Recorded from Kauai, Oahu, Maui, Lanai, and Hawaii, but known to be extant only on Oahu and Hawaii. There have been no records of the species on Maui for more than half a century. The last known plants on Kauai and Lanai died recently (in the 1990's). On Oahu and Hawaii a total of fewer than 100 plants are known to remain. Successful recruitment does not presently occur at most sites. Rats are reported to feed heavily on the seeds at some locations. The populations on Hawaii Island are in areas that have been affected by urbanization, agriculture, and fire. As with most native Hawaiian dry and moist forest plants, the species is threatened by alien plants and animals.
Threats to C. kavaiensis include habitat degradation by grazing cattle, mouflon, axis deer, and feral goats. Additional threats include urban development, fires, and invasion of exotic plants, rodents, exotic insects such as the coffee twig borer (Xylosan
Less than 20 individuals total are found in in 2 populations on the Big Island
Less than 10 individuals total in 2 populations on Oahu
Two individuals in 1 population on Kauai
Nos. of Pop: 5 (Center for Plant Conservation [CPC] 2002)
Nos. of Plants: <32 (CPC 2002)
C. kavaiensis plants, both wild and cultivated produce viable seed. The Division of Forestry and Wildlife, Hawaii Department of Land and Natural Resources (DOFAW) occasionally collects seeds from the wild and propagated plants in Hilo nursery. The seedlings are then transplanted into fenced enclosures where they are supported by watering and weed control (USFWS 1994).
Seeds of C. kavaiensis have been tested by the Center for Conservation Research and Training (CCRT), finding that they are orthodox and can tolerate freezing and drying. The laboratory germination time was one to three weeks (Yoshinaga 2002).
Management goals for C. kavaiensis include reducing current threats such as fire, damage by herbivores, to make habitat improvements, and to encourage natural re-generation. Outplanting nursery-raised trees are also a part of management goals.
Management strategies are focused on fenced exclosures. The fences protect trees from browsing cattle and feral ungulates. They are designed to be large enough for expansions in populations. Fire breaks and fire roads outside the protected areas have been cleared to protect and to give access to the enclosures. Fountain grass removal also increases the probability of regeneration and seedling establishment (USFWS 1994).
The National Tropical Botanical Garden (NTBG) currently has ex situ holdings of 1,160 seeds in its seed bank, which represents four out of the five populations. In addition, there are five plants growing in the nursery and 11 plants in the botanical garden representing two populations.
1. Prevent the destruction of the few remaining wild trees of C. kavaiensis
2. Remove the environmental factors that may prevent natural regeneration and dispersal of C. kavaiensis (ex. control alien species such as fountain grass, insect control and feral ungulate control).
3. Conduct research on limiting factors of C. kavaiensis.
4. Augmenting current populations of C. kavaiensis.
5. Validate and revise recovery objectives for C. kavaiensis.
6. Map genetic diversity in the surviving populations of C. kavaiensis.
7. Conduct pollination biology and seed dispersal studies.
Recommendations derived from M.H. Chapin, M. Maunder, Center for Plant Conservation [CPC] (2002), and USFWS (1994).
1. Develop proper horticultural protocols and pest management for C. kavaiensis
2. Establish secure ex situ stocks with full founder representation.
3. Survey ex situ holdings and conduct molecular fingerprinting.
Recommendations derived from M.H. Chapin and M. Maunder.
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