PARENT SESSION
Poster Session 2: Forest Ecology
Monday, August 8, 5:00 PM - 6:30 PM, Exhibit Hall 220 A-E, Level 2, Palais des congrčs de Montréal
Thirty-one years of change in vegetation composition of a Central European oak forest at the Sikfokut ILTER.
Kotroczó, Zsolt1, Krakomperger, Zsolt1, Papp, Maria*,2, Bowden, Rishard D.3, Tóth, Janos1, 1 University of Debrecen, Debrecen, Hungary2 University of Debrecen, Debrecen, Hungary3 Allegheny College, Meadville, PA
ABSTRACT- The sessile oak - turkey oak forest (Quercetum petraeae-cerris) of ILTER Sikfokut Project has been studied since the beginning of the 1970s in northeast Hungary. Over this period, serious oak deterioration occurred throughout the region. Long-term data at the research station show warmer temperatures and drought conditions, likely contributors to the decline of oak. We followed vegetation changes over the last three decades by remeasuring in 2004 all trees greater than 10 cm in diameter in a one ha plot, and comparing those data to reference data collected in 1973. The original plot had been divided into four quarters, each divided into 4 x 4 m subquadrates. All trees were retagged and their positions were mapped. In 1973, the forest was a densely sprouted even-aged forest of 60 years, with a medium-dense shrub layer and average herb layer. The forest contained 690 Quercus petraea (84%)and 126 Quercus cerris (15%) and one individual of Carpinus betulus. The forest in 2004 is more heterogeneous in tree species, with a dense shrub layer and with few herbaceous plants. Browsing by deer and rooting by feral pigs is extensive throughout the site. During the warm and dry period between 1973-2004, Quercus petraea declined greatly. Of the original 690 individuals, 472 died (68%). However, the mortality rate of the sub-Mediterranean Quercus cerris was only 16%. The ratio of the two oaks has decreased from 5.5 to 2.0. Meanwhile 131 Acer campestre grew out from the high shrub layer and constructed a new lower canopy tree level. Other species, Acer tataricum, Cerasus avium and Carpinus betulus also have increased the tree species diversity since 1973. Oak decline seems to have stopped since the turn of the century, and early successional maples have been increasingly important in the canopy structure. Our study suggests that changes in climate can result in a rapid and drastic shift in vegetation composition in Central Europe
Key words: climate change, long-term study, oak deterioration, maple invasion