20.500.12556/RUL-161971 Vodni potencial sadik doba (Quercus robur) in gradna (Q. petraea) v razmerah različne razpoložljivosti vode v tleh in ozračju Water potential of pedunculate oak (Quercus robur) and sessile oak (Q. petraea) saplings under conditions of different water availability in soil and atmosphere V poskusu je bil analiziran vodni potencial gradna (Quercus petraea) in doba (Quercus robur) ob različnih vremenskih razmerah (s poudarkom na vročih poletnih dneh) in različni razpoložljivosti vode v tleh. Meritve so potekale preko dveh zaporednih dni (16. 7. ter 17. 7.). Prvi dan so meritve potekale v suhem substratu, naslednji dan pa v vlažnem (zalivanje je potekalo 16. 7. zvečer do saturacije substrata v loncih). Vrsti se nista razlikovali v vodnem potencialu merjenem pred zoro. V suhem substratu se je vodni potencial gradna spustil pod vrednost -2,5 MPa. Vodni potencial doba pa je minimum dosegel med vrednostjo -2 ter -2,5 MPa. Statistično značilne razlike niso bile potrjene v suhem substratu. Ravno nasproten vzorec, pa je bil opažen v vlažnem substratu, saj smo nižje dnevne minimume Ψ zaznali pri dobu. Meritve izvedene med vročinskim valom v sredini avgusta 2024 (13. 8.), ob navlaženem substratu, so potrdile nižje dnevne minimalne vrednosti Ψ pri dobu. Rezultati so v diskusiji komentirani upoštevajoč objavljene podatke s področja anatomije lesa, ekofizologije ter ekologije obeh vrst. Daily courses of water potential (Ψ) of pedunculate oak (Quercus robur) and sessile oak (Q. petraea) saplings were investigated under different weather conditions (with a focus on hot summer days) and the availability of soil water. Water potential measurements were taken on two consecutive hot sunny days (July 16 and 17), first after a dry period (dry soil) and the next day after rewatering (soil saturated with water the evening before). On both days species did not differ in pre-dawn water potential (Ψpd). In dry soil Ψ decreased below -2.5 MPa for Q. petraea, while daily minimum Ψ were between -2 and -2.5 MPa in Q. robur. We could not, however, prove the significant differences between the daily minima of Ψ of two species. The opposite pattern was observed in wet soil where Q. robur exhibited lower midday water potentials, which was confirmed with additional measurements during a heat wave in midAugust (August 13). The results are discussed with respect to literature data on wood anatomy, ecophysiology and ecology of both species. vodna bilanca atmosferska suša hrast fiziologija drevesa water balance atmospheric drought oak tree physiology true false false [M. Levstek] Slovenski jezik Angleški jezik Diplomsko delo/naloga 2024-09-18 07:16:07 2024-09-18 07:16:12 2024-09-20 03:29:53 0000-00-00 00:00:00 2024 0 0 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 630*116:582.623.2(043.2)=163.6 245647 207994115 42062.pdf 42062.pdf 1 ED9B257D8BB42D3B236216E6B3C4AFE2 163f04ec2ce27e2bebb5b7266ca7bd829b180e3166cea58d307ee1d1a54230d1 03998e19-757d-11ef-b232-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=190981 Biotehniška fakulteta 0 0 0