@article{BareitherScheffelMetz2017,
  author    = {Bareither, Nils and Scheffel, Andre and Metz, Johannes},
  title     = {Distribution of polyploid plants in the common annual Brachypodium distachyon (s.l.) in Israel is not linearly correlated with aridity},
  series = {Israel Journal of Plant Sciences},
  volume    = {64},
  journal   = {Israel Journal of Plant Sciences},
  publisher = {Taylor \& Francis},
  address   = {London},
  issn      = {0792-9978},
  pages     = {83 -- 92},
  year      = {2017},
  abstract  = {The ecological benefits of polyploidy are intensely debated. Some authors argue that plants with duplicated chromosome sets (polyploids) are more stress- resistant and superior colonizers and may thus outnumber their low ploidy conspecifics in more extreme habitats. Brachypodium distachyon (sensu lato), for example, a common annual grass in Israel and the entire Mediterranean basin, comprises three cytotypes of differing chromosome numbers that were recently proposed as distinct species. It was suggested that increased aridity increases the occurrence of its polyploid cytotype. Here, we tested at two spatial scales whether polyploid plants of B. distachyon s. l. are more frequently found in drier habitats in Israel. We collected a total of 430 specimens (i) along a largescale climatic gradient with 15 thoroughly selected sites (spanning 114- 954 mm annual rainfall), and (ii) from corresponding Northern (more mesic) and Southern (more arid) hill slopes to assess the micro- climatic difference between contrasting exposures. Cytotypes were then determined via flow cytometry. Polyploid plants comprised 90\% of all specimens and their proportion ranged between 0\% and 100\% per site. However, this proportion was not correlated with aridity along the large- scale gradient, nor were polyploids more frequently found on Southern exposures. Our results show for both spatial scales that increasing aridity is not the principal driver for the distribution of polyploids in B. distachyon s. l. in Israel. Notably, though, diploid plants were restricted essentially to four intermediate sites, while polyploids dominated the most arid and the most mesic sites. This, to some degree, clustered pattern suggests that the distribution of cytotypes is not entirely random and calls for future studies to assess further potential drivers.},
  language  = {en}
}
@article{SoliveresMaestreUlrichetal.2015,
  author    = {Soliveres, Santiago and Maestre, Fernando T. and Ulrich, Werner and Manning, Peter and Boch, Steffen and Bowker, Matthew A. and Prati, Daniel and Delgado-Baquerizo, Manuel and Quero, Jose L. and Sch{\"o}ning, Ingo and Gallardo, Antonio and Weisser, Wolfgang W. and M{\"u}ller, J{\"o}rg and Socher, Stephanie A. and Garcia-Gomez, Miguel and Ochoa, Victoria and Schulze, Ernst-Detlef and Fischer, Markus and Allan, Eric},
  title     = {Intransitive competition is widespread in plant communities and maintains their species richness},
  series = {Ecology letters},
  volume    = {18},
  journal   = {Ecology letters},
  number    = {8},
  publisher = {Wiley-Blackwell},
  address   = {Hoboken},
  issn      = {1461-023X},
  doi       = {10.1111/ele.12456},
  pages     = {790 -- 798},
  year      = {2015},
  abstract  = {Intransitive competition networks, those in which there is no single best competitor, may ensure species coexistence. However, their frequency and importance in maintaining diversity in real-world ecosystems remain unclear. We used two large data sets from drylands and agricultural grasslands to assess: (1) the generality of intransitive competition, (2) intransitivity-richness relationships and (3) effects of two major drivers of biodiversity loss (aridity and land-use intensification) on intransitivity and species richness. Intransitive competition occurred in >65\% of sites and was associated with higher species richness. Intransitivity increased with aridity, partly buffering its negative effects on diversity, but was decreased by intensive land use, enhancing its negative effects on diversity. These contrasting responses likely arise because intransitivity is promoted by temporal heterogeneity, which is enhanced by aridity but may decline with land-use intensity. We show that intransitivity is widespread in nature and increases diversity, but it can be lost with environmental homogenisation.},
  language  = {en}
}
@article{MaslinPancostWilsonetal.2012,
  author    = {Maslin, Mark A. and Pancost, Richard D. and Wilson, Katy E. and Lewis, Jonathan and Trauth, Martin H.},
  title     = {Three and half million year history of moisture availability of South West Africa evidence from ODP site 1085 biomarker records},
  series = {Palaeogeography, palaeoclimatology, palaeoecology : an international journal for the geo-sciences},
  volume    = {317},
  journal   = {Palaeogeography, palaeoclimatology, palaeoecology : an international journal for the geo-sciences},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0031-0182},
  doi       = {10.1016/j.palaeo.2011.12.009},
  pages     = {41 -- 47},
  year      = {2012},
  abstract  = {Ocean Drilling Program Site 1085 provides a continuous marine sediment record off southern South West Africa for at least the last three and half million years. The n-alkane partial derivative(13) C record from this site records changes in past vegetation and provides an indication of the moisture availability of SW Africa during this time period. Very little variation, and no apparent trend, is observed in the n-alkane delta C-13 record, suggesting stable long-term conditions despite significant changes in East African tectonics and global climate. Slightly higher n-alkane delta C-13 values occur between 3.5 and 2.7 Ma suggesting slightly drier conditions than today. Between 2.5 and 2.7 Ma there is a shift to more negative n-alkane delta C-13 values suggesting slightly wetter conditions during a similar to 0.2 Ma episode that coincides with the intensification of Northern Hemisphere Glaciation (iNHG). From 2.5 to 0.4 Ma the n-alkane delta C-13 values are very consistent, varying by less than +/- 0.5 parts per thousand and suggesting little or no long-term change in the moisture availability of South West Africa over the last 2.5 million years. This is in contrast to the long-term drying trend observed further north offshore from the Namib Desert and in East Africa. A comparison of the climate history of these regions suggests that Southern Africa may have been an area of long-term stability over the last 3.5 Myrs.},
  language  = {en}
}