abs.qmd

---
title: "Pseudo-absences"
subtitle: "Generate pseudo-absence or background environmental values to compare with occurrence environment"
---

Describe various strategies for generating pseudo-absences.

-   [Pseudo-absences • biomod2](https://biomodhub.github.io/biomod2/articles/vignette_pseudoAbsences.html)
    -   [@barbet-massin2012]

## All background

A common Maxent strategy is to feed all background points into Maxent, and then to use the resulting distribution as a null model. This is the default strategy in Maxent [@phillips2017; @phillips2006; @phillips2008].

## Mask by FAO areas

The FAO areas applicable to species are included in the `aquamapsdata`, presumably from evaluating OBIS observations and the literature.

## Use occurrences from same Family, different species

By using the same family, we can be sure that the pseudo-absences are ecologically similar to the species of interest.