ANNUAL COURSE OF SIMULATED RATE OF PHOTOSYNTHESIS UNDER NATURAL CONDITIONS

Algorithms of a leaf photosynthesis model published by Harley et al. ( 1992) and hourly values of radiation, temperature and air humidity for the years 1990, 1991 and 1992 obtained from the Hydrometeorological I nstitute in Prague, were used to calculate rate of photosynthesis (P-N ) for each hour as well as its hourly and daily totals. Under climatic conditions typical for this region, daily totals of P-N are more clos ely correlated with temperature (R-2 > 0.9) than with irradiance (R-2 of about 0.6 to 0.7). According to the calculated regression a 1 degre es C increase increases daily total of photosynthesis by some 60 mmol CO2 per 1 m(2). An expected increase in temperature as brought about b y the climate change could have beneficial effects on P-N.