Time is an important constraint for every ecological mosaic.
Short-term mosaics, also considered ephemeral, can be created by a seasonal rainfall, by the melting of snow masses in late spring, by the frozen lakes of winter, or by a flowering of algae in a pond. Such mosaics are considered ephemeral, but despite their name often contain rare or endangered species, or are essential for maintaining populations of common species like amphibians.
Many ephemeral mosaics contain a rich flora or fauna or a mix of the two. The time scale is the only distinction possible across mosaics. Species that can interact with ephemeral mosaics have a life cycle synchronized with the time scale of the processes responsible for that mosaic.
The advantage for a species of interacting with such an unpredictable and short-term mosaic can be the use of suddenly appearing resources, or due to the unpredictability, a way to escape predators or to avoid competition. Predation by fish is not possible in temporary ponds, and in this way amphibians escape such types of predation. Also terrestrial predators like snakes need time to locate temporary ponds.
Most terrestrial amphibians use temporary ponds for egg-laying and tadpole development. The reproductive cycle of evolutionarily ancient organisms is completed in a short time in an ephemeral patch!
Mosaics produced by fires are a special case of plant growing. Many dormant seeds can be stored in the soil for a long time, and their development is managed by fires that create clearings in the forest cover.
In this case the mosaic is the product of a process that at the end of the story allows the arrangement of plants in the same patch.
Was this article helpful?