Maharski prekop, Stare gmajne and Blatna Brezovica settlements and the vegetation of Ljubljansko barje (Slovenia) in the 4th millennium cal BC

ABSTRACT – In the 4th millennium cal BC the hinterlands of Ljubljansko barje basin were covered by beech-fir (Abies-Fagus) and mixed oak (Quercus) forests. People of several Eneolithic cultural groups were cutting/burning forests to open the landscape for fields and pastures. This paper focuses on high-resolution palynological analyses of pile-dwelling settlements Maharski prekop, Stare gmajne and Blatna Brezovica to investigate human impact on the vegetation, and to compare past economy and vegetation history in various parts of Ljubljansko barje. The results revealed that there were no major changes of vegetation throughout the 4th millennium cal. BC, neither were there any major differences between vegetation of the selected study sites. Cultural layers from archaeological sites (in larger quantities than off-site cores) contain pollen of plants that were brought to the settlement by people: cereals and other cultivars (Cereal t., Linum), weeds (Centaurea), grazing indicators (Plantago lanceolata, Campanula, Ranunculaceae), ruderal taxa (Chenopodiaceae, Artemisia), (gathered) shrubs (Corylus) and herbs. Traces of anthropogenic impacts from older settlements were detected in sediments below archaeological cultural layers at all study sites. IZVLE∞EK – V 4. tiso≠letju pr. n. ∏t. so na ∏ir∏em obmo≠ju Ljubljanskega barja uspevali prete∫no bukovo-jelovi in hrastovi gozdovi. Ljudje razli≠nih arheolo∏kih kulturnih skupin so te gozdove ob≠asno izsekavali, da so si odprli povr∏ine za potrebe poljedelstva in pa∏e. Raziskava, ki jo predstavljamo v tem ≠lanku, se je usmerila na prou≠evanje palinolo∏kega zapisa na eneolitskih koli∏≠ih Maharski prekop, Stare gmajne in Blatna Brezovica, da bi prou≠ili ≠lovekov vpliv na rastlinstvo in primerjali razvoj vegetacije in nekdanje gospodarstvo na razli≠nih delih Ljubljanskega barja. Rezultati visokoresolucijskih palinolo∏kih raziskav so pokazali, da v 4. tiso≠letju pr. n. ∏t. ni pri∏lo do ve≠jih sprememb vegetacije, prav tako pa nismo zaznali razlik med vegetacijo v okolici posameznih koli∏≠, ki le∫ijo na razli≠nih delih Ljubljanskega barja. Kulturne plasti z arheolo∏kih najdi∏≠ (v ve≠ji meri kot so≠asne plasti v vrtinah izven najdi∏≠) vsebujejo pelod rastlin, ki so jih v naselje prinesli ljudje: ∫ita (Cereal t.) in druge kultivirane rastline (npr. Linum), pleveli (Centaurea), pa∏ni indikatorji (Plantago lanceolata, Campanula, Ranunculaceae), ruderalni taksoni (Chenopodiaceae, Artemisia), nekateri grmi (Corylus) in zeli. Na vseh najdi∏≠ih smo v plasteh pod arheolo∏ko kulturno plastjo odkrili tudi sledove ≠lovekovega vpliva na vegetacijo v ≠asu (domnevnih) starej∏ih naselbin v okolici.


Introduction
Palaeoecological research at Ljubljansko barje has a very long tradition. After the first archaeological, archaeobotanical and palynological research in the 19 th and 20 th centuries (Deschmann 1875;see πercelj 1996.9), palynological research in the 1960s focused on studies of Late Glacial and Holocene vegetation history, economy, and the impact of local Neolithic/Eneolithic populations on the environment. The results of research to date suggest that in the 4 th millennium cal BC the landscape at Ljubljansko barje and its surroundings was forested with predominantly beech-fir and oak forests. The impact of Neolithic/Eneolithic farmers on the vegetation was pronounced: the inhabitants of Ljubljansko barje were cutting forest to open the landscape for agricultural fields and pastures (e.g., πercelj 1966;Culiberg, πercelj 1978;πercelj 1996 andreferences cited there, Jeraj 2002;Jeraj et al. 2009;Andri≠ et al. 2008;Tolar et al. 2011). Furthermore, forest cutting and grazing presumably also led to more subtle changes in vegetation composition. For example, it was suggested that due to small-scale forest clearances and thinning of canopy, forest composition shifted from beech-fir forest towards more open vegetation with more shade-intolerant taxa, such as hazel, oak and hornbeam (πercelj 1988;1996;Gardner 1999). However, despite widespread archaeological and palynological research, many archaeological study sites excavated before the 1990s lacked high resolution palynological sampling and good chronological control.
With the beginning of dendrochronological research in the 1990s, the chronology of archaeological sites improved significantly, suggesting that individual sites were settled only for short time periods, often a few decades (∞ufar et al. 2010 and references cited there). Therefore, together with archaeological re-excavations and new excavations, the need arose to take samples for high-resolution, pollen analysis with chronological control, comparable to the work done at newly dated archaeological sites. In this paper the palynological record of four sedimentary columns

Fig. 1. Ljubljansko barje study area with the archaeological and palaeoecological study sites mentioned in the text. Black dots indicate archaeological sites with palynological results presented in this paper.
The percentage of organic material, carbonates and the remaining inorganic material in the sediment was determined by loss-on-ignition analysis at 550°C and 950°C (Bengtsson, Ennell 1986). The sediment description (Tab. 1) follows Jørgen Troels-Smith (1955).

Tab. 1. Troels-Smith (1955) description of the sediment: Maharski prekop (western cross-section of trench 2), Stare gmajne 2006 (southern cross-section of trench 2), Stare gmajne 2007 (southern cross-section of trench 3) and Blatna Brezovica 2003 (southwestern cross-section of trench 2).
grains of terrestrial taxa and spores (= pollen sum) were counted in each sample, with the exception of silty and sandy layers with very low pollen concentrations at some study sites (e.g., at Blatna Brezovica), where the pollen sum was lower. The concentration of microscopic charcoal was established using two methods: microscopic charcoal (in two size classes, <40μm and >40μm) was counted along with pollen and, in addition to this, Clark's (1982) point count method was used. The pollen and 'loss-on-ignition' data were analysed and plotted using PSIM-POLL 3.00 software (Bennett 1998;PSIMPOLL website). All pollen diagrams were divided into statistically significant zones using binary splitting by sum of squares. Values lower than 0.5 are marked with a solid dot. The archaeological cultural layer is marked by a shaded bar.

Results
The results of sediment description and radiocarbon dating are presented in Tables 1 and 2, the

Radiocarbon dating and age-depth modelling
The results of radiocarbon dating (Tab. 2) are in accordance with the results of previous, dendrochronological research (∞ufar et al. 2010), indicating chronological age of the cultural layer at each archaeological site (∞ufar et al. 2010).
At Maharski prekop sample Beta-229153 (80cm) was omitted from the age-depth model due to age reversal and incompatibility with dendrochronological dating (∞ufar et al. 2010 (Stockmarr 1971). Pollen was identified using a Nikon Eclipse E400 light microscope at 400x magnification, reference collection at the Institute of Archaeology ZRC SAZU and pollen keys (Reille 1992;1995;Moore et al. 1991 (Melik 1927), and possibly also by Late Bronze Age flood erosion at c. 1700 cal BC (Andri≠ et al. in preparation).

Maharski prekop
The pollen column which was collected in 2005 from the western profile of archaeological trench 2 (for archaeological excavations see Velu∏≠ek, ∞ufar 2008) is 160cm long. The archaeological cultural layer is located at c. 86-48cm.
Sediment at the bottom of the profile (160-114cm) is calcareous silty clay (Tab. 1), with a very low percentage of organic material (c. 5-15%) and 25-40% of carbonates, whereas the percentage of remaining inorganic material without carbonates is more than 50% of sediment dry weight ( Fig. 2). At 114-62cm the amount of organic material increases to c. 10-31% (highest in the archaeological cultural layer at 80-68cm), whereas carbonates decrease to 1-22% of sediment dry weight. The percentage of carbonates also remains low at the top of the profile (62-0cm), whereas the amount of organic material decreases and the remaining inorganic material increases, especially at 62-32cm.
The main characteristic of the pollen zone M-3 (62-0cm, after c. 3500 cal BC) is the change in forest composition: Picea and Pinus increase to 4-28% and 2-12% respectively, whereas Abies, Fagus, Quercus, and Corylus decline. The tree pollen sum declines and there is an increase in herbs (Cyperaceae, Poaceae, Cichoriaceae) and monolete fern spores (Filicales). The percentage of degraded pollen grains increases to c. 2-10%.

Stare gmajne 2006
The pollen column which was collected in 2006 from the southern cross-section of archaeological trench 2 (for archaeological excavations see Velu∏≠ek 2009a) is 130cm long. The archaeological cultural layer is located at c. 90-43cm.
The sedimentary composition of the column is very heterogenous (Tab. 1 and Fig. 5). Sediment at 130-116cm is mineral with 14-21% of carbonates, 11-23% of organic material and 63-71% of remaining inorganic material. Further up the profile (116-108cm) the amount of organic material drops to 3-4%, whereas the remaining inorganic material increases. A major change in sediment composition occurs when the percentage of carbonates (106cm) and inorganic material (102cm) declines; the organic material increases to 23-90% of sediment dry weight. At 90-43cm the percentage of carbonates remains low (1-5%), whereas the percentage of organic material (14-59%) and the remaining inorganic matter (37-84%) fluctuates. Above 43cm the percentage of inorganic material is high (74-91%), the amount of organic material is similar to that seen at the bottom of the profile, but with a lower percentage of carbonates.
The pollen composition in zone S-3 (58-43cm; c. 3100-2500 cal BC) is similar to that in S-2, but towards the top of the zone, immediately above the archaeological cultural layer, Pinus and Picea increase to c. 2-13%. The percentage of degraded pollen is higher than in previous zones, with a very low pollen concentration (c. 300-650 grains/1cm 3 ) and highest percentage of degraded pollen grains (27%) at the transition between zones S-3 and S-4.
The percentage of tree taxa stays low in the pollen zone S-4 (43-0cm, after c. 2500 cal BC). The concentration of microscopic charcoal decreases, whereas Alnus, Filicales, Trilete spores and Cichoriaceae increase.

Stare gmajne 2007
The pollen column which was collected in 2007 from the southern cross-section of archaeological trench 3 (for archaeological excavations see Velu∏-≠ek 2009a) is 130cm long. The archaeological cultural layers are located at c. 95-85cm (older phase) and c. 85-70cm (younger phase).
The sediment below the archaeological cultural layers (130-95cm) is calcareous silty clay (Tab. 1), with a very low percentage of organic material (c. 9-17%) and 10-21% of carbonates, whereas the percentage of remaining inorganic material is 69-72% of sedi- ment dry weight (130-95cm, Fig. 7). Further up the profile the percentage of organic material in the archaeological cultural layers increases to 19-33%, whereas carbonates decline to c. 1-4%. At 70-38cm the percentage of organic material decreases again to c. 10% and inorganic material increases to c. 85%. At the top of the profile (38-0cm) there is 15-27% of organic material, the percentage of carbonates remains low (2-4%), and the remaining inorganic material is between 68 and 82%.

Blatna Brezovica
The pollen column which was collected in 2003 from the southwestern cross-section of archaeological trench 2 (for archaeological excavations see Ve-lu∏≠ek 2009c) is 130cm long. The archaeological cultural layer is located at c. 77-57cm depth.
Silty clay at 128cm contains only 7% of organic material, 25% of carbonates and 68% of remaining inorganic material. Up the profile the percentage of carbonates gradually decreases to c. 2-5%, whereas the organic material at 56cm increases to 30%. The main characteristic of sediment between 54 and 34cm is the higher percentage of organic material (28-32%) with wood remains, whereas the percentage of inorganic material decreases to 62-70%. Sediment above 34cm is similar, but with less organic material (25-30%).

Taphonomy and palaeohydrological conditions before, during and after archaeological settlement
The sediment composition was affected by palaeohydrological conditions and human activities. In the first half of the 4 th millennium cal BC, before the establishment of archaeological settlements, the percentage of carbonates is higher at all study sites (15-  (Turk, Horvat 2009) demonstrated that sediment below the archaeological cultural layer contains ostracode valves and oogonia of Characeae, diatoms and fine grain carbonate aggregates (with 60-80% of carbonates in <0.2mm fraction), which presumably deposited in a shallow lake to marshy environment. At the current state of research it is difficult to estimate whether all carbonates in pollen profiles were authigenic, or some were also brought to the basin by river transport.
In the archaeological cultural layers of all study sites the proportion of mineral grains increased, whereas the proportion of carbonates is low, suggesting a marsh environment (Turk, Horvat 2009). Similarly, the results of archaeobotanical research at Maharski prekop indicate that the settlement was presumably located near water, probably lakeshore and/or wetland, which were occasionally flooded (Tolar 2018). Pollen of water plants is, in small quantities, present at all study sites and throughout all sequences (Figs. 3, 6, 8 and 9), but does not show any patterns (e.g., hydroseral succession). On-site taphonomic processes were also affected by people. Both loss-onignition (this study; Figs. 2, 5, 7 and 9) and sedimentological research (Turk, Horvat 2009) have shown an increased percentage of organic matter. A faster sedimentation rate and consequently lower pollen concentration at some sites were also detected as a result of human activity, and possibly also changed hydrological conditions (lower CaCO3 precipitation).
The sediment above archaeological cultural layers contains mostly organic material (this study; Figs. 2, 5, 7 and 9), quartz grains and an increasing percentage of clay towards the top of the profile which deposited on the floodplain (Turk, Horvat 2009). The percentage of degraded pollen increases in the top part (= above c. 60-50cm) of all analysed profiles (Figs. 3, 6, 8 and 9) because of drier conditions due to (present-day) draining activities, farming, and dry and warm summers, which endanger the preservation of the palaeoecological and archaeological record in the area.

Flood events and local vs. regional variability
Several layers containing more quartz (Turk, Horvat 2009) and remaining inorganic material, lower pollen concentration and more degraded pollen (this study; Figs. 2-10, layers marked with arrows) were discovered at all study sites. It is assumed that they formed during flood events, however the subsequent results are only preliminary and further, more detailed geological research (sedimentological, mineralogical and geochemical analysis) is needed to address this topic in more depth.
No clear regional pattern with distinct, synchronous flood events was reconstructed. Due to unprecise chronology (no annually laminated sediment) it is difficult to pinpoint individual flood events. Traces of flooding in the first half of the 4 th millennium cal BC (c. 3750-3450 cal BC and 3200-3100 cal BC) are more apparent and better dated on some (e.g., Stare gmajne 2006) than other study sites. They can be correlated with the 3700-3250 cal BC phase of higher lake levels (Magny 2004; with tripartite flooding in the Alps at c. 3650-3370 cal BC, Magny et al. 2006) and CE cold phase 5 (c. 4200-3650 cal BC, Haas et al. 1998). The 3200-3100 cal BC flooding event partly coincides with the 3332-3160 cal BC 'dendrochronological occupational hiatus' when no archaeological sites were discovered at Ljubljansko barje (∞ufar et al. 2010). The only flooding event that clearly appears on all study sites is located above archaeological cultural layers and coincides with an increase of Picea, Pinus and Abies and decline of other tree taxa (e.g., Fagus, Quercus). A cold (wet) climate favours the spread of needle-leaved taxa (Ellenberg 1988), whereas an increase of Pinus can also be associated with forest regrowth after the abandonment of the settlements and/or metallurgical activities at the beginning of 3 rd millennium cal BC (Velu∏≠ek 2004b).
The visibility and extent of (short-term, annual/decadal?) floods was presumably affected by the (local) topography, hydrological network and other factors. Even in sedimentary profiles, located just few hundred metres apart, differences in sediment composition can be significant, illustrating how local variability vs. regional events shaped the landscape.  Fig. 5) the sediment composition changes more.
Here a high concentration of organic material was found immediately below the archaeological cultural layer (Fig. 5, 100-92cm), suggesting that before archaeological settlement the hydrological conditions probably became drier (but still waterlogged), with a slower sedimentation rate and thus slightly higher pollen concentration (Fig. 6). The sediment in a very thin layer at 96cm contained so much organic material (unidentified plant material, Fig. 11) that the pollen concentration was too low to yield pollen results. The sediment immediately below and above this layer contained an increased percentage of monolete fern spores, especially Thelypteris palustris (the marsh fern growing in sunny wetland areas, e.g., at the edges of marshes and bogs), which presumably started to grow in situ after the hydrological conditions became drier. Alnus tree stumps were also found below the archaeological cultural layer (Velu∏≠ek 2009b). A rapid transition between a lake-marsh and organic, humous layer was detected also by sedimentological research (Turk, Horvat 2009) in drainage ditch 6 (profile SG6), located c. 100m west of the palynological sequence. This rapid transition is in contrast with the gradual lake-marsh to humous sediment transition found in the western part of the settlement (profile SG12, Turk, Horvat 2009). In contrast to Janez Turk and Aleksander Horvat (2009), who suggested that the lack of a gradual transition in profile SG6 was either because the sediment was decomposed or did not form at all (due to sedimentological or erosional gaps), palynological research, presented in this paper (at least in archaeological trench 2) indicates that there seems to be no hiatus at the transition between the lake-marsh sediment and organic layer at c. 102cm (Fig. 5), neither were there any traces of intensive peat degradation (e.g., corroded or degraded pollen; Fig. 6). To summarize, it appears that the eastern part of Stare gmajne (2006) settlement was located in a topographically slightly different environment to the other study sites, possibly in the vicinity of a tributary to the Bistra river feeding the lake, which probably affected the sedimentological processes.

Vegetation history and human impact on the environment of Ljubljansko barje
In this chapter the vegetation composition and sedimentological characteristics at each individual study site, before, during and after archaeological settlement, will be analysed in order to better understand the short-term environmental changes and human impact, and to compare study sites located in different parts of Ljubljansko barje.

Maharski prekop
At c. 5000-4100 cal BC the landscape around Maharski prekop was predominantly forested. The main tree taxa were Fagus and Quercus (Fig. 3), which is comparable with previous research at a study site (πercelj 1975) and on the pollen record of a 'Na mahu' core (Andri≠ et al. 2008;Andri≠ 2009), which is located c. 1km north of Maharski prekop (Fig. 1).
Alnus pollen, together with Cyperaceae, Pediastrum algae and a relatively high percentage of carbonates (Fig. 2), suggests freshwater (lake-wetland) hydrological conditions. The landscape around Maharski prekop was not completely forested. Anthropogenic indicator taxa of cereals and weeds (e.g., Cereal type pollen, Secale, Chenopodiaceae, Artemisia) occur as early as c. 5000 cal BC, with a peak at c. 4400 cal BC. They can be associated with the farming activities of people living at the Resnikov prekop site (located c. 1.5km southeast of the study site, Fig. 1), which is dated to c. 4500 cal BC (Velu∏≠ek 2006;∞ufar, Koren≠i≠ 2006). Unfortunately, these activities were not studied in detail in situ since part of the sedimentary sequence at the Resnikov prekop settlement (including pollen and plant macrofossils) was removed by water (Andri≠ 2006;Culiberg 2006).
After c. 4100 cal BC the forest composition at Maharski prekop changed: the percentage of Abies and Fagus pollen increased, whereas Poaceae and Cyperaceae declined. A similar change was detected also in the 'Na mahu' core, where an increase of Fagus (and later Abies) after c. 4000 cal BC was associated with a wetter climate (Andri≠ et al. 2008). Abies and Fagus thrive well in a humid climate and are susceptible to human impact (Ellenberg 1988). Abies in particular, which needs plenty of rain, is sensitive to fire and grazing (Tinner et al. 1999). Therefore, this change of regional forest composition at the beginning of the 4 th millennium cal BC (which was less clearly seen in other regions of Slovenia, e.g., Bela krajina, Andri≠ 2007), can be associated with a globally colder and wetter climate (e.g., Mayewski et al. 2004;Magny 2004;Denton, Karlén 1973;Seppä, Birks 2001;O'Brien et al. 1995).
Despite generally more forested landscape, people were still cutting/burning smaller surfaces of forest for fields (cereal peak at c. 3900 cal BC) and grazing (Plantago lanceolata pollen). To date no archaeological sites unambiguously dated to 3900 cal BC have been discovered at Ljubljansko barje, with the exception of ∞rnelnik, and possibly Gornje mosti∏≠e (Velu∏≠ek et al. 2018). On the basis of archaeological typology (pottery with stab-and-drag incisions) and dendrochronological research, Maharski prekop settlement was dated to c. 3500-3400 cal BC (3489± 10 cal BC, Velu∏≠ek, ∞ufar 2008;∞ufar et al. 2015; press, see also paragraph below), which is c. 400 years younger than the traces of weak human impact detected on the pollen diagram. Additionally, a new series of radiocarbon dates for samples of animal bones, wood, charcoal and food residue on pottery from Maharski prekop were obtained by researchers of the University of Ljubljana (Mleku∫ et al. 2012.Tab. 1). At least 14 of these new dates (mostly carbonized food/organic residues on pottery) and two wooden piles fall into the period between 4400 and 4000 cal BC, which is significantly older than dendrochronological dating. On the basis of this data a much longer settling period of Maharski prekop was suggested, with intensive occupation between 4400 and 3550 cal BC and two peaks (4400-4000 and 3800-3550 cal BC) (Mleku∫ et al. 2012).
Archaeobotanical research also indicates early farming activities, dated at the transition between the 5 th and 4 th millennium cal BC. At the Strojanova vode site, located c.  est date, oldest c. 3700 cal BC, ∞ufar et al. 2015;Tolar 2018). Both palynological and archaeobotanical research therefore suggest early farming activities in a wider Maharski prekop region. People were present in the landscape, but at the current state of research it is not possible to suggest the exact location of this older settlement (there is no dendrochronological data or Lasinja pottery dated to 4350-3900 cal BC to support this assumption about older settlement, Ve-lu∏≠ek pers. comm.). The main reasons for the current state of research are very complex palaeohydrological conditions and taphonomic processes in this part of Ljubljansko barje. The LIDAR record shows traces of past fluvial activity (Budja, Mleku∫ 2008;2010;Mleku∫ et al. 2012). At Resnikov prekop part of the sequence was removed by water (Andri≠ 2006), and thus water erosion and displacement of artefacts and sediment (including plant micro and macroremains) is possible. The archaeological and palaeoecological record were shaped by taphonomic processes, and further research is needed in the area.
The base of the archaeological cultural layer in the pollen profile at Maharski prekop is not reliably dated. Due to age reversal, the 14 C date of unidentified plant material at 80cm (Tab. 2, Beta-229153) was omitted from the age model (Fig. 3). It is possible that roots of younger plants growing on the site after the abandonment of the settlement were dated, or sediment was redeposited by water. On the other hand, horizontal mobility of animal finds at Maharski prekop seems to be limited and bones were not affected by water erosion (To∏kan et al., in press). A cultural layer, dendrochronologically dated to c. 3500 cal BC, is clearly seen in the pollen diagram (Fig. 3): there is a decline in tree pollen (Fagus, later also Abies and Quercus) and increase in cereals, weeds (e.g., Centaurea, Chenopodiaceae), other herbs (e.g., Poaceae, Lamiaceae, Apiaceae, Filipendula) and microscopic charcoal concentration. The taxonomic precision of archaeobotanical research is better than for pollen, and macroremains of the following culti-vated plants were discovered in the cultural layer: Hordeum vulgare, Triticum monococcum, Triticum dicoccum (in the pollen record shown as Cereal type), Brassica rapa (Cruciferae pollen) and Pisum sp. (Fabaceae pollen) (Tolar 2018 (Haas et al. 1998) and/or forest regrowth after the abandonment of the settlement.

Stare gmajne 2006
At c. 4100 cal BC the landscape around Stare gmajne was (similar to at Maharski prekop) surrounded by beech-fir and mixed oak forests. Traces of human presence in the landscape are already visible in the pollen record (Cereal t., Secale, Artemisia), although to date no archaeological sites dated to c. 4100 cal BC have been discovered in the western part of Ljubljansko barje. A low presence of Cereal t. and other
Human impact on the environment in the vicinity of the Stare gmajne site increased again at c. 3500-3400 cal BC, when small-scale forest clearance occurred (decline of Abies, Fagus, Alnus, Tilia), with an increase in herb pollen (Cereal t., Chenopodiaceae, Ranunculaceae) indicating farming activities, which can be associated with the Ho≠evarica archaeological site (Velu∏≠ek 2004a;end date: 3547±10 cal BC, ∞ufar et al. 2010). Archaeobotanical and palynological research at Ho≠evarica (Jeraj 2004) suggest significant human impact on the surrounding landscape, especially in the reduction of nearby forest and usage of cleared land for farming. Pile-dwellers from Ho≠evarica were cultivating barley and wheat (Jeraj 2002;Jeraj et al. 2009) and kept domesticated animals (pigs, sheep, goat and cattle, To∏kan, Dirjec 2004), which is also visible in the pollen record of Stare gmajne.

Stare gmajne 2007
Archaeological trench 3 was excavated just c. 270m west of trench 2 (see Fig. 4), therefore both pollen diagrams from Stare gmajne (Figs. 6 and 8) are very similar, which is not unusual considering that they were (partly) surrounded by the same vegetation.
The main difference between study sites is that in the western part of Stare gmajne an older cultural layer (3332±10 cal BC) was also discovered in addition to the younger one (3109±10 cal BC, Velu∏≠ek 2009a). Both cultural layers are visible on the pollen diagram (Fig. 8), but human impact in the time of the older phase is more pronounced, which is in accordance with the results of archaeobotanical (Tolar et al. 2011) (Tolar et al. 2011). In the younger cultural layer at about 3100 cal BC, human impact is less pronounced and pollen of some tree taxa (Fagus, Tilia, Quercus) increases again.

Blatna Brezovica
A complete pollen diagram is presented in this chapter while in a previous paper (Golyeva, Andri≠ 2013) only selected data were published. Prior to archaeological settlement, which is dated to c. 3071±14 cal BC (∞ufar et al. 2010), forest of Fagus, Abies and Quercus grew in the area. The first traces of human impact on the environment (forest clearance and anthropogenic indicator taxa at c. 112-80cm) could be connected with the activities of people living in older archaeological settlements at Ho≠evarica (c. 3650-3550 cal BC) and Stare gmajne (c. 3300 and 3100 cal BC), located just across the Ljubljanica river.
During the archaeological settlement the landscape became more open due to forest clearance of Fagus and Quercus, with the latter needed for building material (Koro∏ec 1963;πercelj 1981-82;∞ufar et al. 2010). Similar to at other study sites, an increased percentage of Corylus and herbs (e.g., Cereal t., Chenopodiaceae, Poaceae) was found in the archaeological cultural layer. People living at Blatna Brezovica were cultivating barley (Golyeva, Andri≠ 2014), and possibly also other cereals. The results of phytolith analysis also suggested that Poaceae pollen from the cultural layer could (partly) belong to Phragmites. Phytoliths of young Phragmites plants that were found in the archaeological cultural layer suggest that they were probably used for roofing or other purposes, e.g., bedding, walls (Golyeva, Andri≠ 2014), or boats (Karg, Weber 2019).
After the settlement was abandoned, Abies spread, but the landscape remained relatively open. Pollen of Cyperaceae and Equisetum suggests marsh hydrological conditions.

Comparison of study sites: vegetation history and human impact on the environment
In the 4 th millennium cal BC the vegetation growing around the study sites, which were located in different parts of Ljubljansko barje (Fig. 1), was very si- milar. No major dissimilarities in forest composition were detected, and the main difference between archaeological sites is associated with the fact that each was inhabited in slightly different time periods, which affected the stratigraphic position and thickness of archaeological cultural layers. Pollen of 'anthropogenic indicator taxa' (sensu Behre 1981) such as cultivated plants, weeds and grazing indicators, as well as microscopic charcoal, was found in the cultural layers of all study sites, whereas tree pollen is present in lower percentages.
The cultural layers of all study sites contain pollen of cultivars: c. 0.5-10% of Cereal type pollen, 0-0.5% of Secale, whereas only one Linum pollen grain (flax is self-pollinated and produces only a little pollen) was found in the cultural layer of Stare gmajne (2007). To date no Secale plant macrofossils have been discovered at Ljubljansko barje (Tolar et al. 2011;Tolar 2018), and it is assumed that in prehistory it was a weed growing on cereal fields (Marinova 2006;Maier, Schlichterle 2011). Fabaceae pollen and plant macrofossils (Pisum sativum; Tolar et al. 2011) are also rarely found at Stare gmajne. Fabaceae are insect-pollinated and do not produce much pollen, whereas seeds are rarely preserved due to taphonomic reasons (Jacomet 2009). Ruderal plants and weeds (Chenopodiaceae, Artemisia and Centaurea) probably came to the settlements together with crops, although they were possibly also growing in the settlement, along footpaths and riverbanks. Chenopodiaceae pollen in particular is abundant at Stare gmajne 2006 (up to 40%) and Blatna Brezovica (up to 10%), whereas seeds of Chenopodium album were found in large quantities and it is assumed that they could have been gathered as well (Tolar et al. 2011). In contrast to this, Vitis pollen is not very abundant, although numerous grape pips were discovered (Tolar et al. 2008).
The increased percentage of Corylus and Hedera pollen in archaeological cultural layers can be a consequence of more open landscape and therefore more widespread flowering of these two taxa, or plants were brought to the settlement by people as winter/spring fodder for domestic animals. Hazelnuts were found in considerable numbers at Stare gmajne (Tolar et al. 2011) and Ho≠evarica (Jeraj 2004), whereas to date no Hedera macroremains have been found. Hedera pollen was also found at Italian (Palù di Livenza, Pini 2004) and Swiss pile-dwelling sites, where it is assumed that the plant was used for animal fodder (Arbon Bleiche 3, Brombacher, Hadorn 2004;Kühm, Hadorn 2004).
Pollen of plants characteristic of meadows and pastures was also discovered. The increased percentage of Poaceae pollen in cultural layers can be a consequence of forest clearance and thus more open landscape with grasslands, although not many grassland plant macrofossils were discovered at Stare gmajne (Tolar et al. 2011). Combined pollen-phytolith research at Blatna Brezovica (Golyeva, Andri≠ 2014) suggested that Poaceae pollen grains can also belong to (young) Phragmites plants, which were brought to the settlement by people. Pollen of Apiaceae, Lamiaceae, Plantago lanceolata, Ranunculus, Caryophyllaceae, Campanula, Cichoriaceae, Asteraceae and Filipendula is often present in the cultural layers of all studied sites, but due to palynological taphonomic imprecision it is difficult to identify them at the species level, which would help us to reconstruct environmental conditions. Possibly some of these plants (e.g., Mentha sp. and Thymus sp. which belong to Lamiaceae family) were gathered for uses as spices or for medicinal purposes (Tolar et al. 2011). Plantago lanceolata is a meadow and footpath plant, and a characteristic grazing indicator associated with the impact of domesticated animals (sheep, goat and cattle; To∏kan, Dirjec 2004).
The above review and comparison of pollen with macrofossil and phytolith plant remains indicates that some (cultivated) plants are more visible/abundant than the others. The visibility of plants varies due to: (a) the amount of pollen produced (insect vs. wind pollinated taxa), (b) the distance between fields and the settlement, (c) taphonomic processes on site (e.g. plants brought to the site by people), and (d) the taxonomic precision with which pollen can be identified.
Differences between the pollen record of (off-site) palynological cores and (on-site) archaeological profiles are associated with taphonomy. Pollen that deposited at off-site palaeoecological sites was predominantly transported by wind and water, whereas at archaeological sites it was also brought to the settlement by people. Pollen samples, collected at archaeological sites, therefore contain more anthropogenic indicator taxa (e.g., Cereal type pollen) than palynological cores. The 'Na mahu' palynological core, for example, contains only up to c. 0.5% of Cereal type pollen and c. 0.5% of Chenopodiaceae (Andri≠ et al. 2008), whereas in the cultural layers of archaeological sites this percentage is much higher (0.5-10% and 2-40% respectively; Figs. 3, 6, 8 and 10). Cereals Triticum, Hordeum and Linum (with the exception of Secale, which is allogamous) produce only a little pollen which stays in chaff and is released only during harvesting and threshing (Vuorela 1973), therefore the majority of Cereal t. pollen grains arrived at the settlements together with plants. At all study sites, Cereal t. pollen, which was also found below the archaeological cultural layers, can be associated with older archaeological sites in the vicinity. The percentages of Cereal t. pollen in these layers are usually lower than in the archaeological cultural layer, but often bigger than in off-site cores, probably due to the vicinity of economic activity areas and/or fields of near-by settlements.
The environmental conditions and human impact on the vegetation of Ljubljansko barje can be compared with contemporary study sites in the Swiss Alps, e.g., Arbon Bleiche 3 (Bodensee, 3384-3370 cal BC; Jacomet et al. 2004). The Arbon Bleiche 3 pollen record suggests a wooded landscape (Fagus, Quercus, Abies) with traces of forest clearances and more open landscape in the vicinity of the archaeological sites. Although Abies pollen at Arbon Bleiche is not as abundant as at Ljubljansko barje (c. 5% in both regions), its wood was more often used as a building material. Cereal t. and Linum pollen was found in the archaeological cultural layers of both regions, whereas Chenopodiaceae pollen (< 5%) and seeds (rarely found) at Arbon Bleiche are less abundant than at Ljubljansko barje (Brombacher, Hadorn 2004;Haas, Magny 2004;Jacomet et al. 2004). In both study regions pollen of Corylus and Hedera was found in archaeological cultural layers. At Arbon Bleiche 3 pollen of winter flowering plants (including Corylus and Hedera) was also found in ruminant coprolites, and it was suggested that they derive from leafy hay that was used for winter fodder (Brombacher, Hadorn 2004;Kühm, Hadorn 2004).

Conclusions
A comparison of pollen diagrams from four archaeological settlements (Maharski prekop, Stare gmajne (both settlements) and Blatna Brezovica) confirmed that in the second half of the 4 th millennium cal BC all study sites were surrounded by predominantly wooded landscape. Hilly, hydrologically drier areas further away from the settlements were presumably covered by Fagus-Abies forests, which were in the 4 th millennium cal BC more widespread than in the 5 th millennium BC (presumably due to climatic reasons; Andri≠ et al. 2008). Mixed Quercus woodland, shaped by anthropogenic activities and hydrological conditions, was probably growing closer to the settlements. No major differences between the vegetation of different parts of Ljubljansko barje were detected, and there seems to be no major change in vegetation composition throughout the 4 th millennium cal BC.
Due to human impact (agriculture, grazing, metallurgy), smaller surfaces covered by forest were cut, and the vegetation became more open. Although late-successional, shade-tolerant plants like Fagus and Abies are most susceptible to human impact, the decline of Quercus (and to lesser extent Fraxinus), which was cut for building material (piles), was also detected.
The pollen record was shaped by taphonomic processes, specific to the archaeological sites and associated with economic activities. The sediment of the cultural layers contains more pollen of plants that were brought to the settlement by people: pollen of crops (e.g., cereals), weeds (Centaurea), grazing indicators (Plantago lanceolata, Campanula, Ranunculaceae), ruderal taxa (Chenopodieceae, Artemisia), gathered shrubs/nuts (Corylus) and herbs.
In the 4 th millennium cal BC people living at Ljubljansko barje were also affected by floods, which were significant part of their lives.