View is from Crater Rim Drive about 300 m west of Uwekahuna Bluff toward the west. The northwest caldera rim borders the lower reach of the upland forests and woodlands ecological zone, which extends from Kilauea onto the lower flank of Mauna Loa as high as about 2,050 m (see map and reference below). Rainfall in this zone ranges from about 150 cm a year at Kilauea to less than 100 cm at the upper elevations. Frost is very infrequent at Kilauea but common during winter months on Mauna Loa.
At this location, lava flows are mantled with fragmental deposits from the Keanakako`i Ash Member at least 1 m thick, visible between the plants in middle distance. The last explosive eruption that formed these deposits was in A.D. 1790 and the plants growing here clearly developed sometime later. The most diverse and well-developed forests of the zone are found about 2 km from Kilauea Caldera on the lower slope of Mauna Loa at Kipuka Puaulu.
The plants most visible in this image include the following common names (Family, Genus):
The two grasses are introduced species.
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.