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Sugar Maple Ecology and Health: Proceedings of an International Symposium

During the past four decades, declines of sugar maple have occurred throughout its range. Each decline event has been the subject of intense research.The declines were ephemeral, preventing a complete understanding of conditions and causes.The most recent decline in Pennsylvania was the impetus to organize an international symposium on sugar maple ecology and health. Speakers from the United States and Canada were invited to share their research and explore a variety of topics concerning sugar maple history and ecology, recent sugar maple declines, nutrient and beiowground dynamics in northeastern forests, and interactions of forest health with biotic and abiotic stressors. Posters also were contributed. Attending scientists, natural resource professionals, and land managers participated in two days of talks and discussions and a day-long field trip to sugar maple decline research sites in northwestern Pennsylvania and southwestern New York.

Sugarmaker’s Guide to Pear Thrips Monitoring

Pear thrips surfaced as a new pest of sugar maple, Acer saccharum Marsh., in 1979. Damage from this insect occurs intermittently, and threatens the long-term health of maple trees throughout the northeastern United States and parts of Canada. A method for sampling forest soil to determine pear thrips populations is described that is suitable for sugarmakers. This method requires a minimum of equipment and time, and provides sugarmakers with a reliable estimate of the number of thrips in their sugar_bushes. By sampling and assessing damage annually, sugarmakers will gain an understanding of the relationship between thrips population levels and damage in their stands. Based on this information, potential damage in the spring can be estimated. Sample results are obtained before tapping so sugarmakers can adjust their management practices, such as the number of taps per tree, to minimize stress on trees when damage is likely.

Field Guide for Monitoring Sugar Maple Bud Development

The timing and duration of budbreak of forest trees may be affected by biotic and abiotic factors. This manual provides a visual method for monitoring bud development of mature trees of sugar maple, Acer saccharum Marsh., from the ground. A spotting scope with a 15-45x zoom lens was used for bud rating. The user is supplied with close-up photographs and a brief description of each bud stage. Sample data sheets are also provided. This protocol is currently used in the Vermont Forest Health Monitoring Program.

Sapstreak Disease of Sugar Maple: Development Over Time and Space

Sapstreak disease is a potentially serious problem of sugarbushes and forest stands. It is caused by the fungus Ceratocystis virescens, which invades sapwood of roots and bases of stems through wounds created during logging, saphauling, or other activities. This report describes the results of observations and experiments to learn more about the patterns of disease development and the factors that affect them, within individual trees and within representative forests and sugarbushes.

Photographic Guide of Selected External Defect Indicators and Associated Internal Defects in Sugar Maples

To properly classify or grade logs or trees, one must be able to correctly identify indicators and assess the effect of the underlying defect on possible end products. This guide assists the individual in identifying the surface defect indicator and shows the progressive stages of the defect throughout its development for sugar maple. Eleven types of external defect indicators and associated defects that are particularly difficult to evaluate are illustrated and described.

Height-Diameter Relations of Maple Street Trees

Height and diameter measurements were taken for silver, sugar and Norway maple street trees in Rochester and Syracuse, New York.

Timing of defoliation and its effect on bud development, starch reserves, and sap sugar concentration in sugar maple

Sapling sugar maple (Acer saccharum Marsh.) trees were defoliated artificially at 10-day intervals beginning May 27 and ending August 5, 1981. Refoliation, terminal bud and shoot development, and xylem starch and sap sugar concentration were observed in defoliated and control trees. All defoliated trees refoliated, but decreasingly with later defoliation. Defoliation caused an acceleration in the rate of primordia initiation in terminal shoot apices. After early season defoliations, the developing buds in the axils of the removed leaves abscissed, but axillary and terminal buds on the refoliated terminal shoots survived through winter. In late season defoliation, most buds of refoliated shoots did not survive and the next year’s growth depended on axillary buds formed prior to defoliation. Thus, when progressing from early to late defoliations, the next year’s shoot growth depended decreasingly on the last-formed and increasingly on the first-formed portions of the previous year’s shoot. Early October starch concentration in xylem decreased with later defoliation and was nearly absent in shoots and roots of trees defoliated in late July. There was not, however, a corresponding decrease in sap sugar concentration. Mortality occurred only in late defoliated trees and was associated with starch depletion.

Compartmentalization: A Conceptual Framework for Understanding how Trees Grow and Defend Themselves

The purpose of this chapter is to describe a conceptual framework for understanding how trees grow and how they and other perennial plants defend themselves. The concept of compartmentalization has developed over many years, a synthesis of ideas from a number of investigators. It is founded on observations of trees injured in the field by wind, snow, ice, fire, animals, and insects, as well as during pruning, coppicing, sugaring, and other forest and orchard management practices. It is based on experimental studies of natural and artificial wounds with and without controlled inoculations with selected pathogenic and saprophytic microorganisms.