View is across a small crater that collapsed atop the `Aila`au shield, which was active 350-400 years ago. The northeast part of the caldera borders the rain forest ecological zone, which extends in a narrow band from the caldera along the north side of Hawai`i Volcanoes National Park nearly to the ocean (see map below). Average annual rainfall on the northeast side of the caldera is more than 200 cm.
The rain forest canopy is typically dominated by `Ohi`a trees, beneath which up to 10 species form an open to closed canopy ranging in height from about 6 to 12 m. `Olapa is perhaps the most abundant tree species in the understory. Magnificent tree ferns (Hapu`u `i`i and Hapu`u pulu) often reach heights of 6 m.
A variety of native trees are present in this pit crater, but individual trees are difficult to identify from a distance. A few of the plants that are present include the following common names (Family, Genus):
Seven ecological zones exist within Hawai`i Volcanoes National Park, which includes 97,000 hectares that extend from the ocean to the summits of Kilauea and Mauna Loa volcanoes. Each zone consists of distinct plant and animal communities. Kilauea's caldera is surrounded by three zones: rain forest on the east, upland forests and woodlands on the northwest, and mid-elevation woodlands to the south.
Stone, C.P., and Pratt, L.W., 1994, Hawai`i's plants and animals -- Biological sketches of Hawaii Volcanoes National Park: University of Hawaii Press, p. 399.