Evaluación de clones de Populus spp., a los dos años de edad, en dos micrositios de la región pampeana, Argentina

La producción de álamos en la pampa ondulada de la provincia de Buenos Aires podría constituir una actividad alternativa y/o complementaria, debido a zonas ecológicas favorables para su cultivo. En este contexto es importante conocer el comportamiento de los clones en los diversos ambientes para poder definir cuáles de ellos podrían presentar mayor estabilidad para los diferentes sitios. El objetivo del trabajo fue estudiar la interacción existente entre los parámetros de crecimiento y supervivencia de 16 clones de Populus spp. en dos micrositios geomorfológicamente diferentes en la región pampeana, Argentina. Los clones en estudio provienen de cruzamientos intraespecíficos de P. deltoides e interespecíficos de P. deltoides x P. nigra (Populus x canadensis). Se plantaron en dos ensayos, uno por cada situación geomórfica: loma y bajo, y se completó con un análisis estadístico comparando los ensayos en forma individual y conjunta. Cada ensayo se instaló con un diseño de bloques completos al azar. Las variables analizadas fueron la supervivencia, la altura media y el área basal al concluir el segundo año de crecimiento. Para el sitio regional evaluado, la interacción entre los clones y los micrositios fue significativa para las variables altura y supervivencia. La mayor disponibilidad de agua en el micrositio bajo produjo mayores crecimientos clonales con diferencias significativas respecto del micrositio loma. La estabilidad de los atributos de supervivencia y crecimiento frente a los micrositios es un objetivo fundamental en las plantaciones clonales. Siendo los micrositios una realidad ambiental importante, propia como variable no controlable, la reducción de la variabilidad de respuesta ante ellos permitiría la constitución de unidades de manejo más homogéneas.

Susceptibilidad a Septoria musiva de híbridos inter e intraespecíficos de Populus spp. implantados en dos micrositios de la Pampa Húmeda Argentina

En los álamos, una de las enfermedades con mayor influencia en la cantidad y calidad de la madera producida es la cancrosis originada por Septoriamusiva Peck . El objetivo del trabajo fue determinar en clones híbridos de álamos (Populus spp.) la incidencia y la severidad de la enfermedad producida por Septoria, en dos micrositios de un mismo sitio regional, en Alberti, Buenos Aires, Argentina. Los clones utilizados fueron obtenidos de cruzamientos intraespecíficos de Populus deltoides e interespecíficos de P. deltoides x P. nigra (= P. x canadensis). Se determinó la susceptibilidad a la enfermedad para cada clon/micrositio mediante la estimación de la incidencia, del número de cancros en guías y ramas, y la severidad de daños (ID). Los híbridos inter e intraespecíficos de P. deltoides presentaron respuesta clonal diferencial en la susceptibilidad a la cancrosis en ambas situaciones geomórficas: los híbridos provenientes de cruzamientos intraespecíficos resultaron resistentes, y los provenientes de cruzamientos interespecíficos susceptibles a la enfermedad. Las diferencias significativas entre clones, determinadas para el número de lesiones totales por posición en ambas situaciones geomórficas, no determinaron ID diferentes. El número de cancros identificados en cada posición constituye una herramienta de estimación de la susceptibilidad clonal a la cancrosis más exacta, teniendo en cuenta que los mayores perjuicios ocurren cuando las lesiones se presentan en las guías.

Evaluación del crecimiento inicial de clones de álamo en el norte de la Patagonia

En los valles irrigados de Río Negro y Neuquén, el cultivo de álamos acompañó históricamente la producción agrícola, utilizándose clones de Populus nigra L. en cortinas rompeviento y clones de Populus xcanadensis Moench. para las forestaciones en macizo. Buscando ampliar la disponibilidad de genotipos para los diferentes sitios de cultivo, se instaló un ensayo comparativo con trece clones de álamo en la localidad de Pomona, Provincia de Río Negro. Se evaluaron seis clones de P. xcanadensis ('Triplo', 'Ragonese 22 INTA', "Pangui INTA", "Pudú INTA", y los testigos comerciales 'Conti 12' e 'I-214'), seis clones de P. deltoides ('Harvard', 'Onda', 'Stoneville 67', 'Carabelas INTA', "20-82" y "C-657") y un clon de P. xcanescens. Se utilizó un diseño experimental de bloques completos al azar (DBCA) con quince repeticiones y parcelas de una planta. Luego de cuatro períodos de crecimiento, 'I-214' y 'Triplo' tuvieron los mayores incrementos de DAP, no encontrándose diferencias significativas con los valores de 'Conti 12', 'Ragonese 22 INTA', "Pangui INTA", "Pudú INTA", "20-82" y P. xcanescens. Los menores crecimientos fueron observados en los deltoides 'Stoneville 67' y "C- 657". Los clones 'Ragonese 22 INTA', 'Triplo' y "20-82" constituyen alternativas para el cultivo de álamos en macizos y cortinas rompeviento.

Palynology on a profile from the Krusné Hory Mountains

Site details: The raised bog Fláje-Kiefern (50°429N, 13°329 E; 760 m a.s.l.; size ca. 500x500 m) lies in the Krusné Hory Mountains (Erzgebirge), Czech Republic, about 10 km from Georgenfelder Moor in Germany. Hejny and Slavík (1988) described the phytogeographic region of the Krusne Hory Mountains as 'a region of mountain flora and vegetation, with thermophilous species largely missing. In the natural forests, conifers, especially spruce (Picea excelsa) prevail. The deforested areas have been converted into meadows and pastures'. The climate is cool with annual average temperatures of about 5°C and annual precipitation of about 900 mm. The bedrock is Precambrian crystallinicum.

Palynology on sediment profile Tso Kar in Ladakh

Palynological investigation of a 410 cm long core section from Tso Kar (33°10'N, 78°E, 4527 m a.s.l.), an alpine lake situated in the arid Ladakh area of NW India at the limit of the present-day Indian summer monsoon, was performed in order to reconstruct post-glacial regional vegetation and climate dynamics. The area was covered with alpine desert vegetation from ca. 15.2 to 14 kyr BP (1 kyr=1000 cal. years), reflecting dry and cold conditions. High influx values of long-distance transported Pinus sylvestris type pollen suggest prevailing air flow from the west and northwest. The spread of alpine meadow communities and local aquatic vegetation is a weak sign of climate amelioration after ca. 14 kyr BP. Pollen data (e.g. influx values of Pinus roxburghii type and Quercus) suggest that this was due to a strengthening of the summer monsoon and the reduced activity of westerly winds. The further spread of Artemisia and species-rich meadows occurred in response to improved moisture conditions between ca. 12.9 and 12.5 kyr BP. The subsequent change towards drier desert-steppe vegetation likely indicates more frequent westerly disturbances and associated snowfalls, which favoured the persistence of alpine meadows on edaphically moist sites. The spread of Chenopodiaceae-dominated vegetation associated with an extremely weak monsoon occurred at ca. 12.2-11.8 kyr BP during the Younger Dryas interstadial. A major increase in humidity is inferred from the development of Artemisia-dominated steppe and wet alpine meadows with Gentianaceae after the late glacial/early Holocene transition in response to the strengthening of the summer monsoon. Monsoonal influence reached maximum activity in the Tso Kar region between ca. 10.9 and 9.2 kyr BP. The subsequent development of the alpine meadow, steppe and desert-steppe vegetation points to a moderate reduction in the moisture supply, which can be linked to the weaker summer monsoon and the accompanying enhancement of the winter westerly flow from ca. 9.2 to 4.8 kyr BP. The highest water levels of Tso Kar around 8 kyr BP probably reflect combined effect of both monsoonal and westerly influence in the region. An abrupt shift towards aridity in the Tso Kar region occurred after ca. 4.8 kyr BP, as evidenced by an expansion of Chenopodiaceae-dominated desert-steppe. Low pollen influx values registered ca. 2.8-1.3 kyr BP suggest scarce vegetation cover and unfavourable growing conditions likely associated with a further weakening of the Indian Monsoon.

Age determination and pollen profile of sediment core Trentelmoor, Peine, northern Germany

The filling up of the lake which existed in the basin of the Trentelmoor (40 km E of Hannover, Germany) - in Preboreal times was finished 2000 years ago. Since then fen vegetation has covered the former lake's surface. The postglacial development of the vegetation follows the pattern which is typical of Central Europe. However, due to the poorness of the soils around the Trentelmoor, the frequencies of some tree species differ. Beech for example never reached - for the benefit of oak - that importance which this tree species usually gains on better soils. Human impact becomes recognisable in the upper Neolithic for the first time. The area has been settled continuously, but with changing intensities, throughout the last 3000 years. When the manuscript of this paper went to press the results of two radiocarbon age determinations only were completed. An additional three determinations were completed somewhat later. See the accompanying table for results.

AMS radiocarbon dates and pollen analysis from Zugspitzplatt

On the strongly karstified and almost unvegetated surface of the Zugspitzplatt, at an altitude of about 2290 m in the Wettersteingebirge, there is a doline within which over a period of several thousand years a bed of fine loess-like sediment, almost 1m thick, has accumulated. Notwithstanding the situation of this locality far above the present tree-line, this infill contains quantities of pollen and spores sufficient for pollen analysis without use of any enrichment techniques. Despite poor pollen preservation, it was possible to date the basal layers of this profile on the basis of their pollen assemblages. AMS dating (7415 ± 30 BP) has confirmed that the oldest sediments were laid down during the early Atlantic period, the time of the thermal optimum of the Holocene. At least since that time this site has never been overridden by a glacier. The moraine associated with the Löbben Oscillation between 3400 and 3100 BP - here represented by the so-called Platt Stillstand (Plattstand) - did not quite reach the doline. A diagram shows known Holocene glacial limits. The composition of the pollen assemblages from the two oldest levels with high pollen concentrations strongly suggests that the distance between the doline and the forest was much less during the Atlantic than at present.

Pollen and diatom analysis on varved sediments in Lake Jues (Harz Mountains, Germany)

Studies combining sedimentological and biological evidence to reconstruct Holocene climate beyond the major changes, and especially seasonality, are rare in Europe, and are nearly completely absent in Germany. The present study tries to reconstruct changes of seasonality from evidence of annual algal successions within the framework of well-established pollen zonation and 14C-AMS dates from terrestrial plants. Laminated Holocene sediments in Lake Jues (10°20.70' E, 51°39.30' N, 241 m a.s.l.), located at the SW margin of the Harz Mountains, central Germany, were studied for sediment characteristics, pollen, diatoms and coccal green algae. An age model is based on 21 calibrated AMS radiocarbon dates from terrestrial plants. The sedimentary record covers the entire Holocene period. Trophic status and circulation/stagnation patterns of the lake were inferred from algal assemblages, the subannual structure of varves and the physico-chemical properties of the sediment. During the Holocene, mixing conditions alternated between di-, oligo- and meromictic depending on length and variability of spring and fall periods, and the stability of winter and summer weather. The trophic state was controlled by nutrient input, circulation patterns and the temperature-dependent rates of organic production and mineralization. Climate shifts, mainly in phase with those recorded from other European regions, are inferred from changing limnological conditions and terrestrial vegetation. Significant changes occurred at 11,600 cal. yr. BP (Preboreal warming), between 10,600 and 10,100 cal. yr. BP (Boreal cooling), and between 8,400 and 4,550 cal. yr. BP (warm and dry interval of the Atlantic). Since 4,550 cal. yr. BP the climate became gradually cooler, wetter and more oceanic. This trend was interrupted by warmer and dryer phases between 3,440 and 2,850 cal. yr. BP and, likely, between 2,500 and 2,250 cal. yr. BP.

Pollen profile and age determination of sediment core Schwanengrabenrinne, Brandenburg, Germany

In der Döberitzer Heide nördlich von Potsdam wurden vegetationsgeschichtliche Untersuchungen durchgeführt. Das Untersuchungsgebiet befindet sich im östlichen Teil der Nauener Platte, die bisher vegetationsgeschichtlich weitgehend unerforscht war. In sechs verschiedenen Mooren wurden acht Bohrungen niedergebracht. Die Bohrkerne wurden stratigraphisch und pollenanalytisch untersucht und für die Radiocarbondatierung beprobt. Die Pollendiagramme ermöglichen die Rekonstruktion der Vegetationsentwicklung der terrestrischen Standorte und der Moore in der Döberitzer Heide in den letzten 14.000 Jahren. Neben einer Revision der Gliederungsprinzipien der spätglazialen Vegetationsentwicklung Brandenburgs und einer vergleichenden Betrachtung der Moorentwicklung in der Döberitzer Heide wurde besonderes Augenmerk auf die Geschichte des Döberitzer Lindenwaldes gerichtet, der einen Sonderfall in der brandenburgischen Vegetation darstellt. Die Untersuchungen boten die Möglichkeit, die Ursachen seiner Entstehung zu klären, Aussagen zu den Perspektiven seiner Entwicklung zu treffen und mögliche Entwicklungspotentiale von Lindenwäldern im Land Brandenburg aufzuzeigen.

Pollen profiles from three former lakes in the Lake Garda area

1. Late glacial and postglacial sediments from three former lakes in the Lake Garda area (Southern Alps) were investigated. 2. The pollen diagram from Bondone (1550 m) shows an older phase rich in NAP. A younger one corresponds with the Younger Dryas time according to two radiocarbon determinations. In the Preboreal no climatic deterioration could be found. 3. At first plants, which are nowadays typical for snow-ground, pioneer and dwarf shrub associations, immigrated into the surroundings of Bondone. In Alleröd times larch and pine appeared as the first trees. At the beginning of the Preboreal dense forest existed in that region. During the Alleröd timber line was at about 1500 m. 4. In the pollen diagrams from Saltarino (194 m) and Fiavè (654 m) an oldest period rich in NAP is followed by two stadial and two interstadial phases. Tree birches and larches immigrated during the oldest interstadial phase. 5. In the case of Saltarino and Fiavè only a preliminary dating could be made. A correlation seems to be possible with diagrams published by Zoller as well as with the diagram of Bondone. Discrepances in dating, which arise then, are discussed. According to the two possibilities of dating the youngest stadial is synchronous either with the so-called Piottino stadial or the Younger Dryas time. Consequently the oldest interstadial phase of Saltarino corresponds either with the Bölling or with a pre-Bölling interstadial. The last possibility seems to be more probable. 6. In the southern part of the Lake Garda area reforestation was preceded by a long shrub phase mainly with Juniperus. At about 650 m there was a period with Pinus mugo and only with a small amount of Juniperus before reforestation. A phase with Betula nana well known from areas north of the Alps could nowhere be found. 7. In the area under study larch appeared as the first tree. Lateron it has been the most important constituent of the forests near timber line. Birch, which plays an important role as a pioneer tree in Denmark - for instance at the transition of the pollen zones III/IV - as well as in Southern Germany during Bölling time, was of less importance at the southern border of the Alps. In that area the spreading of Pinus occurred very early causing dense forests. 8. During the last stadial phase (probably Younger Dryas time) dense forests with Pinus and Larix existed at 650 m. In the lower part of the Lake Garda area, however, both thermophilous trees as Quercus and herbs frequently occurred. This leads to the conclusion that during this time tree growth was limited by dryness in lower altitudes of the border of the Southern Alps. Pinus and Juniperus, however, do not show higher values in this period, a fact which cannot yet be explained. 9. A list of plants, which were found in the sediments, is compiled. Helodium lanatum, Dictamnus albus, Mercurialis cf. ovata, Buxus, Cerinthe cf. minor, Onosma, Anthericum and Asphodelus albus are findings, which are of special interest for the history of the flora of that region.

The Global Plankton Database: an inventory and data from the Former Soviet Union expeditions

At present time, there is a lack of knowledge on the interannual climate-related variability of zooplankton communities of the tropical Atlantic, central Mediterranean Sea, Caspian Sea, and Aral Sea, due to the absence of appropriate databases. In the mid latitudes, the North Atlantic Oscillation (NAO) is the dominant mode of atmospheric fluctuations over eastern North America, the northern Atlantic Ocean and Europe. Therefore, one of the issues that need to be addressed through data synthesis is the evaluation of interannual patterns in species abundance and species diversity over these regions in regard to the NAO. The database has been used to investigate the ecological role of the NAO in interannual variations of mesozooplankton abundance and biomass along the zonal array of the NAO influence. Basic approach to the proposed research involved: (1) development of co-operation between experts and data holders in Ukraine, Russia, Kazakhstan, Azerbaijan, UK, and USA to rescue and compile the oceanographic data sets and release them on CD-ROM, (2) organization and compilation of a database based on FSU cruises to the above regions, (3) analysis of the basin-scale interannual variability of the zooplankton species abundance, biomass, and species diversity.

Pollen records and lithology of profiles from Lobsigensee, Switzerland

Lobsigensee is a small kettle hole lake 15 km north-west of Bern on the Swiss Plateau, at an altitude of 514 m asl. Its surface is 2ha today, its maximum depth 2.7 m; it has no inlet and the overflow functions mainly during snow melting. The area was covered by Rhone ice during the Last Glaciation (map in Fig.2). Local geology, climate and vegetation are summarized in Figure 3A-C, the history of settlement in Figures 5-7. In order to reconstruct the vegetational and environmental history of the lake and its surroundings pollen analysis and other bio- and isotope stratigraphies were applied to twelve profiles cored across the basin with modified Livingstone corers (Fig.3 D). (1) The standard diagram: The central core LQ-90 is described as the standard pollen diagram (Chapter 3) with 10 local pollen assemblage zones of the Late-Glacial (local PAZ Ll to Ll0, from about 16'000(7) to 10'000 years BP) and 20 PAZ of the Holocene (local PAZ L11 to L30), see Figs. 8-10 and 20-24. Local PAZ L 1 to L3 are in the Late-Glacial clay and record the vegetational development after the ice retreat: L1 shows very low pollen concentration and high Pinus percentages due to long-distance transport and reworking; the latter mechanism is corroborated by the findings of thermophilous and pre-Quaternary taxa. Local PAZ L2 has a high di versi ty of non-arboreal pollen (NAP) and reflects the Late-Glacial steppe rich in heliophilous species. Local PAZ L3 is similar but additionally rich in Betula nana and Sal1x, thus reflecting a "shrub tundra". The PAZ L1 to L3 belong to the Oldest Dryas biozone. Local PAZ L4 to L 10 are found in the gyttja of the profundal or in the lake marl of the littoral and record the Late-Glacial forests. L4 is the shrub phase of reforestation with very high Junlperus and rapidly increasing Betula percentages. L5 is the PAZ with a first, L7 with a second dominance of tree-birches, separated by L6 showing a depression in the Betula curve. L4 to L7 can be assigned to the Balling biozone. Possible correlation of the Betula depression to the Older Dryas biozone is discussed. In local PAZ L8 Plnus immigrates and expands. L9 shows a facies difference in that Plnus dominates over Betula in littoral but not in profundal spectra. L8 and L9 belong to the Allerod biozone. In its youngest part the volcanic ash from Laach/Eifel is regularly found (11,000 BP). The local PAZ Ll0 corresponds to the Younger Dryas blozone. The merely slight increase of the NAP indicates that the pine forests of the lowland were not strongly affected by a cooler climate. In order to evaluate the significance of the littoral accumulation of coniferous pollen the littoral profile LQ-150 is compared to the profundal. Radiocarbon stratigraphies derived from different materials are presented in Figures 13 and 14 and in Tables 2 and 3. The hard-water errors in the gyttja samples and the carbonate samples are similar. The samples of terrestrial plant macrofossils are not affected by hard-water errors. Two plateaux of constant age appear in the age-depth relationship; their consequence for biostratigraphy as well as pollen concentration and influx diagrams are discussed. Radiocarbon ages of the Late-Glacial pollen zones are shown in Table 10. The Holocene vegetational history is recorded in the local PAZ L 11 to L30. After a Preboreal (PAZ L11) dominated by pine and birch the expansions of Corylus, Ulmus and Quercus are very rapid. Among these taxa Corylus dominates dur ing the Boreal (PAZ L 12 and L 1 3), whereas the components of the mixed oak forest dominate in the Older Atlantic (PAZ L14 to L16). In the Younger Atlantic (PAZ L 17 to L 19) Fagus and Alnus play an increasing, the mixed oak forest a decreasing role. During the period of local PAZ L19 Neolithic settlers lived on the shore of Lobsigensee. During the Subboreal (PAZ L20 and L21) and the Older Subatlantic (L22 to L25) strong fluctuations of Fagus and often antagonistic peaks of NAP, Alnus, Betula and Corylus can be interpreted as signs of human impact on vegetation. L23 is characterized not only by high values of NAP (especially apophytes and anthropochorous species) but also by the appearance of Juglans, Castanea and Secale which point to the Roman colonization of the area. For a certain period during the Younger Subatlantic (PAZ L26 to L30) the lake was used for retting hemp (Cannabis). Later the dominance of Quercus pollen indicates the importance of wood pastures. The youngest sediments reflect the wide-spread agricultural grass lands and the plantation of Pinus and Picea. Radiocarbon dates for the Holocene are given in Figure 23 and Table 4, the extrapolated ages of the Holocene pollen zones in Table 15. (2) The cross sections: Figures 25 and 26 give a summary of the litho- and palynostratigraphy of the two cross sections. Based on 11 Late-Glacial and 9 Holocene pollen diagrams (in addition to the standard ones), the consistency of the criteria for the definition of the pollen zones is examined in Tables 7 and 8 for the Late-Glacial and in Tables 11 to 14 for the Holocene. Sediment thicknesses across the basin for each pollen zone are presented in these tables as well as in Figures 43 to 45 for the Late-Glacial and in Figures 59 to 65 for the Holocene. Sediment focusing can explain differences between the gyttja cores of the profundal. Focusing is more than compensated for through "stretching" by carbonate precipitation on the littoral terrace. Pollen influx to the cross section are discussed (Chapters 4.1.5. and 4.2.3.). (3) The regional pollen zones: Based on some selected sites between Lake Geneva and Lake Constance regional pollen zones are proposed (Table 16, 17 and 19). (4) Paleoecology: Climatic change in the Late-Glacial can be inferred from Coleoptera, Trichoptera, Chironomidae and d18O of carbonates: a distinct warming is recorded around 12' 600 BP and around 10' 000 BP. The Younger Dryas biozone (10'700-10'000 BP) was the only cooling found in the Late-Glacial. The Betula depression often correlated wi th the Older Dryas biozone was possibl not colder but dryer than the previous period. During the Holocene the lowland site is not very sensitive to the minor climatic changes. Table 22 summarizes climatic and trophic changes before 8'000 BP as deduced from various biostratigraphies studied by a number of authors. Ostracods, Chironomids and fossil pigments indicate that anoxic conditions prevailed during the BoIling (possibly meromixis). Changes in the lake level are illustrated in Figure 74. A first lake-level lowering occurred in the early Holocene (10'000 to 9'000 BP), a second during the Atlantic (about 6'800 to 5'200 BP). The first "shrinking" of the lake volume resulted in a eutrophication recorded by laminations in the profundal and by pigments of Cyanophyceae. The second fall in water level corresponds to an increase of Nymphaeaceae. Human impact can be inferred in three ways: eutrophication of the lake (since the Neolithic), changes of terrestrial vegetation by deforestations (cyclicity of Fagus, see Figures 78 to 80), and enhanced erosion (increasing sedimentation rates by inwashed clay, particularly since the Roman Colonization, see Figures 49 and 81). Summary: This paper was planned as the final report on Lobsigensee. However, a number of issues are not answered but can only be asked more precisely, for example: (1) For the two periods with the highest rates of change, Le. the Bolling and the Preboreal biozones, pollen influx may reflect vegetation dynamics. Detailed investigations of these periods in annually laminated sediments are planned. (2) Biostratigraphies other than palynostratigraphy are needed to estimate the degree of linkage or independence in the development of terrestrial and lacustrine ecosystems. Often our sampling intervals were not identical, thus influencing our temporal resolution. (3) 6180- and 14C-stratigraPhies with high resolution will elucidate the leads and lags of these dynamic periods. Plateaux of constant age in the age-depth relationship have a strong bearing on both biological and geophysical understanding of Late-Glacial and early Holocene developments. (4) Numerical methods applied to the pollen diagrams of the cross section will help to quantify the significance of similari ties and dissimilarities across a single basin (with Prof. Birks). (5) Numerical methods applied to different sites on the Swiss Plateau and on the transect across the Alps will be helpful in evaluating the influence of different environmental factors (with Prof. Birks). (6) A new map 1: 1000 with 50cm-contour lines prov ided by Prof. Zurbuchen will be combined with a grid of cores sampling the transition from lake marl to peat enabling us to calculate paleo-volumes of the lake. This is interesting for the two "shrinking periods" (in Fig. 74A numbers 2-6 and 7-10), both accompanied by eutrophication. The pal eo-volume during the Neoli thic set tlement of the Cortaillod culture linked wi th an est l.mate of trophic change derived from diatoms (Prof. Smol in prep.) could possibly give an indication of the size of the human population of this period. (7) For the period with the antagonism between Fagus peaks and ABC-peaks close collaboration between palynologists, geochemists and archeologists should enable us to determine the influence of prehistoric and historic people on vegetation (collaboration with Prof. Stockli and Prof. Herzig). (8) The core LL-75 taken with a "cold letter box" will be analysed for major and trace elements by Dr. Sturm for 210pb and 137Cs by Prof.von Gunten and for pollen. We will see if our local PAZ L30 really corresponds to the surface sediment and if the small seepage lake reflects modern pollution.