Geography 3090A – Biogeography Field Trip
September 13-14, 2008
Climate – Ecozone Relationships at the Crown of the Continent
Aims
To develop an appreciation
of climate-ecozone
relationships around the
Crown of the Continent
hydroclimatological region.
This includes grassland,
foothills fescue, subalpine
boreal and alpine tundra
environments.
Figure 1
St. Mary Lake,
Glacier National Park,
Montana, USA
Objectives
1. To improve our understanding of how climate determines the spatial
distribution of ecozones in the Crown of the Continent region of Alberta, Montana
and British Columbia.
2. To consider the potential impact of climate and land use changes on
grassland, foothills fescue, boreal forest, alpine tundra and krummholz ecozone
distribution and biodiversity.
Rationale
The Crown of the Continent region is home to a fascinating diversity of climate,
flora and fauna, due to the influence of the Rocky Mountains on climate across
the continental divide. To the lee of the continental divide, grasslands have
developed under rainshadowed conditions. With low precipitation from October
to April, high winds and high interrannual variability of summer rainfall, grasses
and drought-resistant shrubs became dominant, along with related fauna. The
exception is along the riversides, where cottonwood and willow trees utilize
groundwater provided by the streams for growth and survival. Human activities,
such as the conversion of natural prairie to farmland, and the establishment of
dams to support irrigation projects have dramatically altered the natural
landscape in this region.
The Eastern slopes of the Rocky Mountains receive occasional orographic
enhancement when the prevailing westerlies reverse to the north of low pressure
systems. Evapotranspiration is also reduced compared to the grasslands below,
due to cooler temperatures. As a result, grasslands transition to foothills fescue
and forest environments, because drought stress is less frequent. We observe a
variety of species in this area, such as trembling aspen, lodgepole pine and
limber pine. At very high altitudes, however, the growth season is short and soils
Geography 3090A – Biogeography Field Trip
September 13-14, 2008
are often undeveloped. Here, we cross the treeline threshold, into alpine tundra
and even rock and ice environments, where a few snowfields and even small
glaciers still remain. Treeline, however, is a complex phenomenon, with a high
altitude treeline (due to cold), a low altitude treeline (due to frequent drought) and
patchy treeless zones within the optimal climate range (in environments rendered
xeric due to geomorphological conditions and exposure). At high altitudes
(around 2000 metres), there are whitebark pine and limber pine. These species
are found in a region with spectacular fauna, including the Clark’s Nutcracker
(which disperses seed), black bears, grizzly bears, elk, mountain goat,
chipmunks, squirrels, and a huge variety of bird species.
Beyond the continental divide in Glacier National Park, we descend into a
region with a distinct climate. While not a true rainforest, due to the loss of
Pacific moisture in other mountain ranges to the west, the prevailing westerlies
move upslope in West Glacier. A range of forest ecosystems are observed as
we travel toward Lake MacDonald. At the Trail of the Cedars, these include
massive Western Red Cedars, hemlocks and cottonwoods of climax forest
environments, where there is so much shade that we find only the most shadetolerant plants, as well as organisms that avoid photosynthesis altogether, like
fungi. Even within this area, however, we do not find continuous coverage of
climax forest. Fire ecology is very important in the area, and there are zones
where relatively recent burns have left grass and shrub openings, which are
eventually colonized by lodgepole pine. These in turn provide shade for
progressively shade tolerant species like spruce, firs, and, eventually, cedars.
There are 20 tree species and 90 shrub species in Glacier National Park, so this
represents just a taste of the diversity that we will be able to experience at the
park and throughout our loop, as shown below.
Figure 1
Main route
to be followed
on Crown of
the Continent
Biogeography
Field Trip
Geography 3090A – Biogeography Field Trip
September 13-14, 2008
Due Date: October 2, 2008
Cost: $100.00. Pay at Cashier’s Office.
Value: 16% of final grade. You may work in pairs, with one report submitted for
each pair. Both students will receive the same grade.
Deliverables
1. Field trip report highlighting the ecozones encountered and sites of interest
(photos are recommended from those with digital cameras). Maximum 2 written
pages (single-spaced, minimum 12 point font and one inch margins) plus images
and properly-cited references, when applicable. (6 marks)
2. Short essay on a biogeographical topic of your choice. Maximum 3 written
pages (single-spaced, minimum 12 point font and one inch margins) plus images
and properly-cited references. (10 marks). Suggested readings have been
provided on the course web site.
Location of Overnight Stay:
Kandahar Lodge, Whitefish Mountain Resort, Montana, USA.
Things to bring:
1. Proper identification for border crossing:
http://www.cbsa.gc.ca/whti-ivho/menu-eng.html
2. ATM/credit cards and United States currency for emergency use and small
purchases.
2. Warm clothing as it can be very cold at high altitude at all times of the year.
3. Good hiking shoes or boots.
4. An extra sweater and an extra pair of socks.
5. Snacks (we may stop for lunch, but you should bring some of your own food
for the trip)
6. Food for dinner (microwaves and a kitchen are available at Kandahar Lodge)
7. Notebook and pencils.
8. GPS unit (optional).
9. Camera and binoculars (optional).
10. Flora and fauna identification guide (optional).
11. A first aid kit will be provided, but you are encouraged to bring a small one of
your own, including all necessary prescriptions etc.
12. A good attitude. Have fun and be observant !