Upland areas include a mixture of grasslands and vernal pool/alkali meadow habitats. Many of the grassland areas have been restored to native grasses and wildflowers. In areas with more alkaline (salty) soils, rainwater tends to naturally puddle in depressions and create what are referred to as "vernal pools". Salt-tolerant native plants grow well in these alkaline areas. In the spring, these areas produce a carpet of protein-rich grass shoots and vernal pools are often filled with invertebrates, providing an important food source for waterfowl and shorebirds that are preparing for spring migration. During the spring and summer months, they provide nesting habitat for ducks, pheasants, meadowlarks, burrowing owls, bitterns, and northern harriers. In the winter and spring, annual grasses provide food for geese, coots, and wigeon. They also support significant numbers of insects, rodents, and reptiles which in turn are important forage items for raptors and birds. Goldfields, downingia, and popcorn flowers bloom brilliantly on the edges of the vernal pools in late spring. Other plants include: saltgrass, saltbush, and annual grasses.