Plant-associated bacteria are important for the growth and health of their host, but little is known about its functional diversity and impact on ecosystem functioning. We studied bacterial nitrogen fixation and methane oxidation from indicator Sphagnum mosses in Alpine bogs to test a hypothesis that the plant microbiome contained different functional patterns depending on their functions within the ecosystem. A high abundance and diversity of nitrogenase genes were detected, mostly specific for each Sphagnum. In contrast, methanotrophs formed highly similar patterns despite a high abundance and diversity of methane monooxygenase genes. Our hypothesis was supported by these contrasting functional patterns together with the result that the Sphagnum sporophyte contained a high proportion of specific diazotrophs (45.5%) but no potential methanotrophs. While essential for plant growth under nutrient-limited conditions, nitrogen-fixing bacteria were highly specific and transferred with the sporophyte unlike the ubiquitous methanotrophs which are important for the climate-relevant ecosystem itself.

Broennimann O., Vittoz P., Moser D. and Guisan A. 2005. Rarity types among plant species with high conservation priority in Switzerland. We investigated the ecogeographic characteristics of 118 Swiss plant species listed as those deserving highest conservation priority in a national conservation guide and classified them into the seven Rabinowitz' rarity types, taking geographic distribution, habitat rarity and local population size into account. Our analysis revealed that species with high conservation priority in Switzerland mostly have a very restricted geographic distribution in Switzerland and generally occur in rare habitats, but do not necessarily constitute small populations and are generally not endemics on a global scale. Moreover, species that are geographically very restricted on a regional scale are not generally restricted on a global scale. By analysing relationships between rarity and IUCN extinction risks for Switzerland, we demonstrated that species with the highest risk of extinction are those with the most restricted geographic distribution; whereas species with lower risk of extinction (but still high conservation priority) include many regional endemics. Habitat rarity and local population size appeared to be of minor importance for the assessment of extinction risk in Switzerland, but the total number of fulfilled rarity criteria still correlated positively with the severity of extinction risk. Our classification is the first preliminary assessment of the relative importance of each rarity type among endangered plant species of the Swiss flora and our results underline the need to distinguish between a regional and a global responsibility for the conservation of rare and endangered species.Key words: Rabinowitz' rarity types, conservation practice, extinction risk, geographic distribution, rarity assessment, vascular plants. IntroductonIn the effort to conserve biodiversity worldwide, resources are often directed toward protecting rare species since these are assumed to undergo the highest risk of 95 Bot. Helv. 115 (2005): 95-108

In response to ongoing local extinction of species and the current biodiversity crisis, the number of rein troduction programs aiming to establish new populations of rare species in the wild has increased, How ever, only a small proportion of these programs has been planned and monitored scientifically and comparative multi-species studies are missing in this context. Therefore, the relative importance of fac tors involved in reintroduction success is poorly known. In 2007, we assessed population growth since introduction as a measure of establishment success of 25 wetland species (rare or extinct in the wild nationwide) and a total of 50 populations in Switzerland that had been introduced at seven restored sites with apparently adequate environmental conditions between 1997 and 2005. We related establishment success to 32 life-history traits of these species obtained from the BiolFlor database, to initial number of introduced plants (propagule pressure with 1-130 individuals introduced per population), and to the ecological distance between source sites and restored sites based on vegetation records. Our results clearly showed the importance of close ecological similarity between source and introduction sites for successful establishment of wetland species into restored pond habitats. In contrast, neither life-history traits nor propagule pressure were related to establishment success in our study. Based on our results, we strongly recommend enforcing ecological studies prior to reintroduction to accurately assess the suitabil ity of restored sites, To unambiguously assess the key determinants of successful establishment, future reintroduction programs should be setup according to experimental designs.

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Bäumler B., Moser D. M., Gygax A., Latour C. and Wyler N. 2005. Biodiversity Monitoring Switzerland 2001-2003; new floristic records, neophytes and red list species. Bot. Helv. 115: 83-93. As part of the Biodiversity Monitoring Switzerland (BDM), comprehensive records of vascular plant species are made along 2.5-km transects and on 10-m 2 plots distributed regularly over the entire surface of Switzerland (www.biodiversitymonitoring.ch). Here we analyse data from 2001-2003 for 275 transects and 773 plots (70'287 floristic records). A comparison with the distribution atlas of vascular plants (based on data from [1982][1983][1984][1985][1986][1987][1988][1989][1990][1991][1992][1993][1994] shows that 3'481 records of indigenous taxa from the BDM were new, i.e. species that had not been found in the corresponding mapping unit previously. Alien species (mostly of non-European origin) represented 2.11% of the 2.5-km transect records and 1.01% of the 10-m 2 plot records. Red list species (critically endangered, endangered or vulnerable) represented 0.26% of the transect records and 0.06% of the plot records. These percentages are low, given that in 2002, the Swiss flora included 17.5% of alien species and 31.5% of red list species. In accordance with its purpose and methodology, the BDM mainly shows the distribution of widespread species, whereas other monitoring approaches are needed for rare species.