Does anyone know how I can estimate species abundance? The formula should be "(Number of species in the survey area/Total area surveyed)*Total area". I just don´t know how to put it into GIS...
(Number of species in the survey area/Total area surveyed)*Total area"
I guess you have data for 'number of species in survey area', 'area surveyed' and 'total area' in three fields of a table, right? If so, then add a new field (say, Estimates) to the table. Open the attribute table in ArcMap. Right-click on the newly addeded 'Estimates' field name and select Field Calculator ...