1-16
LONG-TERM POLLEN MONITORING EXPERIMENTS FOR THE PERIOD 1994-2008 IN THE RILA MOUNTAINS, BULGARIA
Authors: Spassimir Tonkov1*, Elissaveta Bozilova1, Dolja Pavlova1, Ivan Raev2
Number of views: 359
The annual pollen influx in the altitudinal zone 1800-2050 m a.s.l. produced by plant communities in the coniferous and subalpine vegetation belts of the northwestern Rila Mts. was analyzed for the period 1994-2008. The results from the five pollen traps placed on south and north slopes of a ridge revealed the dominance of Pinus diploxylon-type (Pinus mugo, Pinus sylvestris) and relatively constant presence of Picea abies and Pinus peuce pollen, with the exception in years of abundant flowering (1997, 1999, 2003 and partly 2005). The species Fagus sylvatica which grows at lower altitudes showed very good capabilities of pollen dispersal upslope. The trapping results indicated a cyclicity in the flowering of beech, with maximal pollen influx values in years 1994, 1999, 2005 and 2007, most probably dependent on the local climatic conditions. Pollen of deciduous trees such as Quercus, Carpinus betulus, Corylus, Alnus, Betula, although in less quantities, was also recorded in the traps. The herb component constituted only a small part of the total annual pollen influx. The results from long-term pollen trapping experiments could be applied to monitor the future trends in forest development in relation to climate change and local disturbances.