Species, Area, Species, Area, & the Equilibrium Theory & the Equilibrium Theory of Island Biogeographyof Island Biogeography

as a foundation paradigm as a foundation paradigm in conservation biologyin conservation biology

Part 2…Part 2…

Preserve Design Preserve Design GuidelinesGuidelines

IBT & DesignIBT & Design• A. Large is better than smallA. Large is better than small• B. Undivided is better than dividedB. Undivided is better than divided• C. If divided, close is better than C. If divided, close is better than

farfar• D. If divided, distances should be D. If divided, distances should be

equalequal• E. Corridors are better than no E. Corridors are better than no

corridorscorridors• F. Circular is better than narrow F. Circular is better than narrow

(low perimeter to area ratio)(low perimeter to area ratio)

SizeSize

Better Worse

FragmentationFragmentation

Better Worse

DistanceDistance

Better Worse

ClusteredClustered

Better Worse

ConnectivityConnectivity

Better Worse

ShapeShape

Better Worse

IBT & DesignIBT & Design

TheThe SLOSSSLOSS DebateDebate

SSingleingle LLargearge

OOrr

SSeveraleveral SSmall mall

of the same total areaof the same total area

Several Small > Single LargeSeveral Small > Single Large

Florida scrub vertebrates--Florida scrub vertebrates--McCoy & McCoy & Mushinsky 1994Mushinsky 1994

Butterflies, Spain--Butterflies, Spain--Baz & Garcia-Boyera Baz & Garcia-Boyera 19961996

Plants, Norway--Plants, Norway--Saetersdal 1994Saetersdal 1994

Plants in mires, Finland--Plants in mires, Finland--Virolainen et al. Virolainen et al. 19981998

Birds--Birds--Loman & von Schantz 1991Loman & von Schantz 1991

Sequoia-Kings Canyon NP vs. CA State Parks -- Species Richness

3341

1402

195

1485

1951

434

0

500

1000

1500

2000

2500

3000

3500

4000

1 2 3

Comparision

Area

and

Num

ber o

f Spe

cies

SEKI CA State Parks

Area

Plants

Birds

From Stohlgren & Quinn 1993

Megareserves for large predatorsMegareserves for large predators>10>1066 ha ha100 km linear extent100 km linear extent

Simberloff & Abele 1976Simberloff & Abele 1976

• Island A becomes Archipelago AIsland A becomes Archipelago A• Island B becomes Archipelago BIsland B becomes Archipelago B• For A, SS > SLFor A, SS > SL• For B, SL > SSFor B, SL > SS

Simberloff & Abele 1976Simberloff & Abele 1976

Area mArea m22 SppSppAA 475475 7777

----------------------------------------------------------------A1A1 119119 5151A2A2 133133 4848A3A3 8080 4747A4A4 102102 5050

Archipelago AArchipelago A 434434 818181 > 77!!81 > 77!!

Simberloff & Abele 1976Simberloff & Abele 1976

Area mArea m22 SppSpp

BB 168168 5656

----------------------------------------------------------------

B1B1 7171 3636

B2B2 8787 3232

Archipelago BArchipelago B 1581584747

47 < 56!!47 < 56!!

Immediate ComplaintsImmediate ComplaintsDiamond, Terborgh, Diamond, Terborgh,

WhitcombWhitcomb• Not all spp equalNot all spp equal

– Some extinction prone, Total Spp not Some extinction prone, Total Spp not the best measure of successthe best measure of success

– Large predators need 100s-1000s kmLarge predators need 100s-1000s km22

– Colonial nesters, Migrating spp, Spp Colonial nesters, Migrating spp, Spp dependent on coredependent on core

• Small reserves loose the same Small reserves loose the same Spp, so become more similar to Spp, so become more similar to each other, more overlap, Spp each other, more overlap, Spp lists are nestedlists are nested

SLOSS?? It depends!SLOSS?? It depends!

Several Small Several Small

Species overlap (similarity) among Species overlap (similarity) among islandsislands

Simberloff & Abele 1972Simberloff & Abele 1972

• The Diamond IslesThe Diamond Isles• The Lack ArchipelagoThe Lack Archipelago• The Tallahassee ArchipelagoThe Tallahassee Archipelago

Scale dependenceScale dependence

CONSERVATION STRATEGYCONSERVATION STRATEGY

Both grain and extent are critical!Both grain and extent are critical!

Grain: Ecological integrity, Population Grain: Ecological integrity, Population viabilityviability

Hydrology, Black bears, Vagile speciesHydrology, Black bears, Vagile species

Extent: variation in environment and Extent: variation in environment and historyhistory

Local endemics, Poorly dispersed Local endemics, Poorly dispersed speciesspecies

RepresentativenessRepresentativeness

SLOSS is here to stay because grain SLOSS is here to stay because grain & extent maximize different & extent maximize different contributions to biodiversitycontributions to biodiversity

The Umbrella ConceptThe Umbrella Concept

Protecting large animals that require Protecting large animals that require large areas & play important large areas & play important ecosystem rolesecosystem roles--large bird & mammalian predators—--large bird & mammalian predators—protects all speciesprotects all species

Does the Umbrella Species Idea Work?Does the Umbrella Species Idea Work?Carnivore plan would protect 43%Carnivore plan would protect 43%

of North American invertebratesof North American invertebratesNo better than random placementNo better than random placementKerr 1997Kerr 1997

Plants > birds as the umbrella group Plants > birds as the umbrella group for other taxa, S Californiafor other taxa, S CaliforniaRyti 1992Ryti 1992

Vertebrates missed lower plant diversityVertebrates missed lower plant diversityPortugalPortugalAraujo 1999Araujo 1999

Rare species captured common species;Rare species captured common species;Common species did not capture rareCommon species did not capture rareRebelo & Siegfried 1992Rebelo & Siegfried 1992

Other island-like modelsOther island-like models

• Gene flowGene flow• MetapopulationsMetapopulations• Landscape ecologyLandscape ecology

Other SLOSS-like Other SLOSS-like debatesdebates

• GLOSS:GLOSS: Is it better to sample genes Is it better to sample genes from one population or from from one population or from several small populations of the several small populations of the same total size (number of same total size (number of individuals sampled)?individuals sampled)?

• SLOPP:SLOPP: Is it better to protect one Is it better to protect one large population or several small large population or several small populations of the same total size?populations of the same total size?

• FLOSS:FLOSS: Is it better to introduce a Is it better to introduce a species as one large release or species as one large release or several small releases?several small releases?

Conservation as samplingConservation as sampling

• By definition we conserve a By definition we conserve a subset of the originalsubset of the original

• What is the best conservation What is the best conservation sample?sample?

• What are the consequences of What are the consequences of fragmentation?fragmentation?

• Thing and processThing and process

The Two TrianglesThe Two TrianglesThe Constraint of SizeThe Constraint of Size

A continuum of area sensitivityA continuum of area sensitivityStarting with large predators, 10Starting with large predators, 1066 ha ha

Headwaters of streamsHeadwaters of streamsDisturbance regimes, pattern and processDisturbance regimes, pattern and processDependence on multiple habitats; seasonal Dependence on multiple habitats; seasonal movementsmovementsExceptions: rare species dependent on rare habitat;Exceptions: rare species dependent on rare habitat;

air pollution; alien invasions; climate air pollution; alien invasions; climate synchronization;synchronization;

long distance migrationlong distance migrationSize: completeness, wholeness, integrity, healthSize: completeness, wholeness, integrity, health

Costs of management and conservation successCosts of management and conservation successConservation as sampling: bigger areas are better Conservation as sampling: bigger areas are better

samplessamplesFeasible restoration goals depend on sizeFeasible restoration goals depend on sizeBUT any site can play a role…dependent on sizeBUT any site can play a role…dependent on size

The Two Triangles The Two Triangles ContinuedContinued

Small areasSmall areasSmall area requiring species, Small area requiring species, habitatshabitatsConnectors, stepping stonesConnectors, stepping stonesRepresentation: more placesRepresentation: more placesAir, Water, Soil qualityAir, Water, Soil qualityEnvironment: temperatureEnvironment: temperatureHuman-nature connectionsHuman-nature connectionsHuman well-beingHuman well-being