Sugar maple (Acer saccharum Marsh.) decline disease, decreased growth, and regeneration failure have been related to a low supply of Ca and Mg. There is increased interest in augmenting cation availability via liming, but there is little information on the amounts of lime required and the longevity of the lime treatment. A single application of 22.4 Mg ha-1 of dolomitic limestone in 1985 at four forested sites in Potter County, PA has shown that soil, soil water, and sugar maple foliage chemistry are significantly altered by liming and the changes in soils and foliage persist as long as 21-yr post-treatment. By 2001, only 3 kg ha-1 of lime remained undissolved while increases in exchangeable Ca and Mg, and pH continued through 2006 at depths up to 35 to 45 cm.
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The Asian longhorned beetle, Anoplophora glabripennis (Motschulsky), threatens urban and forest hardwood trees both where introduced and in parts of its native range. Native to Asia, this beetle has hitchhiked several times in infested wood packaging used in international trade, and has established breeding populations in five U.S. states, Canada, and at least 11 countries in Europe. It has a broad host range for a cerambycid that attacks living trees, but in the introduced ranges it prefers maples. Identification, classification, and life history of this insect are reviewed here. Eradication is the goal where it has been introduced, which requires detection of infested trees using several approaches, including ground and tree-climbing surveys. Several agencies and researchers in the United States and Europe are evaluating the use of pheromone- and kairomone-baited traps. Control options beyond cutting down infested trees are limited.