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20 Carolinea 72 (2014)
upward migration of vegetation along the moun-
tain slopes resulted in an asynchronous initiation
of similar vegetation types at different altitudes
(cf. Janssen et al. 1974).
For the latter half of the Holocene, especially
pollen types of plants that grow at lower altitudes
(of which the pollen is dispersed upward by oro-
graphic lift) are useful for a palynostratigraphic
division, since their trends are synchronously
reflected in pollen diagrams from sites at higher
elevations, e.g. the pollen types produced by
Quercus , Alnus, Carpinus, Juglans, Castanea,
cultivated crops and agricultural herbs (Jans-
sen & Janssen-Kettliz 1972, Janssen et al. 1974,
J anssen 1979, De Klerk & Hölzer 2009/2010).
However, for the Lateglacial and first half of the
Holocene such an approach is not tenable be-
cause the present-day vegetation belts had not
yet developed and since it is unknown how the
vegetation types of that time were actually dis-
tributed, it is unknown which pollen types were
blown-in from lower elevations ( Janssen et al.
1974).
The chronology of the various vegetation phases
(cf. fig. 3) can be inferred from the various radio-
carbon dates that are available for many paly-
nologicaly analysed sections, whereas for the
Weichselian Lateglacial also the Laacher See
Tephra (LST) can be used as an important mark-
er for dating and correlation of various sections
(cf. Walter-Simmonnet et al. 2008).
The synthetic pollen diagram of fig. 3 displays
mainly high values of pollen attributable to herbs
during the Weichselian Lateglacial. Some fluctu-
ations are discernable that represent changes in
vegetation types during various climatic phases.
During the early Holocene, predominantly Betula/
Pinus forests existed which were later invaded by
Corylus . This resulted in a distinct Betula /Pinus
zone and a C orylus zone in the early Holocene
sections of the various pollen diagrams. Probably
populations of other deciduous tree species ex-
panded gradually during this time-frame, includ-
ing Quercus, Ulmus, Tilia and Fraxinus. The Co-
rylus zone in many pollen diagrams thus grades
into the overlying Corylus/Quercus/Tilia/Ulmus/
F raxinus zone. Although these pollen types show
a clear succession in many pollen diagrams
(cf. fig. 3), the related vegetation changes were
strongly asynchronous at various altitudes and in
different landscape regions ( Visset et al. 1996).
It is thus not practicable to identify more palyno­
stratigraphic zones than a general Corylus/Quer-
cus/Tilia/Ulmus/Fraxinus zone.
The transition to the subsequent Fagus/A bies
zone is clearly visible in most pollen diagrams.
This transition occurred rapidly within only few
centuries (V isset et al. 1996) and was classically
assumed to correspond to the transition from a
warm and moist climate phase to a colder and
drier phase (Hatt 1937, Firbas et al. 1948, G uil-
let et al. 1976). Increasing anthropogenic impact
on the landscape resulted in an increasing de-
position of pollen types attributable to cultivated
plant taxa (fig. 3).
Whereas Carpinus seems to have expanded
gradually during the time-frame of the Fagus/
A bies zone, the introduction of Juglans and Ca-
stanea in the lower regions during the Roman
period (Janssen & Janssen-Kettlitz 1972, V isset
et al. 1996) resulted in an easy recognizable and
largely synchronous pollen zone boundary that
defines the base of the F agus/Abies/Carpinus/
C astanea/J uglans zone. If the temporal resoluti-
on of the pollen diagrams is sufficiently high, a
further differentiation within this zone is possible
by identification of forest regeneration phases
during the Migration period, by increased culti-
vation after the foundation of the monasteries in
the early Medieval, and by cultivation phases of
specific plant taxa (e.g. Cannabis).
After an intensive deforestation during the
post-Medieval at the higher altitudes for fuel,
constructions of buildings, paper production,
and industrial purposes (Polge 1963, Eggers
1964, Stadelbauer 1992, Sell et al. 1998, Gar -
nier 2000), reforestation after ca. 1830/1840
consisted of the plantation of predominantly Pi-
nus and Picea (cf. Polge 1963, Guillet 1971a,
Guillet et al. 1976, Kalis 1984a/b, Sell et al.
1998) which is clearly reflected in most pollen
diagrams as a zone with high values of Pinus
and Picea pollen.There is a long-debated que-
stion whether Picea in the Vosges Mountains
occurs naturally, or has been introduced during
the plantations after 1830/1840 (cf. Strohmeyer,
1913, Bartsch & B artsch 1929, O berdorfer
1937, Firbas et al. 1948, Zoller 1956, Och-
senbein 1963, Polge 1963, Bogenrieder 2001,
D e Klerk & Hölzer 2009/2010). The studies by
Kalis (1984a/b), Kalis et al. (2006) and Edelman
(1985) demonstrated unambiguously that Pi-
cea has been present since several millennia,
probably predominantly on mires. However, it
seems that the natural Picea populations had
a considerably lower pollen production than the
planted specimens and their descendants (De
Klerk & Hölzer 2009/2010).