Climate change effects on physical and
biological systems in and near the
Andrews Forest, Oregon
June 9, 2010
Julia Jones, Geosciences, Oregon State University
with input from Bryan Black, Barbara Bond, Chris Daly, Steven Highland,
Ron Metoyer, Jeff Miller, Kathleen Moore, Alan Tepley, Chris Thomas
Overview
•
•
•
•
Climate of HJ Andrews Forest
Trends in physical climate
Drivers of climate
Biological responses: tree growth, moths
HJ Andrews Forest – landscape setting
Marine influence
Orographic influence
Andrews Forest
Yellow dot is Andrews headquarters
Summer – HJ Andrews Forest and Cascade Range
Winter – HJ Andrews Forest and western Cascades
The Andrews interacts with climate at multiple elevations and topography
creates local winds
3200
Permanent snow/ice zone
Crest of the Cascade Range
2800
McKenzie
River
2000
A 2.5 degree C warming may cause this change in
elevation of the snow zone, depending on how
complex terrain interacts with warming processes
1600
Mack
Silver fir zone
Transient snow zone;
Douglas-fir/western
hemlock forest
WS 6,7,8
WS 1,2,3
WS 10,9
Elevation (m)
Seasonal snow zone;
Sub-alpine forest and
meadows
2400
1200
Lookout
Creek (HJ
Andrews)
800
400
0
Distance from the mouth of the Andrews Forest watershed (km)
Span of gaged
watersheds
Span of snow
zones
Span of vegetation
zones
15
40
Meteorological station in HJ Andrews Forest
Meteorological station near HJ Andrews Forest
Figure 2.6. Climate interactions with topography within the H.J. Andrews (shaded area) and surrounding landforms in the high Cascades are
displayed by a schematic hyposmetric curve, and captured by an array of climate stations and stream gages spanning the major rain/snow and
vegetation zones. Most of the area of the Andrews Forest is in the transient snow zone with Douglas-fir and western hemlock forest. We
expect climate change to affect the boundary of the transient and seasonal snow zones, associated ecotones, and rain-on-snow flooding.
Andrews met stations
with 35 to 50 yr records
Andrews reference stands with
temperature records > 29 yrs
RS86
RS89
Climate diagrams at the Andrews
Climate trends
•
•
•
•
Precipitation
Air temperature
Snow
Streamflow
Carpenter Mt. - Vanmet
Reference stand 10
Trends in annual precipitation (water-year basis), HJ Andrews Forest
No significant trends 1958-05 on annual basis or in any month
Trends in daily minimum temperature, cs2met, 1958-2007:
earlier spring by about one day/year
C. Thomas
Degrees C/yr
Degrees C/yr
Trends in mean monthly air temperature, HJ Andrews Forest
Maximum temperatures
increase in January, March,
May, August, September
Increase in max>min
at ref stands;
Increase in max<min
at met stations
Minimum temperatures
increase in January, April,
May, June, September
Trends in mean monthly air temperature by elevation, HJ Andrews Forest:
Patterns not clearly related to elevation, also affected by changes in canopy
Andrews met stations
with 35 to 50 yr records
Andrews reference stands with
temperature records > 29 yrs
RS86
RS89
Snowpack records in and near the HJ Andrews Forest
V = Vanmet (1273m)
S = Santiam Jct (1140m)
H = Hogg Pass (1460m)
M = McKenzie (1454m)
S
T = Three Creeks
Meadow (1734m)
H
V
From 1988-2007:
M
Van = SantJct* 1.13 + 1
T (F=152.3, p<0.0001, adj
r2 = 0.67)
Van = HoggP*0.55 - 91
(F=57.7, p<0.0001, adj
r2=0.43)
Van = McKnz* 0.46 - 40
(F=48.3, p<0.001, adj r2
= 0.38)
Van = TCrMe*0.82 + 44
(F = 41.2, p<0.0001, adj
r2 = 0.35)
White dot is Andrews headquarters
Average snowpack (mm), 1998-99 to 2002-03 water years
Snowpacks at the Andrews increase with elevation, peak around April 1
Upl = 1294 m
Van = 1173 m
Cen = 1018 m
Pri = 430 m
Snowiest year from 1987-88 to 2003-04: 1998-99
Trend in snowpack anomalies at 5 sites in/near HJ Andrews Forest, 1925-2007
April
More snow
than average
Less snow
than average
Summary of snowpack trends at the HJ Andrews Forest
Sea surface temperature (PDO) explains about half of interannual variation in snow
water equivalent (SWE) at the five snow sites.
Controlling for the effect of PDO and month, SWE declined significantly Jan-May
from 1930-2007 at Santiam Jct and Three Creeks Meadow, but not at McKenzie or
Hogg Pass.
SWE declined 50% at Santiam Jct and 30% at Three Creeks Meadow, 1925-2007
Small watersheds at HJ Andrews, 1952-present
Trends in runoff ratios in spring (March-May), 19582005
Small watersheds with old-growth forest cover: declining spring flows,
no change in summer or winter streamflow
1958-2005
p<0.03
p<0.006
p<0.006
K. Moore
Climate drivers
• Sea surface
temperature
• Continental drought
Air masses originate
from the Pacific
HJ Andrews climate
records span cool and
warm PDO periods
Summer precipitation is higher
than average when sea surface
temperatures are warmer than
average (warm PDO)
Winter air temperatures are
higher than average, and
summer temperatures are cooler
than average in warm PDO
Snowpack higher than average in
cool PDO, lower than average in
warm PDO conditions
Biological responses
• Tree rings
• Moth phenology
J. Miller
Oregon tree-ring chronologies: correlations with climate drivers
Span 1885 through 1990; N = 52
core
Principal components analysis
3
2
1
0
B. Black
Oregon tree-ring chronologies:
correlations with climate drivers
PC1 is a measure of sea surface
temperatures, which are correlated
with winter snowpack and air
temperatures
PC2 is a measure of continental
precipitation, which influences
summer moisture availability
B. Black
Tree ring-width correlation with PC2 (precipitation) varies with
elevation
Faster growth at low
elevation when
moisture is high
Faster growth at high
elevation when
moisture is low, air
temperatures high
1
correlation with PC2
0.8
0.6
Coast Range sites
0.4
0.2
0
-0.2
-0.4
-0.6
0
500
1000
1500
need more
low-elevation
Cascades chronologies!
2000
2500
elevation (m)
B. Black
ring width index
High elevation chronology, Browder Creek, NE of Andrews
Forest
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
1300
insects
insects
Browder Creek master chronology
-Douglas-fir; 1120 m elevation
1400
1500
1600
1700
1800
1900
2000
year
Tree growth positively correlated with
winter sea surface temperatures (JanMar)
-Pacific Decadal Oscillation
-El Nino Southern Oscillation
correlation coefficient (r)
B. Black
ring width index
Low elevation chronology, Willamette Valley, W of Andrews
Forest
1.6
1.4
1.2
1
0.8
0.6
0.4
1700
1750
1800
1850
1900
1950
2000
Year
Tree growth positively correlated with
summer (May-Aug) PDSI
correlation coefficient (r)
B. Black
Trends over time in moth species, HJ Andrews Forest
Abundance, the total number of individuals present, all species, 1986-07
Trends in abundance of common moth species, HJ Andrews Forest
J. Miller
Moth species
emergence and
location varies with
climate
2004: very warm summer,
by mid July common moths
are abundant at high
elevation (n>500), esp. in
forest
2008: very cool summer, by
mid July common moths are
less abundant at high
elevation (n<150), relatively
more abundant in meadow
Y. Tuan, R. Metoyer, J. Miller, S. Highland, J. Jones
Summary of mountain climate effects on physical and biological systems,
HJ Andrews Forest