Page 216 - Special Topic Session (STS) - Volume 2

STS486 Tonio D.B. et al.
Then, the functional approximation of the profiles is computed following
Eq. (3) and it is showed in Fig. 2.

Figure 2: Functional diversity Hill’s numbers of Lazio’s rivers

It is evident that the “Tevere” river is the most diverse because it is above
all other profiles and does not intersect with other curves. On the contrary, the
less diverse river is the “Ratto”, with only one species, followed by the “Quesa”
and “Tronto” with two species. Regarding the other rivers, most of them
cannot be ranked because many profiles intersect.To provide a summary
measure of the biodiversity in the considered region, the mean diversity profile
(solid black line in Figure 3) is computed. Figure 3 shows that, on average, the
stations present 10 different species. The same figure shows the bootstrap
simultaneous confidence bands for the mean estimator of level 1-=95%
(dotted red lines in Fig. 3). We note that, in the first part of the domain, there
is greater variability; this is due to the characteristics of the profile. Indeed, in
the second part of the domain, the profile tends to be very flat and the sample
curves become constant (Di Battista et al., 2016), hence the sample variance
tends to zero.

Figure 3: Functional diversity Hill’s numbers of Lazio’s rivers (solid grey lines) with
their functional mean (solid black line) and bootstrap confidence bands (dotted red
lines) at level 1-=95%
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