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Rdeči hrast (Quercus rubra L.) samoniklo uspeva le na vzhodu Severne Amerike. V slovenske gozdove je bil prvič zasajen pred dobrim stoletjem. Cilj naše raziskave je bil, da ugotovimo kako je les rdečega hrasta iz slovenskega rastišča odporen na navlaževanje in glivni razkroj. Vzporedno smo testiranja izvajali na lesu evropskega hrasta (Quercus spp.) in na smrekovini (Picea abies L.). Beljava je neodporna na glivni razkroj, zato smo za vsa testiranja uporabljali le jedrovino izbranih lesnih vrst. Izvedli smo niz raziskav na področju odpornosti lesa na glivni razkroj in navlaževanje. Poleg tega smo izvedli še anatomske in kemijske analize. Pripravili smo trajne anatomske preparate in na mikroskopski ravni primerjali vpliv zgradbe lesa evropskega hrasta in rdečega hrasta na glivni razkroj. Številne tile v lesu evropskega hrasta predstavljajo bariero, ki otežuje napredovanje hif, medtem ko so v lesu rdečega hrasta tile redke, je pa zato bolj impregnabilen. Določili smo količino ekstraktivov v lesu, delež celuloze, lignina in hemiceluloz. Z računskim modelom Meyer-Veltrup smo na podlagi faktorja odpornosti lesa na biološki razkroj in faktorja odpornosti lesa proti navlaževanju izračunali relativno življenjsko dobo lesa in čas v katerem pričakujemo začetek razkroja lesa. Rdeči hrast v primerjavi z evropskim hrastom izkazuje primerljivo odpornost na navlaževanje, medtem ko je slabše odporen na glivni razkroj, saj vsebuje manjšo količino ekstraktivov in je slabše otiljen. Raziskava podaja dobre izhodiščne podatke za lažje odločitve pri uporabi in zaščiti lesa rdečega hrasta. Red oak (Quercus rubra L.) is native only to eastern North America. It was first planted in Slovenian forests more than a century ago. The objective of the study was to determine the resistance of red oak wood from Slovenian forests to moisture and fungal attack. Testing of red oak wood was conducted in parallel with testing of European oak (Quercus spp.) and Norway spruce (Picea abies L.) wood. The sapwood is not resistant to fungal decay, and thus only heartwood from selected wood species was used for all tests. We conducted a series of studies on the resistance of wood to fungal decay and wetting. In addition, anatomical and chemical analyses were performed. We made permanent anatomical preparations and compared the influence of the wood structure of European oak and red oak on fungal decay at the microscopic level. The numerous tyloses in the wood of European oak provide a barrier to the progression of fungal hyphae, whereas tyloses in red oak wood are rare and therefore easier to treat. The amount of extractives in the wood, and the percentages of cellulose, lignin and hemicelluloses were determined. Using the Meyer-Veltrup model, we calculated the relative resistance dose of the wood and the time within which the wood is expected to begin to decay based on the wood's inherent resistance to biological deterioration and wettability. Red oak shows nearly the same wetting performance compared to European oak, but is less resistant to fungal attack because it contains lower levels of extractives and tyloses. The study provides good baseline data to facilitate decisions on the use and protection of red oak wood.

Tujerodna drevesna vrsta rdeči hrast (Quercusrubra L.) izvira iz Amerike. V Evropo je bila vrsta umetno vnesena leta 1691. V vsej Evropi je prisotna na 350.000 ha, v Sloveniji je četrta najpogostejša tujerodna drevesna vrsta. V Sloveniji so prvi nasadi nastali med letoma 1880 in 1890. V Sloveniji študije o pomlajevanju rdečega hrasta ni, zato smo v naši raziskavi proučevali mladje z vidika gostote, številčnosti in kakovosti. Izbrali smo dva sestoja v gozdu Panovec, ki se uspešno razvijata, sta vitalna in se obilno pomlajujeta. Vrsta se pomlajuje generativno s semeni. Ugotovljena gostota mladja je bila 40.241osebkov na ha. Večina raznosa semena v okoliške sestoje sega do razdalje 25 m. Rdeči hrast je zanimiva drevesna vrsta, ki je v številnih evropskih državah cenjena zaradi svojega kakovostnega lesa. Zaradi hitre rasti in razmeroma dobre odpornosti proti sušibi lahko z vrsto gospodarili tudi v Sloveniji, še posebej na plitvih, kislih in degradiranih tleh. The non-native tree species red oak (Quercus rubra L.) originates from North America. The species was introduced to Europe in 1691. On the European level it covers 350,000 ha and in Slovenia it is the fourth most common non-native tree species. The first plantations were established in Slovenia between 1880 and 1890. There are no studies on the regeneration of red oak in Slovenia, so we studied seedlings and saplings in terms of density, abundance and quality. The study was performed inside two well developed red oak stands in good health condition and with abundant regeneration, originating mainly from seed. The regeneration density of red oak was 40.241 per ha. Most of the seed distribution in the surrounding of seed trees was within a distance of 25 m. red oak is an interesting tree species valued in many European countries for its quality wood. Due to its successful growth and relatively good drought resistance, it should be considered for management also in Slovenia, especially on poor, acidic and degraded soils.