Hello everyone
I am currently using maxent to model the distribution of an australian gecko species.
I am using maxent to identify areas of similar environmental space, to target future surveys.
After removing duplicate records (records within the same grid cell, res of 250m2) i have 16 occurrences (yeah, it's on the low side).
What I've done so far:
- remove duplicate presence records
- test for correlation between environmental variables with LayerStats in R
- used background points from the whole study area (southern wet tropics, 75km from all records)
- remove highly correlated variables according to my (and my supervisor's) ecological knowledge of the species (i.e. kept 'ecologically relevant' layers over less 'relevant' ones
- tuned the model using ENMeval to get the best performing feature classes and reg parameter. (ENMeval found the best performing model with Linear and Quadratic features (not a surprise for such a sample size) and a Regularisation Parameter of 1). Models were evaluated based on a number of parameters, AICc included.
Now I am planning to build an "Ensemble of Small models" following Breiner et al. 2015 (Overcoming limitations of modelling rare species by using ensembles of small models). The ESM script that I'm using calculates AUC and Boyce.
My question is:
- has anyone here used ESMs before, and what you think about it?
- Do you have any suggestions on other steps i might have to implement?
- shall i evaluate my ESM models with some other metrics?
Regards,
Lorenzo