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A transition from widespread humid to more drought tolerant floras characterized tropical terrestrial ecosystems during the Permian (Cisuralian). Tregiovo (Southern Alps, N-Italy) is one of the very few well dated Kungurian (late Cisuralian) plant localities in Euramerica. It was located in eastern palaeoequatorial Pangea. Two units bearing fossil plant assemblages occur in finely laminated sediments deposited in a playa-lake environment. In this paper, the sedimentology of the Tregiovo Basin is reviewed, and new palaeobotanical, palynological and stable isotopic data are presented, in order to reconstruct the palaeoclimatic and palaeoenvironmental conditions of the Kungurian in the Southern Alps. Both fossil plant assemblages are dominated by conifers ( Hermitia , Feysia , Quadrocladus , Dolomitia ), together with sphenophytes ( Annularia ), ginkgophytes ( Sphenobaiera ), pteridosperms ( Peltaspermum ), taeniopterids and sphenopterids. These taxa, which occur with different abundances in the two plant assemblages, both indicate semi-arid conditions. Associated palynoflora, dominated by bisaccate pollen, and extremely rare spore occurrences, is consistent with the xerophytic character of the macroflora, and suggests that the fossil plant record was not affected by collection or preservation bias. Stable isotopic analyses of two stratigraphic sections reveal an upward trend of increasingly negative δ 13 C org (VPDB), which may correlate with roughly coeval records from marine and continental successions such as in North China and South Africa. This isotopic shift may be attributed to a global perturbation of atmospheric δ 13 C, although the influence of local environmental factors cannot be excluded. [ABSTRACT FROM AUTHOR]

Abstract: This paper investigates changes in the vegetation and hydrology at Ljubljansko barje (Slovenia) using a multi-proxy approach (pollen, diatoms, geochemical and stable isotope analysis). During the Lateglacial Ljubljansko barje was a deep, oligotrophic lake surrounded by open woodland comprised predominantly of Pinus and Betula which in the early Holocene, when the lake became shallower and mesotrophic (Fragilaria pinnata, δ 15N~3.3‰, δ 13C~−33.7‰, C/N~7.9), was replaced by broadleaved tree taxa (Tilia, Ulmus, Quercus, Corylus) and Picea. This was followed by the spread of Fagus and after ~9200 cal yr BP Abies and planktonic and oligotrophic diatom taxa (Aulacoseira italica, Gomphonema angustum) as well as an increased allochthonous influx (silt, SiO2, Al2O3). Between ca. 6750 and 6000 cal yr BP the diatom data suggest shallower and oligotrophic conditions, whereas the stable isotope record (increased δ 13C and decreased δ 15N) indicates terrestrial input. Changes in forest composition (increase of Quercus, Alnus, Corylus) and the spread of herb taxa were probably advanced by human impact on the environment. The beginning of organic sedimentation, dated to 6000 cal yr BP, was followed by an increase of Fagus and Abies and by eutrophication and peat growth at ~5200 cal yr BP. [Copyright &y& Elsevier]