Kelemen Imola (szerk.): A Csíki Székely Múzeum Évkönyve 8. (Csíkszereda, 2012)
Régészet - Tibor-Tamás Daróczi: Environmental Changes During the Holocene in Transylvania
ENVIRONMENTAL CHANGES DURING THE HOLOCENE IN TRANSYLVANIA Until the Boreal, hazel (Corylus gen) increased its values in the pollen diagrams (Fig. 2) and, by the offset of this period, became well established.34 Just before the beginning of the period, oak (Quercus gen), lime (Tilia gen) and Common Ash (Fraxinus excelsior) declined in numbers, and spruce (Picea gen) had a period of new spread in low and mid-altitudes, which coincided with the driest period of the Holocene (Fig. 9).35 By the turn to the Boreal, umbellifer (Apiaceae fam) and sedge (Cyperaceae fam) populations of wetlands increased while Lesser Reedmace (Typha angustifolia) and fern (Polypodiacea fam) were significantly lower in numbers.36 Fig. 3. Forest and climate change for NW Transylvania from Preluca Ţiganului and Steregoiu (after Feurdean 2005a, fig. 5) Just before the Atlantic phase, rare instances of beech (Fagus gen) and hornbeam (Carpinus gen.) are documented, indicating the start of the colonisation of the area by these species. At the start of the period, hazel (Corylus gen) was the dominant species with sporadic occurrences of mixed-oak taxa,37 elm (Ulmus gen) and spruce (Picea gen.).38 In the second part of this phase, hazel (Corylus gen.) and spruce (Picea gen.) were the dominant species while Quercetum mixtum, elm (Ulmus gen.) and maple (Acer gen.) are high in percentages (Fig. 3) in the pollen schemes of the area.39 In the lower-lying wetlands, plants of the shore region, e.g. Lesser Reedmace (Typha angustifolia), still o LPAZ Preluca Ţiganului LPAZ Steregoiu Vegetational development Inferred climate events PI 9 Fagus-Cyperaceae- Quercus S19 Fagus-P o&case- Quercvs Fagus forest; grazing pressure in the forest Wetter Drier and possibly wanner 1 2 3 4 -E ^ 5 -j CL, CQ £ 1 6 ^ "s' I öo < j PI 8 Fagus-Quercus- Carpinus-Cyperaceae SI 8 Fagus-Quercus- Carpinus Dense Fagus dominated forest, where Quercus and Carpinus were common. Forest grazing was introduced in the area at 2300 cal. yr BP. Re-expansion of Quercus. Reduction of wetland taxa. Expansion of Fagus. Reduction of Corylus. Picea. Tilia, and Ulmus. Increase of wetland taxa. S17 Fagus-Poaceae- Carpinus P17 Fagus-Quercus- Carpinus S16 Fagus-Picea-Carpinus PI 6 Fagus-Picea-Carpinus SI5 Corylus-PiceaFagus- Carpinus Hiatus SI 4 Corylus-Picea- Ulmus-Quercus Possibly wetter? P15 Picea-Corylus- Carpinus Dense and highly diverse forest with Picea, Corylus and Ulmus. Establishment and expansion of Carpinus. Establishment of Fagus. Reduction of wetland taxa. Gradually wanner and possibly drier PI 4 Corylus-Picea-Ulmus S13 Corylus-Picea-Ulmus Dense Corylus and Picea dominated forest with Ulmus, Quercus, Tilia and Fraxinus. Expansion of Picea. Distinct Fagus peak at 6500 cal. yr BP. Cooler and wetter Drier OO -J 11 11 11 11 1 1 11 1 1 1 1 1 PI 3 Corylus-Ulmus- Filipendula Dense Corylus and Ulmus dominated forest with Picea, Quercus, Tilia and Fraxinus. Increase of wetland taxa. Lower pollen values for Quercus, Tilia, Fraxinus and slightly higher for Picea. Reduction of wetland taxa. Maximum pollen values for Corylus, along with slight reduction of Quercus and Tilia. S12 Corylus-Picea-Ulmus 9 ~ P12 Corylus-Ulmus Sll Corylus-Ulmus-Picea Warm, but with short 10 -j Pll Ulmus-Corylus- Filipendula-Picea S10 Ulmus-Corylus-Picea Dense Ulmus, Corylus and Picea dominated forest with Quercus, Tilia and Fraxinus. Expansion of Corylus along with reduction of Ulmus cooler and possibly drier episodes around 10,200 and 9300 cal. yr BP P10 Ulmus-Picea S9 Ulmus-Picea-Fraxinus Dense Ulmus and Picea dominated forest. Establishment and expansion of Quercus, Tilia and Fraxinus. Establishment of Corylus. Warmer and gradually drier 11 P9 Ulmus-Picea-Betula S8 Ulmus-Pinus-Betula P8 Pinus-Betula-A rtemisia S7 Pinus-Betula-Alnus------1 Open Betula and Pinus forest. 1— Establishment of Ulmus and Picea. Gradually warmer and weiter 34 Feurdean 2004,28. 35 Feurdean 2004, 37. 36 Feurdean, Bennike 2004, 815, 820; Feurdean et al. 2007a, 373. 37 Also known as Quercetum mixtum, consisting of oak (Quercus gen), lime (Tilia gen) and ash (Fraxinus gen). 38 Björkman et AL. 2003, 101; Feurdean 2005a, 437, 443. 39 Feurdean 2005a, 438. 33
