| OPOMBE | Bibliografija: f. 158-168 // Kazala // Povzetek ; Summary // Univ. Ljubljana, Biotehniška fakulteta, Oddelek za lesarstvo // Na 42 neprizadetih in različno prizadetih jelkah (Abies alba Mill.) so bile opravljene v več terminih dormantnega in rastnega obdobja primerjalne raziskave prirastnih in anatomskih značilnosti živih tkiv, meritve koncentracij kalija, magnezija, kalcija in mangana v njih ter meritve električne upornosti (EU) živih tkiv. Za neprizadeta drevesa so značilna debelejša živa tkiva, zlasti prevodni floem in kambijeva cona (KC)ter višje koncentracije K v tkivih. Prizadetost ni vplivala na vsebnost Mg in Mn, koncentracije Ca pa so bile višje pri prizadetih jelkah. Koncentracije preiskovanih elementov so bile najvišje v fiziološko najaktivnejših tkivih, t.j.v KC in prevodnem floemu, v smeri proti zunanji živi skorji so se postopno nižale, na meji KC z zrelim lesom pa so skokovito padle. Debelina KC in koncentracija K je bila v dormantnem obdobju najmanjša ter izmerjena EU najvišja. Debelina KC in koncentracija Kje bila v rastnem obdobju največja ter EU najnižja. S prizadetostjo se debelina živih tkiv, predvsem prevodnega floema in KC, tanjša, znižuje se koncentracija K ter viša EU. Mg, Mn, Ca niso pokazali značilnega sezonskeganihanja koncentracij in niso vplivali na odčitke EU. EU neposredno in objektivno nakazuje delitveno aktivnost KC in vsebnost K v živih tkivih ters tem tudi kondicijo drevja in izglede za njegovo preživetje. // In unaffected and variously affected silver fir (Abies alba Mill.) anatomical characteristics of the living tissues, the content of potassium, magnesium,calcium, and manganese, and electrical resistance of the living tissues were determined at several dates during the dormant and growth seasons. Unaffected trees were characterized by thicker living tissues, especially the cambial zone (CZ) and conducting phloem as well as higher K content. The concentrations of Mg and Mn were not related to the tree health state, and the Ca content was higher in affected firs. The concentrations of all elements were highest in physiologically the most active tissues, that is in CZ and conducting phloem, followed by the nonconducting phloem, and xylem where all concentrations decreased considerably. The thickness of CZ and K concentration reached their minimum while ER was at its maximum in the dormant season. The situation was reversed in the growth season. With increasing tree damage, the thickness of living tissues, specially CZ and conducting phloem, and the concentration of K decreased. ER, on the other hand, increased. The concentrations of Mg, Mn, and Ca did not show any consistent seasonal variation and did not have any detectable effect on ER readings. The conclusion is that ER is directly related to the mitotic activity of CZ and K content in the living tissues, which makes it an objective measurment of tree condition and its survival chances |