Temperature modifies the magnitude of a plant response to Collembola presence

Abstract

Soil properties and the growth and maturation of herbaceous plants are known to be influenced by the soil fauna (Collembola) and by the temperature. But little is known about how these two factors interact. We hypothesised that the vegetative and reproductive responses of Poa annua L. to the presence of soil Collembola density will change according to temperature. P. annua was grown in microcosms with or without Collembola at two different air temperature conditions, 16 °C as a Low T° vs. 19 °C as a High T°. Both factors “Collembola” and “Temperature” significantly influenced several plant and soil variables. The number of flowers, the root biomass of P. annua were higher either in presence of Collembola or under elevated temperature. The same applied for soil ergosterol or K content for example. Soil nitrate content was exclusively affected by the presence/absence of Collembola and not by the temperature. Finally, significantly interactive effects between temperature and Collembola upon several plant or soil variables (root biomass, number of flowers, soil K and Mg content) were shown. Our study suggests that biotic factors (here soil fauna) may strongly interact with climatic variables in regulating plant growth through changes in soil nutrient availability. We provide experimental evidence that climate warming modifies the effect of soil Collembola on the reproduction strategy of the plant.