Title: Spatial%20Sampling%20Designs%20Why%20do%20we%20Need%20Them?
1Long-term monitoring of large, remote areas with
minimal funding hope and encouragement for
natural area managers
Steven Fancy National Monitoring Program
Leader National Park Service
2State of the Parks Report (circa 2000)
- 80 (1/3) of the natural resource parks had no
professional natural resource manager - Another 84 parks had only 1 or 2 natural resource
professionals. - Almost all projects/studies were short-term
staff mostly deals with the crisis of the day. - Sampling designs mostly done by expert opinion
representative sites or convenience.
No Time No Money No Clue
3NPS Natural Resource Challenge
Revitalize and expand the natural resource
program within the NPS improve park management
through greater reliance on scientific knowledge
- Accelerate Inventories
- Design/Implement Vital Signs Monitoring
- Collaboration with scientists and others
- Improve Resource Planning
- Enhance Parks for Science
- Assure Fully Professional Staff
- Control Non-native Species
- Protect Native and Endangered Species
- Enhance Environmental Stewardship
- Expand Air Quality efforts
- Protect and restore Water Resources
- Establish Research Learning Centers
4Economics 101
Funding level (avg. 100,000 per park) would
allow each park to hire one professional position
(GS-9 or 11) plus about 30-40 K operating
Conclusions/Strategy
- Without integration and cost-sharing, parks can
only monitor a few things too few to adequately
track condition of resources - Park buy-in and cost-leveraging through
partnerships are critical must be relevant to
park managers and flexible to allow integration
and partnerships - Establish 32 monitoring networks that share
funding and staffing among parks to gain
efficiencies and consistency.
5The Wedding Cake An alternative to One Size Fits
All
National
Network/Ecosystem
Park
- Primary use of data is at local level for park
management - Indicators and protocols most relevant to each
system are very different e.g., Northwest
Forests vs. South Florida vs. Colorado Plateau - Cost-leveraging through Opportunity very
important for early success and efficiency
Servicewide Core Variables
Network/Ecosystem Core Variables
6Spatial Sampling DesignsWhy do we Need Them?
- We can only sample a very small proportion (often
lt1) of most natural areas but, - Our job is to protect, restore, understand, and
inform others about the entire area, not just
some convenient portion of it. - Need to make scientifically-defensible inferences
to areas beyond the actual areas we sample. - Statistical, design based inferences can only be
made to areas that have a chance of being
included in the sample.
Especially important because we are designing
LONG-TERM MONITORING
7Reality Check Sometimes you just cant get there
8Take Home Messages
A few Lessons Learned about Sampling Design for
Long-term Monitoring
- Design should allow inferences to entire park,
not just some accessible portion of it - Some sort of probability sample should always be
taken, even if you can only start with very small
sample sizes - Judgement sampling, using representative sites
selected by experts, should be avoided - Do not stratify on biological criteria (e.g.,
vegetation maps). Use stratification sparingly,
if at all - Permanent plots that are revisited over time are
recommended to increase precision - It is not necessary to visit plots every year -
rotating panels increase sample size - Co-locate sample sites for various components of
the monitoring program
9Three Examples
- 2-stage mini-grid design for Central Alaska
Network 3 parks gt21 Million acres (size of
Indiana) - GRTS design large river parks in Missouri and
Arkansas - Unequal probability sampling of upland sites in
Northern Colorado Plateau parks (site selection
based on accessibility, climate, geology and
soils)
10First-stage systematic grid with 20 km spacing
11Second-stage mini-grid sample (25 points)
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13Buffalo River Streams 100 sites
Sampling of stream segments with co-location and
co-visitation among monitoring indicators
- Geomorphology
- Aquatic Macroinvertebrates
- Fish Communities
- Ozark Hellbender (giant salamander, TE)
- Mercury
- Lead
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16Northern Colorado Plateau Network (NCPN)
Sampling Design
17Integrated Upland Sampling Design - NCPN
- Collocated Vital Signs vegetative structure,
composition, - condition of focal communities soil/site
stability - upland-hydrologic function soil-crust
structure - nutrient cycling
- Systematic grid of points (50-m spacing)
overlaid on park - used to define anchor points of sampling plots
- Unequal probability of selection of sampling
plots - provides ability to add sites in the future (if
needed) - probability defined by accessibility (high, low)
- probability defined by climate, soils, and
geology - (rel. static surrogate for vegetative
communities)
18Integrated Upland Sampling Design NCPN
Temporal Design
- A split-panel design will be employed that
features - spatial interpenetration
- the ability to evaluate inter-annual variability
- a balance between trend and status assessments
- And that meets Vital Sign sampling objectives
19 Split panel (2-7)9, (1-8)9
10
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2
1
Year/ Panel
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X
X
1
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X
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X
X
5
X
X
6
X
X
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X
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9
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X
1
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X 10 plots 30 plots per year spatially
distributed ca. equally among 4 Ecosites
20Weight of Evidence
21http//science.nature.nps.gov/im/monitor
22http//science.nature.nps.gov/im/monitor
23Take Home Messages
A few Lessons Learned about Sampling Design for
Long-term Monitoring
- Design should allow inferences to entire park,
not just some accessible portion of it - Some sort of probability sample should always be
taken, even if you can only start with very small
sample sizes - Judgement sampling, using representative sites
selected by experts, should be avoided - Do not stratify on biological criteria (e.g.,
vegetation maps). Use stratification sparingly,
if at all - Permanent plots that are revisited over time are
recommended to increase precision - It is not necessary to visit plots every year -
rotating panels increase sample size - Co-locate sample sites for various components of
the monitoring program
A scientifically-defensible sampling design can
be done, and it should be done. Assistance and
examples are available from others.