Transcript Coastal Plain Endemism and its implications for biodiversity

Developing a
blueprint for
conservation of the
longleaf ecosystem
based on centers of
Coastal Plain
endemism
Bruce A. Sorrie
and Alan S. Weakley
University of North Carolina
Herbarium /
North Carolina Botanical
Garden
Endemic areas in North America
• Californian floristic province (Raven & Axelrod 1978)
– 50 endemic genera
– 2125 endemic species
– Ca. 2600 endemic taxa
• Southern Appalachians (Weakley in prep.)
– 2 endemic genera
– 165 endemic taxa
• Ozark-Ouachitas (Zollner in prep.)
– 0 endemic genera
– 31 endemic taxa
• Pacific Northwest
• ?? Southeastern Coastal Plain ??
The Coastal Plain
Southeastern Coastal Plain
Analysis based on:
– over 1000 publications with range information
(county dot maps)
– herbarium records (ca. 25 herbaria)
– taxonomy largely following Kartesz 1999
checklist
– definition of endemic = over 90% of
occurrences within region
Southeastern Coastal Plain
endemism
• 48 endemic genera
• Ca. 1350 endemic species
• 1732 endemic taxa
Why?
• Monotonous, “flatter than a pancake”,
unconsolidated sediments (geologically
“young”), warm temperate to tropical humid
climate, vermin-infested, etc.
• But …
–
–
–
–
Soils diversity (pH 3 – 8.5)
Extremely xeric to variety of wetlands
Coastal habitats, wide diversity of other habitats
Long evolutionary history [never glaciated, refugium
during glaciation events, tropical elements,
Southwestern elements (Astragalus, Eriogonum, etc)]
Dune grasslands
Coastal Plain sandstone glade
South Florida
marl prairies
Endemic genera
Within-region patterns of endemism
and diversity
• What are the patterns?
• What does this tell us about evolutionary
history of the region?
• What are the implications for
conservation?
Subregional endemism
• 8 subregions (of which 5 are “Longleaf
Pine ecoregions”)
• 2 areas outside the province but with
substantial disjuncts (Inland North America
and West Indies/Central America)
The Coastal Plain
Subregions
• Coastal Plain
–
–
–
–
–
–
Mid-Atlantic CP (se. VA south to s. SC)
South Atlantic CP (n. GA to n. FL)
Temperate Florida Peninsula
East Gulf Coastal Plain (sw. GA and w. FL west to se. LA)
West Gulf Coastal Plain (w. LA – e. TX)
Northeastern Coastal Plain (c. VA north to Massachsetts, Nova
Scotia, Newfoundland)
– South Florida
– South Texas and northern Tamaulipas
• Disjunct areas
– Inland (Cumberland Plateau, S. Appalachian bogs, Great Lakes
shores, etc.)
– West Indies and Central America, Bermuda
The “core Coastal Plain” –
the Longleaf Pine ecosystem
Longleaf Pine associates
• 1000 of 1732 endemic
taxa distributed in
– All 5 subregions -- 109 taxa
(11%)
– 4 subregions – 188 taxa
(19%)
– 3 subregions – 155 taxa
(16%)
– 2 subregions – 195 taxa
(19%)
– Only 1 subregion – 353
taxa (35%)
Endemic Taxa Distribution
across Subregions
109
(11%)
188
19%
353
35%
155
16%
194
19%
all 5
4
3
2
only 1
Of the single-subregion endemics:
•
•
•
•
•
East Gulf Coastal Plain – 125 taxa
Florida Peninsula – 122 taxa
Mid-Atlantic Coastal Plain – 44 taxa
South Atlantic Coastal Plain – 33 taxa
West Gulf Coastal plain – 29 taxa
Conservation of the Longleaf Pine
Ecosystem
• Prescribed fire + viable sized landscapes
= public lands (for the most part)
• USDA Forest Service (Apalachicola,
Ocala, Croatan, DeSoto, Conecuh,
Kisatchie, Texas Forests, etc.)
• DOD (Eglin, Bragg, Jackson, Benning,
Stewart, Gordon, Avon Park, etc.)
• State conservation lands
• Some large private preserves (TNC)
Are public lands “protected”?
• USDA Forest Service – pressure for
greater timber production, greater
recreational uses (incl. ORV)
• Dept. of Defense – efforts to get
exemption from conservation laws,
including the Endangered Species Act
Are private lands “protected”?
The Nature Conservancy
– new emphasis on divestiture of preserves to
other stewards
– focus on large landscapes and ecological
systems, not “small sites” and species
Gaps in the system – Mid-Atlantic
Coastal Plain
Of 51 endemics (LLP and non-LLP):
– 32 are well-protected with many occurrences
on conservation lands*
– 19 are not, with few or no protected
occurrences on conservation lands
Gaps in the system – Mid-Atlantic
Coastal Plain
• Marl savannas: Allium sp. nov., Carex lutea, Hypericum
sp. nov., Parnassia caroliniana, Scleria sp. nov.,
Thalictrum cooleyi
• Sandhills: Polygonella polygama var. croomii
• Pineland ponds: Oxypolis canbyi, Sagittaria sp. nov.
• Blackwater rivers: Hymenocallis pygmaea, Isoetes
microvela, Nuphar sagittifolia, Sabatia kennedyana
• Tidal marshes: Oenothera riparia, Ptilimnium sp. nov.
• Mesic bluffs: Rhododendron eastmanii
• Bottomlands: Scirpus flaccidifolius, Trillium pusillum var.
pusillum
Other gaps in the system
• The “Grit”: Altamaha grit communities and
species
• Central portion of the Florida Panhandle –
ponds and fens
• Southwest Louisiana “saline longleaf”
(Natraqualf savannas)
Implications for conservation
• Longleaf associated taxa “turn over” rapidly
• Greatest endemism in FL panhandle (esp. Apalachicola),
FL peninsula (esp. central ridges
• High levels of endemism in all ecoregions of the
Southeastern Coastal Plain and all ecoregions of the
Longleaf Pine Ecosystem
• Conservation needed in all subregions, and in the
distinctive sub-subregions of the subregions
• Viability / manageability an important issue
• But… extreme local endemism means that many
conservation areas will be needed – many of them new
and many unlikely to be large
Pond-cypress savanna, SC
Mid-Atlantic and East Gulf patterns