Vernal pool

Vernal pools, also called vernal ponds or ephemeral pools, are seasonal pools of water that provide habitat for distinctive plants and animals. They are considered to be a distinctive type of wetland usually devoid of fish, and thus allow the safe development of natal amphibian and insect species unable to withstand competition or predation by fish. Certain tropical fish lineages (such as killifishes) have however adapted to this habitat specifically. Vernal pools, also called vernal ponds or ephemeral pools, are seasonal pools of water that provide habitat for distinctive plants and animals. They are considered to be a distinctive type of wetland usually devoid of fish, and thus allow the safe development of natal amphibian and insect species unable to withstand competition or predation by fish. Certain tropical fish lineages (such as killifishes) have however adapted to this habitat specifically. Vernal pools are a type of wetland. They can be surrounded by many communities/species including deciduous forest, grassland, lodgepole pine forest, blue oak woodland, sagebrush steppe, succulent coastal scrub and prairie. These pools are characteristic of Mediterranean climates, but occur in many other ecosystems. During most years, a vernal pool basin will experience inundation from rain/percipitation, followed by desiccation from evapotranspiration. These conditions are commonly associated with Mediterranean climate. Most pools are dry for at least part of the year, and fill with the winter rains. Some pools may remain at least partially filled with water over the course of a year or more, but all vernal pools dry up periodically. Typically, though, a vernal pool has three phases each year: it is inundated in the Winter (Inundated Phase), it dries slowly in the Spring (Flowering Phase), and in the summer it completely dries (Dry phase). A key time during vernal pool development between the flooding and evaporation phases is the flowering of native species, which attracts pollinators and influences seed distribution patterns. Vernal pools favor native species because non-natives can't handle the conditions of the water staying on the landscape for as long as it does, but not long enough to support truly aquatic species.