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Nitrogen availability may be a major factor structuring ectomycorrhizal fungal communities. Atmospheric nitrogen (N) deposition has been implicated in the decline of ectomycorrhizal fungal (EMF) sporocarp diversity. We previously characterized the pattern of decreased sporocarp species richness over an anthropogenic N deposition gradient in Alaska (USA). To(More)
e are living in an era of unprecedented and rapid ecological change (Reid et al. 2005). Through habitat conversion, over-consumption of resources, and worldwide introductions of pests and pathogens, humans are causing species extinctions at a record rate: the sixth extinction crisis in the billion-year history of eukaryotic life on Earth (Eldridge 1998).(More)
Recent projections of climatic change have focused a great deal of scientific and public attention on patterns of carbon (C) cycling as well as its controls, particularly the factors that determine whether an ecosystem is a net source or sink of atmospheric carbon dioxide (CO 2). Net ecosystem production (NEP), a central concept in C-cycling research, has(More)
Net ecosystem production (NEP), defined as the difference between gross primary production and total ecosystem respiration, represents the total amount of organic carbon in an ecosystem available for storage, export as organic carbon, or nonbiological oxidation to carbon dioxide through fire or ultraviolet oxidation. In some of the recent literature,(More)
Leaching losses of nitrate from forests can have potentially serious consequences for soils and receiving waters. In this study, based on extensive sampling of forested watersheds in the Catskill Mountains of New York State, we examine the relationships among stream chemistry, the properties of the forest floor, and the tree species composition of(More)
To investigate the influence of individual tree species on nitrogen (N) cycling in forests, we measured key characteristics of the N cycle in small single-species plots of five dominant tree species in the Catskill Mountains of New York State. The species studied were sugar maple (Acer saccharum), American beech (Fagus grandifolia), yellow birch (Betula(More)
the glow of a sugar maple-covered hillside in full autumn color is an unforgettable sight. Sugar maple (Acer saccharum) (Figure 1) is one of several major tree species of the northern hardwood forest, along with American beech (Fagus grandifolia), yellow birch (Betula alleghaniensis), eastern hemlock (Tsuga canadensis), and several other hardwood and(More)
Lyme disease and gypsy moth outbreaks plague many temperate oak forests. Over the past decade, we have developed models and hypotheses designed to allow us to predict irruptions of both gypsy moths and the tick vector of Lyme disease. We have documented a web of connections involving mast production by oak trees, population responses by white-footed mice,(More)
Forest ecosystems in most industrialized and agricultural regions receive elevated rates of atmospheric nitrogen (N) deposition from air pollution. To evaluate the effects of excess N deposition on carbon (C) and N cycling, we experimentally added N (as NH4NO3) to naturally-occurring, single-species plots of five different tree species that are common in(More)
SUMMARY M ore than four decades of research provide unequivocal evidence that sulfur, nitrogen, and mercury pollution have altered, and will continue to alter, our nation's lands and waters. The emission and deposition of air pollutants harm native plants and animals, degrade water quality, affect forest productivity, and are damaging to human health. Many(More)