Time filter

Source Type

Ymittos Athens, Greece

Schindler S.,University of Vienna | Schindler S.,University of Porto | Von Wehrden H.,Luneburg University | Poirazidis K.,WWF Greece | And 3 more authors.
Ecological Indicators | Year: 2013

Landscape metrics are widely used to investigate the spatial structure of landscapes. Numerous metrics are currently available, yet only little empirical research has comparatively examined their indicator value for species richness for several taxa at several scales. Taking a Mediterranean forest landscape - Dadia National Park (Greece) - as a case study area, we explored the performance of 52 landscape level landscape metrics as indicators of species richness for six taxa (woody plants, orchids, orthopterans, amphibians, reptiles, and small terrestrial birds) and for overall species richness. We computed the landscape metrics for circular areas of five different extents around each of 30 sampling plots. We applied linear mixed models to evaluate significant relations between metrics and species richness and to assess the effects of the extent of the considered landscape on the performance of the metrics. Our results showed that landscape metrics were good indicators for overall species richness, woody plants, orthopterans and reptiles. Metrics quantifying patch shape, proximity, texture and landscape diversity resulted often in well-fitted models, while those describing patch area, similarity and edge contrast rarely contributed to significant models. Spatial scale affected the performance of the metrics, since woody plants, orthopterans and small terrestrial birds were usually better predicted at smaller extents of surrounding landscape, and reptiles frequently at larger ones. The revealed pattern of relations and performances will be useful to understand landscape structure as a driver and indicator of biodiversity, and to improve forest and landscape management decisions in Mediterranean and other forest mosaics. © 2012 Elsevier Ltd. All rights reserved. Source

Karaiskou N.,Aristotle University of Thessaloniki | Tsakogiannis A.,Aristotle University of Thessaloniki | Gkagkavouzis K.,Aristotle University of Thessaloniki | Papika S.,National Park Service | And 6 more authors.
Journal of Heredity | Year: 2014

A number of phylogeographic studies have revealed the existence of multiple ice age refugia within the Balkan Peninsula, marking it as a biodiversity hotspot. Greece has been reported to harbor genetically differentiated lineages from the rest of Balkans for a number of mammal species. We therefore searched for distinct red deer lineages in Greece, by analyzing 78 samples originating from its last population in Parnitha Mountain (Central Greece). Additionally, we tested the impact of human-induced practices on this population. The presence of 2 discrete mtDNA lineages was inferred: 1) an abundant one not previously sampled in the Balkans and 2) a more restricted one shared with other Balkan populations, possibly the result of successful translocations of Eastern European individuals. Microsatellite-based analyses of 14 loci strongly support the existence of 2 subpopulations with relative frequencies similar to mitochondrial analyses. This study stresses the biogeographic importance of Central Greece as a separate Last Glacial Maximum period refugium within the Balkans. It also delineates the possible effects that recent translocations of red deer populations had on the genetic structuring within Parnitha. We suggest that the Greek red deer population of Parnitha is genetically distinct, and restocking programs should take this genetic evidence into consideration. © 2014 © The American Genetic Association 2014. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com. Source

The present paper reports the first record of Piseinotecus gabinierei (Mollusca: Piseinotecidae) in the Aegean Sea; the nudibranchs were found in December 2008 in two different sites on the island of Crete (South Greece). In the first location it was feeding on Eudendrium racemosum, a hydroid very common in this area while in the second location it was found crawling among algae. © 2011 Marine Biological Association of the United Kingdom. Source

Oppel S.,Center for Conservation Science | Dobrev V.,Bulgarian Society for Protection of Birds BirdLife Bulgaria | Arkumarev V.,Bulgarian Society for Protection of Birds BirdLife Bulgaria | Saravia V.,Hellenic Ornithological Society | And 6 more authors.
Ibis | Year: 2015

Many populations of long-distance migrants are declining and there is increasing evidence that declines may be caused by factors operating outside the breeding season. Among the four vulture species breeding in the western Palaearctic, the species showing the steepest population decline, the Egyptian Vulture Neophron percnopterus, is a long-distance migrant wintering in Africa. However, the flyways and wintering areas of the species are only known for some populations, and without knowledge of where mortality occurs, effective conservation management is not possible. We tracked 19 juvenile Egyptian Vultures from the declining breeding population on the Balkan Peninsula between 2010 and 2014 to estimate survival and identify important migratory routes and wintering areas for this species. Mortality during the first autumn migration was high (monthly survival probability 0.75) but mortality during migration was exclusively associated with suboptimal navigation. All birds from western breeding areas and three birds from central and eastern breeding areas attempted to fly south over the Mediterranean Sea, but only one in 10 birds survived this route, probably due to stronger tailwind. All eight birds using the migratory route via Turkey and the Middle East successfully completed their first autumn migration. Of 14 individual and environmental variables examined to explain why juvenile birds did or did not successfully complete their first migration, the natal origin of the bird was the most influential. We speculate that in a declining population with fewer experienced adults, an increasing proportion of juvenile birds are forced to migrate without conspecific guidance, leading to high mortality as a consequence of following sub-optimal migratory routes. Juvenile Egyptian Vultures wintered across a vast range of the Sahel and eastern Africa, and had large movement ranges with core use areas at intermediate elevations in savannah, cropland or desert. Two birds were shot in Africa, where several significant threats exist for vultures at continental scales. Given the broad distribution of the birds and threats, effective conservation in Africa will be challenging and will require long-term investment. We recommend that in the short term, more efficient conservation could target narrow migration corridors in southern Turkey and the Middle East, and known congregation sites in African wintering areas. © 2015 British Ornithologists' Union. Source

Poirazidis K.S.,WWF Greece | Poirazidis K.S.,Technological Education Institute of Ionian Islands | Zografou K.,WWF Greece | Kordopatis P.,WWF Greece | And 4 more authors.
Annals of Forest Science | Year: 2012

Context: This study investigates post-fire natural regeneration of Aleppo pine (Pinus halepensis) forests at Ilia region (Peloponnesus, Greece) following the catastrophic fire of 2007. Aims: The objective of this study is the prediction of P. halepensis post-fire regeneration at a regional scale through an integrated geographic information systems (GIS) model as a basis for post-fire management plans. Methods: The model was developed in three interconnected stages: (1) field data collection, (2) development of two prediction models (based on interpolation of field data and multicriteria evaluation (MCE) that combined factors known to affect regeneration), and (3) combination of applied models using Bayesian statistics. Results: Post-fire pine regeneration presented high variation among the studied plots. Redundancy analysis revealed the positive effect of fallen branches and a negative correlation with altitude. Both modeling approaches (geostatistical and MCE) predicted the post-fire pine regeneration with high accuracy. A very significant correlation (r00.834, p<0.01) was found between the combined final model and the actual number of counted seedlings, illustrating that less than 10 % of the studied area corresponds to sites of very low post-fire pine regeneration. Conclusion:s The combination of GIS models increased the prediction success of different levels of pine regeneration. Lowaltitude areas with low grass cover overlying tertiary deposits were proved the most suitable for pine regeneration, while stands developing on limestone proved least suitable. The proposed methodology providesmanagement authoritieswith a sound tool to quickly assess Aleppo pine post-fire regeneration potential. © INRA /Springer-Verlag France 2012. Source

Discover hidden collaborations