Transcript Envir100LectFeb11

Renewable Resources: Forest
Ecosystems
Original
Today
Frontier
Choices
B
Which seems the poorest
D
choice?
A
C
http://www.cwbiodiesel.com/biodiesel/palm_oil.html
Time Appropriate Questions
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What do forest ecosystems provide?
What is important or valuable?
How do we conserve what is valuable?
What approaches are available for defining
what is important?
• What approaches are available for
conserving?
• Are we kidding ourselves?
Forest ecosystems: Goods & Services
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Fiber - paper and products
Fuel - cooking & heating
Water - quantity and quality
Nutrient cycling
Ecosystem energetics (food chain)
Air - CO2 uptake, O2 release, pollutant removal
Climate stability
Biodiversity/habitat: plant and animal (wildlife)
Medicine and food products
Recreation/mental & social health
Reference: Richard Louv’s Last Child in the Woods (2006)
Ecosystem: A Human Construct
• Definition: An ecological system composed of
living organisms (plants, animals, & microbes)
and their nonliving environment.
• Ecosystems are characterized by:
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Structure & function
Complexity
Interaction of the components
Change over time (e.g., disturbances), “young,
mature, old.”
• Today, these functions must be spatially and
temporally coordinated.
Ecosystem threats?
• Loss of habitat: Land-use change and
irreversible conversion (fragmentation)
• Disruption of biogeochemical cycles
(N,C,P)
• Invasive or introduced exotic organisms
• Toxins, pollutants, human wastes
• Climate change
Ensuring Ecosystem Goods &
Services: Approaches
• Examine three different approaches
– First, we identify specific species we want in
our ecosystem (e.g., wolves, spotted owl,
whitebark pine, etc.).
– Second, we identify a process we want to
maintain (e.g., carbon fixation).
– Third: A more comprehensive or systems
approach.
• Two examples that use this third approach
– NCSSF - small scale, small perspective
– MEA - small to large scale, many perspectives
Whitebark Pine
Approach 1. Save a
species!
Distribution & Importance of
Whitebark Pine
Pinus albicaulis
• High elevation pine
• Large seed
• Special
relationship with a
bird
• Important for other
animals
• Keystone species
in the Rockies
Whitebark Pine: Ecological Importance
• Hardy subalpine conifer, tolerates poor
soils, steep slopes, windy exposures.
• Often the tree line species
• Keystone species (Rocky Mountain
Region)
– Food source - birds, small mammals & bears
– Often colonizes a site, facilitates succession &
promotes diversity
– Regulates runoff, reduces soil erosion
Picture: C.J. Earle
Decline of Whitebark Pine
• White pine blister rust:
Cronartium ribicola, is a rust
fungus with two hosts.
– All North American 5needled pines
– In addition, it infects all
species of the genus Ribes
spp., its alternate host.
– European & Russian
species resistant
• Problems today
– Fire suppression
– Global climate change
– Mountain pine beetle
Situation
• Whitebark pine is likely to disappear.
• What are our choices?
– Do nothing (its “natural”)
– Remove the Ribes
– Breed for resistance
– Introduce resistant European/Russian
species
– Selection and genetic engineering of the
endophyte.
2. Ensure a function!
Manage for Carbon Dioxide Uptake
Monitor
Two goals:
• Understand where the
hidden sink for carbon
dioxide is?
• Use forest systems to
take up CO2.
Approach taken by
Canada - Kyoto
Protocol
Experiment
Methods of Study
Difficulties
• Issues of scale (quality of info
vs. extent of info)
• Monitoring
• Unknowns (soil carbon)
• Searchinger, T. et al. 2008. Science Express
• Fargione, J. et al. 2008. Sci. Express
Lessons from first 2 approaches
• Managing single components or processes:
Hard
• Determination of what to measure, at what
scale, how often, etc.
• Techniques to measure (e.g., what is there
now & how is it changing) are expensive
• Monitoring - expensive, takes time
• Understanding of interactions (e.g.,
cascading effects)
• Regulatory environment may define
• Nature changes (e.g., forest fire, bard owl)
Third Approach
Work on maintaining “properly”
functioning ecosystems
Key: Remember all the functions?
Two examples
• National Commission on
Science for Sustainable
Forestry (NCSSF)
• Millennium Ecosystem
Assessment Program (MEA)
• Mission: to advance the science and
practice of biodiversity conservation and
forest sustainability
• Critical Question: How does an owner or
manager of forest land tell whether
biodiversity and sustainability are being
positively, negatively or neutrally affected by
management practices and decisions?
• Or: Is your land ‘good’, changing, & changing
in what direction?
http://www.ncseonline.org/NCSSF/page.cfm?FID=1426
What’s needed?
• Early warning assessment system that is
– Rapid & cost effective
And that is based on
• Stand level sustainability (condition):
– Development of functional indicators (of
ecosystem services) &
– associated benchmarks
• These indicators/benchmarks should
represent best available
information/science.
Does it works in practice
• Functions, variables and benchmark
levels can be defined
• A sampling scheme has been
designed & tested
• Evaluation is then a comparison of
values and changes in values.
• Subsequent decisions are then based
on goals and objectives set by land
owner.
Does it work?
• Perhaps (actually data from urban to rural
land
• Weakness:
– Assumes that the indicators are correct and
respond in a measurable & timely way
– Assumes that we can react fast enough.
– Does not link objectives over large areas of
land.
• Clearly better than nothing
Yangjuan Village
• Apparently intensive use of the land
• Is the use sustainable? And how does land
use reflect and affect the inhabitants?
• Idea of eco-political tsunamis
Yangjuan Land use
Traditional Buckwheat
Firewood
Livestock
Conversion from local land race
of corn to new hybrid corn
Ecosystem Goods and
Services: Example 2
Definition of Ecosystem Goods and Services
Millennium Ecosystem Assessment Program
Example
Older definition of Ecosystem
goods and services
Ecosystem goods: Biophysical elements
that are directly, or indirectly, consumed
by humans
Ecosystem services: processes that
produce, or support the production of,
ecosystem goods (most involve some
biogeochemical cycle).
Which is not an ecosystem
service?
11%
5%
47%
36%
1%
1.
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5.
Provisioning
Regulating
Cultural
Interventions
Supporting
Newer definition of Ecosystem
goods and services
• Provisional services (e.g., food, fiber, fuelwood,
biochemicals, genetic resources, and water)
• Cultural services (e.g., recreational, ecotourism,
educational, sense of place, cultural heritage, spiritual,
religious and other nonmaterial benefits).
• Supporting services (e.g., primary production, soil
formation & nutrient cycling)
• Regulating services (e.g., water regulation [floods,
irrigation], water purification, climate regulation, land
degradation, and disease regulation)
Example of an Ecosystem Service
• Soil provides the following
ecosystem services
– Significant regulator of the hydrological
cycle
– Shelters seeds, provides medium for
plant growth, provides physical support
– Retains, delivers & derives nutrients
– Significant role in decomposition
– Contributes to cycling, retention &
regulation of major element cycles (N,
P, C, S)
– Carbon storage & cycle
– Role as a purifier (water, nutrients,
etc.)
MEA Conceptual Framework
Global
Regional
Local
Human wellbeing & poverty
reduction
Indirect Drivers of
Change
• Demographic
• Economic
• Sociopolitical
• Science & technology
• Cultural & religious
Direct Drivers of Change
Ecosystem
Services
Life on Earth:
Biodiversity
• Changes in land use & land
cover
• Species removal or
introductions
• Technology
• Climate change
• Natural physical & biological
drivers
• External inputs
MEA Goals
• Identify options that can better achieve core human
development and sustainability goals.
– Recognize & meet growing demands for food, clean water,
health, and employment.
– Balance economic growth and social development with
environmental conservation.
• Better understand trade-offs involved—across
stakeholders—in decisions concerning the
environment.
• Rather than issue by issue, use a multi-sectoral
approach
• Match response options with appropriate level of
governance
Well-Being Defined (MEA)
•Security: Ability to
– a. live in an environmentally clean and safe shelter
– b. reduce vulnerability to ecological shocks & stress.
•Basic material for a good life: Ability to access resources
to earn income and gain a livelihood
•Health: Clean water, air, adequate nourishment, adequate
energy for temperature regulation, good health
•Good social relations
•Freedom & Choice
MEA:
Assessments
& Publications
December 2005
Pressures on Goals of MEA
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Population Growth
Economy, consumption
Combined demand on natural resources
Land degradation & conversion
Invasive organisms
Climate change
Public Health (e.g., HIV, malaria, nutrition)
Template for evaluation
Political acceptance & will (and
consistency)
Conclusion: Difficulties
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Setting limits and distributing responsibility
Scale & variable (s)
Measurement
Monitoring
Assessment
Regulation
Outcomes and Feedback
Choices
Political will = f (human will)