This page last revised 31 August 2008 -- S.M.Gon III
TNC Action Sites
Maps & Figures
· Include all occurrences with viability ranked good or very good. The limited geographic area of the Hawaiian Islands, and the low number of remaining viable ecological systems requires, in our assessment, the greatest possible inclusion of viable conservation targets.
· Add fair ranked occurrences to ensure at least two occurrences of each ecological system per stratification unit (if extant). Diversity of ecological systems is not adequately covered by inclusion of those of good or better rank alone.
Goals for natural communities:
· Select four high ranked/quality occurrences of continuous perennial streams on each high island where streams occur, stratifying by conservation area as appropriate. This results in 20 selected streams in the ecoregion, or more than 10% of the total remaining occurrences.
Goals for special features:
· Select all forest bird concentration occurrences ranked good or very good. Given the history of decline of forest bird species in Hawai‘i, our assessment concludes that all remaining viable occurrences should receive protection.
· No rare plant concentration areas were selected, because all were of poor viability.
· Select all waterbird concentration occurrences recommended by the USFWS recovery plan as needed for recovery. Their recovery assessment is appropriate goal-setting for both scientific and strategic reasons.
the goals described above resulted in a terrestrial target ecoregional portfolio of 16 conservation
including four broadly defined areas that encompass waterbird
concentrations (see Summary Table below). Brief summary descriptions for the
conservation areas are provided in the Appendices.
1: Four Stratification Units (SU) were established to account for
ecological and evolutionary variability across the Hawaiian
Redundant examples of all conservation targets across the four SUs
ensure that island and regional biodiversity is captured in the
ecoregional portfolio of conservation areas.
|Table: Portfolio Assembly Rules
The table at right depicts the end result of the goal-setting process as described above. Redundant representation for ecological systems, stream communities, and viable species concentrations is seen for each of the four stratification units. Each black dot represents a conservation target added to the ecoregional portfolio.
Key to abbreviations: SU = Stratification Unit; ES = Ecological System, NII = Ni‘ihau, KAU = Kaua‘i, OAH = O‘ahu, MOL = Moloka‘i, LAN = Lāna‘i, KAH = Kaho‘olawe, MAU = Maui, HAW = Hawai‘i; Conservation Areas: NII = Ni‘ihau, KAU = Kaua‘i, WAI = Wai‘anae, KOO = Ko‘olau, EMO = East Moloka‘i, LAN = Lāna‘i, KAH = Kaho‘olawe, EMA = East Maui, WMA = West Maui, KOH = Kohala, MK = Mauna Kea, WML = Windward Mauna Loa, K-K = Ka‘ū - Kapāpala, KON = Kona, P-P = Pōhakuloa - Pu‘u Wa‘awa‘a; Targets: ALP = Alpine System, SUB = Subalpine System, MD = Montane Dry System, MM = Montane Mesic System, MW = Montane Wet System, WC = Wet Cliff System, LW = Lowland Wet System, LM = Lowland Mesic system, LD = Lowland Dry System, DC = Dry Cliff System; CPS = Hawaiian Continuous Perennial Stream Community, FBC = Forest Bird Concentration, RPC = Rare Plant Concentration, WBC = Waterbird Concentration. Black dots indicate target selected for portfolio.
Bringing active management to priority ecological systems is the primary goal.
Alien species, such as feral ungulates, are a prevailing threat to native conservation targets in all conservation areas in Hawai‘i.
Minimum Effective Goals
To set thresholds for minimum long-term goals for adequate conservation of ecological systems, we propose to use the lower size, condition and landscape context criteria for a viability rank of "good." This translates practically as a combination of:
For conservation areas with large area occurrences of ecological systems (e.g., Hawai‘i Island, Maui), there might be room to identify subsets of the total area (but exceeding 18,750 acres minimum size) within which to actively reduce threats (and improve condition) and ensure improved landscape context.
What these goals mean for the ecological system occurrences for each Stratification Unit is that some systems with overall good or very good rank can be maintained at that level, while any with fair rank should be improved via active management toward a rank of good. Over half of the ecological system targets in the portfolio require this kind of improvement. These typically lie at lower elevations. The next column offers, in a summary table, the specific recommendations for achieving the desired ranks.
Coastal Conservation GoalsStratification Units
When we first considered adding coastal conservation targets to the initial terrestrial ecoregional assessment, we asked explicitly if the strategy of establishing stratification units involving multiple islands (e.g., Maui Nui) was valid for coastal biodiversity. There is far less distinctiveness of island coastal vegetation, lower endemism, and fewer overall species; therefore less justification for that level of stratification. However, general representation across the main archipelago is proposed, including occurrences on each of the main islands and associated islets. For coastal vegetation, within-island stratification via four major moisture settings (very dry, dry, mesic, and wet) captures the variation of coastal species distribution.
One interesting finer-scale stratification is required for anchialine pool communities. It stands to reason that although the vast majority of pool occurrences are to be found on the island of Hawai‘i, it does not follow that the coastal portfolio should be restricted to that island.
|GOALS FOR COASTAL TARGETS
Anchialine Pools - The majority of anchialine pool occurrences are on the island of Hawai`i. To help stratify geographically, the goal includes at least ten viable pool occurrences per DAR aquifer sector.
Seabird Nesting Concentrations - Recognizing that seabirds once maintained huge nesting concentrations on the main islands, the goal includes at least one viable occurrence per main island, and all viable occurrences on islets.
Native Coastal Vegetation - Recognizing that native coastal communities vary in composition and structure according to moisture setting, our goals include 20% of the shoreline for each main island, with at least two viable occurrences per moisture regime (very dry, dry, mesic, wet).