Add ecological indicator values

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Add ecological indicator values

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Menu: Edit | Add indicator values

 

This option serves to calculate the mean, standard deviation, median, and number of observations of ecological indicator values (e.g. Ellenberg values for nitrogen, pH, etc.) of each relevé and stores these data in separate columns in the database. If the columns are not yet present, they will be added automatically to the database.

 

Range of relevés: Specify the range of relevé numbers on which you want to perform the calculations.

 

Scaling cover values: Specify whether the cover values do (Ordinal or Percentage) or do not (Boolean; only presence or absence of species) has to be taken into account.

 

Ecological items: Choose one or several items for which the calculations should be done.

 

Add columns for…: Specify which indicators have to be calculated.

 

Add: Execute the calculation. The extra columns will be added at the end of the table with header data. The name of the columns consist of three parts, separated by an under score: <alias name subject>_<calculation>_<scale> (e.g. ph_mea_b is: ph, mean and boolean).

 

 

Calculation:

In the case that the cover value of a species is taken into account the numerical indicator value is multiplied with the cover (either by 1 to 9 for ordinal scale or 1-100 for percentage scale).

 

ni: the numerical cover value of species i
ii: the indicator value of species i

 

Mean indicator value = ∑(ii * ni) / ∑(ni)

 

In order to know which percentage value comes with a cover abundance code select Manage, Popup lists, Edit, Cover scales in the menu and check the table.

 

 

 

See Configure the ecological database to define the alias names of the items.