3.5.3 ΔFST indicator
A statistically significant increase of F ST is
observed in one metapopulation (Skåarnja 2), and significant decrease ofF ST in two systems (Jougdadalen and Hotagen 4).
However, when translating these changes to reflect changes in gene flow
among subpopulations none of these three cases exceed the proposed
limiting values for the ΔF ST indicator and they
are thus classified as “Good” (Figure 7b). Skåarnja 2 exhibit an
initial F ST of 0.159 (in the 1970-80s sample), a
25% decrease in gene flow correspond to a limiting upper value forF ST of 0.202 while the observed present (2010s)F ST was F ST=0.180
(corresponding to a 14% decrease in gene flow) and thus below the
limit. In Jougdadalen and Hotagen 4 F ST has
decreased significantly, indicating that gene flow has increased in
these systems. In Jogdadalen, F ST decreased from
0.054 (past) to 0.042 (present), corresponding to a 31% increase in
genetic exchange. Similarly, gene flow increased by 30% in Hotagen 4
(past F ST=0.103 and presentF ST=0.080). Since the increase in gene flow did
not exceeded 50% in neither of these metapopulations, they are both
classified as “Good” (Figure 7b).