This document summarizes an assessment of climate change vulnerability for 12 ecosystems in the Southeast US and Caribbean. Two assessment approaches were used: Phase 1 synthesized literature and GIS data to evaluate sensitivity, exposure, and adaptive capacity. Phase 2 used NatureServe's Habitat Climate Change Vulnerability Index to quantify vulnerability scores for two ecosystems. Both approaches found similar moderate to high vulnerability ratings. Future research needs include better understanding impacts on hydrology, disturbance regimes, and species interactions under climate change. The assessments provide a starting point for adaptation planning but incorporating additional factors could improve the analysis.

1. Assessing climate change vulnerability of
ecosystems in the Southeast
Jennifer Costanza
January 15, 2015

2. Vulnerability assessments: a key step in adaptation planning
USFWS 2010 Climate Change Strategy
Objective:
Develop Expertise In and Conduct Adaptation
Planning for Key Species and Habitats
National Fish, Wildlife, and Plants Climate
Adaptation Strategy 2012:
Vulnerability assessments are important for
management planning and decision-making
under uncertainty.
Glick et al. 2011 Scanning the Conservation
Horizon:
Vulnerability assessments are the first steps
to facilitating ecosystem resistance and
resilience to climate change.

3. Climate change vulnerability as part of
management and conservation
Glick et al. 2011

4. Assessing Climate Change Vulnerability
Glick et al. 2011

5. Objective
Assess climate change vulnerability for a set of
ecosystems in the Southeast and Caribbean.
• Phase 1: Synthesize literature and GIS data on
sensitivity, exposure, and adaptive capacity for 12
ecosystems
• Phase 2: Use NatureServe’s Habitat Climate Change
Vulnerability Index (HCCVI) for 2 of these ecosystems

6. Study area

7. Approach: Ecosystem selection
Initial criteria: likely to be sensitive to climate change
• Coastal or coastal plain regions
• Wetlands
• High elevation systems
• Endemic to geographically discrete conditions, special soils
or other unique environments
• IUCN Threatened
• Suggestions from LCCs
Resulted in a list of 55 potential ecosystems in the Southeast
and Caribbean.

8. Approach: Ecosystem selection
Ecosystem (NatureServe Ecological System)
Caribbean Coastal Mangrove
Caribbean Montane Wet Elfin Forest
Central Atlantic Coastal Plain Wet Longleaf Pine Savanna and Flatwoods
Central Florida Wet Prairie and Herbaceous Seep
East Gulf Coastal Plain Near-coast Pine Flatwoods
East Gulf Coastal Plain Southern Loess Bluff Forest
Edwards Plateau Limestone Shrubland
Edwards Plateau Mesic Canyon
Nashville Basin Limestone Glade and Woodland
South-Central Interior Mesophytic Forest
Southern Coastal Plain Nonriverine Cypress Dome
Southern Coastal Plain Seepage Swamp and Baygall

9. Many vulnerability assessments have been done for species

10. Vulnerability assessments for ecosystems or habitats are
more challenging.
St. Mark’s National Wildlife Refuge. Credit: Alan Cressler

11. Cedar glade, Rutherford Co., TN, Credit: Alan Cressler
Vulnerability assessments for ecosystems or habitats are
more challenging.

12. Phase 1 assessment approach
Climate factors that affect:
• Distribution of the ecosystem
• Important ecological processes
• Dominant plant species
• Plant and animal species of conservation importance
Focus on:
• Non-climate stressors
• Ecosystem function
• Connectivity
• Environmental/topographic complexity
• Protection status and management
Qualitative, relative vulnerability rating

13. Phase 1 major GIS data
Sensitivity
• WorldClim 1950-1999 data: seasonal max and min temperature, total precipitation
Exposure
• Downscaled climate projections (K. Hayhoe et al.), averaged across GCMs for
A1FI and B1 scenarios, 2040-2060, 2080-2100
• NOAA sea level rise: recent data and projections for 1 ft and 6 ft rise
• Sea level rise vegetation impacts from SLAMM modeling
Adaptive Capacity
• Current ecosystem total area (GAP land cover)
• Mean patch size (GAP land cover)
• Proportion under conservation protection (US Protected Areas Database)
• Proximity to urban areas (GAP land cover)
• Projected urbanization (Terando et al. 2014)
• Human modification (Theobald et al. 2012)
• Elevation heterogeneity (National Elevation Database)

14. Phase 1: literature and other sources
• Scientific literature
• Reports
• Wildlife Action Plans
• US Forest Service Tree Atlas for dominant species
Especially for:
• Climate sensitivities
• Non-climate threats like invasive species
• Management concerns

15. Phase 1 Example results for
East Gulf Coastal Plain Near-coast Pine Flatwoods

17. Phase 1 Sensitivity
East Gulf Coastal Plain Near-coast Pine Flatwoods
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Dominant species (longleaf, slash pine, wiregrass) have low sensitivities here.
Fires and hurricanes are important and are sensitive to climate.
Some rare salamanders and other species depend on mesic, periodically saturated soils.
The ecosystem is also sensitive to sea level rise.

18. Phase 1 Exposure
East Gulf Coastal Plain Near-coast Pine Flatwoods
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Phase 1 Exposure
East Gulf Coastal Plain Near-coast Pine Flatwoods

20. Phase 1 Exposure
East Gulf Coastal Plain Near-coast Pine Flatwoods
For most seasons, time periods and scenarios,
conditions could become hotter and drier.
The water table could become lower, especially
during dry periods (Lu et al. 2009).
Wildfires could become more common or more
intense, but there is uncertainty and debate about
this.
Between 1% and 8% of the ecosystem may be
directly inundated by sea level rise, and 2-3% could
change vegetation type.
Hurricane intensity is projected to increase, leading
to overstory tree mortality, especially on older,
unburned sites.
Longleaf and slash pine are not projected to change
in importance (US Forest Service Tree Atlas).

21. Phase 1 Adaptive Capacity
East Gulf Coastal Plain Near-coast Pine Flatwoods
Recent fire suppression is a major threat.
Relatively small average patch size (0.9 ha)
Occurs fairly close to development, likely placing
more constraints on management.
6% projected to be developed by 2050, 12% by
2100
Invasive species such as cogongrass are
problems.
But…
Species in this system occur in other adjacent
systems.
High degree of protection: over 50% is
protected currently.
0%
10%
20%
30%
40%
50%
60%
Proportionofecologicalsystemextent
Protected Developed Developed
2050 2100

22. Phase 1 Overall vulnerability
East Gulf Coastal Plain Near-coast Pine Flatwoods
Moderate
Some sensitivity and exposure, especially to changes in
fires, hurricanes, hydrology, and sea level.
Substantial adaptive capacity.

23. Phase 1 Example results for
Nashville Basin Limestone Glade and Woodland

24. Flat Rock Cedar Glades and Barrens, TN, Credit: Alan Cressler

25. Phase 1 Sensitivity, Exposure, Adaptive Capacity
Nashville Basin Limestone Glade and Woodland
Sensitivity:
• Seasonal extremes in moisture, and longer term drought, often in late summer and fall
• Many plant species tolerate abiotic stress
• Woody invasion into grasslands slows under drought
Exposure:
• Temperature increases, especially minimum temps.
• Precipitation projections more uncertain
• Could lead to more droughts
• Changes in hydrology uncertain
Adaptive Capacity:
• Limited geographic distribution and restricted to unique edaphic conditions
• Threatened by conversion to human land uses, especially in
Nashville-Murfreesboro area
Vulnerability: High due to low adaptive capacity and potential changes in drought and
hydrology.

27. Phase 2 Assessment Approach: HCCVI for two ecosystems
Adapted from Comer et al. 2012

28. Phase 2: HCCVI
Two ecosystems:
East Gulf Coastal Plain Near-Coast Pine Flatwoods
Nashville Basin Limestone Glade and Woodland
Two time periods:
Mid-century (c. 2050)
Late century (c. 2100)
Minimum and maximum values for each time period when applicable
from alternative emissions scenarios or other uncertainty.

29. Phase 2: Dynamic process alteration
and dynamic process forecast
LANDFIRE State-and-transition model for longleaf pine ecosystem

30. Phase 2: Dynamic process alteration
and dynamic process forecast

31. Current: Dynamic process alteration
Future: Dynamic process forecast
Phase 2: Dynamic process alteration
and dynamic process forecast

32. Dynamic
process
alteration
Dynamic
process
forecast
Pine Mid C. min. 0.68 0.31
Flatwoods Mid C. max. 0.68 0.31
Late C. min. 0.68 0.31
Late C. max. 0.68 0.29
Nashville Mid C. min. 0.49 0.22
Basin Mid C. max. 0.49 0.22
Late C. min. 0.49 0.21
Late C. max. 0.49 0.21

33. Phase 2: Calculation of climate stress index
The degree to which climate will change in the future in an ecosystem’s range.
Compared recent (1980-1999) climate data (Maurer et al. 2002)
with projected data (K. Hayhoe) for each ecosystem.
Monthly minimum and maximum temperature, precipitation
(36 variables)
For each variable at each climate data pixel:
Does the projected mean value exceed the recent value +/- 2 stdev.?
Climate stress index:
1 – proportion of variables that exceed recent values
Average across pixels in the ecosystem.

34. East Gulf Coastal Plain
Near-Coast Pine Flatwoods

35. Nashville Basin Limestone Glade and Woodland

36. Climate stress
index
Pine Mid C. min. 0.85
Flatwoods Mid C. max. 0.75
Late C. min. 0.75
Late C. max. 0.55
Nashville Mid C. min. 0.88
Basin Mid C. max. 0.78
Late C. min. 0.77
Late C. max. 0.51

37. Phase 2: Calculation of envelope shift index
The degree to which the suitable climate envelope will change.
Define the current climate envelope using MaxEnt and map to the current
landscape.
Project where that envelope will occur in the future under alternate scenarios.
Envelope shift index: Average suitability score for the ecosystem’s current extent.

38. East Gulf Coastal Plain Near-Coast Pine Flatwoods
Observed
B1
A2
A1FI
Mid-century

39. East Gulf Coastal Plain Near-Coast Pine Flatwoods
Observed
B1
A2
A1FI
End of century

40. Envelope shift
index
Pine Mid C. min. 0.81
Flatwoods Mid C. max. 0.63
Late C. min. 0.54
Late C. max. 0.25
Nashville Mid C. min. NA
Basin Mid C. max. NA
Late C. min. NA
Late C. max. NA

41. System Period Sensitivity Indirect
Effects
Adaptive
Capacity
Resilience Vulnerability
Pine Mid C. min. 0.74 0.79 0.50 0.64 Low
Flatwoods Mid C. max. 0.65 0.77 0.42 0.60 Moderate
Late C. min. 0.65 0.79 0.42 0.61 Moderate
Late C. max. 0.50 0.77 0.37 0.57 Moderate
Nashville Mid C. min. 0.55 0.70 0.45 0.57 Moderate
Basin Mid C. max. 0.49 0.66 0.37 0.52 High
Late C. min. 0.49 0.70 0.37 0.53 High
Late C. max. 0.36 0.66 0.32 0.49 Very High
Phase 2: HCCVI Vulnerability Scores

42. ●
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Moderate
Moderate
Low Low
Moderate
High
Moderate
High
Very high
0.00
0.25
0.50
0.75
1.00
0.000.250.500.751.00
Resilience
Sensitivity
System and time period
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Pine Flatwoods mid−century min
Pine Flatwoods mid−century max
Pine Flatwoods late−century min
Pine Flatwoods late−century max
Nashville Basin mid−century min
Nashville Basin mid−century max
Nashville Basin late−century min
Nashville Basin late−century max
Phase 2: HCCVI Vulnerability Scores

43. Assessing vulnerability:
Summary and future needs
Both approaches gave relatively similar vulnerability ratings for the two ecosystems
Each approach has advantages:
• Phase 1 approach was able to incorporate a wider variety of information and provide
more nuanced assessment
• Phase 2 approach produced quantitative scores that could be compared to one another
Need to incorporate:
• Species interactions
• Feedbacks and interactions among vulnerability components
Need to consider:
• Individual responses to climate change: ecosystems will not likely change as a unit
• Assessing vulnerability for ecosystems is more complex than for species
• What is the desired future condition?
• Focus on major species and ecological processes?

44. Sources of uncertainty and future research needs
• Potential change in precipitation
• Effects of climate on cloud cover (for Caribbean Elfin
Woodlands)
• Impacts on hydrologic regime
• Impacts on disturbance regimes
• Future of biotic interactions, tropic relationships, dispersal
under climate change
Assessing vulnerability will be important to do for a wider
number of ecosystems in the Southeast.

45. Thank you!
Collaborators:
Jaime Collazo, Matthew Rubino, NC State, Coop. Fish and Wildlife Research Unit
Scott Beck, NC State
Milo Pyne, Rickie White, NatureServe
Adam Terando, USGS Southeast Climate Science Center
Funding:
USGS Southeast Climate Science Center
USGS Gap Analysis Program
Contact me with questions or for a copy of our draft report:
jennifer_costanza@ncsu.edu