The constant search of strategies that they lead towards the sustainable development makes
the environmental indicators exposition more and more frequent. The target of these indicators
is to give useful information for the control of the conservation of the environment.
The use of formulae that allow quantifying the conservation of the vegetation makes possible
the securing of an indicative value of the state of naturalness of the vegetation. Also, the use of
natural types of habitat instead of phytosociology associations allows simplifying the proposed
formulation, obtaining completely valid results.
Finally, the effect of the change of scale in the calculation of the value of the index does not
suppose changes in the validity of the obtained value. Nevertheless, we must consider that the
values obtained are only comparable in works realized to equal scale
