July 3rd, 2014

Charlotte Germain-Aubreycgermain@ufl.edu

ECOLOGICAL NICHE MODELING: PRACTICAL

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 ?