GERMINATION OF THREE NATIVE PLANT SPECIES

Germination responses of seeds of three native plant species-Nemophila menziesii H. & A. ssp. menziesii, Layia platyglossa (F. & M.) Gray ssp. platyglossa, and Clarkia rubicunda (Lindl.) Lewis & Lewis ssp. rubicunda-were investigated at atmospheric CO2 levels of 0.03%, 0.07%, 0.14%, and 0.2 1% in controlled greenhouse experiments. Seeds were germinated in a 1:1 (vol/vol) mixture of vermiculite and sponge rock under natural conditions of daylengths and temperatures. Elevations in CO2 concentrations did not significantly affect the germination responses of any of the three species, but their patterns of germination differed. The data suggest that increasing CO2 concentrations such as those anticipated in the next century may not significantly affect germination of native plant species.