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Vascular flora of four satellite islets of the Egadi Archipelago (W Sicily), with some notes on their vegetation and fauna 51

Considering that Podarcis siculus shows a high
morphological plasticity and that all the micro-
insular races described in the past are now treated
as mere synonyms of the species, an accurate field
data collection focused on many different meristic
and morphological parameters should be carried out
in order to assess the pattern and the range of vari-
ability of PRE and ROT lizard populations.

CONCLUSIONS

Small areas, few or no available niches:
effects on microinsular assemblages

If compared with other islets with a similar Figure 13. Limonium lojaconoi: Prèveto (photo L. Scuderi)
size, like Strombolicchio on Aeolian Islands (Lo
Cascio & Pasta, 2008a) or Lampione on Pelagian Goodbye or see you soon?
Archipelago (Lo Cascio & Pasta, 2012), the stud-
ied islets do not show a remarkable botanical Although they have visited PRE and GAL
value. Nonetheless, they give hospitality to nine nearly in the same period, the check-lists written
species of biogeographic and/or conservation in- down by the two different couples of co-authors
terest, i.e. Dianthus rupicola subsp. rupicola, show rather striking differences, perhaps because
Iberis semperflorens, Limonium aegusae, Limo- of the different intensity and duration of summer
nium bocconei, Limonium lojaconoi (Fig. 13), drought period. For example, this could be the case
Limonium ponzoi, Helichrysum panormitanum, of all the 11 species (Avena cfr. barbata, Bellis
Polycarpon alsinifolium and Silene sedoides annua, Calendula arvensis, Chenopodium opuli-
subsp. sedoides, and to several plants which be- folium, Diplotaxis erucoides, Erodium malacoides
came extinct or are extremely rare on Egadi is- and E. moschatum, Lagurus ovatus, Solanum lycop-
lands: for example, at FLE thrive 4 out of less than ersicum, Sonchus tenerrimus and Urtica mem-
10 plants of Chamaerops humilis present in the branacea) which have been observed at PRE only by
whole Egadian archipelago, while PRE hosts per- A & JS. The presence and commonness of these
haps the last individual of Ranunculus bullatus, annual pioneer therophytes linked to disturbed habi-
apparently extinct at Favignana (S. Pasta, pers. tat is probably subject to annual fluctuations due to
obs.). The same “refugium” role is played by local climatic regime and species patterns (e.g. low
Strombolicchio, which hosts the only known Aeo- numbered and/or extremely localized populations).
lian (and Sicilian) populations of Ephedra po-
dostylax Boiss. and Eokochia saxicola (Guss.) The same goes also for 13 of the 15 taxa which
Freitag et G. Kadereit (Lo Cascio & Pasta, 2008b). have been seen only by LS & SP, i.e. two hemicryp-
tophytes (Ferula communis and Parietaria lusi-
On the other hand, only two aliens, probably
recently introduced by seagulls, i.e. Solanum ly-
copersicum (PRE) and Malephora crocea (FLE),
were noticed. The first one behaves as a casual on
many little islets (Lo Cascio & Pasta, 2008b; Cal-
darella et al., 2010), while the second is becoming
a more and more frequent invasive within the
halo-lithophilous communities of circum-Sicilian
islands (Romano et al., 2006).