69 research outputs found
Evolution and biogeography of the endemic Roucela complex (Campanulaceae: Campanula) in the Eastern Mediterranean
At the intersection of geological activity, climatic fluctuations, and human
pressure, the Mediterranean Basin – a hotspot of biodiversity – provides an
ideal setting for studying endemism, evolution, and biogeography. Here, we
focus on the Roucela complex (Campanula subgenus Roucela), a group of 13
bellflower species found primarily in the eastern Mediterranean Basin. Plastid
and low-copy nuclear markers were employed to reconstruct evolutionary
relationships and estimate divergence times within the Roucela complex using
both concatenation and species tree analyses. Niche modeling, ancestral range
estimation, and diversification analyses were conducted to provide further
insights into patterns of endemism and diversification through time.
Diversification of the Roucela clade appears to have been primarily the result
of vicariance driven by the breakup of an ancient landmass. We found geologic
events such as the formation of the mid-Aegean trench and the Messinian
Salinity Crisis to be historically important in the evolutionary history of
this group. Contrary to numerous past studies, the onset of the Mediterranean
climate has not promoted diversification in the Roucela complex and, in fact,
may be negatively affecting these species. This study highlights the diversity
and complexity of historical processes driving plant evolution in the
Mediterranean Basin
The native flora of Mountain Panachaikon (Peloponnese, Greece): new records and diversity
Mass Taxon-Sampling as a Strategy towards Illuminating the Natural History of Campanula (Campanuloideae)
Speciose clades usually harbor species with a broad spectrum of adaptive
strategies and complex distribution patterns, and thus constitute ideal
systems to disentangle biotic and abiotic causes underlying species
diversification. The delimitation of such study systems to test evolutionary
hypotheses is difficult because they often rely on artificial genus concepts
as starting points. One of the most prominent examples is the bellflower genus
Campanula with some 420 species, but up to 600 species when including all
lineages to which Campanula is paraphyletic. We generated a large alignment of
petD group II intron sequences to include more than 70% of described species
as a reference. By comparison with partial data sets we could then assess the
impact of selective taxon sampling strategies on phylogenetic reconstruction
and subsequent evolutionary conclusions
Modelos de endemicidad a lo largo de un gradiente altitudinal en Sierra Nevada (España) y Lefka Ori (Creta, Grecia)
Aim: High mountains in the Mediterranean region of Europe are particularly rich in endemic vascular plants. We aimed to compare the altitudinal patterns of vascular plant species richness and the proportion of endemic species in two Mediterranean region: Lefka Ori on the island of Crete (Greece) and Sierra Nevada on the Iberian peninsula.
Location: Sierra Nevada, Granada (Spain); Lefka Ori, Crete (Greece).
Methods: Data from standardised permanent plots settings on summit sites (comprising eight plot sectors, covering the upeermost 10 altitudinal metres) of different elevations were used (GLORIA Multi-Summit approach; www.gloria.ac.at). Species numbers, rates of endemic species, and soils temperature were compared by means of ANCOVA and linear regression.
Results: The two regions, though climatically similar, showed strikingly different patterns: In Sierra Nevada, the proportion of endemic vascular plants (species restricted to Sierra Nevada) showed a stepwise increase from the lowest to the highest summit. In contrast, the proportion of endemic species restricted to Crete was not significantly different between the four summits in Lefka Ori. In both regions the observed trends were largely consistent with the altitudinal distribution of the endemic species obtained from standard floras.
Main conclusions: The geographic positions of the two regions, i.e. island versus mainland and the higher elevation of Sierra Nevada are suggested to be the primary causes of the observed differences.
The high degree of endemism in the cold environments of Mediterranean mountains’ upper bioclimatic zones indicates a pronounced vulnerability to the impacts of climate change. A continued and intensified species monitoring in the mountains around the Mediterranean basin, therefore, should be considered as a priority research task.Objetivo: Las zonas de alta montaña en la regiĂłn mediterránea europea son particularmente ricas en plantas vasculares endĂ©micas. Nuestro objetivo es comparar los modelos altitudinales para la riqueza de plantas vasculares y la proporciĂłn de endemismos en dos regiones mediterráneas: Lefka Ori en la isla de Creta (Grecia) y Sierra Nevada en la PenĂnsula IbĂ©rica.
Localización: Sierra Nevada, Granada (España); Lefka Ori, Creta (Grecia).
MĂ©todo: Los datos proceden de un muestreo estandarizado en varias cimas situadas a diferentes altitudes (GLORIA Multi-Summit approach; www.gloria.ac.at). El nĂşmero de especies, tasas de endemicidad, y temperatura del suelo se compararon por medio de ANCOVA y regresiĂłn lineal.
Resultados: Las dos regiones objeto de análisis, aunque similares climáticamente, muestran patrones llamativamente diferentes: en Sierra Nevada, la proporción de plantas vasculares endémicas (especies restringidas a Sierra Nevada) muestra un incremento gradual desde la cima más baja a la más alta. En contraste, la proporción de endemismos restringidos a Creta no fue significativamente diferente entre las cuatro cimas de Lefka Ori. Las tendencias observadas en ambas regiones fueron en gran parte consistentes con la distribución de las especies endémicas obtenida de las floras para cada región.
Conclusiones principales: La posición geográfica de ambas regiones, por ejemplo. isla frente a continente, y la mayor elevación de Sierra Nevada se sugieren como las principales causas de las diferencias observadas.
El alto grado de endemicidad en los ambientes frĂos de las zonas bioclimáticas superiores de las montañas mediterráneas evidencia una marcada vulnerabilidad a los impactos del cambio climático. Por lo tanto, el seguimiento continuado e intensivo de las especies de montaña alrededor de la cuenca mediterránea, deberĂa considerarse como una tarea investigadora prioritaria.He set up of the permanent plots and data collection was supported by the FP-5 project GLORIA-Europe (2001-2003) No EVK2-2000-00056 of the European Commission
Differentiation of Centaurea sect. Acrolophus and Phalolepis in the mountains of SE Sterea Ellas
Revision der europäischen und nordafrikanischen Vertreter der Subsect. Heterophylla (Wit.) Fed. der Gattung Campanula L
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