Incorporating a Bias File for Maxent in SSDM Package (R)

[Melissa Petford]

Hello everyone,

I am trying to create a stacked species distribution model in R using the SSDM package with the Maxent algorithm.

I would like to incorporate a bias file to account for sampling bias. To do this, I attempted to call a Maxent argument using the following line in my code:

maxent.args = list(arg1 = "biasfile=biasrast")

The code ran without errors, and I received my stacked model. However, it appears that the bias file was not applied when selecting background points. When I plotted the background points from one of the individual ensemble models, they were randomly distributed across the entire study area rather than being influenced by the bias layer.

Has anyone successfully integrated a bias file into the SSDM package? Alternatively, is there a way to directly specify a predefined set of background points?

I would really appreciate any advice on this, as I am a bit stuck on how to proceed.

Best regards,

Melissa