Download et al. - WordPress.com

Climate change:
A threat for the Andean bear?
Shaenandhoa García-Rangel
Juan Papadakis
Edgard Yerena
Departamento de Estudios Ambientales, Universidad Simón Bolívar
Venezuela
20th International Conference on Bear Research and Management, Ottawa – Canada 2011
Topics
• The Latin-American context to global warming.
• The Andes mountain range
• The Andean bear
• Climate change – Andean-bear project
• Objectives
• Methods
• Preliminary results
• Limitations and future directions
The Latin-American context
In Latin America, climate impacts are very significant and expected to
irreversibly affect key ecosystems and the services these provide.
(Vergara 2007)
• In 2005, over 80% of coral reefs across the Caribbean basin suffered
bleaching as a consequence of heat stress.
• Risk of coastal flooding and salinization.
• Increase in sea-level rise across the South Atlantic Coast.
• Hurricanes trends have intensified.
• Costs of impacts > 2 times since 1970.
• 4 of 10 most active years have been recorded since 1997.
• Changes in precipitation and temperature patterns.
• Amazonian drought of 2005 and the prospect of Amazonian
dieback. Critical role in precipitation patterns across South America.
(GEOLAC 2010, Vergara, 2007)
The Latin-American context
Human-pop. growth > mean
Exploitation of natural resources
Total GHG contribution: 11.78%
Net forest loss > 0.5% yearly
(Eclac, 2009, Geolac 2010, FAO 2005 )
The Latin-American context
THE ANDES MOUNTAIN RANGE
• Global circulation models
Temperature increases > lowlands
Change the ecology of the Andes
(Vergara, 2007)
• Rapid Glacier Retreat
• Troposphere warming
• Shift in the freezing point isotherm
1986
2007
Cotopaxi Glacier, Ecuador
30% decrease 1956-1976
38.5% decrease 1976-2006
(UNEP, Cathalac;Vergara 2007)
The Latin-American context
THE ANDES MOUNTAIN RANGE
• Global circulation models
Temperature increases > lowlands
Change the ecology of the Andes
(Vergara, 2007)
• Rapid Glacier Retreat
• Troposphere warming.
• Shift in the freezing point isotherm.
• Vulnerability of high-mountain ecosystems
• Water cycle disruptions .
• Disappearance of high-altitude water bodies.
• Increase occurrence of fires.
(Palminteri et al. 2001, Vergara 2007)
The Latin-American context
THE ANDES MOUNTAIN RANGE
• Global circulation models
Temperature increases > lowlands
Change the ecology of the Andes
(Vergara, 2007)
• Rapid Glacier Retreat
• Vulnerability of high-mountain ecosystems
Reduction of water supplies for food production and urban areas
Limitations in hydroelectric power generation
Highest concentration of human population
High deforestation rates
(Palminteri et al. 2001, Vergara 2007)
The Latin-American context
VULNERABLE
Climate change – Andean-bear project
THE ANDEAN BEAR
VULNERABLE (Goldstein et al. 2008)
Carnivore in SA moving faster towards extinction
(Cardillo et al. 2004)
Population trends
Habitat loss 2-4% a year
High levels of fragmentation
(Goldstein et al. 2008)
Climate change – Andean-bear project
OBJECTIVES
• To evaluate the impact of global warming on the
Andean bear across the Northern Andes.
• To compare the impact of global warming and
land-cover change on the Andean bear across
the Northern Andes.
• To evaluate the role of protected areas to secure
Andean-bear habitat in the future.
 PRELIMINARY RESULTS
 ANALYSIS LIMITATIONS
 FUTHER QUESTIONS RISEN
(Rodriguez et al. 2003)
Climate change – Andean-bear project
METHODS
Species Distribution Models (SDMs) for different scenarios
Changes in Andean-bear habitat suitability
1) Species presence data (1844 ~ 2004): 544 records.
•
GBIF (http://data.gbif.org/welcome.htm): 33 records.
•
Yerena (1994): 108 records.
•
Sánchez-Mercado (2008): 404 records.
Climate change – Andean-bear project
METHODS
1) Species presence data (1844 ~ 2004): 544 records.
Climate change – Andean-bear project
METHODS
1) Species presence data (1844 ~ 2004): 544 records. (ArcGIS 9.3)
2) Independent variables
• WorldClim (http://www.worldclim.org/)
•
Average conditions: Today
• Model: CCCMA, scenario B2. Year = 2050
(Flato et al. 2000)
Temp. max and min.
Precipitation
Elevation
Climate change – Andean-bear project
METHODS
• WorldClim (http://www.worldclim.org/)
•
Model: CCCMA, scenario B2. Year = 2050 (Flato et al. 2000)
Climate change – Andean-bear project
METHODS
1) Species presence data (1844 ~ 2004): 544 records.
2) Independent variables
• WorldClim (http://www.worldclim.org/)
•
Average conditions: Today
• Model: CCCMA, scenario B2. Year = 2050
(Flato et al. 2000)
Temp. max and min.
Precipitation
Elevation
• DMSP-OLS Nighttime Lights Time Series V.4.
•1992 and 2009 models. http://www.ngdc.noaa.gov/dmsp/download.html)
• GBIF (http://data.gbif.org/welcome.htm)
• Food resources according to Figueroa and Stucchi (2009)
Families: 5
Genera: ~10
Species: 18
Climate change – Andean-bear project
METHODS
1) Species presence data (1844 ~ 2004): 544 records.
2) Independent variables
ArcGIS 9.3
Maximum Entropy Method (Phillips et al. 2006)
3) SDMs
• Scale: 30 arc-seconds (~1 km). Maxent Versión 3.3.3e, HPTQ.
Jack-knifing procedure for variable importance.
AUC measure for model evaluation. 15% testing dataset.
“Maximum test sensitivity plus specificity” threshold for output.
Today
• Climate
• Climate + Food resources
• Climate + Nightlights
• Climate + Food resources +
Nightlights
Future
• Climate
• Climate + Food resources
Climate change – Andean-bear project
RESULTS
450,000
400,000
0.934
0.935
350,000
0.941
0.934
0.935
Area (Km2)
300,000
250,000
0.945
200,000
150,000
100,000
50,000
0
Clim
Clim + FR
Clim + NL
Models
Today
Futuro
Clim + FR + NL
Climate change – Andean-bear project
RESULTS
Model: Climate
Model: Climate + Food resources
Today
Today
Future
Future
Climate change – Andean-bear project
RESULTS
Food resources are important modulators of Andean-bear’s habitat
suitability.
Model: Climate + Food Resources
Today
Variable contribution: 42.8%
Future
Variable contribution: 36.8%
Climate change – Andean-bear project
RESULTS
Today
2050
Climate change – Andean-bear project
RESULTS
Today
2050
Climate change – Andean-bear project
DISCUSSION
1. Preliminary results show that climate change do not seem to pose a
major threat to Andean bears in the middle-term (2050).
• Land-cover change and human-population growth are known
threats to the species, and so they must be incorporated in any
assessment regarding climate change.
2. Models show potential Andean-bear habitat suitability.
• Areas are considerably overestimated but relative variations could
be indicators of future scenarios.
• No historic barriers or restriction due to human developments are
incorporated.
• We require information on land-cover change to be able to draw
guidelines for conservation.
Climate change – Andean-bear project
DISCUSSION
3.
Changes in the distribution of food resources could open new spaces
to the Andean bear.
• Species overlap remains within the Northern Andes.
•Andean bears are constrain to the limits of the Northern Andes by
some unidentified factor (Temperature?, food resources?).
Climate change – Andean-bear project
WHAT’S NEXT?
1. To increase coverage and time-span of Andean-bear present points.
2. To explore differential weighting of food resources and the inclusion of
other species.
3. To incorporate land-cover change projections.
4. To evaluate prediction behavior with CSIRO and HADCM3 climatic
models and other scenarios available.
5. To evaluate the role of protected areas to secure Andean-bear habitat.
Acknowledgements
• Dr Chris Servheen.
• Dr Martyn Obbard.
• Dr Ada Sánchez-Mercado.
• Érika Pedraza.
• Bear Specialist Group.
• Laboratorio de Sensores Remotos y Análisis Geoespacial.
• ESRI Conservation Program.
Universidad Simón Bolívar
Thank you!
Climate change – Andean-bear project
RESULTS
70.00
60.00
Percentage (%)
50.00
40.00
30.00
20.00
10.00
0.00
Venezuela
Colombia
Today Clim
Today Clim + FR
Ecuador
Future Clim
Future Clim + FR
Perú
Climate change – Andean-bear project
80
Percentage of data points (%)
70
60
50
40
30
20
10
0