7 research outputs found

    Adaptive Diversity of Beech Seedlings Under Climate Change Scenarios

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    The ability of beech ( Fagus sylvatica L.) populations to adapt to the ongoing climate change is especially important in the southern part of Europe, where environmental change is expected to be more intense. In this study, we tested the existing adaptive potential of eight beech populations from two provenances in N.E. Greece (Evros and Drama) that show differences in their environmental conditions and biogeographical background. Seedling survival, growth and leaf phenological traits were selected as adaptive traits and were measured under simulated controlled climate change conditions in a growth chamber. Seedling survival was also tested under current conditions in the field. In the growth chamber, simulated conditions of temperature and precipitation for the year 2050 were applied for 3 years, under two different irrigation schemes, where the same amount of water was distributed either frequently (once every week) or non-frequently (once in 20 days). The results showed that beech seedlings were generally able to survive under climate change conditions and showed adaptive differences among provenances and populations. Furthermore, changes in the duration of the growing season of seedlings were recorded in the growth chamber, allowing them to avoid environmental stress and high selection pressure. Differences were observed between populations and provenances in terms of temporal distribution patterns of precipitation and temperature, rather than the average annual or monthly values of these measures. Additionally, different adaptive strategies appeared among beech seedlings when the same amount of water was distributed differently within each month. This indicates that the physiological response mechanisms of beech individuals are very complex and depend on several interacting parameters. For this reason, the choice of beech provenances for translocation and use in afforestation or reforestation projects should consider the small scale ecotypic diversity of the species and view multiple environmental and climatic parameters in connection to each other

    Long term post-fire vegetation dynamics in north-east Mediterranean ecosystems. The case of Mount Athos Greece

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    Fire is an ecological and disturbance factor with a significant historical role in shaping the landscape of fire-prone environments. Despite the large amount of literature regarding post-fire vegetation dynamics, the north-east Mediterranean region is rather underrepresented in the literature. Studies that refer to the early post fire years and long term research are rather scarce. The current study is conducted in the socially and geographically isolated peninsula of Mount Athos (Holly Mountain) in northern Greece, and it studies vegetation dynamics over a period of 30 years since the last fire. Field data were collected 11 years since the event and were used to identify the present plant communities in the area, using TWINSPAN, and the factors affecting their distribution using CART. Four Landsat (TM, ETM, OLI) images are employed for the calculation of NDVI, which was found effective in detecting the intercommunity variation in the study area, and it is used for long term monitoring. The study includes four communities, from maquis to forest which are common in the Mediterranean region covering a wide altitudinal range. The results suggest that fire affects the various communities in a different way and their recovery differs significantly. While forest communities recover quickly after fire, maintaining their composition and structure, the maquis communities may need several years before reaching the pre-fire characteristics. The dry climatic conditions of the study area are probably the reason for the slow recovery of the most fire prone communities. Given that climate change is expected to make the conditions even drier in the region, studies like this emphasize the need to adopt measures for controlling wildfires and preventing ecosystem degradation

    Angiosarcoma of Kidney: A Case Report and Review of Literature

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    Extracorporeal shock wave lithotripsy in the treatment of pediatric urolithiasis: a single institution experience

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    PURPOSE: To compare the efficacy and safety of the electromagnetic lithotripter in the treatment of pediatric lithiasis to that of the earlier electrohydraulic model. MATERIALS AND METHODS: Two groups of children with lithiasis aged between 10 and 180 months who underwent extracorporeal shock wave lithotripsy (ESWL). In the first group (26 children), ESWL was performed by using the electrohydraulic MPL 9000X Dornier lithotripter between 1994 and 2003 while in the second group (19 children) the electromagnetic EMSE 220 F-XP Dornier lithotripter was used from April 2003 to May 2006. RESULTS: In the first group, 21/26 children (80.7%) were stone free at first ESWL session. Colic pain resolved by administration of an oral analgesic in 6 (23%), brief hematuria (< 24 h) resolved with increased fluid intake in 5 (19.2%), while slightly elevated body temperature (< 38°C) occurred in 4 (15.3%). Four children (15.3%) failed to respond to treatment and were treated with ureteroscopy. In the second group 18/19 children were completely stone free at first ESWL session (94.7%). Complications were infrequent and of minor importance: colic pain treated with oral analgesic occurred in 1 (5.26%), brief hematuria (< 24 h), resolved with increased fluid intake in 4 (21%) and slightly elevated body temperature (< 38°C) monitored for 48 hours occurred in 6 (31.5%). Statistical analysis showed that electromagnetic lithotripter is more efficacious and safer than the earlier electrohydraulic model. CONCLUSIONS: Technological development not only has increased efficacy and safety of lithotripter devices in treating pediatric lithiasis, but it also provided less painful lithotripsy by eliminating the need for general anesthesia

    Seed adaptive traits of Fagus sylvatica populations in Northeastern Greece

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    Fagus sylvatica in Europe is expected to be severely affected by the ongoing climate change. In this article, seed adaptive traits, in terms of morphology and germination, of F. sylvatica populations of different postglacial lineage and intrapopulation genetic diversity were evaluated. Eight plots from two geographical provenances, Evros and Drama, were selected. Provenance shaped both morphology and germination patterns, but the effect was more pronounced on germination. Seeds from Drama were larger and heavier than those from Evros but exhibited a higher degree of dormancy and slower germination. High among-plots variability on morphology and germination was also observed, especially in Evros. This higher variability was consistent with the higher level of genetic diversity observed at genomic and chloroplast DNA markers at small or larger spatial scales from previous published studies on the same plots. Results suggested the existence of different seed adaptation strategies, mainly between provenances, as a result of possible adaptation to different environmental conditions, whereas a possible influence of a generally complex pattern of admixture between different beech subspecies and postglacial lineages could not be excluded

    Changes in Watering Frequency Stimulate Differentiated Adaptive Responses among Seedlings of Different Beech Populations

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    Seasonality, rather than annual precipitation levels, is expected to affect the adaptive responses of plant populations under future climate change. To estimate adaptive traits’ variation, we conducted a common garden experiment with two beech populations from contrasting climatic origins (Evros with longer drought intervals during summer and higher precipitation seasonality, and Drama representing a more temperate ecosystem). We simulated two different watering treatments (frequent vs. non-frequent) on beech seedlings, according to predicted monthly precipitation levels expected to prevail in 2050 by the CSIRO MK3.6 SRESA1B model, considering as reference area a natural beech stand in Mt. Rodopi, Greece. A series of morphological and stem anatomical traits were measured. Seedling survival was greater for the Evros population compared to that of Drama under non-frequent watering, while no difference in survival was detected under frequent watering. Leaf morphological traits were not generally affected by watering frequency except for leaf circularity, which was found to be lower under non-frequent watering for both populations. Stomata density in leaves was found to be higher in the Evros population and lower in the Drama population under non-frequent watering than frequent. Stem anatomical traits were higher under non-frequent watering for Evros but lower for the Drama population. Multivariate analyses clearly discriminated populations under non-frequent rather than frequent watering, indicating genetic adaptation to the population’s environment of origin
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