The role of human disturbance in Late Holocene vegetation changes on Kullaberg, southern Sweden

A pollen record from a small peatland located on Kullaberg in northwestern Sk?ne, southern Sweden, revealed that grazing pressure might have been the major disturbance agent controlling the vegetation, at least from ca. 1500 B. C. until the latter part of the nineteenth century. The pollen data also indicate a step-by-step increase in grazing pressure, expressed as a marked increase in non-arboreal pollen representation at ca. 1500 B. C., A. D. 650 and A. D. 1650. The increase at A. D. 650 probably indicates a more regular and intensive use of the area, resulting in a forest structure that was much more open than earlier, together with an expansion of Fagus, which rapidly replaced Quercus as the local forest dominant. At about this time the first patches of heath vegetation originated, but they probably only covered a small part of Kullaberg. Larger areas with an intensively grazed Calluna heath, as shown by eighteenth century maps, probably evolved around ca. A. D. 1650, when much of Kullaberg seems to have been deliberately deforested. Received February 20, 2001 / Accepted September 12, 2001     

Mangroves of Oman during the late Holocene; climatic implications and impact on human settlements

Pollen and micropalaeontological analyses carried out on mangrove swamp sediments of Suwayh, Oman (22°05.589'N, 50°40.033'E) reveal environmental changes linked both to climate (monsoon) and geomorphological (sea-level) variations during the Late Holocene. A Rhizophora mangrove developed at Suwayh around 6000 years B. P. under climate conditions marked by an increased tropical influence as compared to the modern situation, with dominant summer rains. The later extension of Prosopis cineraria at Suwayh provides evidence for a different rainfall pattern, with a winter rainy season. Pollen and micropalaeontological composition shows three episodes influenced by the sea water at Suwayh. The most important corresponded to the mangrove episode centred ca 6000 B. P. This was followed by two episodes of slight seawater incursion at ca. 5100 and 4500 B. P. responsible for the formation of a brackish laagon. Comparison based on ¹⁴C measurements on shell recovered from both the sedimentary sequence of Suwayh and the nearby archaeological sites demonstrates that close relations existed between man and mangroves during the Neolithic and the Early Bronze Age. Received October 31, 2001 / Accepted January 24, 2002 Correspondence to: Anne-Marie Lézine     

Methodological and practical aspects of the presentation and interpretation of microscopic charcoal data from lake sediments

Analysis of microscopic charcoal particles is a useful part of palaeoecological research and is mostly used in conjunction with pollen analysis. However, there is considerable variation in the methodology of charcoal analyses. This paper considers various methods for the analysis of microscopic charcoal and the presentation of charcoal data in the context of a study of the upper sediments of two lakes Estonia. The results are evaluated by comparing both the pollen and charcoal data with documentary evidence of forest fires over the past 60 years. Indications of fires both varying in extent and at different distances from the lakes are evaluated in both the pollen and charcoal diagrams. The results suggest that the total area curve for charcoal particles per unit mass of sediment dry matter (cm² g⁻¹) provides the best indicator of forest fires. Fires in the study area are reflected differently in the charcoal and pollen curves. It is suggested that the charcoal data have the potential to indicate disturbance at a greater distance from the coring site than indicated by the pollen data. Received February 5, 2002 / Accepted August 14, 2002     

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     

Stone Age to recent land-use history at Pegrema, northern Lake Onega, Russian Karelia

The village of Pegrema in Karelia may be regarded as a Stone Age innovation centre in the large Lake Onega area. Two pollen and plant macrofossil diagrams are presented which represent the first contribution to the study of human impact in the area using anthropogenic pollen indicators. A continuous but sporadic human presence from the Mesolithic onwards is demonstrated. While there is no archaeological evidence relating to the period 4200–3000 B.P., the pollen data suggest continuous, though rather sparse human presence. The data do not support any natural catastrophes in Pegrema as has been suggested elsewhere. Cerealia pollen is recorded earlier than expected (c. 5000 B.P.=. In the Bronce Age and Iron Age, the settlement of the Zaonezhye peninsula is reflected by a slight increase in herb pollen representation, sporadic Cerealia pollen and several periods of regression in Picea. The long introductory period of agriculture to the area, as well as the similarities and discrepancies between different sources of evidence (palaeoecological, archaeological and historical) are discussed at some length. The start of land clearance for permanent cultivation in the profile Pegrema S was dated to the late 13^th century. The beginning of more intensive field cultivation in the 15^th century is clearly seen in the pollen succession at both localities. The fluctuation in anthropogenic indicators can be related to population density based on historical data. The village of Pegrema was depopulated in 1956 which is reflected in a distinct decline in settlement indicators. Received February 17 / Accepted May 19, 2000     

Untangling anthropogenic and climatic influence on riverine forest in the Kruger National Park, South Africa

Understanding the interplay between climatic and anthropogenic factors is a major challenge in palaeo-ecology. In particular, it is often difficult to distinguish anthropogenic and “natural” fire in the charcoal record. In this paper, analysis of fossil pollen, charcoal, diatoms and isotopic evidence from Mapimbi, a small lake in the Kruger National Park, South Africa, suggests that for most of the past ca. 700 years, the riverine gallery forests surrounding Mapimbi were primarily influenced by climate, and benefited during warmer, wetter periods. The transitions between four, statistically different phases in the time-series data coincide with regional climate records previously constructed from speleothem data, and are consistent with the transition from the medieval warm period ending in the 14th century a.d. to the cooler, drier conditions prevailing during the little ice age of ca. a.d. 1400–1800. The data also suggest a period of significant, anthropogenic influence after a.d. 1800, when maize was grown and the incidence of localised fires increased. An increase in woody cover in recent decades may be associated with the management of the area by Kruger National Park. A decline in cultivation occurred in the end of the 20th century linked with changes in socio-political organisation.     

Archaeobotany of the Old Prague Town defence system, Czech Republic: archaeology, macro-remains, pollen, and diatoms

The stone fortification of Prague Old Town was constructed shortly after A.D. 1230. Large-scale archaeological and archaeobotanical research has been carried out in this area in recent years. The deep moat and the drainage ditch have been excavated at several places in front of a line of former ramparts. During the initial period of their existence, the moat and the ditch contained only minimal waste. A sudden change in the management of these features occurred at the beginning of the 14th cent., when they started to be filled with large amounts of rubbish. This article concentrates on the evaluation of these rubbish strata at three profiles through the drainage ditch and one profile through the dry moat. The results of plant macro-remains (including wood), pollen, and diatom analyses clearly demonstrate the development of the local (aquatic) environment from being relatively clean to highly polluted. An actualistic (phytosociological) approach was adopted to reconstruct the local environment of the town periphery in detail, and to distinguish a variety of habitats that were situated in the economic hinterland of the city. Some species from the rich assemblages of plant remains are interpreted in terms of their use in High Medieval households. Diatom analysis completes the picture by providing the proxy data on water quality history in the drainage ditch. Received September 15, 2001 / Accepted May 21, 2002     

On the Late Pleistocene and Holocene history of vegetation and human impact in the Ücker valley, north-eastern Germany

A high-resolution Late Pleistocene and Middle to Late Holocene pollen profile of regional significance is presented. The coring site is located in a mire between two lakes. Ober- and Unter-ückersee, in Brandenburg, north-eastern Germany. The study was carried out in an archaeological context. It provides information about the history of vegetation, climate and human impact in the ücker river valley and the surrounding hills, the Uckerm?rker Hügelland. Hence, it is an important contribution for the reconstruction of the past vegetation of this area of Brandenburg. Seven AMS ¹⁴C-dates based on pollen concentrates provide a chronology for the middle Holocene part of the profile. Phases of intensive human activity can be shown from the middle Neolithic times until the Roman Iron Age. Received February 1, 2000 / Accepted January 18, 2001     

Domestic burnt offerings and sacrifices at Roman and pre-Roman Pompeii, Italy

Excavations below the A.D. 79 destruction levels in two houses at the Roman town of Pompeii, Italy included programmes of sieving and flotation for the recovery of biological remains. In addition to the usual finds of charred plant material and bones representing crop processing or food waste, and mineralised remains from sewage, were numerous burnt offerings. Cones and seeds of stone pine, fruit such as fig and grape and nuts such as walnut and hazel were present in many of them. Some of the offerings contained burnt bone, with the heads and feet of cocks (male domestic fowl) being particularly well represented. There was some change in the plants and animals used for the burnt offerings with time. These offerings could be related to domestic worship described in literary sources and depicted as offerings on altars in Pompeiian wall paintings at shrines to the Lares (household gods). The burnt offerings resulted in the preservation by charring of fruit that are not usually burnt during their processing for consumption. They also presented a taphonomic problem because re-worked charred material from burnt offerings was likely to have been a major component of other charred assemblages from the sites. Received November 22, 2001 / Accepted February 26, 2002     

The fruit of their labour: plants and plant processing at EeRb 140 (860±60 uncal B.P. to 160±50 uncal B.P.), a late prehistoric hunter-gatherer-fisher site on the southern Interior Plateau, British Columbia, Canada

Palaeoethnobotanical analysis of Late Period contexts (860±60 uncal B.P. to 160±50 uncal B.P.) at the site of EeRb 140, indicates that it probably served as a seasonal work area, utilised during the mid to late summer by the residents of an adjacent pit-house winter village. Food processing was evidently the primary plant-related activity at this open-air hunter-gatherer-fisher site on the British Columbia Plateau in Canada. One feature appears to have functioned as both an open hearth for the drying and preservation of berries and as a pit-oven, possibly for preparing foods for immediate consumption. Comparisons of the archaeobotany of EeRb 140 with Plateau ethnographies suggest that women's task group activities are represented here. Most significantly, the identification of a specialised plant-processing site in such close proximity to a winter village contrasts strongly with existing ethnoarchaeological models for the British Columbia Plateau and introduces a type of site not previously identified archaeologically in this region. Received August 14, 2001 / Accepted March 13, 2002     

Biostratigraphy and <Superscript>14</Superscript>C dating of a lake sediment sequence on the north-west Estonian carbonaceous plateau,interpreted in terms of human impact in the surroundings

The sediment stratigraphy of a medium-sized mixotrophic lake (Ruila) situated below the highest shoreline of the Baltic Ice Lake in the West-Estonian Lowland is described. The lake is without natural inlets our outlets. The reconstruction of vegetation and land-use history based on pollen data, combined with available archaeological data and detailed ¹⁴C dating allows us to give a provisional reconstruction of the temporal and spatial pattern of natural and human induced environmental changes in north-west Estonia during the Holocene. Both radiocarbon dates derived from terrestrial macrofossil dating by accelerator mass spectrometry (AMS) and conventional dating of bulk lake sediment are discussed. The isolation of the lake basin from the Yoldia Sea took place ca. 9700 cal B. C. The Ancylus Lake transgression at ca. 8400 cal B. C. did not reach the basin, but caused a ground water rise, seen in the sediment stratigraphy of the lake. The first signs of human impact on the pollen record appear ca. 5400 cal B. C. (Late Mesolithic). The history of arable farming has been divided into three periods: 1) introduction of crop cultivation and animal husbandry (1500 cal B. C. – A. D. 500); 2) establishment of animal husbandry A. D. 500–1000) and 3) establishment of crop cultivation and intensive cattle breeding (A. D. 1000–today). Due to unfavourable eda-phic conditions the introduction of arable farming was delayed for more than 1000 years compared with elsewhere on the north coast of Esotnia, and intensity of land-use never reached the same proportion as in these areas. Received August 15, 2001 / Accepted August 5, 2002 Correspondence to: Leili Saarse     

Coevolutionary interactions between a haploid species and a diploid species

We investigate a general model describing coevolutionary interaction between a haploid population and a diploid population, each with two alleles at a single locus. Both species are allowed to evolve, with the fitness of the genotypes of each species assumed to depend linearly on the frequencies of the genotypes of the other species. We explore the resulting outcomes of these interactions, in particular determining the location of equilibria under various conditions. The coevolution here is much more complex than that between two haploid populations and allows for the possibility of two polymorphic equilibria. To allow for further analysis, we construct a semi-symmetric model. The variety of outcomes possible even in this second model provides support for the geographic mosaic theory of coevolution by suggesting the possibility of small local populations coevolving to very different outcomes, leading to a shifting geographic mosaic as neighboring populations interact with each other through migration.     

Man and environment around lake Maliq (southern Albania) during the Late Holocene

The archaeological site of Sovjan is located at the edge of lake Maliq. It was occupied from the early Bronze Age to the early Iron Age. Pollen data from a short sequence of peat deposits dated between 4255±50 and 2420±45 uncal B.P. and charcoal, seeds and wood from archaeological deposits have provided new information on human activities in the region. They are discussed in the general frame of agricultural developments in the Balkans. Regional environment (regarding vegetation and hydrology) and climate are also discussed. Received June 15, 2000 / Accepted March 8, 2001     

Transport of L-proline,L-proline-containing peptides and related drugs at mammalian epithelial cell membranes

Summary. Membrane transport of L-proline has received considerable attention in basic and pharmaceutical research recently. Of the most recently cloned members of the solute carrier family, two are “proline transporters”. The amino acid transporter PAT1, expressed in intestine, kidney, brain and other organs, mediates the uptake of proline and derivatives in a pH gradient-dependent manner. The Na⁺-dependent proline transporter SIT1, cloned in 2005, exhibits the properties of the long-sought classical IMINO system. Proline-containing peptides are of interest for several reasons. Many biologically important peptide sequences contain highly conserved proline residues. Xaa-Pro peptides are very often resistant to enzymatic hydrolysis and display, in contrast to Pro-Xaa peptides, a high affinity to the H⁺/peptide cotransporter PEPT1 which is expressed in intestinal, renal, lung and biliary duct epithelial cells. Furthermore, several orally available drugs are recognized by PEPT1 as Xaa-Pro analogues due to their sterical resemblance to small peptides.     

The long history of Cannabis and its cultivation by the Romans in central Italy, shown by pollen records from Lago Albano and Lago di Nemi

The cores from the Albano and Nemi lakes, near Rome, were studied within the European Union funded PALICLAS project and provided high resolution records of the Late-glacial and Holocene. Pollen evidence of increasing human influence on vegetation was recorded in the Holocene parts of both diagrams, and the Cannabis (hemp) curve was one of the major signs. In this paper we present unambiguous pollen evidence from the Cannabaceae records for the cultivation of hemp in central Italy by the Romans. The oldest records of Cannabis and Humulus (hop) date from to the Late-glacial. Hop pollen values rise during the mid Holocene, while hemp pollen becomes more abundant from ca. 3000 cal B.P. onwards. The highest earliest hemp peak (21%) is dated to the 1st century A.D. This ‘Cannabis phase’, with the abrupt rise of hemp pollen soon after the rise of cultivated trees (Castanea, Juglans and Olea) is associated with the increase in cereals and ruderal plants. This unambiguous proof of cultivation by Romans around 2000 B.P. occurs as well as a long lasting pre-Roman presence of hemp in the area, which is natural and possibly also anthropogenic. Subsequent clear episodes of cultivation in the medieval period were found. Received February 4, 2002 / Accepted September 13, 2002 Correspondence to: Anna Maria Mercuri, e-mail: mercuri.annamaria@unimo.it     

New evidence for the use of root foods in pre-agrarian subsistence recovered from the late Mesolithic site at Halsskov, Denmark

Roots and tubers, together with other plant storage organs such as rhizomes, bulbs, corms, etc. are known to be a source of human food. Until very recently, however, remains of root foods were rarely identified from archaeological contexts in temperate Europe. New evidence for the use of root foods has been recently recovered from the early Erteb?lle settlement at Halsskov in Denmark. Remains included charred bulbs of Allium cf. ursinum and tubers of Conopodium majus. They were accompanied by charred remains of parenchymatous tissues derived from underground parts of other plants. All parenchymatous remains were recovered from features that could be interpreted as pit-cooking depressions. A minimum of two periods of root food gathering can be assumed, spring to early summer and autumn. The presence of charred seeds of Nuphar pumilum suggests that either the seeds or rhizomes (or both) were use as food. Received September 4, 2001 / Accepted February 27, 2002     

The effect of extractants on degradation of L-glutamate and L-arginine in the course of shaking and filtration at low temperature

Summary. The effects of demineralized water (DEMI H₂O) and 0.5 M ammonium acetate (0.5 M AAc) on losses of L-glutamic acid and L-arginine in the course of shaking and filtration at low temperature (6 °C) were tested. The concentration of L-glutamic acid decreased by 6.3% in DEMI H₂O and by 4.9% in 0.5 M AAc, whereas the L-arginine concentration decreased by 6.0% (DEMI H₂O) and 10.7% (0.5 M AAc). We found a significantly (P < 0.05) higher degradation of L-arginine in 0.5 M AAc compared with that of DEMI H₂O.     

Brucellosis, botflies, and brainworms: the impact of edge habitats on pathogen transmission and species extinction

Ecological interactions between species that prefer different habitat types but come into contact in edge regions at the interfaces between habitat types are modeled via reaction-diffusion systems. The primary sort of interaction described by the models is competition mediated by pathogen transmission. The models are somewhat novel because the spatial domains for the variables describing the population densities of the interacting species overlap but do not coincide. Conditions implying coexistence of the two species or the extinction of one species are derived. The conditions involve the principal eigenvalues of elliptic operators arising from linearizations of the model system around equilibria with only one species present. The conditions for persistence or extinction are made explicit in terms of the parameters of the system and the geometry of the underlying spatial domains via estimates of the principal eigenvalues. The implications of the models with respect to conservation and refuge design are discussed. Received: 10 June 1999 / Revised version: 7 July 2000 / Published online: 20 December 2000     

Effects of 28 days of beta-alanine and creatine monohydrate supplementation on aerobic power,ventilatory and lactate thresholds,and time to exhaustion

Summary. The effect of beta-alanine (β-Ala) alone or in combination with creatine monohydrate (Cr) on aerobic exercise performance is unknown. The purpose of this study was to examine the effects of 4 weeks of β-Ala and Cr supplementation on indices of endurance performance. Fifty-five men (24.5 ± 5.3 yrs) participated in a double-blind, placebo-controlled study and randomly assigned to one of 4 groups; placebo (PL, n = 13), creatine (Cr, n = 12), beta-alanine (β-Ala, n = 14), or beta-alanine plus creatine (CrBA, n = 16). Prior to and following supplementation, participants performed a graded exercise test on a cycle ergometer to determine VO_2peak, time to exhaustion (TTE), and power output, VO₂, and percent VO_2peak associated with VT and LT. No significant group effects were found. However, within groups, a significant time effect was observed for CrBa on 5 of the 8 parameters measured. These data suggest that CrBA may potentially enhance endurance performance.     

Primary kidney growth and its consequences at the onset of diabetes mellitus

Summary. Diabetes mellitus is a primary contributor to progressive kidney dysfunction leading to end-stage renal disease (ESRD). In the early phase of diabetes, prior to the onset of further complications, both kidney size and glomerular filtration rate (GFR) increase. Glomerular hyperfiltration is considered a risk factor for downstream complications and progression to ESRD. Abnormalities in vascular control have been purported to account for the glomerular hyperfiltration in early diabetes. In this review we discuss a tubulo-centric concept in which tubular growth and subsequent hyper-reabsorption contribute to the onset of glomerular hyperfiltration that demarks the early stage of diabetes. Kidney growth, in this concept, is no longer relegated to a compensatory response to hyperfiltration, but rather plays a primary and active role in its genesis and progression. As such, components of kidney growth, such as the polyamines, may provide a means of early detection of diabetic kidney dysfunction and more effective therapeutic intervention.