In reaction to Forest Decline and global warming effects, a long-term project has been launched in 1985 at the Federal Research and Training Centre for Forests, Natural Hazards and Landscape (BFW) that aims to investigate processes of forest tree reproduction in seed orchards as well as in different forest Stands. Flowering and seed production processes are investigated since 1988. Examinations of Intercorrelation between pollen production, female blossom development and weather conditions shall allow a prediction of seed production and help to ascertain fitness of forest trees. In cooperation with the operators of several stations of the European Allergological Network (EAN) a forest Reproduction - Monitoring - Network has been established subsequently. (http://bfw.ac.at/rz/pollen.main). During the first ten years in 7 locations of Austrian forest standings flowering (pollen) and seed production were examined. After this period, during which the regional correlation between pollen and seed production was established, seed trapping was stopped and only pollen traps (volumetric and gravitation types) are used. Data of more than 45 stations are available and between 15 and 20 anemophilous tree species are registered at present. For the presented investigation only complete datasets from more than 15 years were taken into consideration. First results show mostly positive trends or no significant trends north of the alpine ridge and in the east of Austria. The main object of this investigation is to point out first visible clear negative trends in pollination of forest tree species in certain regions of Austria and to analyze the climatically background. As an example three negative trends in pollen production in Salzburg, Northern Tyrol and Eastern Tyrol are worth mentioning: the dropping pollen numbers of spruce (Picea abies) In the Pinzgau, the strong decrease of elm (Ulmus) pollen in Zams (N. Tyrol) and the decline of green alder pollen (Alnus viridis) In the region of Lienz (Eastern Tyrol). After intensive causal analysis, using meteorological data of the "Zentralanstalt für Meteorologie und Geodynamik" (ZAMG) of the next closest station to the location of pollen trap, a connection to climate change in all this cases is evident: - The decrease of spruce pollen (Pinzgau) started by the impacts of a heavy storm catastrophe called "Lothar" in December 1999, followed by storm effects in 2002, 2003 and 2004. The tree numbers of mature spruce had been diminshed by about 40 % in this region during these six years. - Dutch elm disease has advanced into "Oberes Inntal" (Zams) between 1993 and 2002 because the higher absolute minimum temperatures of April and May did not disturb the spread of the vector bark beetles (Scolytus multistriatus, S. scolytus, S. triarmatus). - The regression of green alder, dependent on a minimum of soil moisture, may be proven by the comparison of increasing maximum temperatures and decreasing rain (snow) fall during wintertime in the respective region. The increase of catastrophic storm and hail events northern of the alpine ridge will damage forest tree species more than in the past. The increase of temperature and the additional decrease of precipitation in the alpine valleys and especially southern of the alpine rim will especially affect tree species dependent on high soil moisture content.
