Global biogeography of mating system variation in seed plants

Citation

Moeller D, Briscoe Runquist R, Moe AM, Goodwillie C, Cheptou P, Eckert CG, Elle E, Johnston MO, Kalisz S, Ree RH, Sargent RD, Vallejo-Marín M, Winn AA & Geber MA (2017) Global biogeography of mating system variation in seed plants. Ecology Letters, 20 (3), pp. 375-384. https://doi.org/10.1111/ele.12738

Abstract
Latitudinal gradients in biotic interactions have been suggested as causes of global patterns of biodiversity and phenotypic variation. Plant biologists have long speculated that outcrossing mating systems are more common at low than high latitudes owing to a greater predictability of plant–pollinator interactions in the tropics; however, these ideas have not previously been tested. Here, we present the first global biogeographic analysis of plant mating systems based on 624 published studies from 492 taxa. We found a weak decline in outcrossing rate towards higher latitudes and among some biomes, but no biogeographic patterns in the frequency of self-incompatibility. Incorporating life history and growth form into biogeographic analyses reduced or eliminated the importance of latitude and biome in predicting outcrossing or self-incompatibility. Our results suggest that biogeographic patterns in mating system are more likely a reflection of the frequency of life forms across latitudes rather than the strength of plant–pollinator interactions.

Keywords
Biotic interactions; breeding system; floral evolution; latitudinal gradient; life history; outcrossing; plant–pollinator interaction; pollination; self-fertilisation; sexual system

Journal
Ecology Letters: Volume 20, Issue 3