| This study combined monitoring and experimental techniques to examine natural population parameters and physiological response to temperature of the invasive kelp Undaria pinnatifida in Monterey Harbor, California. Natural population density, reproductive condition, and seawater temperature were recorded throughout a 20-month study. Recruitment was sampled in experimental sporophyte density plots throughout a 9-month experiment. Physiology experiments were conducted in two temperature treatments over a 55-day period coincident with reproduction measurements and nutrient analysis.;Natural population fluctuation and reproductive condition appeared to respond to seasonal variations in temperature range. Warm temperature treatments increased C:N and blade senescence but decreased time to reproduction and peak spore output. Sporophyte density reduced recruitment at high levels, likely resulting from intra-specific competition. Because Undaria pinnatifida is an opportunistic species responding to changes in an unpredictable environment it may have a distinct advantage when it comes to invasion success. |
