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Robert P. Long

Supervisory Research Plant Pathologist
Sustaining Forests in a Changing Environment
335 National Forge Road
Irvine, PA 16329
United States
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Research Highlights

Using fertilizer to promote diverse seedling development in Allegheny hardwood forests

Year: 2017
Fertilizing the forest understory slows the development of dominance by sweet birch, favors development of black cherry following overstory removal, and favors red maple in partial cut shelterwood stands.

Black cherry regeneration difficulties: Are They Related to Stand Age or Something Else?

Year: 2017
Forest managers report that black cherry regeneration is impeded by poor and erratic seed production. Tree stand age has been suggested as one of the causal factors affecting seed production. Forest Service scientists monitored black cherry seed production over seven years to see whether stand age a...

Black Cherry Crown Health and Mortality on the Allegheny National Forest

Year: 2016
Black cherry, an important timber and wildlife species in the Allegheny hardwood forest, is suffering from poor crown health and increased mortality across northern Pennsylvania. Research is in progress to determine the biotic and abiotic factors causing this change in black cherry health status and...

Changes in Black Cherry on the Allegheny Plateau

Year: 2016
Increased tree mortality, decreased seed production, and seedling growth. Managers and scientists have been observing these changes in black cherry on the Allegheny Plateau and are working together to sharpen the research focus and utilize long-term research to improve forest management.

Long-Term Effects of Forest Liming on Soil, Soil Leachate, and Foliage Chemistry in Northern Pennsylvania

Year: 2015
In many areas of the northeastern United States and Canada, base cations have been depleted by long-term inputs of acidic deposition. Forest liming restores base cations, which improves the crown health, growth, and seed production of sugar maple. Forest Service scientists now know that forest limin...

Liming Effects Help Maintain Sugar Maple Growth and Health and Persist for More Than 20 years

Year: 2014
Long-term inputs of acidic deposition have depleted soils of calcium (Ca) and magnesium (Mg) on ridge-top, unglaciated sites in Pennsylvania. Sugar maple requires adequate supplies of these elements to maintain growth, crown health, and flower and seed production. Soils sampled as part of a long-ter...