100 research outputs found
A csermelyciprus (Myricaria germanica) Ășj hazai elĆfordulĂĄsa
A közlemĂ©ny a MagyarorszĂĄgon igen ritka Myricaria germanica mĂĄsodik olyan elĆforÂdulĂĄsĂĄrĂłl szĂĄmol be, amely ember ĂĄltal lĂ©trehozott termĆhelyrĆl ismert. A faj HejĆpapi mellĆl (SajĂłâHernĂĄd-sĂk), egy kavicsbĂĄnyĂĄbĂłl kerĂŒlt elĆ. A faj legközelebbi lelĆhelye mintegy 60 kilomĂ©terre talĂĄlhaÂtĂł, Ăgy az elĆfordulĂĄs a szĂ©l ĂĄltali terjedĂ©s (anemochoria) hatĂ©konysĂĄgĂĄt jelzi. Ăgy tƱnik a kavicsbĂĄnyĂĄk megfelelĆ termĆhelyet jelenthetnek e hazĂĄnkban veszĂ©lyeztetett cserjefajnak.</jats:p
Emergence of a new salt-tolerant alien grass along roadsides? Occurrence of Diplachne fusca subsp. fascicularis (Poaceae) in Hungary
This paper reports the occurrence of a North American salt-tolerant taxon, Diplachne fusca subsp. fascicularis (Lam.) P.M.Peterson et N.Snow in Hungary (Central-Europe). Two earlier Hungarian observations of D. fusca were known from 1915, near GyĆr (West Transdanubia), later the taxon was collected by PĂ©nzes in 1958, in downtown BudatĂ©tĂ©ny (central Hungary. Both observations seem to be occasional. Recently, the taxon has started spreading in Europe, mainly on rice paddy fields, with a serious invasion potential. In North America its appearance on ruderal habitats, as well as along roads and other linear infrastructures is a well known phenomenon. The Hungarian population was found near CeglĂ©d (Central Hungary) on the roadside of the E40 primary main road in September 2018. In July 2019 more than one thousand (mostly vegetative) individuals were detected. The salt content of the habitat shows remarkable temporal and spatial variability. At one meter distance from the edge of the paved road soil salt content was higher in spring (after the winter de-icing regime), than in autumn. Salt concentration was highest in the vicinity of the road, and decreased with increasing distance from it. Germination tests revealed a significant negative effect of NaCl concentration on germination rates, but germination occurred even on extremely saline substrates with 1.5% NaCl concentration. Considering its biology and reproduction strategy, the further spread of Diplachne fusca is highly presumable
Using traditional ecological knowledge in discovery of rare plants: a case study from Turkey
Sustainable (and adaptive) management of natural resources is usually based on long term local experiences with nature. Local traditional communities often possess rich ecological knowledge connected to nature and traditional resource use and management. This knowledge can provide unexpected new information for researchers, and show new opportunities and ways for professionals in conserving rare and threatened species.We found significant new populations of the rare Ophrys lesbis in a private area next to the settlement of Ăamlık, MuÄla, and Orchis punctulata in the graveyard of Kadılar, Antalya with the help of local rural people. We firstly report the replanting of some orchid species (Orchis papilionacea, O. italica, and Barlia robertiana) in kitchen gardens of Ăamlık and Bayır, in MuÄla Province.The presence of significant orchid populations (e.g., the biggest ever found for Ophrys lesbis) in an area, where local owners have been actively harvesting salep from year to year for decades suggests that the moderate salep harvesting can be sustainable for long run. Based on our observations, Turkish salep harvesters can help botanists and conservationists find new locations of rare threatened orchid populations, and therefore indirectly help in conserve these populations
Application of support vector machines on the basis of the first Hungarian bankruptcy model
In our study we rely on a data mining procedure known as support vector machine (SVM) on the database of the first Hungarian bankruptcy model. The models constructed are then contrasted with the results of earlier bankruptcy models with the use of classification accuracy and the area under the ROC curve. In using the SVM technique, in addition to conventional kernel functions, we also examine the possibilities of applying the ANOVA kernel function and take a detailed look at data preparation tasks recommended in using the SVM method (handling of outliers). The results of the models assembled suggest that a significant improvement of classification accuracy can be achieved on the database of the first Hungarian bankruptcy model when using the SVM method as opposed to neural networks
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