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With the aim to study the vegetational changes related to the variations of sea level during the Holocene in the SE of Buenos Aires province, Argentina, a palynological study was performed at an exposed profile at La Ballenera creek (38º 19'S, 57º 57'W). The 230 cm long sediment profile dated in 6790 yr B.P. near the base and in 4120 yr B.P. at the top with an intermedia te date of 6120 yr B.P. produced a pollen and stratigraphic record. Five zones are distinguished in the profile. The lowermost zone, before 6790 yr B.P., represents regional vegetation dorninated by Poaceae and without marine influence. The sediments consist of massive muds, rich in organic matter and very fine sands. After 6790 yr B.P. began the marine influence suggested by the first appearance of marine elements (acritarchs) and the increasing values of Chenopodiineae. The sediments become rich in medium and coarse sands and contain fossiliferous layers (Littoridina sp.). Then a fresh water input is suggested by the high values of Cyperaceae. Between ca. 6200 and ca. 5500 yr B.P. the marine elements continue increasing, suggesting a great marine influence. A halophilous community dominated by Chenopodiineae and the aquatics Ruppia and Botryococcus indicate brackish conditions. Towards ca. 5000 yr B.P. the Chenopodiineae reach the highest values indicating a salt marsh vegetation. The greatest marine influence occurs between ca. 5000 and 4100 yr B.P., characterized by the highest values of marine elements. At the end of the profile the increasing of Chenopodiineae suggests again the establishment of the salt marsh community.KEY WORDS. Pollen. Vegetation. Sea level change. Holocene. Argentina. 

The relation between pollen germination "in-vitro", fluorochromatic reaction and dye with cotton blue in lactofenol test as indicator of pollen viability in two Solanum sec. Cyphomandropsis species (Solanum glaucophyllum Desf. and Solanum stuckertii Bitter) is studied. The statistic analysis proves cotton blue in lactofenol test datam are of scarce value. The fluorochromatic reaction and the germination "in-vitro" test don't show significatives differences; the results are similar in the flowers of the first and second day of anthesis in Solanum glaucophylum and in flowers of the second day of Solanum stuckertii. Meanwhile the pollen from the first day of anthesis flowers of Solanum stuckertii dye an 87% in fluorachromatic reaction, only the 25% of them can germinate "in vitro". This study demonstrates that the fluorochromatic reaction manifests the presence of pollen grains with alive cytoplasm, but by germination "in-vitro" test the exact percentage of germination is obtained.KEY WORDS. Viability. Fluorochromatic reaction. Pollen. Cultivation "in vitro". Solanum.

This paper investigates the pollen taphonorny, based on the analysis of superficial samples in and near a "sac" cave with a single entrance (Cueva de José, 37° 38' N; 1° 7' W), in the semiarid Spanish south-east. Statistical comparisons and the isopoll maps for herbs, shrubs and trees, four shrubby zoophilous pollen [Helianthemun (Cistaceae), Lamiaceae hexacolpate, Coronilla (Papilionaceae) and Cichorioideae] and an anemophilous pollen (Pinus) show that the spatial distribution, concentration and preservation of pollen inside the cave are not homogeneous and are influenced by the cave's morphology, water leaks and types of pollination. The biotic vector, represented by insects and animals (mainly through excrement) is an important source of pollen in the cave sediments. The isopoll curves show that all the types that represent the regional vegetation are present in the cave in different percentages, depending on their distance from the entrance. Local vegetation is over-represented and this should be taken into consideration before any palaeoenvironmental reconstruction is made on the basis of pollen samples from archaeological sites. On the other hand, the isopoll maps permitted an assessment of the possible places where fossil profiles could be obtained with the minimum bias, as long as the entrance to the cave has always remains the same. The pollen grains are better preserved inside the cave than outside, which is another valuable piece of information for the use of pollen records in the interpretation of past vegetation.KEY WORDS. Pollen analysis. Taphonomy. Caves. Isopoll maps. Spain.

Fossil pollen evidence from the archaeological sequence Chorrillo Malo 2 is used to infer vegetational and climatic changes which occurred during the past 5000 yr in the steppe environments of the Parque Nacional Los Glaciares (50º 30' S; 72° 40' O). The vegetational and paleoclimatic history is based on the comparison with modern pollen analogs documents across the region. Detrented correspondence analysis (DECORANA) from Chorrillo Malo 2 and two additional palynological records in the region is also used to establish past changes in the steppe environments a grass steppe dominated the sequence between 5000 and 4500 yr BP. In El Sosiego 4 (north of the lago Argentino), Chorrillo Malo 2 and Charles Fuhr 2 (east of the lago) sequences, a shrub steppe of Asteraceae tubuliflorae prevailed between ca. 4500 and 1900 yr Br. An expansion of the grass steppe is registered from 1900 and 200 yr BP. During the last 200 years a shrub steppe is developed in areas located east and north of the lago Argentino. Dominance of grass versus shrub steppe is related with changes in hydric availability.KEY WORDS. Patagonia. Holocene. Pollen. Vegetation history. Archaeological sequences.

In order to typify honeys from the southern area of the Austral Pampeanous District, a study about botanical origin and physico-chemical characteristics was carried out on 43 honey samples collected along 1995, 1996 and 1997. Fourty morphological types were identified to the closest possible taxon. Eucalyptus L' Hér. genus was dominant in 98% of the samples. According to the elected criterion, 83,7% or 46,5% of the samples may be considered monofloral. Two introduced weeds, Diplotaxis tenuifolia (L.) DC and Centaurea spp., showed a very high frequency of occurrence (93% and 86% respectively), nevertheless only 2% of the samples were determined as monofloral from D. tenuifolia and none of them of Centaurea spp. Pollen from native species was rare. The colour of 79% of the samples was ranged within extra light amber and amber. A positive relation between colour and Eucalyptus pollen percentage, in samples in which Eucalyptus was dominant, was found. Hydroxymethylurfural content was low (2,99±2,36 mg kg-1), showing an adequate heat treatment of honey during decapping and extracting processes by the beekeepers.KEY WORDS. Melisopalynology. Honey. Pollen analysis. Physico-chemical analysis.

Airborne pollen concentration in the Mar del Plata atmosphere was analyzed during two consecutive years. Also plant sources and flowering development was studied. Quercus was the selected taxon. Pollen amount depends on plant number and spatial distribution. Pollen patterns agree with floral phenology. Q. robur productivity was higher in 1993 due to better conditions before flowering time. On the contrary Q. ilex annual sum was higher in 1994; a cyclic reproductive rhythm is postulated. Meteorological conditions during dispersion are not enough to explain interannual variability.KEY WORDS. Airborne pollen. Flowering phenology. Productivity. Dispersion. Urban vegetation.

This paper presents the results of a palynological study from a pond sediment core obtained at Laguna La Colorada (37º 04' S 56º 58' O). A total of 54 pollen taxa were identified along a 140 cm long sediment sequence where 15 pollen samples were collected at regular intervals. The zonation of the obtained pollen diagram was based on an stratigraphycal constrained Cluster Analysis preformed to pollen taxa with values highest than 2% of pollen sum. Two zones were identified in the sequence: a bottom section, with prevalence of Poaceae and low values of Chenopodiineae and Myriophyllum. These taxa indicate extension of the grassland and reduction of the body water that corresponds to a drier period. The top section, with prevalence of aquatic plants, indicates a moister period. In the most upper section both palynological taxa and sediment characteristics evidence human activity.KEY WORDS. Palinology. Pond core. Late Holocen. Buenos Aires Province. Argentina.

This work deals with identification and registration of the flowering period of plants known or suspected of causing pollinosis in Bahía Blanca city and surrounding area. Firstly 21 species were selected for study, and pollen was collected. This material was then used by allergy specialist physicians to obtain the allergens that were tested on patients affected by pollinosis. The flowering calendar of 21 species is presented. The period in which the most species of Poaceae and Chenopodiaceae families are in flower, is coincident with an increase in the intensity and the frequency of the disease symptons, tested by allergy specialists. This study is still in progress because more knowledge of the allergenic flora is required for the diagnosis and treatment of pollinosis.KEY WORDS. Anemophilous pollen. Pollinosis. Allergenic flora.