Middle Miocene palynoflora of the Legnica lignite deposit complex ...

cinerea, and Acer saccharum. In these forests
the tree layer is composed of more levels, and
shrub and herb layers are also well developed.
In south-eastern part of North America grow
beech–magnolia forests characterized by the
great species diversity and presence of evergreen
species. They consist of Fagus grandifolia
var. caroliniana, Magnolia (predominantly
M. grandifl ora), and Tilia species, as
well as Acer fl oridanum, Carpinus caroliniana
and Liquidambar styracifl ua (Podbielkowski
1978a, b, Barnes 1991).
Broad-leaved forests in uplands and mountains
of eastern Asia are fl oristically also very
rich. The principal species in northern part of
this region are Quercus mongolica (and Q. dentata
in southern part), Fraxinus rhinchophylla,
Kalopanax ricinifolia, Phellodendron amurense,
Tilia mandschurica, and Acer mono, whereas
in lower altitudes grow rich deciduous forests
with Tilia amurensis, Fraxinus mandschurica,
Juglans mandschurica, Ulmus macrocarpa,
Phellodendron amurense, and Acer mandschuricum.
The lower tree layer is formed by Carpinus,
Padus, Cerasus, and others. The shrub
layer is of a great diversity, with Acanthopanax
sessilifl orum, Aralia mandschurica, as well as
Lonicera and Diervilla species. Climbers (such
as Vitis amurensis) are very numerous. The
herb layer is also very rich (Panax schin-seng
grows there). Towards the south coniferous
forests with Pinus, Cryptomeria japonica, as
well as Quercus monogyna, Juglans, Acer species,
and Magnolia kobus prevail. Main genera
of the shrub layer are Lonicera, Syringa,
Rhododendron, and Ligustrum. Climbers and
epiphytes are numerous there. In the northern
part of this area and in mountain regions grow
coniferous and mixed forests with deciduous
trees, whereas towards the south subtropical
forests with a conciderable frequency of Pinus,
Cunninghamia lanceolata, and Cryptomeria
japonica, as well as evergreen oaks (e.g. Quercus
fabri) occur. The dense shrub layer is dominated
by Rhododendron species. In subtropical
zone, in lower mountain belt and lowlands,
humid forests grow with deciduous tree domination.
Liriodendron chinense, Liquidambar,
Acer, Quercus (many evergreen species), Magnolia
(many evergreen), Castanopsis, Aesculus,
Ilex, Meliaceae, Araliaceae, Fabaceae, and
Rosaceae are important there. Some species
from subtropical and tropical zones (such as
Diospyros and bamboos) as well as climbers
71
and epiphytes also play a considerable role
(Podbielkowski 1987a, Ching 1991).
Mixed broad-leaved forests with a special
variety of species, and of particular fl oristic
interest for comparisons with the Neogene
plant communities, occur east of the Black Sea
(Colchis Province) and west of the Caspian Sea
(Lenkoran depression and Talysh Mountains).
The Colchian forests cover the mountain slopes
from sea level up to 600 m. These are relict forest,
in which Quercus iberica, Carpinus caucasica,
Zelkova carpinifolia, and Pterocarya
fraxinifolia prevail (Röhrig 1991). There also
occur Carpinus orientalis, Fagus orientalis,
Fraxinus excelsior, Acer laetum, A. ibericum,
Ulmus glabra, U. suberosa, Prunus spinosa,
and Tilia caucasica. The shrub layer is formed
by Lonicera caprifolium, L. caucasica, Cornus
mas, Hedera helix, and others (Stuchlik & Kvavadze
1993). In the Lenkoran and the Talysh
Mountains (Talyshskiye Gory) occur forests
with Acer velutinum, Alnus subcordata, Carpinus
caucasica, Diospyros lotus, Fraxinus excelsior,
Gleditsia caspica, Parrotia persica, Populus
hyrcana, Prunus caspica, Ulmus elliptica,
Zelkova carpinifolia, and rarely Fagus orientalis.
The dense undergrowth is formed by Buxus
hyrcana, Crataegus, Danaë racemosa, Ilex hyrcana,
and Ruscus hyrcanus. Climbers such as
Hedera pastuchovii, Periploca graeca, Smilax
excelsa, and Vitis orientalis are also present
(Röhrig 1991).
It is necessary to stress that various species
of Acer, Betula, Celtis, Fraxinus, Quercus,
Ulmus, and Rhus, as well as Rosaceae,
Fabaceae, and Ericaceae, recorded in the studied
material, could grow in both swamp and
mesophytic plant communities. It is also diffi -
cult to say in which communities conifers grew.
Taxodium pollen grains come from swamp
forests, whereas some pollen grains of Pinus,
Sequoia, Abies, Tsuga, Picea, and Sciadopitys
could originate from long-distance transport,
from such plant communities as coniferous forests
growing on more elevated terrains (Stachurska
et al. 1971, 1973, Oszczypko & Stuchlik
1972, Sadowska 1977, Słodkowska 1994).
Some pollen grains of the above-mentioned
genera of conifers could originate from trees
growing as an admixture in both mixed mesophytic
or wet forests. Forests from the eastern
part of North America, dominated by Pinus
serotina, P. caribaea, P. strobus, Picea rubra,
and Tsuga canadensis are an example of wet