Browsing by Author "Kleinpeter, Dorothea"

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    Living at the dry limits: ecological genetics of Tillandsia landbeckii lomas in the Chilean Atacama Desert
    (2019) Koch, Marcus A.; Kleinpeter, Dorothea; Auer, Erik; Siegmund, Alexander; Río López, Camilo del; Osses Mc-Intyre, Pablo; García B., Juan Luis; Marzol, Maria V.; Zizka, Georg; Kiefer, Christiane
    The northern Chilean Atacama Desert is among those regions on Earth where life exists at its dry limits. There is almost zero rainfall in its core zone, and the only source of water is a spatio-temporally complex fog system along the Pacifc coast, which is reaching far into the hyperarid mainland. Hardly any vascular plants grow in these areas, and, thus, it is intriguing to be faced with a vegetation-type build-up by one single and highly specialized bromeliad species, Tillandsia landbeckii Phil., forming regular linear structures in a sloped landscape. We studied the genetic make-up of a population system extending an area of approximately 1500 km2 and demonstrated a fne-scale correlation of genetic diversity with spatial population structure and following an elevational gradient of approximately 150 m. Increase in genetic diversity is correlated with increased ftness as measured by fowering frequency, and evidence is provided that outbreeding is linked with a large-distance fying pollinator feeding occasionally as generalist on its fowers, but not using the plant as source for larvae feeding. Our data demonstrate that establishment of linear vegetation structure is in principle a process driven by clonal growth and propagation of ramets over short distances. However, optimal conditions (slope, elevation, fog occurrence) for linear growth pattern formation also increase sexual plant reproductive ftness, thus providing the reservoir for newly combined genetic variation and counteracting genetic uniformity. Our study highlights the Tillandsia vegetation, also called Tillandsia lomas, as unique and genetically diverse system, which is highly threatened by global climate change and disturbance of the coastal fog system.
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    Vegetation growth and landscape genetics of Tillandsia lomas at their dry limits in the Atacama Desert show fine-scale response to environmental parameters
    (2020) Koch, Marcus A.; Stock, Clara; Kleinpeter, Dorothea; Río López, Camilo del; Osses, Pablo; Merklinger, Felix F.; Quandt, Dietmar; Siegmund, Alexander
    Ecosystem dry limits have been studied in the context of species biology, fitness, and interactions with biotic and abiotic parameters, but the interactive effects of these parameters remain underexplored. Therefore, information on the putative effects of global climate change on these ecosystems is often lacking.", "We analyzed the interplay between fine-scale landscape genetics and biotic and abiotic factors of terrestrial Tillandsia lomas in the hyperarid Atacama Desert, characterized by a fog-dependent vegetation type almost entirely dominated by one single vascular plant species.", "We showed that metapopulations of Tillandsia landbeckii are genetically connected over many hundreds of square kilometers, and despite having a large potential for clonal propagation, genetic diversity is regionally and locally structured. At the landscape level, genetic diversity correlates well with fitness parameters such as growth, flowering, and vegetation density. We also observed fine-scale correlation with a 3-D landscape model indicating a positive feedback with seasonal fog occurrence and availability. The various interactions of biotic and abiotic factors resulted in regular linear banding patterns of vegetation arranged orthogonally toward the landscape slope. Ex situ growth experiments indicated that T. landbeckii grows at optimal rates in this extreme hyperarid environment, and we can extrapolate mean biomass production for this ecosystem.", "Synthesis. Our results suggest that the unique ecosystem of terrestrial Tillandsia lomas in the hyperarid Atacama Desert is an evolutionarily balanced and fine-scaled system. The vegetation itself is composed of long-lived and persistent modules. We developed a descriptive model of the various interacting factors, thereby also highlighting the severe threat caused by global climate change potentially associated with fog disturbance patterns along the Chilean Pacific coast.