"El Niño" - Leben für die untergehende Pflanzenwelt der Atacama

Grau, Jürke

doi:10.1002/(sici)1521-415x(200001)30:1<4::aid-biuz4>3.0.co;2-m

Cited by 3 publications

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“…Meanwhile, an increasing number of indications point to a decline of the Loma vegetation in the northern part of the desert, probably associated with the loss of some species (e.g., FollMaNN 1995;richter 1995;ruNdel et al 1997;dilloN and hoFFMaNN 1997;Grau 2000;Muñoz-Schick et al 2001;PiNto et al 2001;PiNto and kirberG 2005;PiNto 2007). Although some aspects of the vegetation decline has already been approached in a few studies on the current conservation status of some cactus species (belMoNte et al 1998;PiNto and kirberG 2005;PiNto 2007), the actual dimensions and origins of the deterioration processes remain so far unknown.…”

Section: Introductionmentioning

confidence: 99%

Phytogeographic divisions, climate change and plant dieback along the coastal desert of northern Chile

Schulz¹,

Gutiérrez²,

Richter³

2011

Erdkunde

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Along the hyper-arid Chilean coastal desert between 30°S and 18°S the Loma vegetation undergoes a gradual transition from open shrubland to small isolated areas of a scarce plant cover. Floristic and physiognomic features allow a differentiation of five Loma formations, each of them characterized by a distinctive spectrum of plant communities. However, particularly in the northern section of the investigation area, numerous indications point to a strong vegetation decline including a deterioration of plant cover, reduction of the vitality of various taxa, probably also a local loss of some perennial species, and even a dieback of specific populations. These signs of a retrogression, which coincide with a regional disappearance of Guanaco herds in the coastal area between 20°S and 23°30'S, became apparent in the second half of the past century and were most likely provoked by recent climate change in the arid coastal region. Especially the decrease of rainfall frequency might have negative implications for the regeneration and preservation of plants. In addition, a strong reduction of cloudiness in the northernmost section affects plant growth due to further limitations in the water disposability. A projected sustained decline of rainfall is expected to continue endangering the surprisingly high floristic diversity of the sensitive ecosystem complexes in the coastal desert. Zusammenfassung: Entlang der perariden chilenischen Küstenwüste von 30°S bis 18°S verändert sich die Loma-Vegetation von offenen Strauchbeständen hin zu isolierten Pflanzenvorkommen geringer Deckung. Floristische und physiognomische Kriterien erlauben eine Untergliederung in fünf Abschnitte, die sich jeweils durch ein eigenes Spektrum an Pflanzengesellschaften auszeichnen. Allerdings belegen im Norden des Untersuchungsgebietes zahlreiche Merkmale eine Verminderung der Vitalität einzelner Sippen, den lokalen Verlust einiger perenner Taxa und sogar den Niedergang ganzer Populationen einzelner Arten. Dieser Vegetationsrückgang, der mit den Verlust von Guanaco-Herden aus der Küstenregion zwischen 20°S und 23°30'S einhergeht, zeichnet sich vor allem seit der zweiten Hälfte des letzten Jahrhunderts ab und ist mit großer Wahrscheinlichkeit auf Veränderungen im Klima der ariden Region zurückzuführen. Insbesondere die Abnahme der ohnehin bescheidenen Regenhäufigkeit dürfte sich negativ auf die Regeneration und den Erhalt der Pflanzen auswirken. Zudem beeinflusst ein Rückgang der Bewölkung im Norden der chilenischen Küstenwüste die Lebensbedingungen der Vegetation aufgrund weiterer Beschränkungen im Wasserhaushalt negativ. Die absehbare weitere Abnahme der Niederschläge wird die überraschend große Pflanzendiversität des höchst sensiblen Loma-Ökosystem-Komplexes auch in Zukunft bedrohen

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Section: Introductionmentioning

confidence: 99%

Phytogeographic divisions, climate change and plant dieback along the coastal desert of northern Chile

Schulz¹,

Gutiérrez²,

Richter³

2011

Erdkunde

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“…The South American plant genus Oziroë (Hyacinthaceae-Oziroeoideae) has recently been the subject of investigations on geo-specific speciation (Speta 1998;Grau 2000;Guaglianone and Arroyo-Leuenberger 2002). Its karyotype has become an object of interest, partially due to its large span of chromosome sizes and to its unusual chromosomal feature, a peg-like terminal constriction on one metaphase chromosome pair.…”

Section: Introductionmentioning

confidence: 99%

Characterization of a peg-like terminal NOR structure with light microscopy and high-resolution scanning electron microscopy

et al. 2005

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An atypical peg-like terminal constriction ("peg") on metaphase chromosomes of the plant genus Oziroë could be identified as a nucleolus organizing region (NOR) by detecting 45S rDNA with correlative light microscopy (LM) and scanning electron microscopy (SEM) in situ hybridization (ISH). Using high-resolution 3D analytical SEM, the architecture and DNA distribution of the peg-like NOR were characterized as typical for chromosomes, albeit with significantly smaller chromomeres. ISH procedure was improved for SEM concerning signal localization, labeling efficiency, and structural preservation, allowing 3D SEM analysis of the peg-like NOR structure and rDNA distribution for the first time. It could be shown that implementation of FluoroNanogold markers is an attractive tool that allows efficient immunodection in both LM and SEM. A model is proposed for the peg structure and its mode of condensation.

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“…seems to be closely related to Bomarea (BAYER 1998a). It is restricted to a small area in the north of Chile (HUNZIKER 1973;GRAU 2000).…”

Section: Introductionmentioning

confidence: 99%

The delimitation, infrageneric subdivision, ecology and distribution of BomareaMirbel (Alstroemeriaceae)

Hofreiter

Tillich

2002

Feddes Repertorium

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The genus Bomarea (Alstroemeriaceae) was revised for the last time by Baker (1888). Since then the number of validly published names has increased from 75 to recently 280. A revision is urgently needed. Extended field studies in Peru (A. H.) revealed the experience to start this project. In the present paper the taxonomic history of the genus is described and the delimitation of Bomarea to the closely related genus Alstroemeria is analysed. Among the most important differences between the two genera are the fruit structure and the basic chromosome numbers, in Alstroemeria x = 8 and in Bomarea x = 9. The three known subgenera of Bomarea are redefined, mainly on ovary and fruit characters, and a fourth subgenus is added. The members of subgen. Bomarea s.str. (c. 100 species) have an inferior ovary and a dehiscent capsule, in subgen. Sphaerine (c. 15) the plants are always not twining, they have an inferior ovary and indehiscent and strikingly coloured fruits. In subgen. Wichuraea (c. 15) the ovary is semi‐inferior, and the fruit is a dehiscent capsule. In Baccata Hofreiter subgen. nov. (3) the plants are twining, the ovary is inferior and develops into an indehiscent fruit with a thick fleshy pericarp. A key to determine the subgenera is given in English and Spanish. For each subgenus the typical growth forms and their variability, habitat preferences and general distribution are discussed. Field studies in Peru revealed a high variability within the populations of Bomarea. Based on these experiences the systematic value of different characters is discussed. In general, the vegetative characters were found to be most variable, while selected generative characters are appropriate to characterise systematic groups. The greatest amount of character variability was found in subgen. Wichuraea, the most constant characters are found in subgen. Sphaerine.

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"El Niño" - Leben für die untergehende Pflanzenwelt der Atacama

Cited by 3 publications

References 0 publications

Phytogeographic divisions, climate change and plant dieback along the coastal desert of northern Chile

Phytogeographic divisions, climate change and plant dieback along the coastal desert of northern Chile

Characterization of a peg-like terminal NOR structure with light microscopy and high-resolution scanning electron microscopy

The delimitation, infrageneric subdivision, ecology and distribution of BomareaMirbel (Alstroemeriaceae)

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