The influence of climate change on radial growth of norwey spruce (Picea abies L.) in eastern Slovenia

Podnebje se je v Sloveniji začelo spreminjati že v osemdesetih letih prejšnjega stoletja. Te spremembe so in še vedno povzročajo povišane povprečne letne temperature, zmanjšane količine letnih padavin, vse več vročinskih valov in posledično več sušnih obdobij. Smreka na račun oslabelosti zaradi sušnih stresov in posledičnih napadov podlubnikov izgublja svoj delež v lesni zalogi predvsem na rastiščih, kjer je bila v preteklosti umetno vnešena in pospeševana. Ker je smreka še vedno ena izmed pomembnejših gospodarskih drevesnih vrst v Sloveniji, smo z dendrokronološkimi analizami želeli preveriti vpliv opisanih klimatskih dejavnikov na njeno rast na nižinskih lokacijah. Opravili smo analizo debelinskega priraščanja smreke na 6 različnih lokacijah v nižinah Slovenije in podatke obdelali s pomočjo različnih računalniških programov (ATRICS, PAST-5, CDendro) na Gozdarskem inštitutu Slovenije v Ljubljani. V vseh primerih smo opazili vplive klimatskih sprememb, ki se odražajo kot negativen vpliv vedno višjih poprečnih temperatur in pozitiven vpliv padavin na debelinsko priraščanje smreke, kar kaže na povečevanje vpliva sušnega stresa na rast dreves. Z analizo drsečih korelacij smo dokazali, da se vpliv opisanih klimatskih dejavnikov povečuje s približevanjem sedanjosti.The climate in Slovenia began to change in the 1980s. These changes were and still are caused by increased average annual temperatures, reduced annual rainfall, more heat waves and consequently more droughts. Spruce is losing its share in the growing stock at the expense of weakness due to drought stresses and consequent attacks by beetles, especially on sites where it has been artificially introduced and accelerated in the past. As spruce is still one of the most economic important tree species in Slovenia, we wanted to use dendrochronological analysis to verify the influence of the described climatic factors on its growth in lowland locations. We performed an analysis of spruce thickness increment at 6 different locations in the lowlands of Slovenia and processed the data with the help of various computer programs (ATRICS, PAST-5, CDendro) at the Slovenian Forestry Institute in Ljubljana. In all cases, we observed the effects of climate change, which are reflected as a negative effect of temperatures and a positive effect of precipitation on the radial growth of spruce, which indicates an increase in the impact of drought stress on tree growth. By analyzing the sliding correlations, we proved that the influence of the described climatic factors increases with the approximation of the present