Download Recent range contraction of the endangered Pyrenean desman

Recent range contraction of the endangered Pyrenean
desman (Galemys pyrenaicus) in the French Pyrenees
[email protected]
Anaïs
Charbonnel1,2,3,
Laffaille2,4,
Pascal
Marjorie
Biffi2,3,
Frédéric
Blanc1,
Mélanie
Némoz1,
Laëtitia
Buisson2,3
© A. Charbonnel
Background
• The effects of global change on semi-aquatic mammals is little known in spite of a large number of endangered species
• Most Species Distribution Model (SDM) studies consider climate change alone but other components of global change can contribute to species range shifts
• In SDM studies applied to freshwater taxa, the hydrology is frequently overlooked due to the lack of data at large spatial scale but fine resolution
• Stream flow variables can be simulated using hydrological models, and then included in SDMs through an integrated modeling approach
Research questions
• Do hydrological variables explain the distribution of a semi-aquatic mammal at broad scale and fine resolution?
• Do SDMs accounting for climate, land-use and hydrological changes that have occurred during the last 25 years predict accurately the species distribution shift?
Material & methods
Results
• Biological model: the Pyrenean desman (Galemys pyrenaicus)
− Increasingly endangered
− Endemic to the Pyrenees and the Iberian Peninsula
− Uses streams in mountainous regions
− Lives in aquatic habitats and feed on aquatic invertebrates
• Accurate simulation of hydrology both in time and space
140
Measured
Mesuré
Simulated
Simulé
3/s)
3
Flow
débit(m
(m
s)
120
100
Example of simulated and
recorded stream flow at the
measuring station “Pont de
Rieulhes”, at a monthly time step.
80
60
40
Land use
Assessment of the
accuracy of the
simulations
Topography
Climate
2011
2010
2009
2008
2007
2006
2005
© E. Delgado
2004
2002
• Simulation of stream flow:
2003
20
• Study area: French Pyrenees
• Substantial climatic and hydrological changes over the last 25 years,
but negligible land use change
Examples of variables:
Historical simulated flow (m3/s)
Historical temperature (°C)
Historical agricultural land (%)
Soil type
• Species Distribution Models:
140
15
0.01
1.6
Flow change (%)
Field sampling
100
0
Temperature change (%)
Agricultural land change (%)
Environmental variables
Faeces detection along 500-m river section
(Corine Land Cover)
119
0
34
-49
3
Mean change: - 0.6 m3/s
Mean % of change: - 12 %
100
0
-100
Mean change: - 0.33 %
Mean change: + 0.5 °C
Mean % of change: + 5 %
© A. Charbonnel
No detection
Detection
TEM
(Carthage)
Current: 2011 - 2013
1222 river sections
RAI
FLO
SLO
FOR
AGR
NAT
OBS
TRI
POP
URB
Contribution of the
environmental variables to
the distribution of the
Pyrenean Desman.
(ROE & Geofla)
Ensemble of SDMs
(consensus approach)
Historical variables
Historical
Current
0
(SWAT simulations)
10 20 30 40
Historical: 1985 -1992
637 river sections
• Importance of climatic and hydrological variables
Importance
(CERFACS)
Historical
model
Historical distribution
• Climatic and hydrological changes have led to a decline in the
probabilities of presence (cf. projected distribution)
• The stronger range contraction modeled (cf. current distribution)
suggests that climatic and hydrological changes are not the sole drivers
-0.38
of this contraction
Probability of presence
1.0
Historical sampling
0.5
0.0
Projected distribution
Current variables
Current sampling
Current
model
Current distribution
Mean: 0.70
Historical distribution
Mean: 0.59
Projected distribution
Mean: 0.32
Current distribution
Conclusions
• Coupling hydrological models with SDMs enables to account for the effect of hydrological changes on range shifts of freshwater species
• Both climate and hydrology are important drivers of the Pyrenean desman distribution, suggesting that this species is sensitive to global change
• Other factors (e.g. predation) may have contributed to the rapid range contraction of the species
Contact details
1Conservatoire d’Espaces Naturels Midi-Pyrénées, 75 voie du TOEC - BP 57611 - 31076 Toulouse, France
2CNRS; UMR 5245; CNRS; EcoLab (Laboratoire Ecologie Fonctionnelle et Environnement); 31326 Castanet-Tolosan, France
de Toulouse; INP, UPS; EcoLab (Laboratoire Ecologie Fonctionnelle et Environnement); 118 Route de Narbonne, 31062 Toulouse, France
4Université de Toulouse; INP, UPS; EcoLab (Laboratoire Ecologie Fonctionnelle et Environnement); ENSAT, Avenue de l’Agrobiopole, 31326 Castanet-Tolosan, France
3Université
Acknowledgments
Fédération Aude Claire, Fédération des Réserves Naturelles Catalanes, Office National des Forêts, Groupe de Recherche et d’Etudes pour la Gestion de l’Environnement, Office National de la Chasse et
de la Faune Sauvage, Parc National des Pyrénées, Conservatoire d’Espaces Naturels Ariège, Conservatoire d’Espaces Naturels Aquitaine.
A. Maire, S. Sauvage, J-M.Sanchez-Pérez and their students, F. D’Amico, J. Brown & M. Williams-Tripp.