The past and present distribution of a rare segetal weed darnel ryegrass (Lolium temulentum) in Slovakia is presented. The study is based on revision of herbarium specimens from 12 herbaria and a ...field survey carried out during 2005-2009. Altogether, 95 localities of this species were recorded in Slovakia. Prior to 1950 it was a relatively abundant taxon recorded and confirmed at 75 localities throughout the country, but then it began to vanish. Only 20 localities were recorded between 1950 and 1990, and in 1999 it was evaluated as extinct from Flora of Slovakia. However, since 2005 new occurrences were discovered in northern Slovakia (Orava and Pieniny regions), and its status had been changed. Results of the study are summarised in the map of historical and actual species distribution.
V članku je predstavljena nekdanja in današnja razširjenost segetalnega plevela omotne ljulke (Lolium temulentum) na Slovaškem. Raziskava temelji na reviziji herbarijskih primerkov iz 12 herbarijev in terenskega pregleda v letih od 2005 do 2009. Na Slovaškem smo zabeležili 95 rastišč. Pred letom 1950 je bila omotna ljulka razmeroma pogosta, ugotovili smo namreč 75 rastišč po celotni državi, po tem letu pa je začela izginjati. Potrdili smo samo 20 rastišč med letoma 1950 in 1990, leta 1999 pa je bila vrsta ocenjena kot izumrla v flori Slovaške. Vendar smo po letu 2005 odkrili nova nahajališča v severni Slovaški (območji Orava in Pieniny) in tako spremenili njen status. Rezultati raziskave so prikazani na karti nekdanje in sedanje razširjenosti vrste.
The succession of vegetation on acidic sandy fields after abandonment was studied and obtained results were compared with similar data from eastern part of Europe. The vegetation changes head towards ...oligotrophic Corynephorus-grasslands, because nutrients from the upper layer of soils are gradually washed out. Dry, occasionally blowing sand enables the growth of psammophytes very well. The paper compares the succession models on abandoned sandy fields, and semi-natural acidic sandy dunes in western part of Slovakia, southern Moravia, Hungary and Croatia. In spite of amazing similarities, some differences are displayed using spectra of life forms and presentation of weeds.
Proučevali smo sukcesijo vegetacije na opuščenih kislih peščenih poljih in primerjali rezultate s podobnimi podatki iz vzhodne Evrope. Spremembe vegetacije so usmerjene proti oligotrofnim traviščem z vrsto Corynephorus, saj se hranila postopomo izperejo iz zgornjih talnih plasti. Suh pesek, ki ga občasno prinese veter omogoča uspevanje psamofitom. V članku smo primerjali sukcesijske modele na opuščenih peščenih poljih in polnaravnih kislih peščenih Dinah v zahodnem delu Slovaške, južne Moravske, Madžarske in Hrvaške. Kljub veliki podobnosti smo izpostavili določene razlike s spektrom življenskih oblik in prisotnostjo plevelnih vrst.
On the basis of laboratory experiments it was found that to achive the required technological effect it is not necessary to reach a maximum rate of damage to the vegetable tissue, i.e. the weed ...destruction by electric spark discharges can be achieved at several times less consumption of energy.
During electric spark treatment of weeds were experimentally ascertained dependences of the consumption of energy required for dependable damage to the stalk cores, on the number of the ...simultaneously treated plants. It is shown that such dependents may be presented by power functions having exponent lower, nearer to 1 or by linear functions.
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