Ella Martin

Student Speaker | Étudiant.e
Biotic interactions are predicted to be stronger towards the tropics due to latitudinal gradients in climate, productivity, and biodiversity. This hypothesis is often tested using seed predation as a measure of biotic interactions, and previous studies have supported the prediction, showing greater seed removal in tropical sites. While these experiments are often time-controlled, this ignores the effect of the amount of time seeds spend exposed to predators, which could alter the observed trends. The actual intensity of predation therefore depends on not only the strength of predation, but also the exposure time, or the amount of time it takes seeds to germinate. In this project we synthesize data from 90 studies reporting time to germination of the seeds of over 1500 species from the Arctic to Argentina to test for latitudinal gradients in seeds’ time to germination. Preliminary results show that despite higher predation pressure and generally better germination conditions, seeds in the tropics do not appear to germinate faster than those in the temperate zone.