Army's Hawaiian plant propagation aids recovery.

The Army Garrison Hawaii has eight training areas on the islands of O'ahu and Hawai'i (the "Big Island"). Within the boundaries of these areas, there are more than 100 endangered species, including birds, several snails, and a large number of plants. Many of the species number fewer than 50 individuals in the wild. They occur in small, widely distributed populations of a few individuals on lands of the State of Hawaii, U.S. Fish and Wildlife Service, City and County of Honolulu, The Nature Conservancy, and other private owners.

One of the Army's most important conservation measures in the Hawaiian Islands is the collection and propagation of rare plant species. Two horticulturists, one plant propagation specialist, and one propagule (1) management specialist work full-time on this effort. The Army has access to three greenhouses, a mid- and low-elevation greenhouse on O'ahu and a high-elevation greenhouse at Pohakuloa on the island of Hawai'i, with a combined growing space of over 10,000 square feet (930 sq. meters). Since 1995, the Army has shared the mid-elevation nursery on O'ahu with the State's Division of Forestry and Wildlife. Over 2,000 plants are grown each year in these greenhouses and placed into natural habitats.

The Army also has collected thousands of seeds, which are stored either at the National Seed Storage Laboratory or the University of Hawaii (UH) Seed Conservation Laboratory at the Harold Lyon Arbretum. Trials are conducted at the UH lab by the Army's propagule management specialist to determine the viability of Hawaiian plant seeds stored under various conditions. This information can then be used by anyone carrying out plant restoration in Hawaii. Growth chambers are used for studying germination requirements of these rare species in a controlled environment. This technique promotes maximum germination and the best use of a limited seed supply. The germinated seeds are then transferred to sterile media and to one of the greenhouses.

Seed storage also ensures that there is material available for reintroduction purposes should a species become extinct in the wild. In fact, two plant species, Cyanea superba and Phyllostegia kaalaensis, have been saved from extinction through these efforts. Several of the plant species managed by the Army do not produce viable seeds. In these instances, it is necessary to try alternative propagation and storage techniques. The Army has had success with cuttings and micropropagation for many of these problem species. One example of a plant that does not produce viable seeds is Fluggea neowawrae. This dioecious (separate male and female plants) tree species is highly threatened by an introduced insect for which there is currently no control. The trees are rapidly declining in number, and cuttings are the only proven method to acquire stock for storage and propagation. Without this method, the species would surely go extinct.

The UH Lyon Arboretum Micropropagation Laboratory. is a crucial member of the micropropagation effort. Micropropagation is the practice of rapidly multiplying stock plant material to produce a large number of progeny plants, using modern plant tissue culture methods. The lab grows plants through this method and disseminates them to the Army greenhouses once established in their test tubes. It also houses a "living collection" of some of the rarest Hawaiian plants that can be used for future propagation and outplanting efforts.

The combined method of taking cuttings followed by micropropagation was used for Phyllostegia kaalaensis. Cuttings of this critically endangered plant were taken from wild populations in 1996 and 1997. Since that time, all wild populations have been extirpated by the effects of non-native feral ungulates, weeds. drought, and possibly disease. The cuttings were preserved in micropropagation for years as a genetic back-up of plants that were also being propagated in the greenhouse. The microproopagation facility was the only facility successful in propagating clones from a few of the populations, and without this success restoration efforts with this taxon would be grim.

The final method used by the Army to ensure the availability of plant material is ex situ (off site) storage or the "living collection." The Army has partnered with schools, colleges, and botanical gardens to achieve this goal. This storage method is often necessary for the larger plant species and those that do not produce viable seeds. The Army is hopeful that this combination of techniques, and working in partnership with a wide variety of organizations, will eventually lead to the stabilization of some of Hawaii's endangered plant species.

(1) A propagule is a structure (such as a cutting, seed, or sprite) that propagates a plant.

Michelle Mansker is Manager, of the Natural Resource Program of the Army Garrison Hawaii at Schofield Barracks, Hawaii ([e-mail]).