Precipitation timing and soil substrate drive phenology and fitness of Arabidopsis thaliana in a Mediterranean environment

In Mediterranean climates, the timing of seasonal rains determines germination and flowering phenology, which in turn may affect fitness. As climate change alters seasonal precipitation patterns, it is important to ask how these changes will affect the phenology and fitness of plant populations. We addressed this question experimentally with the annual plant species Arabidopsis thaliana.
In a first experiment, we manipulated the date of rainfall onset and recorded germination phenology on sand and soil substrates. In a second experiment, we manipulated germination date, growing season length, and mid-season drought to measure their effects on flowering time and fitness. Within each experiment, we manipulated seed dormancy and flowering time using multilocus near-isogenic lines segregating strong and weak alleles of the seed dormancy gene DOG1 and the flowering time gene FRI.  We synthesized germination phenology data from the first experiment with fitness functions from the second expe..., ,