The paper evaluates models for simulating short-term variations in isoprene and monoterpene emissions from plants, influenced by light and leaf temperature. Isoprene emissions increase with photosynthetically active radiation up to a saturation point and exhibit an exponential increase at temperatures below 30°C, peaking at about 40°C before declining rapidly. Monoterpenes also show an exponential increase with temperature, but their emission rates vary among species and factors. The authors recommend using model G93 for isoprene emissions, which performs well for various plant species, and equation (5) with β = 0.09 K⁻¹ for monoterpene emissions. Sensitivity analyses show that uncertainties in model parameters can lead to significant errors in emission rate predictions, particularly under extreme conditions. The study emphasizes the importance of accurate simulation of diurnal emission rate variations for realistic hydrocarbon concentrations in regional tropospheric photochemical models.The paper evaluates models for simulating short-term variations in isoprene and monoterpene emissions from plants, influenced by light and leaf temperature. Isoprene emissions increase with photosynthetically active radiation up to a saturation point and exhibit an exponential increase at temperatures below 30°C, peaking at about 40°C before declining rapidly. Monoterpenes also show an exponential increase with temperature, but their emission rates vary among species and factors. The authors recommend using model G93 for isoprene emissions, which performs well for various plant species, and equation (5) with β = 0.09 K⁻¹ for monoterpene emissions. Sensitivity analyses show that uncertainties in model parameters can lead to significant errors in emission rate predictions, particularly under extreme conditions. The study emphasizes the importance of accurate simulation of diurnal emission rate variations for realistic hydrocarbon concentrations in regional tropospheric photochemical models.