Interactive effects of White Pine Needle Damage and climate change on forest health across the...
1
Interactive effects of White Pine Needle Damage and climate change on forest health across the Northeastern United States Cameron McIntire 1 , Heidi Asbjornsen 1 , Isabel Munck 2 , Kirk Broders 1 and Bill Livingston 3 University of New Hampshire, Durham, NH. 2 United States Forest Service, Durham, NH. 3 University of Maine, Orono, ME. Regional Defoliations 5-Jun 20-Jun 5-Jul 20-Jul 4-Aug 19-Aug 3-Sep 0 20 40 60 80 Needle Length (mm) A Changing Climate 0% 5% 10% 15% June July August Percent Defoliation Bethel, ME Durham, NH Lyman, ME Hillsborough, NH Growth Declines Introduction 1960 1970 1980 1990 2000 2010 0 1000 2000 3000 4000 5000 6000 Low WPND Severity Basal Area Increment (mm2) 0 2 3 -10% 10% 30% 50% 70% 8.3% 47.4% 52.8% Crown Defoliation Class Percent Decline Photo: Stephen Wyka 2014 Disease Outbreak • The climate in the Northeastern U.S. has already experienced increased annual temperature and total precipitation (Fig. 1); a trend that is expected to continue. Variability in climate may exacerbate WPND if wetter and warmer-than-average springs and summer droughts persist in the future. Higher amounts of SPRING rainfall are thought to facilitate the spread of WPND associated fungi. 1940 1950 1960 1970 1980 1990 2000 2010 20 30 40 50 Mean Annual Precipitation (in) 40 42 44 46 48 50 Concord, New Hampshire Mean Annual Temperature (°F) • White Pine Needle Damage (WPND) is a complex of rain dispersed fungal pathogens that infect and defoliate the needles of eastern white pine (Pinus strobus L.). Since the spring of 2009 the northeastern United States has been experiencing an outbreak of WPND that continues to persist and spread throughout the region. • WPND defoliates second and third year needles prior to the current year needle elongation. This effectively thins the crowns and often results in the premature death of the lower branches. WPND represents a significant threat to tree health and has been known to result in tree mortality in extreme cases. Study Area Map: Tom Luther, USFS • The US Forest Service has established eight permanent study plots for monitoring WPND throughout the NE region spanning four cold hardiness zones. The 2014 field season focused on sites within the 4a , 4b, 5a, and 5b climate zones. • Methods: In 2014 litterfall was measured using 0.18m 2 traps (n=5) in 3 plots at 4 of the study sites. Litter was collected at the end of each month starting in May then dried and sorted for P. strobus needles. Stem counts at each plot were used to normalize litterfall based on basal area of white pine and to estimate total foliar dry weight using an allometric relationship to DBH (Levia 2008). Levia, D.F. 2008. A generalized allometric equation to predict foliar dry weight on the basis of trunk diameter for eastern white pine (Pinus strobus L.) Forest • Methods: Dendrochronological analysis at the Fox State Forest (Hillsborough, NH) was conducted on increment cores (n=60) from a total of 20 tree classified as either low or high severity of WPND infection (Fig. 4). • Trees identified as having >30% WPND affected crowns in the spring (crown class 2, 3) show a mean decline of 50% compared to pre-outbreak growth patterns. Healthy tees or of low severity defoliation (crown class 0) show minimal declines and often positive growth over the same time interval (Fig. 5). Acknowledgements • Needles become chlorotic and are cast during a large pulse in June, then intermittently drop throughout the rest of the growing season. Thee degree of defoliation severity differs between sites (Fig. 2). • Current year needles are not yet fully elongated at the time of needle drop. This represents a loss of photosynthetic potential during a large portion of the growing season (Fig. 3). Bethel Hillsboro ugh Lyman Durham Cumulativ e Defoliati on 20% 10% 29% 8% Future Work • Analysis of leaf level photosynthesis, stomatal conductance, water use efficiency, and whole tree water use. • Dendrochronological analysis to quantify growth declines at each of the permanent study sites. • Silvicultural thinning treatments for developing management recommendations. References I am extremely greateful to Isabel Munck, Bill Livingston, Kirik Broders, and Heidi Asbjornsen for their assistance in designing the sampling and analysis. Field work would not have been possible without the help of Stephen Wyka, Sydney Snelling, Jake Mavrogeorge, Conor Brenton, Connor Madison, Kate Jennings, Katie Accashian, Lauren Buzinski, Stacie Powers, Andy Ouimette, Lucie Lepine, Rand Snyder, Inge Seaboyer, and Jen Weimer. Figure 1. Annual trends in temperature and precipitation; Concord, NH. Figure 2. Monthly (May-August, 2014) pine litterfall proportional to the total estimated foliar dry weight at four of the permanent study plots. Figure 3. Mean (n=3) needle elongation measured on three trees in Durham, NH. Figure 5. WPND induced growth decline at Fox Forest, NH. Results Figure 4. Standardized chronology converted to units of basal area increment (BAI) from the Fox Forest, NH. Results
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Transcript of Interactive effects of White Pine Needle Damage and climate change on forest health across the...
Interactive effects of White Pine Needle Damage and climate change on forest health across the Northeastern United States
Cameron McIntire1, Heidi Asbjornsen1, Isabel Munck2, Kirk Broders1 and Bill Livingston3
University of New Hampshire, Durham, NH. 2United States Forest Service, Durham, NH. 3University of Maine, Orono, ME.
Regional Defoliations
5-Jun 20-Jun 5-Jul 20-Jul 4-Aug 19-Aug 3-Sep01020304050607080
Nee
dle
Leng
th (m
m)
A Changing Climate
0%
5%
10%
15%
20%
MayJuneJulyAugust
Perc
ent D
efol
iatio
n
Bethel, ME Durham, NH Lyman, ME Hillsborough, NH
Growth DeclinesIntroduction
1960 1970 1980 1990 2000 20100
1000
2000
3000
4000
5000
6000
Low WPND SeverityHigh WPND Severity
Basa
l Are
a In
crem
ent (
mm
2)
0 2 3-10%
10%
30%
50%
70%
8.3%
47.4%52.8%
Crown Defoliation Class
Perc
ent D
eclin
e
Photo: Stephen Wyka 2014
Disease Outbreak
• The climate in the Northeastern U.S. has already experienced increased annual temperature and total precipitation (Fig. 1); a trend that is expected to continue. Variability in climate may exacerbate WPND if wetter and warmer-than-average springs and summer droughts persist in the future. Higher amounts of SPRING rainfall are thought to facilitate the spread of WPND associated fungi.
1940 1950 1960 1970 1980 1990 2000 201020
30
40
50
Mea
n An
nual
Pr
ecip
itatio
n (in
)
40
42
44
46
48
50 Concord, New Hampshire
Mea
n An
nual
Tem
pera
ture
(°F)
• White Pine Needle Damage (WPND) is a complex of rain dispersed fungal pathogens that infect and defoliate the needles of eastern white pine (Pinus strobus L.). Since the spring of 2009 the northeastern United States has been experiencing an outbreak of WPND that continues to persist and spread throughout the region.
• WPND defoliates second and third year needles prior to the current year needle elongation. This effectively thins the crowns and often results in the premature death of the lower branches. WPND represents a significant threat to tree health and has been known to result in tree mortality in extreme cases.
Study Area
Map: Tom Luther, USFS
• The US Forest Service has established eight permanent study plots for monitoring WPND throughout the NE region spanning four cold hardiness zones. The 2014 field season focused on sites within the 4a , 4b, 5a, and 5b climate zones.
• Methods: In 2014 litterfall was measured using 0.18m2 traps (n=5) in 3 plots at 4 of the study sites. Litter was collected at the end of each month starting in May then dried and sorted for P. strobus needles. Stem counts at each plot were used to normalize litterfall based on basal area of white pine and to estimate total foliar dry weight using an allometric relationship to DBH (Levia 2008).
Levia, D.F. 2008. A generalized allometric equation to predict foliar dry weight on the basis of trunk diameter for eastern white pine (Pinus strobus L.) Forest Ecology and Management. 255, 1789-1792
• Methods: Dendrochronological analysis at the Fox State Forest (Hillsborough, NH) was conducted on increment cores (n=60) from a total of 20 tree classified as either low or high severity of WPND infection (Fig. 4).
• Trees identified as having >30% WPND affected crowns in the spring (crown class 2, 3) show a mean decline of 50% compared to pre-outbreak growth patterns. Healthy tees or of low severity defoliation (crown class 0) show minimal declines and often positive growth over the same time interval (Fig. 5).
Acknowledgements
• Needles become chlorotic and are cast during a large pulse in June, then intermittently drop throughout the rest of the growing season. Thee degree of defoliation severity differs between sites (Fig. 2).
• Current year needles are not yet fully elongated at the time of needle drop. This represents a loss of photosynthetic potential during a large portion of the growing season (Fig. 3).
Bethel Hillsborough Lyman DurhamCumulative Defoliation 20% 10% 29% 8%
Future Work• Analysis of leaf level photosynthesis, stomatal conductance,
water use efficiency, and whole tree water use.• Dendrochronological analysis to quantify growth declines at
each of the permanent study sites.• Silvicultural thinning treatments for developing
management recommendations.
References
I am extremely greateful to Isabel Munck, Bill Livingston, Kirik Broders, and Heidi Asbjornsen for their assistance in designing the sampling and analysis. Field work would not have been possible without the help of Stephen Wyka, Sydney Snelling, Jake Mavrogeorge, Conor Brenton, Connor Madison, Kate Jennings, Katie Accashian, Lauren Buzinski, Stacie Powers, Andy Ouimette, Lucie Lepine, Rand Snyder, Inge Seaboyer, and Jen Weimer.
Figure 1. Annual trends in temperature and precipitation; Concord, NH.
Figure 2. Monthly (May-August, 2014) pine litterfall proportional to the total estimated foliar dry weight at four of the permanent study plots.
Figure 3. Mean (n=3) needle elongation measured on three trees in Durham, NH.
Figure 5. WPND induced growth decline at Fox Forest, NH.
Results
Figure 4. Standardized chronology converted to units of basal area increment (BAI) from the Fox Forest, NH.
Results
