Slide 1
Rain opens a brief opportunity
A desert can produce sudden growth after suitable rainfall. Many annual plants spend unfavourable periods as seeds rather than active green shoots.
More to Read
The visible bloom is only one stage of the population. A dry-looking landscape can still contain a seed bank whose members wait for conditions that allow a complete life cycle.
Slide 2
Not every shower is enough
Germination depends on the amount and timing of moisture as well as temperature. A little rain does not guarantee a large bloom.
More to Read
Growing too soon risks exhausting a seed's reserves before another dry spell. Seasonal cues help connect emergence with an opportunity long enough for roots, flowers and new seeds to develop.
Slide 3
Annual plants work quickly
Desert annuals can grow, flower and set seed during a short favourable interval. Their strategy avoids enduring the driest months as exposed foliage.
More to Read
Perennial shrubs and succulents solve the same environment differently through lasting structures and water economy. The desert community combines escape from drought with tolerance of it.
Slide 4
A pulse moves through the food web
Fresh growth and flowers provide resources for insects and other animals. The response to rain can spread beyond the plants that first germinate.
More to Read
Consumers may differ in how quickly they respond or arrive. Ecological activity can therefore unfold in a sequence, rather than every population increasing on the day the rain falls.
Slide 5
The next dry period begins
After successful reproduction, many annual plants die and leave new seeds. The landscape can become sparse-looking again while the cycle continues.
More to Read
A single spectacular year does not describe average desert conditions. Long records of rainfall, germination and seed production reveal the irregular opportunities on which these plants depend.
Sources
- Plants of Death Valley
National Park Service
- Plants of Mojave National Preserve
National Park Service