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- Plue, Jan, et al.
(author)
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European soil seed bank communities across a climate and land-cover gradient
- 2020
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Other publicationabstract
- This is the data set used for the publication Buffering effects of soil seed banks on plant community composition in response to land use and climate, published in the journal Global Ecology and Biogeography.Aim.Climate and land use are key determinants of biodiversity, with past and ongoing changes posing serious threats to global ecosystems. Unlike most other organism groups, plant species can possess dormant life-history stages such as soil seed banks, which may help plant communities to resist or at least postpone the detrimental impact of global changes. This study investigates the potential for soil seed banks to achieve this.Location. EuropeTime period. 1978 – 2014Major taxa studied. Flowering plantsMethods.Using a space-for-time/warming approach, we study plant species richness and composition in the herb layer and the soil seed bank in 2796 community plots from 54 datasets in managed grasslands, forests and intermediate, successional habitats across a climate gradient.Results.Soil seed banks held more species than the herb layer, being compositionally similar across habitats. Species richness was lower in forests and successional habitats compared to grasslands, with annual temperature range more important than mean annual temperature for determining richness. Climate and land use effects were generally less pronounced when plant community richness included seed bank species richness, while there was no clear effect of land use and climate on compositional similarity between the seed bank and the herb layer.Main conclusions.High seed bank diversity and compositional similarity between the herb layer and seed bank plant communities may provide a potentially important functional buffer against the impact of ongoing environmental changes on plant communities. This capacity could, however, be threatened by climate warming. Dormant life-history stages can therefore be important sources of diversity in changing environments, potentially underpinning already observed time-lags in plant community responses to global change. However, as soil seed banks themselves appear, albeit less, vulnerable to the same changes, their potential to buffer change can only be temporary, and major community shifts may still be expected.MethodsThis dataset is a collection of 41 published and 5 unpublished data sets, consisting of 2796 plots with corresponding seed bank and herb layer community data. Sampling effort varied across data sets, but involved sampling of the soil and subsequent germination trials in a greenhouse to determine seed bank composition. Herb layer communities were determined by the identification of plants in relevés. Please consult the readme file and published paper for further details.Usage NotesPlease contact database or individual data set authors for further information and collaboration when using the data set or any of its component parts. Please also note that some of these data sets have already been published alongside their orginal papers. Finally, please cite data and datasets according to community standards.
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| 2. |
- Rydgren, Knut, et al.
(author)
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Infrequent sporophyte production maintains a female-biased sex ratio in the unisexual clonal moss Hylocomium splendens
- 2010
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In: Journal of Ecology. - : Wiley. - 1365-2745 .- 0022-0477. ; 98:5, s. 1224-1231
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Journal article (peer-reviewed)abstract
- P>1. Sex ratios in unisexual bryophytes are most often female biased, whereas male-biased sex ratios predominate in unisexual seed plants. This 'bryophyte paradox', i.e. that sex ratios are biased in favour of the sex associated with the highest reproductive costs, has remained unexplained. 2. Analysis of sex-ratio patterns via the influence of sex distribution on population growth rates (lambda) has not previously been carried out for bryophytes. We used this method to model how variation in sex ratio and sporophyte frequency influences lambda in the clonal bryophyte Hylocomium splendens. We obtained lambda by matrix modelling of synthetic experimental populations derived from demographic field data, using a linear two-sex model. 3. In our set of experimental populations lambda varied between 1.13 and 1.27 in response to variation in sex ratio and sporophyte frequency, with the highest lambda obtained for the combination of a very low sporophyte frequency and a slightly female-biased sex ratio. 4. Our results explain the female-biased sex ratio of H. splendens by the slightly lower survival of and production of vegetative offspring by males than by non-sporophytic females. 5. Synthesis. According to our models, female dominance is the predicted outcome of low to moderate fertilization success and male performance intermediate between that of sporophytic and of non-sporophytic females. Our results therefore explain how a female-biased sex ratio can be maintained despite higher costs of reproduction in females than in males. In dioecious bryophytes, males and females must grow in close contact for fertilization to take place. Better performance of male ramets than of the female ramets they fertilize also explains how male clones can expand into female clones. A similar performance hierarchy of males and females may occur in unisexual clonal seed plants, but more efficient fertilization systems by pollination prevents the selective advantage of unfertilized females from being realized. This explains why vascular plant populations tend to be male biased. We hypothesise difference in fertilization distance range between sperm and pollen as a simple explanation why ramet level sex ratios are in general male dominated in clonal seed plants and female dominated in clonal bryophytes.
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