Download Lecture 4: Wilderness Ecosystems

Lecture 4: Wilderness
Ecosystems
Outline
 What: flora and fauna
 Where: biogeographical zones and
ecosystem mosaics
 Process: cycles, pyramids and relationships
 Trends: extinctions, re-introductions and
climate change
 Seminar: Guest Lecture – Mark Fisher on
Self Willed Land
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1. What: flora and fauna
 Wilderness management based on
ecological considerations
 Sensitive management of human use to
minimise disturbance of natural
ecosystems
– e.g. limiting use within carry capacities
 Understanding of basic ecology is essential
“The ecosystem is the basic fundamental unit in ecology,
because it includes both organisms... and abiotic
environments, each influencing the properties of the other
and both necessary for the maintenance of life.” (Odum, 1954)
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1. What: flora and fauna (cont’d)
 Elements
– ecosystems are divided into 2 parts:
•
•
abiotic (minerals, climate, water and other
non-living elements)
biotic (plants, animals, fungi, bacteria and
other living organisms)
– linked by 2 forces:
•
•
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flows of energy through the ecosystem
nutrient cycles within the ecosystem
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1. What: flora and fauna (cont’d)
 Solar radiation = primary energy input
–
–
used by autotrophs (plants) to convert abiotic
elements into complex organic substances via
photosynthesis
heterotrophs (ingestors and decomposers) use
autotrophs as food base
 Gravity
–
drives long-term movement of material from
headwaters to oceans
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1. What: flora and fauna (cont’d)
 Components include:
abiotic factors (sunlight, geology, etc.)
– abiotic processes (weathering,
evaporation, etc.)
– biotic elements (flora and fauna)
– linkages and flows of energy, water and
nutrients by biotic and abiotic means
– temporal fluctuations (diurnal, seasonal,
etc.) and spatial variations (location and
size)
–
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1. What: flora and fauna (cont’d)
 Wilderness ecosystems
– Same components as any other ecosystem
•
•
biotic and abiotic material
linked by energy and nutrient flows
– Role of man in wilderness ecosystems?
– Human influence is lacking (to varying
degrees) in wilderness ecosystems
 True wilderness ecosystem
characterised by lack of human
influences and impacts
 Man needs to be included as a
transient heterotroph (modern man)
or permanent resident heterotroph
(primitive peoples)
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1. What: flora and fauna (cont’d)
Question:
To what extent can primitive
peoples (both ancient and
modern) be considered a natural
part of wilderness ecosystems?
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1. What: flora and fauna (cont’d)
 Remember... the word wilderness comes
from “wild-deor-ness”... place of wild beasts
 Definition of wilderness wildlife?
– Leopold (1933) - those species harmful to or
harmed by economic land use
– previous focus on larger species
– include all species in an ecosystems approach
 Usefulness of indicator species
– larger herbivores and carnivores
– at or near top of food chains
– general health of lower trophic levels
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1. What: flora and fauna (cont’d)
 The character of a wilderness is often
represented by its resident wildlife
“Wilderness without wildlife and wildlife without freedom
of wilderness are virtually unthinkable, their
interdependency is so formally established in our minds.”
(Hendee et al., 1990, p.263)
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1. What: flora and fauna (cont’d)
 Wilderness dependent wildlife:
– species particularly vulnerable to human interference
– e.g. Grizzly Bear
 Wilderness associated wildlife:
– species commonly associated with wilderness habitats,
but can survive in modified ecosystems
– e.g. Mule Deer, Elk, Beaver
 Common wildlife:
– species found in wilderness, but equally at home in
higly modified ecosystems
– e.g. Racoon
 Exotic/non-native species
– introduced by man and do not naturally belong
– e.g. Grey Squirrel in UK
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1. What: flora and fauna (cont’d)
 Wildlife’s role in wilderness
– inseparable part of wilderness
• for many people presence of certain animals is
tantamount to wilderness (e.g. Greenland)
• e.g. Milton (1972) on Alaska refers to Caribou as
carrying the soul of the wilderness because of their
freedom and vast range
• Strong lure for recreation/aesthetics/inspiration
• Political focus
– role in development, maintenance and
modification of soil and vegetation (autotrophic
environment)
– management preserves these processes by
preserving wildlife
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1. What: flora and fauna (cont’d)
 Wilderness’ role in wildlife
– crucial to survival of some species
– e.g. Alaskan Brown Bear requires all ingredients
of wilderness:
• wide range
• solitude
• particular types of food
– role as reservoirs of species
– e.g. Pine Martin in Minnesota
• much depleted numbers then recent expansion
• originated from Boundary Waters Canoe Area
Wilderness (BWCAW)?
– key to wildlife diversity is diversity of habitat
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2. Where: biogeographical
zones and ecosystem
mosaics
 Ecosystem elements arranged spatially into
wilderness environments
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–
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alpine tundra, savannah, mixed boreal forest, etc.
examples from web
global pattern
 Within individual wilderness ecosystems
variation
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–
ecosystem mosaics
dynamic patchwork of abiotic and biotic elements
•
•
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interaction between the physical and the biological
e.g. the role of large herbivores
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2. Where: biogeographical zones
and ecosystem mosaics (cont’d)
Question:
What do you think the
natural ecosystem mosaic
for Britain should look like?
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3. Process: cycles, pyramids
and relationships
 Ecosystem dynamics (succession)
– Ecosystems are dynamic entities
– Long-term changes and short-term cyclical
fluctuations
– Succession = the orderly process of
ecosystem development involving changes
in structure and process
• Directional and predictable
• Results from modification of physical
environment by biotic community
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Ecology and ecosystems (cont’d)
 Succession culminates in climax
(stabilised ecosystem)
– maximum biomass
– maximum linkage between
organisms per unit energy flow
 Succession involves change from
lower to higher order ecosystems
towards a climax
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Ecology and ecosystems (cont’d)
 2 types of succession:
–
–
primary = slow and natural progression towards
climax
secondary = rapid changes after interruption of
primary succession (e.g. after fire)
 After interruption succession moves again
towards climax
 Few ecosystem reach climax due to regular
interruption by fire, storms, etc.
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Ecology and ecosystems (cont’d)
 Preditor-prey relations
– Focus on large carnivores
– Changes in predator populations:
• prey populations (density and demography)
• sympatric carnivores
• all lower levels of ecosystem
– Predators as “Umbrella species”
• enhance and maintain species diversity
– Problems:
• low reproductive rates
• management increasingly required
• replacement by human predation?
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4. Trends: extinctions, reintroductions and climate
change
 Trends in wilderness ecosystems
– the shrinking wilderness
• reduced habitat and range of wilderness
dependent species
• effect on isolated populations?
• e.g. restricted gene pool and movement
– rise in number of extinctions
• local and global
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4. Trends: extinctions, re-introductions
and climate change (cont’d)
 Wolf (Canis lupus)
– originally the most widespread of modern
mammals (circum-polar)
– greatly reduced contemporary distribution (mainly
North America - Canada and Alaska)
– remaining population approx. 50,000
– cultural perception - “evil personified” (Peterson)
– competition with humans:
• for prey
• predation of domesticated livestock
– persecution and virtual extinction in Europe
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4. Trends: extinctions, re-introductions
and climate change (cont’d)
 Example: the wolf in Yellowstone
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–
–
–
–
–
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1875 - Yellowstone designated a national park
people like to see elk
wolves eat elk
wolf exterminated in Yellowstone
elk population increases beyond sustainable level due
to over grazing
NPS introduce winter feeding of elk
concentrates elk in feeding areas
removes ‘wild-ness’ of elk
alternative = cull
recent re-introduction of wolves to Yellowstone and
areas of Idaho by FWS but not without problems
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4. Trends: extinctions, re-introductions
and climate change (cont’d)
Question:
What indigenous fauna is
missing from Britain and what
(if any) should be re-introduced
and why?
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4. Trends: extinctions, re-introductions
and climate change (cont’d)
 The role of wilderness is important in
respect to climate change
– preservation of unaltered pristine
ecosystems
– maintaining ecological and genetic
diversity
– maintaining areas and
routes/corridors for species
migration
•
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horizontally and vertically
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4. Trends: extinctions, reintroductions and climate change
(cont’d)
 Preservation
– preservation from the effects of human influence
and development
– value of wilderness ecosystems:
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•
•
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refuges for wilderness dependent species
natural laboratories for study and comparative study
with altered ecosystems
recreational and educational environments
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4. Trends: extinctions, reintroductions and climate change
(cont’d)
 Maintaining diversity
– bastions of ecological diversity
– e.g. NWPS, USA
• identified 261 natural ecosystems in USA
• all represented in NWPS
• 1000’s of human altered ecosystems
• BUT majority of diversity in just 261 natural
ecosystems
– diversity of valuable resources:
• pharmaceutical products, timber, water,
animal products, etc.
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4. Trends: extinctions, reintroductions and climate change
(cont’d)
“The job of wilderness management is often to ensure
that the dynamics of the ecosystem and the resulting
successional change - the natural trajectory of the
ecosystem - proceed without disruption or distortion
by humans.”
Hendee et al. (1990, p.247)
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Reading
Agee, J.K & Johnson, D.R (eds) (1988) Ecosystem
management for parks and wilderness. University of
Washington Press, Seattle. [especially chapters 5
and 6]
Hendee, J.C, Stankey, G.H & Lucas, R.C (1990)
Wilderness management. Fulcrum Publishing,
Colorado. [Chapters 10 and 11]
Hendrix, G & Morehead, J (1983) Everglades
National Park: an imperilled wetland. in Ambio 12
(3/4) p.153-157.
Leopold, A (1949) A Sand County Almanac with
essays on conservation from Round River.
Ballantine Books, New York. [esp. Chapters
‘Thinking like a mountain’ and ‘Escudilla’ and Part
3]
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Workshop
Guest Lecture:
Mark Fisher
“Self Willed Land”
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Task
 Web poster proposals
– Organise yourselves into groups of between 6 and
8 students
– Read web poster handout (online)
– Identify a topic for research
• See list of examples
• Discuss among yourselves
• Identify information sources
– Complete proposal form (online) for hand in at
next week’s lecture
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Next week...
4. The concept of landscape
 Landscape character: nature and people
 Perception: evaluation and assessment
 Policy development
 Workshop: video “A postcard from the
country – The Highlands of Scotland: In
search of wilderness”
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