Walker - 1967 - A geography of Italy

PART I I ; SOME PH YSIC A L GEOGRAPHY
Mediterranean nuance, as suggested by the presence o f the ilex and by the
cultivation o f the olive and lemon, is most obvious in the Garda area with its
lower rainfall, its more abundant sunshine and its calcareous rock surface.
Ib THE VALLE PADANA. The main characteristics o f this area have already been
noted. In the short winter temperature inversion causes prolonged foggy and
frosty spells; but snow rarely hes for more than a day or two. The rainfall regime
and the long growing period are favourable to agriculture but convectional disturbances
with severe hailstorms are a serious menace in autumn.
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n Insular and peninsular Italy
U a THE RIVIERA LIGURE. This is an extraordinarily mild area benefiting to the
full from the winter warmth o f the Ligurian Sea. Although subject to the
maestrale from time to time, on the whole it is sheltered and most winds reaching
it from the north are warmed adiabatically. The Riviera di Ponente is decidedly
drier and somewhat milder than the Riviera di Levante (San Remo 678 mm,
Spezia 1140 mm).
n b THE TYRRHENIAN COAST. The northern half compares unfavourably with
the Riviera in winter and is drier than the southern half because o f the screening
effect o f Corsica. Towards the south the autumnal maximum gives way to a
winter one.
lie THE ADRIATIC COAST. This is less mild in winter than the corresponding
latitudes on the T3n:rhenian coast because it is more exposed to the northeasterly
continental influences. Southwards the total rainfall decreases (cf.
Tyrrhenian) and the length o f the summer drought increases (Ancona 120 mm
in the three summer months, Bari 76 mm).
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Ud THE APENNINES. This zone still exhibits the characteristically Mediterranean
summer drought, longer and more unbroken towards the south, but the
winters, which eliminate the olive, are longer and more severe than on the
neighbouring coastlands. Over 1500m snow is frequently experienced and may
lie for weeks; the crests, especially in the Abruzzi, are usually capped till April.
In intermontane basins temperature inversion is common.
He SICILY and I l f Sa r d in ia . The most ‘typically’ Mediterranean zones with a
long summer drought and a simple winter rainfall peak.
V E G E T A T IO N
An appreciation o f the vegetational tapestry o f Italy invites consideration of
three contributory influences, namely, the climate now, the climate in the past
and the influence o f Man.
With worsening conditions at the end o f the Pliocene, the subtropical vegetation,
which till then had covered much o f the European mainland, began to
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