my question is about the relative abundance in the guild table: should all rows sum up to one? is it meant in regard to the individuals or the species?
Welcome to the forum @Sabine!
The relative abundance values are relative to the sum of all values in the column, for example, in the sample guild table from the user’s guide:
SPECIES ... relative_abundance Apis 0.75 Bombus 1 Apis2 0.75 Bombus2 1
The sum of relative abundance values is 3.5. 0.75/3.5 = 0.214 and 1/3.5 = 0.286, thus, you could equivalently write the table so it sums to one like this:
SPECIES ... relative_abundance Apis 0.214 Bombus 0.286 Apis2 0.214 Bombus2 0.286
It is kind of confusing. If you have data on the actual abundance of each pollinator, you could use that directly, for example:
SPECIES ... relative_abundance Apis 55 (bees per hectare) Bombus 70 (bees per hectare)
If you don’t have this data, but just an estimate, like “there are twice as many Bombus as Apis”, you could write that as
SPECIES ... relative_abundance Apis 1 Bombus 2
If you have no data at all, you could weight them equally:
SPECIES ... relative_abundance Apis 1 Bombus 1