Hawaiian Rare Plant Concentrations

Hawaiian High Islands Ecoregion
This page last revised 16 August 2006 -- S.M.Gon III

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Viability of forest bird concentrations were derived from recent assessments by the USGS/BRD.

'I'iwi on koli'i
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

The 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

Rare plant concentrations on the island of O'ahu

Unlike 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 Rare plant concentrations of Maui

The 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.

Portfolio decision

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 database.

	Hawaiian High Islands Ecoregion This page last revised 16 August 2006 -- S.M.Gon III
Home Introduction Ecoregion Conservation Targets Viability Goals Portfolio TNC Action Sites Threats Strategies Acknowledgements ▫ Tables Maps & Figures CPT Database Appendices Glossary Sources . 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 The 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 Unlike 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 The 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. Portfolio decision 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 database.