Critical climatic factors that may impact Northeastern alpine plant communities Kenneth Kimball and

1
Critical climatic factors that may impact
Northeastern alpine plant communities
Kenneth Kimball and Doug Weihrauch --
Appalachian Mountain Club
2
The Spatial Time Scale Question

• Is the regions climate static?
• No, on geologic timescale a wide range of
  variability, from glaciers to warm periods.
• If we use the period after the last deglaciation,
  during the last half century, yes, the climate
  appears to be changing rapidly
• Rate of change spatially is not uniform across
  the world greater at higher latitudes

3
(No Transcript)
4
Agung (Bali)
Pelée
St. Helens

Krakatoa
Pinatubo
5
Climate across the Northeast is already changing

• Since 1900 avg. increase of 0.14 F/decade
• From 1970-2002 avg. increase of 0.5 F/decade
• Annual temperatures (avg.) across NE have warmed
  almost 1.7ºF since 1970
• Winters have been warming fastest, at 1.3ºF per
  decade since 1970
• Winter snowpack is decreasing
• Plants are flowering earlier in the Spring
• Extreme heat in summer is becoming more frequent
• In future, models predict w/ current to increased
  
• GHG emissions upwards of 5 to 10 F incr.
• by end of century

6
Rising Northeast Temperatures(annual average)
F)
12
Higher 6.5-12.5oF
o
observations
10
higher emissions
8
lower emissions
Lower 3.5-6.5oF
6
temperature change (
4
2oF warming since 1970
1900
1950
2000
2050
2100
Source NECIA / UCS (see www.climatechoices.org/n
e/)
7
What are recent trends for northeastern mountains
- temperature? (Grant and Pszenny, 2005)
8
What are the trends for todays northeast climate
- precipitation? (Huntington et al. 2004)

• In northern NE the hydrologic record since 1949
  shows the ratio of snow to total precipitation
  decreasing and spring runoff is earlier

9
Average Snowfall ME, NH, VT
13 (14.6) Decrease (1953-1993)
(Rock et al., 2001)
10
What are recent trends for northeastern mountains
- snowfall? (AMC, 2005)
11
What are recent trends for northeastern mountains
- snowmelt? (AMC, 2005)
12
The Changing Face of Winter
Under High-emission Scenario
13
Evidence of a Rising Cloud-ceiling

• Richardson et. al (2003) using airport data along
  the Appalachian Mountains show a significant
  rising trend in cloud-ceiling height over the
  past three decades (1973-1999). Most pronounced N
  of 37th latitude (6.6 m/yr).

14

• If recent climate trends hold up or
• accelerate, what are the implications for
• the Northeasts alpine ecosystems?

15
How Rare is the Alpine Zone? Only 5 of the
terresterial part of the world is covered by
alpine and tundra vegetation. East of the
Mississippi River in the US there are less than
13 square miles of alpine habitat, mostly in the
Presidential Range, NH and Katahdin Range, ME.
16
NE alpine ecosystems are glacial relicts

• Lake sediment cores (pollen macrofossil
  assemblages) indicate that the White Mtn region
  deglaciated 13,000 yrs BP
• 10,300 - 9,000 years BP, temperatures increased
  to modern levels or slightly above subalpine
  forests established, effectively isolating the
  alpine vegetation from the retreating tundra
  vegetation to the north
• majority of species in the paleoflora have
  geographic affinities to Labrador, northern
  Québec and Greenland
• Lower and mid-elevation plant communities
  changed much more with shifts in climate during
  post deglaciation period to present than
  treeline/alpine zone
• Climate variability post deglaciation resulted in
  slight oscillations in treeline (at times
  possibly slightly higher than present) larger
  impact was loss of species diversity in alpine
  zone

Summary from White Mountains (Spear 1989, 1994,
1999)
17
What Causes Treeline in the Northeast?What is
more important Temperature or Precipitation?
18
Treeline is Highly Dependent on Exposure to
Wind and Clouds

• In the Katahdin Range treeline (trees lt2.5 m or 8
  ft) varies from 857m to 1518m in elevation (range
  of 2100 ft)

• Temperature decreases with elevation
• Cloud frequency increases with elevation
• Clouds need wind to be deposited
• Winds get accelerated on ridges

19
What is the Alpine Zone?--Strong winds, icing
from clouds and short growing seasons cause trees
at higher elevations in the northeast to be
shorter in stature --- the sub-alpine zone.
--When these factors become more extreme, plant
life can be reduced to almost a single stratum of
vegetation but a few inches to a foot or two in
height -- the alpine zone.
20
Perennial, Long-life span is the Norm for Alpine
and Artic Species
Expect Time Lag in Response to Climate Change
Invading species need to first displace existing
species
21
Climate Change - A Threat to the Alpine Zone?

• Eastern alpine zones cannot move higher if the
  climate warms.
• Being protected on public lands they make
  excellent biomonitors to the effects of climatic
  vegetation.
• AMC has mapped the northeastern alpine habitats
  and treeline to monitor for any shifts in alpine
  vegetation communities and the treeline.

22
Major Alpine Plant Community Types

• Birch-Alder
• Paper birch
• Mountain alder

• Cushion-Tussock
• Diapensia
• Lapland rosebay
• Alpine azalea

• Herbaceous Snowbank
• Various herbaceous species
• Certain heath species

• Cliff
• Steep exposed bedrock
• Variable vegetation

• Krummholz
• Black spruce
• Balsam fir

• Fellfield
• Limited vascular flora
• Predominantly boulders
• Various lichen species

• Sedge Meadow
• Bigelow sedge

• Heath Shrub-Rush
• Various heath species
• Three-forked rush

23
Katahdin Alpine Plant Communities
24
Birch-Alder (1-6)
25
Krummholz - crooked wood (3 23)
26
Herbaceous Snowbank (1)
27
Cliff (14-Katahdin)
28
Fellfield - field of rocks (43-67)
29
Heath Shrub-Rush (10-34)
30
Cushion-Tussock (5-8)
Diapensia - Diapensia lapponica
31
Sedge Meadow (1-7) Butterflys and Pipits
32

• Endemic Butterflies of the New England Alpine Zone

White Mountain Fritillary (Boloria titania
montinus)
White Mountain Arctic (Oeneis melissa semidea)
Katahdin Arctic (Oeneis polixenes katahdin)
33
(No Transcript)
34
(No Transcript)
35

• Summary for Northeastern Mountains
• Changes in precipitation and cloud cover will
  strongly influence treeline and alpine vegetation
  communities
• Increases in spring-summer temperature will
  increase the pollutant burden to the regions
  mountains, may increase late frost exposure
• Alpine ecosystems are already limited to the
  regions highest peaks and have little option to
  migrate, therefore could be susceptible to
  extinction

36
What's at Immediate Risk?

• Loss of further species diversity in the alpine
  zone and minimal likelihood for recolonization
  for the rarer, northern tundra artic species
• Early flowering alpine species susceptible to
  late frost? MOUNTAIN WATCH!!!!
• Sedge, cushion tussock and snowbank communities
  give way to shrubs?
• Endemic alpine plants, butterflies and American
  pipit