TY - JOUR A1 - Schwarzer, Christian A1 - Huamani, Fatima Cßceres A1 - Cano, Asunción A1 - La Torre, María I. La A1 - Weigend, Maximilian T1 - 400 years for long-distance dispersal and divergence in the northern atacama desert : insights from the Huaynaputina pumice slopes of Moquegua, Peru N2 - The Huaynaputina eruption (1600 AD, Moquegua, S Peru) in the northern Atacama Desert denuded the Ornate area of all vegetation and deposited deep pumice layers. Data on the flora, climate and soil characteristics of these slopes near Ornate at 1600-2600 m a.s.l. are provided. Fifty-nine angiosperm species established themselves on the pumice slopes in the past ca. 400 years, with the bulk of the small and herbaceous species and several species new records for Peru. Three Ornate sites were sampled in both a dry and a wet year and species numbers differed widely (14 versus 45 spp.). Among areas compared floristic composition is most similar to the Lomas de Tacna, and has less in common with geographically closer Lomas or Sierra formations. Nine species represent highly disjunct populations (200->700 km) from their nearest known living populations in central Peru, Chile, or Argentina/Bolivia and appear to have reached the area via long-distance dispersal. Abiotic conditions may have played an important role in limiting the establishment of species from the neighboring vegetation. Four taxa on the pumice slopes show clear morphological differences to populations elsewhere, two of them may represent neoendemics of the Ornate pumice, indicating rapid morphological divergence. (C) 2010 Elsevier Ltd. All rights reserved. Y1 - 2010 U6 - https://doi.org/10.1016/j.jaridenv.2010.05.034 SN - 0140-1963 ER - TY - THES A1 - Schwarzer, Christian T1 - Climate change, adaptive divergence and their effects on species interactions in European bog-plant communities Y1 - 2018 ER - TY - JOUR A1 - Schwarzer, Christian A1 - Joshi, Jasmin Radha T1 - Ecotypic differentiation, hybridization and clonality facilitate the persistence of a cold-adapted sedge in European bogs JF - Biological journal of the Linnean Society : a journal of evolution N2 - Recent research has shown that many cold-adapted species survived the last glacial maximum (LGM) in northern refugia. Whether this evolutionary history has had consequences for their genetic diversity and adaptive potential remains unknown. We sampled 14 populations of Carex limosa, a sedge specialized to bog ecosystems, along a latitudinal gradient from its Scandinavian core to the southern lowland range-margin in Germany. Using microsatellite and experimental common-garden data, we evaluated the impacts of global climate change along this gradient and assessed the conservation status of the southern marginal populations. Microsatellite data revealed two highly distinct genetic groups and hybrid individuals. In our common-garden experiment, the two groups showed divergent responses to increased nitrogen/phosphorus (N/P) availability, suggesting ecotypic differentiation. Each group formed genetically uniform populations at both northern and southern sampling areas. Mixed populations occurred throughout our sampling area, an area that was entirely glaciated during the LGM. The fragmented distribution implies allopatric divergence at geographically separated refugia that putatively differed in N/P availability. Molecular data and an observed low hybrid fecundity indicate the importance of clonal reproduction for hybrid populations. At the southern range-margin, however, all populations showed effects of clonality, lowered fecundity and low competitiveness, suggesting abiotic and biotic constraints to population persistence. KW - biogeography KW - bog/mire plants KW - Carex limosa KW - climate change KW - glacial divergence KW - global change KW - leading/trailing edge KW - population differentiation KW - sexual/asexual reproduction Y1 - 2019 U6 - https://doi.org/10.1093/biolinnean/blz141 SN - 0024-4066 SN - 1095-8312 VL - 128 IS - 4 SP - 909 EP - 925 PB - Oxford Univ. Press CY - Oxford ER - TY - JOUR A1 - Schwarzer, Christian A1 - Heinken, Thilo A1 - Luthardt, Vera A1 - Joshi, Jasmin Radha T1 - Latitudinal shifts in species interactions interfere with resistance of southern but not of northern bog-plant communities to experimental climate change JF - The journal of ecology N2 - The persistence of species under changed climatic conditions depends on adaptations and plastic responses to these conditions and on interactions with their local plant community resulting in direct and indirect effects of changed climatic conditions. Populations at species' range margins may be especially crucial in containing a gene pool comprising adaptations to extreme climatic conditions. Many species of northern European bog ecosystems reach their southern lowland range limit in central Europe. In a common-garden experiment, we experimentally assessed the impact of projected climatic changes on five bog-plant species (including peat moss Sphagnum magellanicum) sampled along a latitudinal gradient of 1400km from Scandinavia to the marginal lowland populations in Germany. Populations were cultivated in monocultures and in experimental communities composed of all five species from their local community, and exposed to five combinations of three climate treatments (warming, fluctuating water-tables, fertilization) in a southern common garden. Whereas most monocultures showed a decreasing biomass production from southern to northern origins under southern environmental conditions, in the experimental mixed-species communities, an increasing biomass production towards northern communities was observed together with a shift in interspecific interactions along the latitudinal gradient. While negative dominance effects prevailed in southern communities, higher net biodiversity effects were observed in northern subarctic communities. The combined effects of climate treatments increased biomass production in monocultures of most origins. In communities, however, overall the treatments did not result in significantly changed biomass production. Among individual treatments, water-table fluctuations caused a significant decrease in biomass production, but only in southern communities, indicating higher vulnerability to changed climatic conditions. Here, negative effects of climate treatments on graminoids were not compensated by the slightly increased growth of peat moss that benefited from interspecific interactions only in northern communities.Synthesis. We conclude that shifting interactions within multispecies communities caused pronounced responses to changed climatic conditions in wetland communities of temperate southern marginal, but not of northern subarctic origin. Therefore, future models investigating the impacts of climate change on plant communities should consider geographical variation in species interactions an important factor influencing community responses to changed climatic conditions. KW - additive partitioning of biodiversity effects KW - biodiversity KW - ecosystem services KW - ecosystem stability KW - intraspecific divergence KW - multifactorial environmental change KW - nitrogen deposition KW - northern peatlands KW - Sphagnum magellanicum KW - wetland ecosystems Y1 - 2013 U6 - https://doi.org/10.1111/1365-2745.12158 SN - 0022-0477 SN - 1365-2745 VL - 101 IS - 6 SP - 1484 EP - 1497 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Schwarzer, Christian A1 - Joshi, Jasmin Radha T1 - Parallel adaptive responses to abiotic but not biotic conditions after cryptic speciation in European peat moss Sphagnum magellanicum Brid JF - Perspectives in plant ecology, evolution and systematics N2 - Sphagnum magellanicum Brid. is a worldwide distributed peat moss and an ecosystem-engineer in temperate and boreal bog ecosystems suggesting a great adaptive potential to different environmental conditions. Phenotypes of S. magellanicum have been described as one species so far, although this has been questioned by the detection of several genetic groups in a recent global study. Concordant with morphological uniformity, our analyses of Mid-to Northern European plants revealed only minimal variation in nuclear nrITS and plastid rps4 sequences. However, we detected two distinct genetic groups within Europe by analyzing microsatellite data of 298 individuals from 27 populations. Plants formed an Eastern and a Western European cluster, with overlapping areas in northern Germany and southern Sweden where plants of both clusters coexist within populations but show no signs of admixture. These two cryptic taxa seem therefore to be reproductively isolated. Bayesian analyses indicated that reproductive isolation occurred before the end of the late Pleistocene glaciations. After the meltdown of the glaciers, both clusters colonized northern and central Europe from glacial refugia in the West and possibly from Euro-Siberian populations. To test for divergent adaptation to environmental conditions, we exposed plants of both clusters to experimental climate warming treatments at two different plant-diversity levels (monocultures vs. mixtures) for two years. Despite their different evolutionary history, plants of both genetic clusters responded equally to climate treatments in our southern common garden near Potsdam, Germany. However, only eastern cluster populations benefited from plant-community diversity and increased their biomass in mixtures. These differences in their ecological niche match the diverging microhabitat preferences observed in situ and may effectively hamper genetic exchange if distances between microhabitats are too large for Sphagnum sperm movement. (C) 2017 Elsevier GmbH. All rights reserved. KW - Bryophyte KW - Global change KW - Adaptation KW - Allopatric/sympatric speciation KW - Biodiversity KW - Post glacial colonization Y1 - 2017 U6 - https://doi.org/10.1016/j.ppees.2017.03.001 SN - 1433-8319 VL - 26 SP - 14 EP - 27 PB - Elsevier CY - Jena ER -