Vernal pools are rare, shallow bodies of water that fill with rain water in the winter, produce wildflowers in the spring, and are dried up by the end of summer. The word “vernal” means spring. The closest vernal pool reservation to Sacramento is at Mather Field off of the Sunrise Boulevard exit on Highway 50.
Unlike ponds, which hold water year-round, vernal pools are seasonal and hold water until it evaporates in the summer, said Volunteer Tour Docent Amanda Schmidt. The water comes from rain, not runoff from a stream or lake, so there are no fish, she added.
Vernal pools are able to hold water until the sun dries them up because of the layer of hardpan that lies benath the surface of the pool, according to the tour guide. She said that water is unable to penetrate the hardpan which keeps it from seeping into the ground.
Native and non-native introduced plants cohabitate in the Mather Field vernal pool habitat, according to Schmidt. She went on to add that early settlers introduced filaree, a non-native plant found commonly in grasslands, to the region originally as feed for their cattle, but it has now flourished and is a challenging competitor for native plants.
Schmidt told the tour group that frying pan poppies, a relative to the golden poppy, are native to the region. According to the Mather Field online botany tour, this is a flower that usually appears in early spring.
Schmidt guided the group Sunday through the mushy grounds of the fragile habitat, pointing out and naming flowers as the two-hour tour walked on.
The spokepod plant, shown above, is easily identifiable by its characteristic round seed pods, Smchidt said.
Schmidt told her tour that he lack of winter rain has not allowed the Mather Field vernal pools fill as they usually would and therefore the wildflowers haven’t been able to blossom the way they have in previous years.
She went on to say that once the spring rain is finished, the pools will then be allowed to gradually dry and the flowers will bloom into their characteristic rings of flowers in the dried pool beds.
The solid yellow hawkbit flowers are an introduced flower, while tidy-tips are native and have white on the edge of their petals to serve as a bullseye target for pollinating insects, Schmidt informed the tour.
Tourgoer Hillary Johnson leads her daughter Elle around the perimeter of the pool after taking a closer look into its clear and shallow depths.
Shown above are the beginnings of the blossoming flowers that will grow in rings from the outer portions inward as the season warms and the pools dry. Schmidt said that she believes there will be more flowers in bloom in the next couple of weeks.
Tours of the pools are available for the next two Sundays, April 22 and April 29.