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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 numberof remaining viable ecological systems requires, in our assessment, thegreatest possible inclusion of viable conservation targets.
· Add fair ranked occurrences to ensure at least two occurrencesof each ecologicalsystem per stratification unit (if extant). Diversity ofecological systems is not adequately covered by inclusion of those ofgood or better rank alone.
Goalsfor natural communities:
· Select four high ranked/quality occurrences of continuous perennial streams oneach high islandwhere streams occur, stratifying by conservation area as appropriate. This results in 20 selected streams in theecoregion, or more than 10% of the total remaining occurrences.
Goalsfor 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 planas neededfor recovery. Their recovery assessment is appropriate goal-setting for both scientific and strategicreasons.
Applyingthe goals described above resulted in a terrestrial target ecoregional portfolio of 16 conservationareas,including four broadly defined areas that encompass waterbirdconcentrations (see Summary Table below). Brief summary descriptions for theconservation areas are provided in the Appendices.
|Figure1: Four Stratification Units (SU) were established to account forecological and evolutionary variability across the Hawaiianarchipelago.Redundant examples of all conservation targets across the four SUshelpsensure that island and regional biodiversity is captured in theecoregional portfolio of conservation areas. |
|Table: Portfolio Assembly Rules |
The table at right depicts the end result of the goal-setting processas described above. Redundant representation for ecological systems,stream communities, and viable species concentrations is seen for eachof the four stratification units. Each black dot represents aconservation 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 WetSystem, LM = Lowland Mesic system, LD = Lowland Dry System, DC = DryCliff 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 isthe primary goal.
Alien species, such as feral ungulates, are a prevailing threat to native conservation targetsin all conservation areas in Hawai‘i.
Minimum Effective Goals
To set thresholds for minimum long-term goals for adequate conservation of ecological systems, wepropose to use the lower size, condition and landscape context criteriafor a viability rank of "good." This translates practically as a combination of:
For conservation areas with large area occurrences of ecologicalsystems (e.g., Hawai‘i Island, Maui), there might be room toidentify subsets of the total area (but exceeding 18,750 acres minimumsize) within which to actively reduce threats (and improve condition)and ensure improved landscape context.
What these goals mean for the ecological system occurrences for eachStratification Unit is that some systems with overall good or very goodrank can be maintained at that level, while any with fair rank shouldbe improved via active management toward a rank of good. Over half ofthe ecological system targets in the portfolio require this kind of improvement.These typically lie at lower elevations. The next column offers, in asummary table, the specific recommendations for achieving the desiredranks.
Coastal Conservation GoalsStratification Units
When we first considered adding coastal conservation targets to theinitial terrestrial ecoregional assessment, we asked explicitly if thestrategy of establishing stratification units involving multipleislands (e.g., Maui Nui) was valid for coastal biodiversity. There is far less distinctiveness of island coastalvegetation, lower endemism, and fewer overall species; therefore lessjustification for that level of stratification. However, generalrepresentationacross the main archipelago is proposed, including occurrences on eachof the main islands and associated islets. For coastal vegetation,within-island stratification via four major moisture settings (verydry, dry, mesic, and wet) captures the variation of coastal speciesdistribution.
One interesting finer-scale stratification is required for anchialinepool communities. It stands to reason that although the vastmajority 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 andstructure 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).