or potential threat to the juvenile H. americanus population in the wild.

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  TB195: Element Concentrations in Maine Forest Vegetation and Soils

  Chandra J. McGee, Ivan J. Fernandez, Stephen A. Norton, and Constance S. Stubbs

  Bioaccumulation of trace metals in plant tissues can present a health risk to wildlife, and potentially to humans. The Passamaquoddy Tribe in Maine was concerned about health risks of cadmium (Cd) because of a health advisory for moose liver and kidney consumption due to high Cd levels. In addition to Cd, this study evaluated concentrations of aluminum (Al), calcium (Ca), copper (Cu), iron (Fe), potassium (K), magnesium (Mg), manganese (Mn), nickel (Ni), phosphorus (P), lead (Pb), and zinc (Zn) in four common terrestrial moose-browse species, associated forest soils, and two species of aquatic vegetation on Passamaquoddy tribal land in eastern Maine. Elements were organized into three groups (A, B, and C) based on the patterns of concentration differences in vegetation among ecosystem types. Elements in group A included the nutrients Ca, K, Mg, and P and showed a pattern of significantly higher concentrations in hardwood and aquatic vegetation compared to softwoods. Group B elements included the four metals, Cd, Cu, Mn, and Zn, and exhibited a pattern of higher concentrations in hardwoods compared to softwoods and aquatic vegetation. Group C elements did not fit the patterns of group A or group B and included the remaining four elements Al, Fe, Ni, and Pb. Total O horizon soil concentration means for all elements, except Ni and Pb, were significantly higher in hardwood compared to softwood forest types. This study provides uncommon and important baseline vegetation and soil trace metal concentrations from a remote region in Maine of interest to environmental professionals.

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  TB191: Conservation and Management of Native Bees in Cranberry

  Jennifer L. Loose, Francis A. Drummond, Constance Stubbs, and Stephen Woods

  Threats to agriculturally important pollinators have serious implications for human beings. A loss of bees translates to less successful crop pollination, thus reduced yield and poorer quality fruits. Native bees have the potential to serve as commercial pollinators. A diverse pollinator complex comprised of both honey bees and native bees should result in stable pollination levels and should be resistant to threats such as disease, fluctuating honey and crop prices, and honey bee transportation costs. Adding the goal of native bee conservation to land management increases the ecological integrity of an ecosystem by conserving a unique biological interaction that is the basis for most native wild plant reproduction. This report describes pollination in the cranberry agroecosystem and outlines steps to take to manage native bees in cranberry.

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  TB186: Assessing Silviculture Research Priorities for Maine Using Wood Supply Analysis

  Robert G. Wagner, Ernest H. Bowling, and Robert S. Seymour

  To identify the highest priorities for silviculture research in Maine, the authors of this report quantified the absolute and relative influence of future silvicultural investments (tree planting, herbicide application, and PCT) and commercial thinning on projected harvest levels and future wood supplies in Maine. They also quantified the absolute and relative importance of the growth and yield assumptions (via sensitivity analysis) used in estimating the influence of these silvicultural treatments on projected harvest levels and future wood supplies in Maine; and based on the absolute and relative importance of the growth and yield assumptions and on the influence of differing levels of future investment, they ranked which areas of silviculture research are likely to be most important for improving Maine’s future wood supply.

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  TB187: Forest Vegetation Monitoring in Acadia National Park

  J. D. Eckhoff, G. B. Wiersma, and J. A. Elvir

  The goal of this report is to present the results of the vegetation component of the PRIMENet study at Acadia. The results include a classification of vegetation types and their locations within Cadillac Brook and Hadlock Brook watersheds; a synthesis of the primary and meta tree, sapling, and seedling data from the two study watersheds; and foliar chemical analyses using Acer rubrum and Picea rubens from Cadillac Brook and Hadlock Brook watersheds. This report provides the baseline information for long-term forest vegetation monitoring in the deciduous and coniferous forests in Cadillac Brook and Hadlock Brook watersheds. Ongoing interest and studies on the status of the natural resources within Acadia National Park makes availability of information from previous work, such as the baseline data in this report, very important.

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  TB188: Tow Tank Scale Modeling in the Design of Tidal Upwellers

  John Riley

  In February 1999 an ad hoc committee of representatives of Maine’s shellfish aquaculture industry, The University of Maine, and the Maine Sea Grant College Program met to discuss priorities for research to improve the performance of tidally powered shellfish upwellers. Information from this meeting was incorporated into a proposal submitted later in the year to the Maine Aquaculture Innovation Center. The project was funded and work began in January 2000. The project involved engineering analysis, field measurements of shellfish seed properties, and scale-model testing conducted in the university wave/towing tank with the overall goal of optimizing the design of a tidal upweller used for nursery production of oyster and hard clam seed. This report describes the model-testing compone

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  TB189: The Cost of Producing Milk in Maine: Results from the 2002 Dairy Cost of Production Survey

  Timothy J. Dalton and Lisa A. Bragg

  This report summarizes the results of the 2002 Dairy Cost of Production survey implemented by The University of Maine and the Maine Milk Commission. Funding for this report was provided by the Maine Milk Commission. Analysis and discussion of the data in this report centers on four major groups called clusters. Cluster analysis attempts to identify groups of farms from within the sample of survey respondents that have relatively homogenous characteristics.

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  TB190: Spider Predation in Agroecosystems: Can Spiders Effectively Control Pest Populations.

  Darlene Maloney, Francis A. Drummond, and Randy Alford

  Recent trends in agriculture towards reduced pesticide use and ecological sustainability have lead to increased interest in spiders as potential biological control agents. Although the Chinese have augmented spider populations in field crops as a pest management strategy for centuries, much debate remains as to whether spiders will effectively control pest populations in U.S. agricultural ecosystems. This technical bulletin reviews the literature to describe the reduction of insect pest densities by spiders and the effects of pesticides on spiders. In addition to addressing the question of whether spiders can be effective biocontrol agents, the authors outline techniques to conserve and enhance spider assemblages.

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  TB180: Baseline Data for Long-term Forest Vegetation Monitoring at Bear Brook Watershed in Maine

  J. D. Eckhoff and G. B. Wiersma

  This report includes comprehensive information on the primary and meta forest vegetation data assembled from Bear Brook Watershed in Maine (BBWM). This information represents the first in-depth inventory of the forest vegetation, both woody and non-woody in multiple strata, within the two watersheds initially established at BBWM, West Bear and East Bear, and also the areas adjacent to the east and west of these watersheds. For long-term monitoring of vegetation responses to the continued manipulations and/or the recovery of the ecosystems at BBWM, access to the vegetation baseline information contained within this report is essential.

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  TB182: Agricultural Land Changes in Maine: A Compilation and Brief Analysis of Census of Agriculture Data, 1850-1997

  SoEun Ahn, William B. Krohn, Andrew J. Plantinga, and Timothy J. Dalton

  The purpose of this study is to compile the best available long-term historical information on agricultural land use in Maine and to briefly analyze these data to develop a statewide description of Maine's land use history from the mid-1800s to present. Our emphasis is on compiling statistically based information and, in particular, land use data reported in the Census of Agriculture. Objectives were (1) to compile available statewide data on agricultural land and land cover (LULC) in Maine, 1850-1997; (2) to examine temporal and spatial patterns in the LULC of Maine; and (3) to discuss the implications of the major trends in LULC for selected natural resources of current economic and ecological concern.

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  TB183: Investment, Ownership and Operating Costs of Supplemental Irrigation Systems for Maine Wild Blueberries

  Timothy J. Dalton, Andrew Files, and David Yarborough

  This study investigates the investment and annual cost of supplemental irrigation equipment used on lowbush blueberries and calculates breakeven yields required to pay for annual costs and the earliest possible payoff period to recover investment costs. Using an economic-engineering approach to simulating investment and operating costs, this project assesses breakeven requirements on irrigation investment. The report reviews several of the technical factors contributing to the irrigation decision, calculate economic costs and are breakeven measures, but only introduce some of the financial factors for a grower to consider.

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  TB184: Least-Cost Options for the Collection, Treatment, and Disposal of Biomedical Waste in Maine.

  Andrew C. Files, Thomas G. Allen, and George K. Criner

  This study examines the cost effectiveness of using current treatment technologies to sanitize, disinfect, shred, and dispose of biomedical waste within the state in relation to the costs of current disposal practices in Maine. The study employs a linear programming model to determine the combination of treatment facilities, transportation options, and disposal sites to treat all waste produced in Maine at the lowest statewide cost. A least-cost solution is developed for three different scenarios. The first two scenarios assume that all treated waste must be shredded in accordance with current regulatory requirements. The third scenario assumes that regulations are changed to require only that the sharps portion of the biomedical waste stream be shredded. All scenarios assume that the treatment facilities would be located on-site at one or more hospital locations, that there are no barriers to inter-hospital shipment of waste for treatment, and that any hospital has the option to continue shipping its waste out of state.

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  TB185: Designing a Labeling Policy for Genetically Modified Food: Results of Focus Group Research

  Mario F. Teisl, Lynn Halverson, Kelly O'Brien, and Brian Roe

  The labeling of genetically modified foods is a topic of growing, and sometimes cantankerous, public debate—a debate whose outcome could dramatically alter the operation of the U.S. production agriculture, processing, distribution and retailing sectors. The debate surrounding the labeling of genetically modified foods is largely about how much information to supply to consumers to facilitate effective choice and how that information should be supplied. Although there seems to be empirical evidence of a mainstream desire for the labeling of genetically modified foods, we know of no study that has provided guidance to policy makers as to the best method of labeling genetically modified foods. Therefore, the goal here is to explore and to evaluate possible approaches for labeling genetically modified foods. The authors conclude their report with 11 recommendations.

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  TB176: Agrelation: A Computerized Decision-making Tool for Coloraod Potato Beetle Population Management and Environmental Quality Concerns

  Charles R. Ziegler, Francis A. Drummond, Darrell W. Donahue, and Stewart N. Smith

  Many facets of Maine potato production have been simulated with computer models and expert systems. Given the ongoing improvement of computer technology and validation of past efforts, scientists can now combine several agricultural submodels into one holistic and user-friendly computer application. This bulletin reports on the development of one such application—Agrelation—aimed at modeling a portion of Maine potato production and management.

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  TB178: Methods for Evaluating Carbon Fractions in Forest Soils: A Review

  Jennifer L. Evans, Ivan J. Fernandez, Lindsey E. Rustad, and Stephen A. Norton

  This publication was developed as part of an effort to evaluate the existing methodologies for determining carbon fractions in soils that might be applied to the question of forest soil C sequestration. A great deal of research has been done on this topic although often focused on agronomic soils. Forest land managers will be increasingly interested in identifying methods to monitor and to evaluate the effects of forest practices on soil C reserves. As well researchers are interested in this and the logical linkages to N cycling. Ultimately practical methods that can be widely utilized will be needed; these may come from current methods or be developed through research. This review offers a framework for this area of investigation.

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  TB179: Oxygen Supplementation for Aquaculture Biofilters

  John Riley and Daniel Hagopian

  There is conflicting evidence concerning the negative effects of high concentrations of dissolved oxygen on nitrifying bacteria. This project was developed to determine what happens to an established slime layer in a fixed-film, flow-through bio-filter, exposed to oxygen supersaturation. Specific objectives were to determine qualitatively and quantitatively whether the treatment is actually beneficial after acclimation, and whether rapid fluctuations in DO are detrimental to an acclimated culture.

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  TB181: 2000 Milk Processing Costs in Maine

  Timothy J. Dalton, George K. Criner, and John Halloran

  The objective of this study is to provide an estimate of the theoretically lowest achievable costs of processing and distributing milk in Maine. This processing and distribution margin (referred hence as "margin") is estimated for a state-of-the-art processing plant assumed to be located in the Portland, Maine, area. The plant is assumed to produce and distribute a line of products including white milk, chocolate milk, orange juice, and other fruit drinks, and to distribute additional purchased products such as cheeses and yogurts. This report will present information for four plants to better study the impact of plant size and production scope on costs.

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  TB172: Evaluation of Entomopathogens for Biological Control of Insect Pests of Lowbush (Wild) Blueberry

  Francis A. Drummond and Eleanor Groden

  To maintain the economic viability of Maine’s blueberry farms, to offer alternative pest control strategies in light of the implementation of the Food Quality Protection Act of 1996, and to reduce the human health and environmental risks associated with pest management, these researchers have been researching biological control tactics. This technical bulletin outlines protocols and experimental design necessary for evaluation of entomopathogens targeted against the significant direct and indirect pests associated with lowbush blueberry.

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  TB177: Evaluation of an Experimental Filter Medium for Water Re-use Systems

  John Riley, David Cole, and Robert Bayer

  This report describes the development and testing of a new material for use as a filter medium in recirculating aquaculture systems and other water quality control situations. The material consists of a combination of activated carbon and a hydrophilic urethane foam in a homogeneous matrix. Its physical properties relevant to filtration were determined. It was then tested for its ability to remove various dissolved organic compounds and inorganic nitrogenous compounds in the form of a synthetic waste-water containing ammonia and nitrite. Finally it was subjected to long-term use in the biofilter of a fish culture system. It proved to be a successful filter medium for several applications and showed great potential for use in biofilters installed in recirculating aquaculture systems and other fish and shellfish culture facilities.

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  TB171: Investigations into the Potential of Measuring Biodiversity in Maine's Forests with Forest Inventory and Analysis (FIA) Data

  Thomas G. Allen and Andrew Plantinga

  We present here the results of our initial effort to use FIA data to assess biodiversity in Maine's forests. Biodiversity is a complex issue and, from the start, it was apparent that the FIA data are inadequate for examining all facets of biodiversity. Nevertheless, the FIA provides the most comprehensive and detailed data on Maine's forests and can be used to measure some indicators of forest biodiversity, in particular those related to tree species and stand characteristics.

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  TB174: Maine Wild Blueberries Field Winnowing Systems

  Darrell W. Donahue, Alfred A. Bushway, Keith E. Moore, and Ben J. Lagasse

  The objective of this study was to determine if there were differences in berry quality between the two winnowing systems currently used in the Maine wild blueberry industry. The following experiment was performed three times during the 1997 field season.

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  TB175: A Numerical Method and Supporting Database for Evaluation of Maine Peatlands as Candidtate Natural Areas

  Ronald B. Davis and Dennis S. Anderson

  In Maine, non-tidal peatlands comprise the last major terrestrial ecosystem group remaining largely undisturbed by humans, and for which there still exists a full range of options for protection in near-pristine condition. To make the best choices of areas to protect, ecologically based prioritization of candidate natural areas is needed. This technical bulletin presents a quantitative method of evaluation of the natural features of peatlands—providing the fundamental tool for establishing peatland protection priorities. We apply the method to the evaluation of 76 Maine peatlands representing all the morphologic/hydrologic peatland types in the biophysical regions of the state.

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  TB169: Chemical and Physical Properties of the Mapleton, Monson, Saddelback, and Sisk Soil Map Units

  Robert V. Rourke

  Mapleton, Monson, Saddleback, and Sisk soil map units were each sampled at five locations. Soil descriptions and locations were documented in the field. Soil samples were removed from each horizon in a 30-cm square to a 100-cm depth or to bedrock whichever came first. Laboratory analyses of each soil horizon sampled included texture, volume of stones, organic content, bulk density, soil water retention, soil reaction, exchangeable cations, extractable acidity, and exchange acidity. Soil descriptions and tables of soil properties were constructed for each sample site. Soil data for each soil map unit was summarized by horizon using weighted means.

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  TB170: The Flora and Plant Communities of Maine Peatlands

  Dennis S. Anderson and Ronald B. Davis

  The objectives of this study are (1) to classify and describe the plant communities of Maine peatlands, (2 ) to demonstrate the relationships between the communities, (3) to characterize the communities in terms of physical and chemical variables, (4) to show the geographic distribution of the communities, (5) to investigate the relationships between plant communities and peatland geomorphic/hydrologic types, (6) to report the areal cover of vegetation cover-types (aggregated communities ) for individual peatlands, and (7) to document the flora of Maine's peatlands, including vascular plants, bryophytes, and lichens.

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  TB163: Insect Predation of Seeds and Plant Population Dynamics

  Jianxin Zhang, Francis A. Drummond, Matt Liebman, and Alden Hartke

  This review provides a framework for understanding the mechanisms of insect seed predation, the diversity of insects that prey on seeds, and the ecological and evolutionary consequences of insect seed predation. Insect seed predation can play significant roles in reducing plant population growth, modifying intraspecific and interspecific competition, shifting spatial and temporal distribution, affecting species evolution, and plant community structure, both in natural and agricultural ecosystems.

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  TB164: Precipitation Chemistry at the Greenville, Maine, NADP/NTN Station

  Ivan J. Fernandez and Llew Wortman

  This report details results from the Greenville, Maine, NADP/NTN site supported by the Maine Agricultural and Forest Experiment Station. The site is located in Piscataquis County at 69°39'52" longitude and 45°29'23" latitude at approximately 322 m elevation. The site consists of a single Aerochem Metrics® Automatic Sensing Wet/Dry Precipitation Collector that provides samples for chemical analysis and a Belfort® Recording Rain Gage and Event Recorder for accurate determinations of precipitation volume. Samples are collected every Tuesday morning 52 weeks a year.

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  TB165: Chemical and Physical Properties of the Danforth, Elliotsville, Peacham, and Penquis Soil Map Units

  R. V. Rourke

  The soils reported in this bulletin have developed in several different parent materials. The Danforth soil has developed from very deep, well drained, loose, high coarse fragment till derived from slate and fine-grained metasandstone. The Elliottsville soils have developed in moderately deep, well drained till derived from slates, metasandstones, phyllite and schists. The Penquis soils developed in moderately deep, well drained till of similar lithology as Elliottsville, but with a higher component of weathered and crushable rock fragments throughout the soil profile. Peacham soils are developed in very deep, very poorly drained, dense till derived from phyllite, schist, and granite.

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  TB166: Maximum Entropy Estimation of Land Use Shares and Transitions

  Andrew J. Plantinga and Douglas J. Miller

  This study presents a methodology for estimating land use shares and transitions. Our approach emphasizes the importance of land quality in determining land use. Land quality is an index of the physical characteristics of land such as soil depth, slope, and water capacity. We develop a procedure for recovering the probability that land of a given quality is put t o a particular use. In addition, we identify the probability that land shifts from one use to another.

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  TB167: Management and Winter Hardiness of Hairy Vetch in Maine

  Jean-Luc Jannink, Laura C. Merrick, Matt Liebman, and Elizabeth A. Dyck

  The research presented here describes a set of three different experiments that sought to establish appropriate management practices for hairy vetch in Maine, and to determine whether variability for winter hardiness exists among germplasm available commercially or from gene banks. Specific objectives of the first experiment were to evaluate effects of planting date and companion crop on crop and weed dry weight and total above-ground N content, at two sites differing in drainage. In a second experiment, the winter hardiness of hairy vetch from six commercial sources and the effect of a rye companion crop on hardiness were evaluated. In a third experiment, 69 V. villosa accessions from three gene banks were evaluated for winter hardiness, vigor, flowering date, and seed production.

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  TB168: Time-Series Analysis of Maine Stumpage Prices

  John B. Lindahl and Andrew J. Plantinga

  The authors of this bulletin analyze price series for stumpage in Maine. For each available species and product group (sawlogs, pulpwood), they test for stationarity and fit autoregressive integrated moving average (ARIMA ) models to the data based on preliminary diagnostics. They then perform in-sample and out-of-sample price forecasts. The central objective or this work is to characterize the processes for Maine stumpage prices in order to identify opportunities for using reservation price policies to increase timber and land values. These results are of particular value to nonindustrial timber growers for use in scheduling harvests.

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  TB160: The Horse Flies and Deer Flies of Maine (Diptera, Tabanidae)

  L. L. Pechuman and Richard Dearborn

  The distribution of Maine Tabanidae is of special interest because of the number of species with more southern ranges which reach their northeastern limit in Maine. A few northern species reach their southern limit in the state. This paper includes all of the species known or likely to be found in Maine with specific localities by county for the more unusual species and for species not found throughout the state.

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  TB161: Forestry Investments and Option Values: Theory and Estimation

  Andrew J. Plantinga

  This bulletin considers option values related to a principal problem for forestry investors, the timing of harvests. The purpose is to present a general theory of the rotation problem under uncertainty and irreversibility and provide a methodology for empirically estimating option values. Modifications of the framework for analyzing options values related to other aspects of forestry investments are also discussed.

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  TB162: Red Maple and White Pine Litter Quality: Initial Changes with Decomposition

  Mairin T. Delaney, Ivan J. Fernandez, Jeffrey A. Simmons, and Russel D. Briggs

  The specific objectives of this study were (a) to define the organic and inorganic composition of foliar litter from red maple (Acer rubrum L.) and white pine (Pinus strobus L.), and (b) to determine the shifts in the organic and inorganic composition of these two litter types during the initial stages of decomposition. These two species were chosen because of their prominence in the northeastern U.S. and the contrast they afforded in litter quality characteristics which have a strong influence on litter decomposition.

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  TB152: The Effect of Juvenile Wood on the Properties of Aspen Flakeboard

  Kenneth D. Roos, James E. Shottafer, and Robert K. Shepard

  While the effects of juvenile wood tissue on solid wood products and paper have been known for some time, little information is available regarding its influence on structural flakeboard. Juvenile and mature wood tissue were identified b y their physical and mechanical properties in quaking aspen (Populus tremuloides Michx.). Sections of juvenile and mature wood were separated from 1-foot bolts of aspen. These sections were used to prepare three distinct types of structural flakeboard : juvenile wood-based, mature wood-based, and one formed from an equal mixture of the two. The panels were tested for selected mechanical and physical properties. The juvenile wood-based panels performed significantly better than the mature wood-based in respect to modulus of rupture, thickness swell, and water absorption, while also exhibiting somewhat higher values for modulus of elasticity, internal bond strength, compressive shear strength, and linear expansion. The panels made with a mixture of the two types of flakes did not display some of the poorer characteristics of the mature wood panels.

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  TB154: Phosphorus and Potassium Availability in Wood Ash-Amended Soils: An Incubation Study

  Tsutomo Ohno and M. Susan Erich

  The objective of this study was to monitor the temporal changes in soil properties and plant availability of P and K in wood ash-amended soils during a 72-week incubation period.