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Ecological Niche Modeling : practical. July 3 rd , 2014 Charlotte Germain-Aubrey [email protected]. Look at a set of conditions under which a species occurs naturally (presence data ) When possible, also look at conditions under which the species does NOT occur ( absence data ) - PowerPoint PPT Presentation
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ECOLOGICAL NICHE MODELSLook at a set of conditions under which a species occurs naturally (presence data)When possible, also look at conditions under which the species does NOT occur (absence data)
BUILD THE MODEL
Apply the model in space (around where it occurs naturally, or in another area), or in time (where did it use to occur, or where will it occur in the future)
PROJECT THE MODEL
Occurrence data: where the species is present, but not where it is absent
Distribution map: where the species is absent, but not where it is present
Step 1: gather points
• Occurrence points• Specimens
from museum• Observation
points• Distribution
map (absence map)
http://scienceasaverb.wordpress.com/2010/10/29/introduction-to-ecological-niche-modeling-environmental-niche-modeling-species-distribution-modeling-part-two-what-is-niche-modeling/
Step 2: gather environmental data
• Climatic• Geological• Soil• Water• Chemicals
• Species interaction• positive:
obligate host• negative:
excluding competitor
http://scienceasaverb.wordpress.com/2010/10/29/introduction-to-ecological-niche-modeling-environmental-niche-modeling-species-distribution-modeling-part-two-what-is-niche-modeling/
Step 3: Extract environmental values at points of occurrence
http://scienceasaverb.wordpress.com/2010/10/29/introduction-to-ecological-niche-modeling-environmental-niche-modeling-species-distribution-modeling-part-two-what-is-niche-modeling/
Step 4: Build a model
Here, a very simple model: 95% of the species distribution for each environmental variable
http://scienceasaverb.wordpress.com/2010/10/29/introduction-to-ecological-niche-modeling-environmental-niche-modeling-species-distribution-modeling-part-two-what-is-niche-modeling/
Step 4: Build a model
Here, a machine learning model comparing the presence and absence
MaxEnt
http://scienceasaverb.wordpress.com/2010/10/29/introduction-to-ecological-niche-modeling-environmental-niche-modeling-species-distribution-modeling-part-two-what-is-niche-modeling/
Step 5: project the model
Here projection in the space and time of occurrence
http://scienceasaverb.wordpress.com/2010/10/29/introduction-to-ecological-niche-modeling-environmental-niche-modeling-species-distribution-modeling-part-two-what-is-niche-modeling/
Step 5: project the model
Here, a projection into a new area
http://www.oceanecology.ca/species_model_data.jpg
Biodiversity encyclopedias
Point occurrences,Valid taxonomies
Range maps, Validation services
Species occurrencedatabases
Range maps
Species data
National biological data
Online conservation tools
Environmental data
ITIS
ITIS
Maximum Entropy algorithm used (machine-learning) to build and project niche models.
25% of dataset set aside for testing the model and giving feedback on how well it performs (machine learning process)
MAXENT
species,longitude,latitudebradypus_variegatus,-65.4,-10.3833bradypus_variegatus,-65.3833,-10.3833bradypus_variegatus,-65.1333,-16.8
WHAT IS YOUR QUESTION ? WHERE IS YOUR DATA ?