TNC Action Sites
Maps & Figures
Viability of forest bird concentrations were derived from recent assessments by the USGS/BRD.
Forest birds contribute to vital ecological processes, such as pollination
'Elepaio, a Hawaiian flycatcher, is a member of the forest bird concentration.
Hawaiian Rare Plant Concentrations
Definition and Viability of Rare Plant Concentrations
Using the Hawai‘i Natural Heritage Program (HINHP)
geodatabase of rare plant occurrences in the Hawaiian Islands, contour plots of
plant densities were generated for all islands (see figures below). Highest
densities of rare plant taxa were present on Kaua‘i and O‘ahu, with diminishing
density in the Maui Nui group and Hawai‘i Island.
A rare plant concentration was recognized if
rare plant density exceeded 16 occurrences per square kilometer AND the high density area extended beyond native
dominated ecological system boundaries. This occurred in only three places:
Kaua‘i, along the Na Pali cliff systems (below), O‘ahu, in the Wai‘anae
Mountains (below, bottom), and on Maui, in the West Maui Mountains (next column, top). All other high density rare plant areas occurred
within native-dominated ecological systems.
Rare Plant Concentration: Kaua‘i
vast majority of rare plants on Kaua'i occur within native ecological
systems (lavendar), however a concentration extends outside of these
native areas along the north coast of the island.
Rare Plant Concentrations: O‘ahu
on Kaua'i, many of the rare plant concentrations of the Wai'anae
conservation area (western O'ahu) occur outside of native ecological
systems (lavendar), many of which have been greatly reduced and
damaged. They are extremely vulnerable to threats such as fire,
ungulates, invasive weeds, rodents, pathogens, and drought, and are
considered of low viability.
(continued next column)
Rare Plant Concentration: West Maui
vast majority of rare plants on Maui lie within
native ecological systems (lavendar), however a concentration
extended outside of these native areas on the northwestern flanks of the West Maui conservation area.
Expert assessment of viability
For the Kaua‘i, O‘ahu and West Maui examples,
we polled the HINHP database, as well as botanists and managers with current
knowledge of the status of the rare plant concentrations. Their assessments
are recorded in the Conservation Planning Tool database associated with this plan. In all cases, overall
viability was assessed as poor, with populations showing a history of decline
in both population size and condition. Landscape context was also poor, since
the rare plant concentrations were defined on the basis of their location
outside of native-dominated ecological systems.
A decision was made that there were no viable
rare plant concentrations to include in the ecoregional portfolio, but that botanically
rich areas such as Kaua‘i and O‘ahu should be recognized as prime locations for
conservation agencies with mandates to protect and recover rare and endangered
plant taxa and engage in habitat restoration. The rare plant density for the
Wai‘anae region of O‘ahu is the highest in the ecoregion.
More information on the rare plant concentrations, such as the
specific species in each concentration and data summarizing trends
in population, is available in the Conservation Planning Tool