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This document is a profile of Martina Legris, a postdoctoral researcher at the Center for Integrative Genomics at the University of Lausanne in Switzerland. Martina's interest in plant science was inspired by her upbringing in a family of veterinarians and farmers, as well as her experiences playing with plants and animals in nature. She decided to pursue a career in research after participating in scientific meetings and outreach activities, where she met inspiring scientists and learned about their research. Martina is motivated by her love for her work and the sense of duty to contribute to society. She considers her mentors and female colleagues with children to be role models, and she appreciates the opportunity to choose her research topics and the variety of tasks in her everyday life. Martina's research focuses on plant development in response to light and temperature signals from the environment. She has published papers on the convergence of light and temperature signaling pathways in plants and the regulation of meristem activity. Martina's favorite plant is Ceiba speciosa, a large tree native to South America, and she also has a fondness for Arabidopsis thaliana, a tiny plant that has allowed her to uncover exciting aspects of plant biology. [Extracted from the article]

The objectives of this paper were to review the literature on the responses of root systems to elevated CO2 in intact, native grassland ecosystems, and to present the results from a 2-yr study of root production and mortality in an intact calcareous grassland in Switzerland. Previous work in intact native grassland systems has revealed that significant stimulation of the size of root systems (biomass, length density or root number) is not a universal response to elevated CO2. Of the 12 studies reviewed, seven showed little or no change in root-system size under elevated CO2, while five showed marked increases (average increase 38%). Insufficient data are available on the effects of elevated CO2 on root production, mortality and life span to allow generalization about effects. The diversity of experimental techniques employed in these native grassland studies also makes generalization difficult. In the present study, root production and mortality were monitored in situ in a species-rich calcareous grassland community using minirhizotrons in order to test the hypothesis that an increase in these two measures would help explain the increase in net ecosystem CO2 uptake (net ecosystem exchange) previously observed under elevated CO2 at this site (600 vs 350 μl CO2 l−1; eight 1.2-m2 experimental plots per CO2 level using the screen-aided CO2 control method). However, results from the first 2 yr showed no difference in overall root production or mortality in the top 18 cm of soil, where 80-90% of the roots occur. Elevated CO2 was associated with an upward shift in root length density: under elevated CO2 a greater proportion of roots were found in the upper 0-6-cm soil layer, and a lower proportion of roots in the lower 12-18 cm, than under ambient CO2. Elevated CO2 was also associated with an increase in root survival probability (RSP; e.g. for roots still alive 280 d after they were produced under ambient CO2, RSP = 0.30; elevated CO2, RSP = 0.56) and an increase (48%) in median root life span in the deepest (12-18 cm) soil layer. The factors driving changes in root distribution and longevity with depth under elevated CO2 were not clear, but might have been related to increases in soil moisture under elevated CO2 interacting with vertical patterns in soil temperatures. Thus extra CO2 taken up in this grassland ecosystem during the growing season under elevated CO2 could not be explained by changes in root production and mortality. However, C and nutrient cycling might be shifted closer to the soil surface, which could potentially have a substantial effect on the activities of soil heterotrophic organisms as CO2 levels rise. [ABSTRACT FROM AUTHOR]

This paper gives a detailed outline of Swiss vegetation history during the last 18 000 years. For each pollen zone, a map is given showing vegetation development from the late Würmian to the present. A concise historical review of the Swiss pollen analytical research during the last 60 years is presented is followed by some discussion of the central European glacial refugia. Based on a selection of over 100 pollen-analytical]y investigated sites, the development of Swiss vegetation since the late Würmian can be presented as follows: 1. Oldest Dryas. After the Würm maximum the ice network melted back quickly to small mountain glaciers. At some localities, several types of an Artemisia-Chenopodiaceae-Juniperus-Ephedra-Helianthemum-Poaceae steppe/tundra have been recorded, representing an apparent uniformity over the whole Swiss area. 2. Bölling Interstadial. This first, late Würmian, warm phase is characterized by the occurrence of Betula, Hippopha&euml, Juniperus, Ephedra and Salix. 3. Older Dryas. Little evidence for this period has yet been found in Switzerland. 4. Alleröd Interstadial. This marked warm phase led to a typical late Würmian reforestation, with both Betula and Pinus up to about 1200-1600 m above sea level. 5. Younger Dryas. In the whole alpine area there is good evidence for this last, late Würmian climate deterioration, which led to renewed glacier activity and to an alpine timber-line depression of 200 300 m. 6. Preboreal. For the central Alps and the Prealps a wide occurrence of Pinus sylvestris/mugo, P. cembra, Larix and Betula has been recorded, whereas in southern Switzerland the first mixed oak forest developed. 7. Boreal. Corylus and mixed oak forest spread in some cases rapidly over a wide area, chiefly in the Prealps, the Plateau, the Jura and in southern Switzerland. In the high mountains Pinus sylvestris/mugo, P. cembra and Larix still dominated.8. Older Atlantic. In both the Plateau and the Prealps, Corylus and mixed oak forest dominated, whereas in the continental Alps Pinus slvestoris/mugo, P. cembra and Betula grew with some elements of mixed oak forest. In the Grisons the immigration of Picea from east to west has been identified; in the eastern Prealps abies spread. 9. Younger Atlantic. This period is characterized in' a first maximum of' the timber-line extension to an altitude of about 2300 m. The spread of Fagus from west to east is seen on both the montane and subalpine belt, first Abies and later Picea dominated. Picea immigration to the west continued. 10. Subboreal. Until 3000 yr B.P. forest achieved its optimum development with a distribution tip to 2000 in above sea level. In both the Plateau and the Jura the major spread of Fagus took place in this period. Piece;now reached southwestern jura and even the Lake Geneva region. 11 .Subatlantic, This period is characterized by man's influence on the vegetation .According to the evidence of both pollen anal sis and archaeology, the first anthropogenic influences on Swiss vegetation took place between 6000 and 4500 yr B.P. In the anthropogenic timber-line belt secondary forests of Betula, Allunus and Pinus formed. On the southern alpine border, the Romans introduced Castanea, whereas on the Plateau Picea, Abies and Pinus have been planted. [ABSTRACT FROM AUTHOR]