Slide 23: Species distribution datasets...2
When using existing data, it is important to bear a number of things in mind.
Firstly, ad hoc museum data only provides us with positive (presence only) records - there are not likely to be many recorded absences of species in a given locality.
Atlases may have both presence and absence data, depending on the accuracy and comprehensiveness of the database. It is important to note that the scaling down of atlas data to finer resolutions is not a good idea to do without taking into account the risks, and without extensive validation of the model being used.
Using a flagship or indicator species to model the distribution or health of an ecosystem has both advantages and drawbacks. In such a case, it is essential to determine the objective of the model (in terms of ecosystem function, biodiversity assessment or change detection), and the sensitivity of the indicator species to the conditions being tested. Some species may make good indicators of biodiversity health under one set of conditions, but not another.
Thus, the adaptation response in such a case depends on the flagship species selected.