TB200: Carbon and Nutrients in Maine Forest Soils

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.https://digitalcommons.library.umaine.edu/aes_techbulletin/1005/thumbnail.jp

Mechanisms Controlling Metal and Phosphorus Dynamics in an Experimentally Acidified Watershed in Maine

The Bear Brook Watershed in Maine (BBWM) is a long-term (14+ years), whole-watershed experiment designed to study ecosystem responses to acid deposition. One watershed has been treated bimonthly by helicopter with nitrogen and sulfur since 1989. Results have documented progressive acidification of soils and streams, substantial losses of soil nutrients (e.g., calcium), increased nitrogen cycling, and changes in tree foliar chemistry. Little research has been done on phosphorus, a critical nutrient in ecosystems. This project will evaluate the effects of long-term watershed acidification on metal mobilization (focusing on aluminum and iron) and linked effects on phosphorus at BBWM by studying soils, soil solutions, stream water, and biota (e.g., foliage, roots, and soil microorganisms).Policy makers have focused on emissions regulations to control nitrogen and sulfur due to known ecological effects on forests and streams such as acidification, nitrogen saturation, and base cation depletion. Little is known about how these ecological changes will, in turn, affect phosphorus cycling. Understanding changes in this key nutrient may be pivotal to understanding underlying mechanisms of forest decline and surface water quality, and will therefore be fundamental to policy and management planning

B818: Preliminary Protocols for Sampling and Analysis of Ash and Sludge Amended Forest Soils

Over the past decade there has emerged a clear recognition that the escalating production of waste materials by society poses a serious problem, and that significant amounts of many waste materials must be recycled or disposed of by more ecologically integrated means. In Maine, we are fortunate to enjoy the benefits of a rural state rich in natural resources. It is these resources that provide the basis for many of our industries, well demonstrated by our forest resources so vital to the forest products industry and to Maine\u27s economy. In recent years forests have also been looked to as a source of wood fuel for power generating facilities, and this trend is likely to continue. These and other activities lead to the generation of waste materials that may be considered either effluents, sludges, solid waste, or ash. Some processes can create materials laden with toxic organic compounds or heavy metals that pose serious threats to the environment. Others are relatively clean and interest in land applications of these materials has increased due to the high costs of landfilling. While agricultural lands may provide a cost effective receptor site for waste materials, these soils also are a direct conduit to the human food chain and may not be advisable sites when questions remain over potential health risks associated with a particular waste. Thus some of our extensive forest lands in Maine are being considered as sites for waste application and disposal, which holds promise when carefully carried out based on a scientific understanding of forest ecosystem responses. This bulletin offers some preliminary guidelines to serve as a starting point for the systematic assessment of the effects of ash and sludge application to northern New England forest soils.https://digitalcommons.library.umaine.edu/aes_bulletin/1099/thumbnail.jp

TB126: Vertical Trends in the Chemistry of Forest Soil Microcosms Following Experimental Acidification

A soil microcosm experiment was conducted (a) to compare dilute H2SO4, NH4NO3 fertilizer, and prilled S as possible experimental soil-acidifying treatments and (b) to observe soil chemical response to simulated throughfall and acidifying treatments. Simulated throughfall had a significant effect on soil chemistry, resulting in increased exchangeable bases and pH in the mineral soil horizons but little effect on the O horizon. Of the acidification treatments only simulated acid rain had significant effects on soil chemistry when compared to the control and the dry treatments. This reflected the relatively slow dissolution rate of the dry treatments coupled with the short duration of the experiment. Simulated acid rain decreased exchangeable base cations and pH while increasing exchangeable Al. The 2.5-cm layer of Bs horizon material immediately below the abrupt E horizon boundary proved to be the soil layer most responsive to chemical alteration.https://digitalcommons.library.umaine.edu/aes_techbulletin/1062/thumbnail.jp

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

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\u2752 longitude and 45°29\u2723 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.https://digitalcommons.library.umaine.edu/aes_techbulletin/1040/thumbnail.jp

Workshop: A Cross-Biome Synthesis of Ecosystem Response to Global Warming; October 1998 in Santa Barbara, CA

Greenhouse gas emissions are expected to increase mean global temperature by 3-5 C in the next 50-100 years. The consequences of this warming for primary ecosystem processes are not yet understood, and have become tile focus of an emergent field of ecological research. This project will bring together a multi-disciplinary, international group of scientists representing 22 soil/air warming sites from seven countries to synthesize the current knowledge on the effects of elevated temperature on terrestrial ecosystems. In addition, the participants will use this forum to discuss and launch a new GCTE Ecosystem Warming Consortium, which will have far reaching effects in supporting and promoting future information exchange, technology transfer, and synthesis efforts in ecosystem warming research

TB119: Selected Relationships for Trace Metals in Maine Low Elevation Spruce-Fir Forest Floors

Results from the analysis of trace metals in the forest floor from three study areas northern Maine commercial spruce-fir stands showed significant, positive correlations were frequently evident between ash-free concentrations of Individual pairs of trace metals. Only Pb concentrations at one location were found to vary significantly among soil drainage classes. Overall, ash-free trace metal concentrations were less than what has been found at sites receiving high loadings of atmospheric deposition in the Northeast. Few historical data are available to adequately determine if Maine forest floor trace metal concentrations are greater than the natural levels expected in commercial forests, but it appears possible that current concentrations reflect contributions from the atmosphere above background conditions.https://digitalcommons.library.umaine.edu/aes_techbulletin/1079/thumbnail.jp

TB134: A Laboratory Study to Assess Methods for Predicting pH Change of Ash Amended Forest Soils

The objective of this study was to compare several commonly used lime requirement tests and soil capacity factors for their ability to predict pH change following wood-ash amendment. The ability to predict pH change is important because it is one of the criteria used to prescribe rates of ash amendment to forest soils.https://digitalcommons.library.umaine.edu/aes_techbulletin/1070/thumbnail.jp

TB105: The Composition of Equilibrium Soil Solutions from Forest Soil B Horizons

The objective of the present study was to evaluate the composition of B horizon equilibrium soil solutions from selected Maine forest soils. The B horizon was chosen for evaluation because it (1) best expressed the weathering processes active in the soil, (2) occupied the greatest volume of the solum, (3) had the most complex chemistry of the major horizons, and (4) provided the major corridor in forested ecosystems for subsurface flow and chemical alteration of ground waters.https://digitalcommons.library.umaine.edu/aes_techbulletin/1089/thumbnail.jp

TB138: Variability Factors Involved with Land Application of Papermill Sludge

The goal of this case study was to assess two components of variability associated with the land application of papermill sludge. These included (1) changes occurring within a temporary sludge stockpile, and (2) spatial variability of application to the site. Understanding the magnitude of such changes will assist in accounting for variability inherent in such land application operations.https://digitalcommons.library.umaine.edu/aes_techbulletin/1196/thumbnail.jp