Stem injuries of red spruce trees of the Adirondack Mountains, New York, USA

Numerous studies have shown that red spruce (Picea rubens Sarg.) trees growing in high elevation areas of the northeastern United States have experienced a growth decline. The most obvious symptom is apical dieback, the death of first-year, over-wintering terminal buds and stems (stems with needles). Although, these symptoms and the anatomical characteristics of these symptoms have been documented, there is no recent, extensive, and quantitative documentation of the numbers of stems that show these symptoms. The purpose of this research was to determine the numbers and percentages of first-year stems that show these symptoms for stems produced in 2002, 2003, and 2004. This research project was designed to determine the degree of missing and dead stems that result from apical dieback for over-wintering stems on two branches per direction, eight directions per tree, four trees per elevation, and four elevations per mountain for each of four mountains in the Adirondack Mountains of New York. For this study, 944 stems of 2002 growth, 2151 stems of 2003 growth, and 5832 stems of 2004 growth were analyzed. For 2003 and 2004 stem samples, 206 (10%) and 1851 (32%) stems were missing/dead. Of the three new stems (two lateral stems and one central stem) produced on each established stem, central stems had higher survival rates than lateral stems. There were no statistically significant effects of direction of stems around trees or among the four elevations sampled per mountain. Since higher elevations had more stem deaths several decades ago, we conclude that the lack of an elevational effect or an directional effect on trees may have resulted from relatively high levels (32% missing/dead stems for 2004) of stem death that are currently present for red spruce trees in the Adirondack Mountains.