UVM Theses and Dissertations
Format:
Print
Author:
Kosiba, Alexandra Maya
Dept./Program:
Natural Resources
Year:
2012
Degree:
MS
Abstract:
Red spruce (Picea rubens Sarg.) decline has been quantitatively attributed to foliar winter injury caused by freezing damage. The results of this injury include foliar mortality, crown deterioration, and negative carbon (C) balances that can lead to tree health declines and eventually mortality. In2003, a severe region-wide event damaged over 90% of red spruce in the Northeastem U.S. We assessed the influence of the 2003 winter injury event on growth declines and C sequestration of red spruce trees by measuring the xylem growth (basal area increment) in a series of forest stands in Vermont (VT), New Hampshire (NH), and Massachusetts (MA) where winter injury was quantified in 2003. Although previous work showed two-years of significant linear relationships between winter injury and growth declines, here we show that growth declines relative to pre-injury growth (2002) persisted for an additional (third) year. Using these three years of significantly reduced growth, we estimated that the 2003 winter injury event reduced the regional C sequestration of red spruce trees>17.78 cm DBH by about 716,252 metric tons of C (approximately 2,624,411 metric tons of C0₂).
Because winter injury in 2003 was positively and significantly related to plot elevation, we also examined relative changes in red spruce growth for three elevation groups: low (<765 m), mid (765-920 m) and high (> 920 m) elevation. Relative growth was below 2002 levels and significantly less for high compared to low elevation groups from 2003-2006, after which growth between these groups was indistinguishable through 2010. In 2007, and continuing through 2010, trees in mid elevation plots exhibited significantly higher growth relative to pre-winter injury levels. Eight years after the winter injury event, mid elevation plots had significantly higher mean cumulative growth than high elevation plots. As of 2010 trees in the high elevation plots continued to show a cumulative C loss -an enduring legacy of the 2003 winter injury event. While we found long-lasting reductions in growth following the 2003 winter injury event, we also discovered an unprecedented upsurge of growth in recent years, particularly in 2009 and 2010.
Because winter injury in 2003 was positively and significantly related to plot elevation, we also examined relative changes in red spruce growth for three elevation groups: low (<765 m), mid (765-920 m) and high (> 920 m) elevation. Relative growth was below 2002 levels and significantly less for high compared to low elevation groups from 2003-2006, after which growth between these groups was indistinguishable through 2010. In 2007, and continuing through 2010, trees in mid elevation plots exhibited significantly higher growth relative to pre-winter injury levels. Eight years after the winter injury event, mid elevation plots had significantly higher mean cumulative growth than high elevation plots. As of 2010 trees in the high elevation plots continued to show a cumulative C loss -an enduring legacy of the 2003 winter injury event. While we found long-lasting reductions in growth following the 2003 winter injury event, we also discovered an unprecedented upsurge of growth in recent years, particularly in 2009 and 2010.