Application of the Ecological Models and the Desired Future Condition Concept to Conservation Planni

1
Application of the Ecological Models and the
Desired Future Condition Concept to Conservation
Planning and Management Workshop on the
Development of Fire Manangment Plans for
Conservation Areas Cristo Rey, Belize 19-21
February 2008
Douglas Zollner, Director of Conservation
Science The Nature Conservancy, dzollner_at_tnc.org
2
Ecological Models What do they do for us?

• Whats here now? (current condition)
• How did we get here? (historical - recent
  management and impacts)
• Where are we headed?
• Where do we want to be? (desired future
  condition)

3
What models are

• Conceptual or mathematical representations
• Abstractions or simplifications
• Illustrations of ecological relationships
• Foundations for predictions
• Documentation of assumptions
• Basis for hypotheses and decisions

4
What models are not

• Better than the data
• Representations of reality or truth
• Answers in and of themselves

5
Ecological Modeling Concepts

• Reduces complexity
• Facilitates prediction of ecosystem structure,
  function, and change
• Allows progress with incomplete knowledge
• Can be built at any scale
• Represent varying degrees of uncertainty

6
Why are models useful?

• Communication and mutual understanding
• Guideing conservation and management
• Documenting cause-effect relationships
• Defining appropriate scales for action
• Simulating long-term dynamics (desired future
  condition)
• Exploring alternative strategies

7
Why are models useful?

• Providing feedback on assumptions
• Using science to find common ground
• Identifying research needs
• Developing monitoring plans

8
(No Transcript)
9
Figure 1. El Ocote moist/wet tropical forest
fire state-transition model
Infrequent Fire 100 year interval
Frequent fires 1-40 years
Moist/wet tropical forest closed canopy 6-45 cm
organic/duff Fuel model 8 Stable
Ficus/Acacia woodland/savanna Open canopy, no
organic soil Fuel model (2/3) Stable
Clearing, grazing frequent fire
No fire (100 years)
Uno grande fuego El nino-drought, infrequent
Fire every 3 years
50 years with no fire
Fire every 1-2 years and/or clearing
Frequent fire (more than 1-50)
Grassland FM 3 Shrubland FM 5-6
Once burned moist/wet tropical forest shrubs,
dense, woody debris Less than 6 cm organic
soil Fuel model (4,5,6 ish) Unstable
Frequent fire
10
Figure 2. La Sepultura pine-grass woodland fire
state-transition model
Fires every 5-7 years
Fire every 3-5 years
Pine woodland with grass understory FM 2 Low
risk, Stable BA 40 - 70
Pine/shrubs FM 9 70-100 BA Medium risk Stable
Fire every 5-7 years
Fire every 3-5 years
Crown fire after 10 years of fuel build - up/
or cut
Restoration plant pines, fire every 3-5 years
Fire every 3-5 years
Pasture - converted Grassland FM 3 Shrubland
FM 5-6
Grassland with some pine FM 3 Stable BA 10 or
less
Annual fire
Frequent fire
11
Figure 3. La Encruijiada Marsh - Mangrove state
transition model
No fire
Surface fire every 1-20 years
Typha - Thalia Marsh Deep organic soil Fuel model
4 Stable
Mangrove (saline) or Zapotanal (freshwater) Fuel
model 8 Stable
No fire
Fire
Ground fire
Fire 1-20
No fire over the long term 50 years
Open water Unstable
12
ELT Diagram with Potential Natural Vegetation
Cover Types
13
Ponderosa Pine Forest Dynamics - Jemez Mountains
PP Forest ? TPA multi-age stands? even-aged
clumps? ? surface fuels ? CF risk
Burned PP Forest standing dead trees little/no
soil or grass cover
Rx Fire Only (large scale)
Thinning to 40-100 TPA at WUI
Insects
Thin Burn to 100 TPA (med. scale)
severe
PP Woodland 100 TPA multi-age stands? even-aged
clumps? understory grass or oaks dominant?
PP Forest dead live trees little grass cover
Crown Fire high-intensity spring/summer El
Nino?La Nina
moderate
Thinning to 60-100 TPA (small scale)
Succession Recruitment, 6 yrs
Surface Fire
Drought Insects
Repeated Thin Burn landscape scale
PP-MC Forest 1,000-1,300 TPA even-aged
stands many sm-diam trees little grass cover high
fuel loads
Active FS 20th c.
PP Forest ? sm-diam TPA dead live trees little
grass cover
Thinning to 40-60 TPA at WUI
OG (19th c.) ? surface fuel de facto FS
Active FS 21st c.
PP Savanna 40 TPA multi-age stands? even-aged
clumps? understory grass or oaks dominant?
Surface Fire low-intensity MRI 2-15
yr spring/summer
Thinning to 40 TPA at WUI
PP Woodland 100-? TPA multi-age stands even-aged
clumps grassy understory
Surface Fire low-intensity MRI 2-15
yr spring/summer
14
(No Transcript)
15
Constructing Ecological Models Iterative,
Iterative, Iterative

• Accept that it will never be complete
• Clarify purpose and scale
• Choose model structure
• List important states and transitions
• Illustrate known and unknown transitions between
  states.

16
mid- seral closed
mid- seral open
early seral
late- seral closed
late- seral open
succession
low intensity fire
high intensity fire
Oak-pine forest
thinning
17
Departure of Current from Desired Conditions and
Management Implications
Seral Management Class Density
Stage Current Desired Priorities A
All Early 12 5-25 Maintain B
Closed Mid 48 0-15 Reduce C Open Mid 20
5-22 Maintain D Open Late 2
30-65 Increase E Closed Late 18
5-20 Maintain 100 100
CC - current condition by area community HRV -
modeled historic range of variation
18
Middle Fork Ecosystem Restoration Area

• Cover Types
• Oak-Hickory Closed
• Canopy Forest 67
• Oak-Pine Closed
• Canopy Forest 8
• Oak-Pine Woodland/
• Savanna 12
• Pine Closed Canopy
• Forest 10

Current Condition October 2003
19

• Cover Types
• Oak-Hickory Closed
• Canopy Forest 16
• Oak-Hickory
• Woodland 35
• Oak-Pine Woodland/
• Savanna 38
• Pine Woodland/
• Savanna 10

Desired Future Condition
20
Unhealthy Forest with Low Biodiversity
Herbaceous Understory 20-40 species/acre Tree
Density 300 tree/acre
21
Healthy Forest Health with High Biodiversity
Herbaceous Diversity - 100- 150 species/
acre Tree Density - 38-76 trees/ acre