white pine decline in maine
DESCRIPTION
White Pine Decline in Maine. C. Granger, H. Trial, D. Struble Forest Health and Monitoring Division Maine Forest Service. M. Fries, W.H. Livingston Department of Forest Ecosystem Science University of Maine. S. Howell S.W. Cole Engineering, Inc. Bangor, ME. December 2002. Background. - PowerPoint PPT PresentationTRANSCRIPT
White Pine Decline in Maine
M. Fries, W.H. Livingston
Department of Forest Ecosystem Science
University of Maine
C. Granger, H. Trial, D. Struble
Forest Health and Monitoring Division
Maine Forest Service
S. Howell
S.W. Cole Engineering, Inc.Bangor, ME
December 2002
Background
• Tree decline and mortality from 1997- 2000
• Southern Maine– Scattered locations– Simultaneous
appearance
• Dense, pole-size stands
Fries et al. 2002
• Field abandonment– By 1940 total number of
farms in Maine declined by 80 %
– From 1872-1995 over 7 million acres converted back to forest
• Consequences– Plow pans– Soil compaction– Rooting restrictions
Fries et al. 2002
Background Continued
Steve Howell, 2000 Brown and Lacate, 1961
• White pine rooting depth inhibited by:
–Plow pans–Lithological discontinuity (abrupt texture change from fine to course)
–Shallow water table or bedrock
• White pine roots will grow deep if soil-structure inhibitors not present
Fries et al. 2002
Rooting Habits of White Pine
• Predisposition to drought stress– Shallow rooting depth
potential– High stand densities– Poor prior growth
• Drought prior to 1997 initiated decline
Fries et al. 2002
White Pine Decline: Hypotheses
Portland
WellsWells
LebanonLebanon
HollisHollis
LimingtonLimington
CascoCasco
NobleboroNobleboroOxfordOxford
New GloucesterNew Gloucester
MassabesicMassabesic
Methods: Sampling
• Paired sites in nine locations– High mortality– Low mortality
Fries et al. 2002
48 ft
Methods: Sampling Site Design
•Modified Forest Health Monitoring (FHM)
- 4 adjacent circles- Each 48’ in diameter
Fries et al. 2002
Summary of Methods for Evaluating Hypotheses• Hypothesis - Shallow soil restrictions predisposed white
pine to drought- Measure and characterize soil restrictions
• Hypothesis – High stand density and poor prior growth also predispose white pine to drought damage - Compute stand density - Measure prior growth using tree ring analysis
• Hypothesis - Drought prior to 1997 initiated decline
- Examine climate data- Ascertain year of last growth on dead trees using tree
ring analysisFries et al. 2002
Results• Mortality
– High mortality= 31% of stems
– Low mortality =2% of stems
Significantly different
• Depth to rooting restriction – High mortality
= 24.6 cm– Low mortality
= 44.8 cmSignificantly different
Fries et al. 2002
• Plow pan (2 sites)• Water table (1 site)• Bedrock (1 site)• Lithological
discontinuity (5 sites, 3 with plow layer)
Decline Associated with Shallow Soil Restrictions
(<30cm)
Harvard Forest DioramaFries et al. 2002
High Mortality Plots Compared to Low Mortality Plots• Before mortality
– Smaller DBH
– More stems
– Initial BA similar
• After mortality
– understocked for size class
– density similar to low mortality plots
(Philbrook et al 1979)
Fries et al. 2002
Growth of Surviving Trees• Number of years of declining growth, 1995-2000 in
surviving trees did not differ between plot types– High mortality sites: 2.8– Low mortality sites: 2.4
• Growth trends in surviving trees in high and low mortality plots did not differ
Fries et al. 2002
Prior Growth of Dead White Pine
• Period of reduced growth >24 yrs (7 of 8 sites)
• Ages similar (43 vs 45 yrs)
• Smaller DBH (19 vs 25 cm)
Legend
O – Dead trees (n=29)
- Surviving Trees (n=13)
I – Standard Error
Increment growth of dead vs. surviving trees at Limington
Fries et al. 2002
Year of Last Growth
Increment
Last year of growth
% dead trees
high mortality
% dead trees
low mortality
1990 1% 0%
1991 0% 0%
1992 0% 0%
1993 0% 0%
1994 1% 0%
1995 9% 0%
1996 31% 67%
1997 33% 33%
1998 19% 0%
1999 2% 0%
2000 1% 0%
2001 2% 0%
• Percent of dead trees sampled
• Peaked in 1996-97
Fries et al. 2002
Prior to 1997, 1995 Worst Drought Year
Standardized Stream Flows for Little Androscogin
-4
-3
-2
-1
0
1
2
3
May June July Aug. Sept. Oct.
Month
Sta
nd
ard
ized
Str
eam
Flo
w
1949
1978
1995
(Number of standard deviations from 89 yr mean)
Fries et al. 2002
Drought Prior to 1997
Year Little Androscoggin Oyster SheepscotAUG SEPT AUG SEPT AUG SEPT
1990 -1.4 -0.7 -0.8 -0.2 0.6 0.1
1991 -1.8 -0.5 -0.9 0.6 -2.1 0.0
1992 -0.2 -0.6 0.3 -0.5 -0.3 -0.6
1993 -1.5 -1.5 -1.1 -1.5 -0.9 -0.5
1994 -1.3 -1.2 -1.6 -0.8 -0.8 -1.3
1995 -2.8 -2.8 -1.7 -1.9 -2.1 -2.61996 -0.7 -1.0 -0.7 -0.8 0.0 0.1
1997 -1.1 -0.5 -1.3 -0.6 -0.8 -0.8
1998 -0.6 -1.1 -0.4 -0.8 -0.6 -1.0
1999 -1.3 -1.6 -3.2 -4.6 1.6 -1.7
2000 -0.2 -1.4 -0.6 -0.7 -0.5 -0.9
2001 -1.9 -2.2 -1.8 -1.4 -1.7 -1.3
Standardized Stream Flows Indicate Severe Regional Drought in 1995
Fries et al. 2002
1995 Standardized Stream Flows
Station
Yr. of Record May June July Aug. Sept. Oct.
St. John (north) 76 -0.8 -1.7 -1.9 -1.6 -2.0 -1.7
Mattawamkeag (north) 68 -0.7 -0.8 -1.7 -2.2 -2.3 -2.2
Narraguagus (east) 54 -1.2 -0.7 -0.9 -1.3 -1.3 -1.4
Saco (NH mt.) 99 -2.2 -1.5 -1.5 -1.4 -1.5 -1.4
Carrabassett (mt.) 100 -2.0 -1.5 -1.3 -1.4 -1.6 -1.3
Sandy (mt.) 74 -2.1 -1.5 -1.3 -1.6 -1.7 -1.4
Little Androscoggin 89 -2.0 -1.7 -2.1 -2.8 -2.8 -1.8
Sheepscot 72 -2.0 -0.4 -1.1 -2.1 -2.6 -1.4
Oyster 67 -2.1 -1.1 -1.3 -1.7 -1.9 -1.5
Fries et al. 2002
Drought localized to southern Maine and far northern Maine
Climate Data Location of stream gauge stations and weather stations
Fries et al. 2002
Other ConsiderationsBiotic Stress
Ips bark beetleArmillaria
root rot
• 88 trees sampled at DBH and roots – Dominant
– Few needles, red needles, no needles
• % of trees with pests – 63.6% Cerambycidae
– 60.2% Ips spp.
– 56.8% Armillaria spp.
• All secondary in nature
Fries et al. 2002
• Plowing changed soil characteristics that predispose pine to decline
– Plow layer
– Lithological discontinuity • Pine regenerated on sites to
which it is not adapted
– High water table
– Shallow bedrock • Mortality present where field
abandoment was highest – in south but not in north
Conclusions:
Field Abandonment Created Conditions Leading to White Pine Decline
Harvard Forest Diorama
Fries et al. 2002
Additional Conclusions
Steve Howell, 2000
• Density might be an additional predisposing factor
• Mortality thinned-out poorly growing trees
• Surviving trees growing normally
• Drought is the likely inciting stress in white pine decline– 1995 year of severe drought
in southern Maine– 1995-1998 period for years
of last growth– 1997-2000 period of visual
mortalityFries et al. 2002