Phenological development of fagus sylvatica L. and Aesculus hipocastanum L. in relation to mean monthly temperatures for the Kočevje locality during 1961-1990
Analiza nastopa fenoloških faz gozdnega drevja in grmovja v dolgem časovnem nizu nam pojasnjuje odvisnost med časom pojavljanja določene fenofaze ter meteorološkimi razmerami. Na lokaciji Kočevje smo ugotavljali korelacijo med nastopom fenofaz za bukev (Fagus sylvatica L.) ter navadni divji kostanj (Aesculus hippocastanum L.) ter povprečnimi eno-, dvo- in tromesečnimi temperaturami zraka za obdobje od leta 1961 do 1990. Korelacije so tesnejše, če uporabimo povprečja temperatur dveh ali treh zaporednih mesecev. Največji delež pojasnjene variabilnosti pri bukvi smo dosegli z modelom za napoved začetka rumenenja listja (58 %). Kot prva pojasnjevalna spremenljivka se pojavlja povprečna temperatura v mesecih februarju, marcu in aprilu, kot drugapa povprečna temperatura mesecev julija, avgusta in septembra. Pri navadnem divjem kostanju smo največji delež pojasnjene variabilnosti dosegli zmodelom za napoved začetka splošnega cvetenja (65 %), na katero najbolj vplivajo povprečne temperature mesecev aprila in maja ter mesecev januarja, februarja in marca. Na splošno je začetek rumenenja listja pri bukvi dober kazalec temperaturnih razmer rastišča.Long-term phenological development of forest trees and shrubs is an important indicator of changes in the onset of specific phenological phase at different sites in relation to meteorological conditions. Correlation analysis and linear multiple regression were used to establish relationship between phenological phases for Fagus sylvatica and Aesculus hippocastanum and mean monthly air temperatures for the Kočevje locality in the period 1961-1990. Correlation coefficients between the onset of phenological phases with air temperature of the previous 2-3 months were relatively high. For Fagus sylvatica, the highest variability was explained with phenological model for the beginning of leaf colouring (58 %) with first independent variable mean monthly temperature for the months of February, April and May and as second independent variable mean monthly temperature for the months of July, August and September. For Aesculus hippocastanum, the highest variability was explained with phenological model for the beginning of flowering (65 %) with first independent variable mean monthly temperature for the months of April and May and as second independent variable mean monthly temperature for the months of January, February and March. In general, the beginning of leaf colouring in Fagus sylvatica is a good indicator of temperature characteristics of the site
