Trends in growth and vitality of pedunculate oak forests in Srem from the aspect future Sava river water level change

Abstract

The decline in vitality and dieback of oak forests is increasingly present Vojvodina. This is old challenge for forestry, which again became actual. The paper used dendrochronological methods with the intention to describe trends in growth of pedunculate oak forests in Srem and trends of the water level of the Sava River and air temperature, which are defined as critical to the vitality of these forests. Predicted were water levels of Sava River in the 21st century with overview of its implications on the oak forests growth. Samples were taken from three stands in Srem (Stara Vratična, Smogva and Blate). Flows of Sava river were taken according to five climate scenarios for the periods 2012-2040 and 2042-2070, and converted into the water levels. A trend of decrease in growth in all three stands in last 30 years was observed, together with decrease in water level and temperature rise. Predicted future water levels of the Sava River were in general lower than those in the period 1951-1981, and higher than in the period 1982-2012. The differences between the various scenarios, as well as the impossibility of adequate simulations of extreme events, leavs space for further considerations.

Opadanje vitalnosti i sušenje šuma je sve više prisutno u šumama hrasta lužnjaka u Vojvodini. Stari izazov za šumarstvo koji ponovo postaje aktuelan. U radu su korišćene dendrohronološke metode sa namerom da se prikažu trendovi prirasta hrasta lužnjaka u Sremu i trendovi vodostaja reke Save i temperature koji su definisani kao kritični za vitalnost ovih šuma. Izvršeno je predviđanje vodostaja Save u 21. veku i dat osvrt na njen uticaj na šume lužnjaka. Uzorci su uzeti iz tri sastojine u Sremu (Stara Vratična, Smogva i Blate). Razmatrano je pet klimatskih scenarija budućih protoka reke Save za period 2012-2040 i 2042-2070, koji su preračunati u vodostaje. Uočen je trend smanjenje prirasta u sve tri istraživane sastojine u proteklih 30 godina, kao i trend smanjenja vodostaja i porasta temperature. Projekcije budućih vodostaja reke Save su u većini slučajeva bile niže od onih u periodu 1951-1981, a više od onih u period 1982-2012. Razlike između različitih scenarija, kao i nemogućnost verodostojne simulacije ekstremnih voda, ostavlja prostora za dalja razmatranja.