The lateglacial vegetation and radiocarbon dating of Lake Trilistnika, Rila Mountains (Bulgaria)

Pollen analysis, supplemented by 5 ¹⁴C dates, was carried out on the lateglacial section (160 cm) of a core retrieved from the glacial Lake Trilistnika (2216 m) in the northwestern Rila Mountains (Bulgaria). The reconstruction of the lateglacial vegetation history is linked for the first time to a chronological framework for the time window 13000–10000 b.p. The delimitation of an interstadial/stadial cycle, analogous with the Bølling/Allerød-Younger Dryas from Western Europe, is based on important changes in the pollen stratigraphy. Mountain-steppe vegetation composed of Artemisia, Chenopodiaceae, Poaceae and other cold-resistant herbs, with isolated stands of Pinus and Juniperus-Ephedra shrubland, dominated the landscape after the ice-retreat. Interstadial conditions were established before 12815±130 b.p. The spread of tree vegetation at lower elevation as a response to the climate improvement was confined to the time interval 12110±95–11140±75 b.p. The Younger Dryas stadial is characterised by a re-advance of the mountain-steppe vegetation. The results are compared with other sites of lateglacial age from the high mountains (Rila, northern Pirin, western Rhodopes) in southern Bulgaria.     

17. Lake Skakavitsa (Bulgaria): Late Holocene vegetation dynamics in north-western Rila Mountains

The occurrence of symptoms of pollen allergy is closely related to the presence of airborne pollen. In the region of southeastern Poland this kind of allergy appears usually from the middle of May till the end of July, when Gramineae and Cerealia pollens are discharging. This was confirmed by palynological studies here reported, performed in the years 1982–1987, and coupled with simultaneous assessment of 60 patients suffering from pollinosis. The results show that the total number of pollen types is variable in consecutive years. This indicates that both the exposition of patients to pollen allergens and the disease symptoms might vary.     

14. Lake Sedmo Rilsko (Bulgaria): Lateglacial vegetation history

The length of the pollen deposition period covered by an individual moss sample is a matter of discussion. Here we evaluate (1) how many years of pollen deposition are contained in individual moss samples, (2) which factors (i.e. moss type, geographical location and thickness of sample) affect the pollen content, and (3) whether the time span of the pollen deposited in the moss is related to the pollen type. The pollen deposition period covered by 20 individual moss samples adjacent to pollen traps was estimated using the accumulation method. The investigated moss samples usually contain pollen from a period of two to five years. The length of the time period covered by the moss depends on the thickness of the moss cushion and, therefore, we recommend estimating the time period over which the moss has been growing by the increment method. Compared to pollen traps, mosses tend to accumulate more Poaceae and bisaccate grains (especially Picea) but less Cyperaceae pollen. Betula and pollen tetrads tend to be equally represented in mosses and traps. This study demonstrates that moss samples may contain sufficient pollen to be a reliable modern analogue for Quaternary peat and sediment samples but cannot be used to calculate pollen accumulation rates.     

On the holocene history of vegetation in SE Bulgaria (Lake Arkutino,Ropotamo region)

Palynological studies and investigations on macrofossil remains have been carried out on two profiles of the Holocene sediments of Lake Arkutino situated near to the Black Sea coast of SE Bulgaria. Lake Arkutino is a freshwater lake with shallow water. The lake is separated from the Black Sea by a dune barrier. Sedimentation started at about 6100 B.P. No marine or brackish influence could be traced in the sediments although the lake level is around sea level. The history of vegetation does not display major fluctuations except for the lake vegetation itself and for the swamp forests (Longos forests) surrounding the lake. Forests on normal mineral soils were mainly occupied by deciduous oaks throughout the last 6100 years. Deciduous oaks are represented in the pollen diagrams by the Quercus robur type and the Quercus cerris type. Until about 5800 B.P., one of the two pollen diagrams indicates that forests still contained more Pinus and Corylus than afterwards. After 5800 B.P., Fagus and a hundred years later together with Carpinus betulus became more important in addition with submediterranean elements as Carpinus orientalis, Fraxinus ornus and Phillyrea. After 5200 B.P., Carpinus betulus became somewhat less important. Indicators for human influence are rare. The archaeological record speaks for a small population in the area under study since the 12th century B.C. Swamp forests of the so-called Longos forests type started to develop at about 3000 B.P. The macrofossil record offers possibilities to trace hydrological changes by tracing the history of hydrophyte and reed plant comminties. From about 5100 to at least 4000 B.P., the record for Lemnetea and Potametea communities is poor and the processes of terrestrialization was interrupted. It can be assumed that the highest Black Sea transgression which is dated to 5700–4000 B.P. and which showed a sea level 3–4 m higher than today heavily influenced Lake Arkutino. That may have resulted in a higher lake level and in some water supply from the nearby river Ropotamo which would explain certain changes in the sediments and in the composition of hydrophyte communities.     

Studies on the vegetation history of Lake Varna region,northern Black Sea coastal area of Bulgaria

On the basis of pollen analytical investigations of two cores from Lake Varna and Lake Beloslav, the vegetation history of the Lake Varna region is traced back to the beginning of the 6th millennium B.C. A two-fold zoning system is used whereby the pollen diagrams are divided into pollen zones, based on tree migration patterns, and settlement periods. Pollen zone 1 is characterised by the absence of Carpinus betulus and Fagus sylvatica. The spread of hornbeam started at ca. 6500 B.C. (pollen zone 2) and beech at ca. 6200 B.C. (pollen zone 3), the latter being the last tree to spread into the region and considerably enrich the forests of the study area. Of the many pollen taxa representing plants that are favoured by open habitats and hence potentially indicative of human impact, only a few taxa are regarded as reliable indicators of human activity. These include above all Triticum-type, and also Secale and to a certain extent Plantago lanceolata, Rumex and Polygonum aviculare. The spatial pattern of settlements is somewhat different in the areas represented by the two profiles. At both sites the first period of settlement occurred during the 6th millennium B.C. (early Neolithic). After the Neolithic period, the main settlement periods of the Eneolithic and the Early and Middle Bronze Age are recorded. On the other hand, land-use history during the Greek and Roman periods is poorly recorded. Studies on the stratigraphy, diatoms and molluscs indicate that the sixth Black Sea transgression (6500–5800 B.C.), which reached –10 m, had considerable influence on the limnological environment.     

Towards the vegetation and settlement history of the southern Dobrudza coastal region, north-eastern Bulgaria: A pollen diagram from Lake Durankulak

Palynological investigation and radiocarbon dating of a 6-m core from lake Durankulak, north-eastern Bulgaria, enables vegetation development and human occupation from ca. 5500–5300 cal. B.C. onwards to be traced. Steppe vegetation that included with groves of deciduous trees asQuercus, Ulmus, Carpinus belulus andCorylus changed to a forest-steppe after 4000 cal. B.C. The archaeopalynological record indicates three distinct phases of human activity as follows: (1) 5300–4200 cal. B.C. (late Neolithic and Eneolithic) during which farming, that included a substantial arable component, was pursued, (2) 3500–3000 cal. B.C. (transition to early Bronze Age) when stock rearing appears to have dominated, and (3) after 1300 cal. B.C. (late Bronze Age) when arable farming again assumed importance. The palynological data correlate well with the rich archaeological record for human settlement that is available for the region from late Neolithic times onwards.     

Holocene vegetation history of the southern Levant based on a pollen record from Lake Kinneret (Sea of Galilee), Israel

Lake Kinneret, also known as the Sea of Galilee and Lake Tiberias, is located in the northeast of Israel. At a lake level of 211 m b.s.l. (below mean sea level), the central basin is 43 m deep. The maximum length of the lake is 21 km (N–S) and its maximum width is 12 km (W–E). Lake Kinneret’s surface area is 166 km². A new 17.8 m long sedimentary core was drilled in 2010. Here, we present the entire palynological record from it, which covers the last?~?9,000 years. Special emphasis is given to the natural and human-influenced vegetation history of Galilee in comparison to that of the more southerly Dead Sea region. Significant signs of human impact are the first Olea (olive) increase during the beginning of the Chalcolithic period between 7,000 and 6,500 years ago, as well as the prominent Olea phase during the Hellenistic/Roman/Byzantine period between 2,300 and 1,500 years ago. Mediterranean macchia and bathas scrub vegetation, as known in the area today, has developed in the southern Levant under human impact since the last ca. 1,500 years.     

7. Mire Straldza (Southeastern Bulgaria): Late Holocene vegetation history

Aeroallergens of the southeastern Missouri region were determined by skin test frequencies of 817 consecutive individuals and compared and contrasted with five years of air sampling using the Rotorod sampler. Household inhalants were found to induce the most frequently positive skin tests, especially house dust, feathers, house dust mite, wool, cat epithelium, tobacco, dog epithelium, and horse epithelium. Among the trees, pollen extracts of Acer saccharum (maple), Acer negundo (box-elder), Carya ovata/C. illinoensis (hickory/pecan), Juglans nigra (walnut), and Ulmus americana (elm) were the most commonly positive. A slightly higher level of skin reactivity was found to grass pollen extracts with Anlhoxanthum odoralum (sweet vernal), Phleum pratense (timothy), Cynodon dactylon (Bermuda), Agrostis alba (red top) and Festuca elatior (meadow fescue), all being quite similar in incidence, but Sorghum halepense (Johnson grass) was clearly less important. Ambrosia spp. (ragweed) and Xanthium commune (cocklebur) were the most frequent weed reactions with ragweed the most prominent allergen of outside environmental origin. Of the genera of fungi, skin tests to Epicoccum were most frequently positive. When reactivity level is considered, the other important fungi are Alternaria, Candida, Cladosporium, Curvularia, and Fusarium. Air sampling data generally correlates well with the positive skin tests frequencies i.e., the most numerous pollen, ragweed, has the highest skin test frequency and reactivity level. Similarly among the fungi the most numerous spores, Cladosporium, Alternaria, Fusarium, and Epicoccum have the highest frequencies and reactivity levels. Certain species appear to be able to sensitize patients in lower concentrations, such as box-elder and the grasses. Oak pollen and Cladosporium spores appear in large numbers, but seem less sensitizing.     

Studies on the Holocene history of vegetation in the region of lake Srebarna (northeast Bulgaria)

The results of pollen analysis of two sediment cores from lake Srebarna (northeast Bulgaria) are presented. On the basis of the palynological data and the radiocarbon dates a reconstruction of the past flora and vegetation is made. For the first time a continuous palaeosuccession is established for the area of the Danubian Dobrudza and the Ludogorie district of northeast Bulgaria: a dominance of mixed xero- and mesophilous oak woods with Carpinus betulus, Ulmus, Tilia, Corylus during the Atlantic period; mixed oak woods with increasing importance of Tilia, Ulmus, Acer and a considerable presence of Carpinus betulus and Fagus during the Sub-boreal period; degradation of the woodland vegetation and transition to secondary plant communities with Carpinus orientalis and herbs during the Sub-atlantic period. Received January 5, 2001 / Accepted March 13, 2001     

6. Peat-bog Begbunar (Osogovo Mountains,south-west Bulgaria): Four millennia of vegetation history

The aim of this study was to estimate the polleniferous potential of the most common plant communities and crops across the landscape through the study of pollen loads collected by Apis mellifera. We analysed pollen load samples from hives located in Mallorca (western Mediterranean) for one year and compared the results with a phytosociological study of the foraging area. We also analysed meteorological data to evaluate the influence of some environmental factors on the pollen production phenology. We identified 74 different pollen types (66.2% from native flora, 25.7% from exotic flora, and 8.1% from crops) belonging to 33 families. The highest polleniferous potentials in the landscape were attained by sclerophyllous forests (Quercetea ilicis) in spring, crops in autumn, wild annual rangelands (Stellarietea mediae) in winter and gardens in late summer. Our results suggest that the higher the coverage present in a vegetation class, the higher the quantity and diversity of pollen that may be provided to pollinators; therefore, its polleniferous potential may be higher. Some meteorological conditions (rainfall, temperature and daily hours of sunlight) may affect this potential through their influence on flowering phenology.     

中国新记录属——异型盘菌属（英文）

异型盘菌属Allophylaria首次在我国发现,包括1个新种和1个中国新记录种,均来自云南。新种小孢异型盘菌A.minispora的鉴别特征为子囊盘类白色,具柄;子囊顶孔在碘液中呈蓝色,32?45×3.8?5μm;子囊孢子梭形,无油滴,4.3?5.8×1.5?2.5μm;习居于草本植物茎上。原产于澳大利亚的果荚生异型盘菌A.atherospermatis首次在中国报道。提供了上述种的宏观和微观特征的详细描述及图示。     

Late-glacial vegetational history of Lake Kremensko-5 in the northern Pirin Mountains,southwestern Bulgaria

The core of Lake Kremensko-5, one of the cirque lakes in the northern Pirin Mountains of southwestern Bulgaria, contains sediments from more than 13,500 years b.p. and a pollen stratigraphy that can be correlated with the interstadial/stadial cycle of the Late-glacial period. Artemisia and Chenopodiaceae predominate in the basal part of the sequence, indicating the presence of mountain steppe type vegetation soon after the ice retreat. A sharp increase of Pinus diploxylon-type and Poaceae after 12,360 b.p. is followed by a return of Artemisia and Chenopodiaceae, marking the Younger Dryas. Its abrupt termination must result from an unconformity, for high values of Quercetum mixtum, dated at other sites in the Pirin Mountains as early Holocene, are missing here, perhaps because of erosion at a time of low lake level related to the high insolation maximum during the early Holocene.     

Postglacial evolution of vegetation and environment in the Scheldt Basin (northern Belgium)

The infill of abandoned river channels is the main information source on postglacial vegetation and landscape evolution in inland northern Belgium. Palynological studies of these deposits also contribute to a better understanding of the environmental context of the numerous archaeological sites in this area. The results are presented of palynological analyses, including pollen, spores, non-pollen palynomorphs and microcharcoal from the palaeochannel infill at seven sites in the Scheldt and Durme valleys in northern Belgium. Based on the regional vegetation evolution and radiocarbon dating, a biozonation for the Scheldt Basin is constructed encompassing the final Late-glacial and Holocene period. The local taxa show a hydroseral succession from open-water environment, through reed or sedge fen to carr forest. Salix and Viburnum opulus were important elements in the Early Holocene riparian and carr vegetation, but are often underrepresented in pollen diagrams from larger valleys. There are indications for human disturbance and agriculture between 7,000 and 6,400 cal bp. The simultaneous decline of elm and lime in the study area around 4,000 cal bp can be linked to human impact.     

First records of the parasite Symbiocladius rhithrogenae (Zavrel, 1924) (Diptera: Chironomidae) in several streams of Rila Mountain,Bulgaria

Parasite stages of Symbiocladius rhithrogenae (Zavrel, 1924) (Diptera: Chironomidae) were found in several streams from the Rila Mountain. A total of 19 sites (18 from the Iskar River and one from the Struma River catchments) were sampled, from which the parasite was recorded only in four (Levi Iskar, Rilska, Malyovishka and Cherni Iskar Rivers). Both pupa and larvae of S. rhithrogenae were found attached only to mayfly larvae of the genus Rhithrogena Eaton, 1881, while other Heptageniidae species were ignored. This specialisation could be connected to an overlap between the seasonal cycles of the parasite and its host. We discussed the bioindicative potential of S. rhithrogenae.     

Late Miocene vegetation and climate reconstruction based on pollen data from the Sofia Basin (West Bulgaria)

The analysis of fossil palynomorh assemblages in the Late Miocene freshwater sediments of the Sofia Basin (West Bulgaria) was done to collect data on the vegetation and climate dynamics during the Late Miocene. On the basis of pollen data, we described the main palaeocomunities developed in the region. The mixed mesophytic forests dominated the vegetation in which species of Quercus, Ulmus, Zelkova, Fagus, Carpinus, Betula, Castanea, Corylus, Pterocarya, Carya, Juglans, and Eucommia played important roles. Swamp forests were also recorded, including Taxodiaceae, Alnus, Glyptostrobus, Nyssa, and Myrica. Herbaceous vegetation was distributed in the middle part of the section, with a maximum of 35.5%. The vegetation dynamic passes through several phases, which were associated with changes in paleoclimate and palaeoecological conditions. Coexistence Approach (CA) was applied to palynological data to calculate four climatic parameters. The values of coexistence intervals for mean annual temperatures are 13.6–16.6 °C, with winter temperatures being 3.7–6.6 °C and summer temperatures being 23.6–27.8 °C. Mean annual precipitation ranged most frequently between 828 and 1308 mm. The palaeoclimatic reconstruction illustrates existence of a warm-temperate and relatively humid climate with higher mean annual temperature than the present day climate.