missing environmental data

[Champ]

Hi All,

I am new to maxent and need your help to resolve this issue.

I am running maxent model for some plant species using bioclimatic global data.

In each model run, I receive the warning message "Sample at xx.xxxx, yy.yyyy in ....csv is missing some environmental data (e.g.bio12). I received this message only for bio 12. Is something wrong with my asc file? When i examined the bio12 layer on arcmap i don't see any issue.

I received this message continuously for number of occurrence records that represent quite a big spatial area and hence i selected "suppress similar visual warnings'. Then the model runs well. Is this erroneous? 

Can somebody explain me what is happening here and how should i proceed with this situation? 

I appreciate your directions.

Champ

[Neftalí Sillero]

Hi,

You receive this warning because some points are located outside the area with environmental data. Maxent is only warning that these points receive NoData values (normally -9999) from the variables. So you need to check the limits of your study area. You can increase your study area or simply delete these points. If the points are located in the coast, there is no easy solution.

Best,

Neftalí

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Neftalí Sillero
Assistant Researcher
Personal website | Research Gate | Academia | Google Scholar | ORCID

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[Champ]

Hi Neftali,

Thanks for the response. I mapped all occurrences on one of my asc layer and removed all outliers before run maxent. I don't see any more outliers. 

And i cant believe so many outliers again , more than 100. In all species i got the warning messagesimilar way, "missing some environmental data (e.g.bio12)' . Is that a problem in bio12 layer? . And my layers are global layers. 

Champ 

[Francisco Amorim]

Hello,

As you can see the message says "(e.g. bio12)" if you are using the global layers and you didn't mess up with projections in this specific layer, I would say that data is probably missing for all the layers and maxent is picking bio12 as an example.

This is a long shot, but is there any chance that your points are not in the same projection that the layers or that point projections are messed up?

As Neftali said, if these data points are in the coast, this might be a little difficult to correct. If you are using a large pixel size maybe moving your points to the closest pixel won't produce that much error, but would be better to hear from others.

Cheers

-- 
Francisco Amorim

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[Champ]

Hi Famorim

Thanks and appreciate your response. All my projections are WGS 84 and my environmental layers are in same extent (90, 180, -180, -60). However  extents of my point data layers are different and always less.

I used all available global occurrence data (mainly GBIF). So I filtered my occurrences to reduce the spatial bias. For that i converted my point data to raster and i used my asc global grid layer for filtering. Then I converted this raster to point. calculated geometry of x and y. and imported as a text file. 

champ