Transcript Restoration of Ecosystems

Restoration of Ecosystems
Jen Morse
Heather Bechtold
West Hylebos Creek, WA
Hemlock forest in VT
Outline
• Introduction to restoration
– Overview of restoration projects
• Myths of restoration ecology
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Carbon copy
Field of dreams
Fast forward
Cookbook
Command and control
• Lessons learned from past efforts
– Is restoration important?
– Are current methods working?
– Recommendations for future projects
• Group discussion
– Do we know enough as scientists to inform such efforts
Ecological restoration is the process of assisting the
recovery of an ecosystem that has been degraded,
damaged, or destroyed. It is an intentional activity that
initiates or accelerates an ecological pathway—or
trajectory through time—towards a reference state.
• Intentional activity: method, tools, implementation
• Recovery: ecosystem will be healthier than current
degraded state
• Damaged by human or natural causes
• Toward a historic trajectory or reference state
http://www.ser.org/content/ecological_restoration_primer.asp
Motivations for
restoration
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Restoring ecosystem services
Mitigating impacts to ecosystems elsewhere
Habitat for threatened or endangered species
Aesthetic concerns, moral reasons
Legal requirements (Clean Water Act, etc.)
Improve human livelihoods
Empower local people
Improve ecosystem productivity
Adapted from SER and IUCN (2004). Ecological Restoration: a
means of conserving biodiversity and sustaining livelihoods
Restoration of…
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Rivers and streams
Drylands and deserts
Old agricultural fields
Prairies and savannas
Wetlands
Forests
Long leaf pine restoration, Nature
Conservancy, Sand Hills, North Carolina
Urban stream restoration,
Durham, North Carolina
Island Press: Science and Practice of Ecological Restoration Series
Part II: Restoration of Damaged Ecosystems
Spectrum of restoration
• Spanning a very wide range of size and scope
Stream reach scale: ~100m – 1km
Iraq: marshland loss of 17,000 km2
Restoration: deciding to act
1. Determine that an ecosystem is
damaged
– Who decides? What are the
criteria?
2. Who is responsible for
overseeing the restoration?
3. Motivating factors?
Goose Creek, Durham, NC, USA
– Laws, government agencies, NGOs
Restoration: planning phase
• Goals for the restoration
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Habitat for wildlife
Improved ecosystem functions
Improved appearance
• Project design
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Timeline, permits, contracts
Funding, budget
Planned restoration of
Everglades , south Florida, USA
Restoration: Implementation
Techniques
• Engineering interventions
• Disturbance regime:
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fire, flooding
Planting native vegetation
Removing invasive species
Restoration: post-implementation
1. Monitoring
2. Reporting
3. Evaluation
Myths of restoration ecology
Hilderbrand et al. 2005. The myths of restoration ecology. Ecology and Society 10:19
Myth: simplified guiding principle
- limitations and assumptions?
Carbon copy
• Selecting goals and targets
• Previous or reference state
• Clementsian view: static endpoint
or climax
• Disturbance is not good
• Aiming for specific composition
Hilderbrand et. al. 2005. The myths of restoration ecology. Ecology and Society 10:19
Carbon copy (cont.)
• Assembly rules and ecological
succession
– Restoration = “accelerated succession”
• Ecosystems are dynamic, shifting
mosaics
• Restoration targets (mandated?)
– Pre-settlement conditions?
– Pre-disturbance?
• Appropriate, realistic,
• Allows impacts to continue
• Alternative: functional equivalency?
Hilderbrand et. al. 2005. The myths of restoration ecology. Ecology and Society 10:19
Field of Dreams
• “If you build it, they will come”
• Physical template
– Biota and function will self-assemble
– Dynamic regime
• Assembly process  repeatable trajectory
• Wetland and stream restoration
– “self-design”
• Effectiveness is debated (depends on goals)
– Limitations of dispersal, stochasticity of assembly, …
Hilderbrand et. al. 2005. The myths of restoration ecology. Ecology and Society 10:19
Fast-Forwarding
• Accelerate ecosystem development
– Dispersal, colonization, community assembly
• Initial species composition determines succession
and desired end point
– Vegetation planting
• Recreate links between biota and physical
environment
• Motivated by need to show rapid recovery (<5y)?
• Little evidence that acceleration is successful
– Need longer time horizons (20+ years)
Cookbook
• Same techniques across all projects
• Similar ecosystems will respond
identically to restoration techniques
• Often published handbooks
• Engineering approaches
• Repeatable methods
• Rarely adaptive, often ignore
uncertainty
• How idiosyncratic are ecosystems?
• Do they behave predictably?
Command and Control
(Sisyphus Complex)
• Common in natural resources mgt.
• Active intervention and control
• Knowledge, ability, foresight to manage ecosystem
state indefinitely
• Frequent intervention decreases system resilience
• Treating symptoms rather than the root of the
problem
• Political-social mandates to “do something”
Moving Beyond the Myths
• Provide a starting point for restoration design
• Identifying themes:
– Planning for surprise, allow for uncertainty
– Helps to set realistic goals
• Incorporating science:
– Experiments in adaptive
management
– Testing multiple approaches
• Final myth: Bionic World
Ecosystem Stressors
• Habitat Degradation
• Invasion of Species
• Climate Change
Ecosystem Stressors
• Habitat Degradation
• Invasion of Species
• Climate Change
# of restoration projects recorded in NRRSS
Bernhardt et al 2005
Habitat Degradation
• Land-use change
– Agriculture
– Urban development
• Restoration goals
– Return an ecosystem to some previous state
– Inform scientific and policy decision making
– Develop tools to evaluate ecosystem health
How do you evaluate ecosystem health?
Sept 2008
June 2009 Craig Miller
Measure Ecosystem Structure
• Patterns in space and time
– biological communities and their resources
(chemistry), distribution
• Biotic indicators
– Abundance, diversity and presence/absence
Streams:
– Fish, invertebrates
– Algae
– Macrophytes
Sensitive
Tolerant
Measure Functional Processes
• Can be equated with ecosystem-level
– Rates and pattern of processes
• Less commonly used in ecological assessments
• Integrate abiotic and biotic aspects
• Examples of functional processes
– Leaf decomposition
– Nutrient retention
– Metabolism
• Can compare across sites
– Within or across landscapes
– Multiple streams, forests, grasslands etc.
To develop a common set of metrics by
which to measure stream restoration
success.
Examine the links between ecological
theory and stream restoration
Develop a series of specific
recommendations to improve how stream
restoration is carried out and its success
evaluated.
Disseminate this information broadly and
on an on-going basis.
(http://nrrss.nbii.gov/)
Determining Restoration Success
• 67% of restoration projects are
considered successful
– Post-project appearance
– Positive public opinion
– 90% had no measurable goals/ lack
success criteria
• Pre and post monitoring efforts are lacking
– Mean cost of monitoring efforts are
similar to projects without
– Low effort data collection and analyses
– Earn mitigation credits or have incentives
Bernhardt et al. 2005, Palmer et al. 2010
NRRSS Project Recommendations
• Greater assessment of ecological
effectiveness
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Integration of projects in the watershed
Project implementation based on data metrics
Document and make accessible outcomes
Appropriate goals and evaluation metrics
• Citizen involvement
• New restoration design manuals
– Certification programs
Successful Restoration
• Target more than physical structure
– Enhanced habitat heterogeneity does not relate to increased diversity
– Restore functional processes
– Use of softer self sustaining techniques (i.e. floodplain instead of
armor)
• Suite of stressors
– Target most limiting factor
• Assessment and long-term monitoring
– Habitat and spp
– Nutrients
– Function
• Conservation and protection
– Storm water management
– Incentive programs (CRP-USDA)
Roni et al. 2008, Palmer et al. 2009