Managed pollinators in the pollination supply area


I have a doubt about how to model managed pollination in the following situation:
There is a farm which has both natural and commercial (pulp) forests. The farm owner manages some hives in these forests to produce honey. Therefore, the pollinator`s abundance in these forests is not natural, but enhanced by these managed hives.
We would like to evaluate the pollination ES this farm provides to other farms nearby. So, my question, after all, is: how do I account for these enhanced pollinators’ abundance in the pollinators’ supply area?
Does anyone have any tips?
Thank you very much,

Hi @rearmelin -

We generally recommend using the Pollination model for native bees, which can be connected with different land cover types. However, it seems like the model would work if you create a specific land cover class for the managed bees, and assign that class to the pixels where the managed bee hives are located, along with the necessary values for nesting and floral resources in those pixels, and the necessary values in the Guild table for those particular bees.

~ Stacie

Hi Stacie,

Thank you very much for the ideas. Since the guild table is the same for all land use classes, in doing the way you suggest I would have both the native and the managed bees in all land use classes, right?
How can I make the managed pollinators specific for a single land use class? The biophysical table does not allow us to specify which bee species are found in each land use class.
Just to be clear, I do not want to exclude native pollinators from the analysis, I just want to add these extra sources of pollinators (those managed outside the crop sites) to the analysis.
An alternative procedure, I think, would be to use the exponential function based on sites and foraging distances to estimate how many of the managed bees would reach the crop sites, divide this estimate by the appropriate stock rate and then set the result as “p_managed” in the Farms Map vector (only when there would be no other foraging site blooming closer to the managed bees site). Does this make sense to you?
Thank you again,

Hi Renato -

I’m suggesting that you could create a new, separate land use class specifically for the managed bees. If you have geospatial data with the locations of the managed hives, you could use that layer to assign a new land use class like “Managed bees” to the pixels in the original land use map, using GIS techniques. Then your land use map would have classes something like:

1 Forest
2 Agriculture
3 Urban
9 Managed bees

Depending on your analysis, it may be useful to have multiple new land use classes, which reflect the original land use + managed bees, like
11 Forest + Managed bees
12 Agriculture + Managed bees

Then you would have the specific managed bee class(es) in your biophysical table, so you can assign appropriate values to them, separate from the wild bees.

You can also run the model separately for managed and wild bees, if you want to clearly separate the resulting maps.

~ Stacie

Hi Stacie,

Thank you again for your answer.
I did understand when you suggested creating a new land use class in the land use map raster. What I still do not understand, as I mentioned in my previous reply, is how to make this new class specific for the managed bees. Let me try to be more clear about my doubts on this issue:
The biophysical table is the only model input where it is possible to set specific information for each land-use class. But it only allows me to set levels of nesting sites and floral resources availability. It does not accept inputs like the list of pollinators that should be considered in each land-use class or the relative abundance of these pollinators for each land-use class. Therefore, since the nesting and flora parameters are used by the model to estimate the abundance of native bees, whatever values for nesting sites and floral resources availability I set for the new land use class you suggested would be used by the model to estimate the abundance of all the pollinators listed in the guild table for this new land-use class, the native ones and the managed ones. Am I wrong about this? If so, please correct me.
The guilds table also does not allow me to specify in which of the land use classes each of the pollinators should be considered nor the pollinators’ relative abundances in each of these land use classes. Therefore, whatever I set in the guilds table will be considered for all land use classes of the biophysical table. There is no way to set anything specific for the new land use class. Am I wrong about this? If so, please correct me again.
In summary, if my understanding of how the biophysical and the guild tables work is correct, there is no way to set a new land use class to consider only a specific pollinator (a managed one in my case). And if this conclusion is correct, creating a new land use class will not be much different than simply adding the managed pollinator to the guilds table. In both cases, native as well the managed pollinator would be considered in all land use classes.
What am I missing Stacie?
In time, I would love to hear your comments about the alternative approach I mentioned in my previous reply.
Thank you again for your advice,

What if you created a specific “Substrate” type for the managed bees, which would only occur in the specific land cover class(es) where the managed bees occur, and only the managed bees would use them? The “availability” could be 1 in these managed bee classes, and 0 in all other land use classes.

Then the Guild table would list high “suitability” for the managed bee “substrate” for the managed bee guild, and 0 suitability for non-managed bee guilds. Would something like this address your needs?

~ Stacie

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Hi Stacie,

It sounds great, thank you! I will test this idea. Thank you very much again!