‘Islands in the Sky’ -

• Guayana Shield centered in southern • 1.2 X 106 m2 • sandstone table mountains of Formation

Autana, 1300 m

‘Islands in the Sky’ - Tepuis

• Roraima Formation - Precambrian, highly leached sandy marine sediments laid down 1.5 - 1.8 billions years ago

• Roraima Formation uplifted during formation of Atlantic in Cretaceous Roraima, 2723 m Autana, 1300 m • tepuis formed with erosion of major river systems () – vicariance? • tepuis are resistant (quartzite) mesas

Kukenán, 2650 m Neblina, 3014 m

1 ‘Islands in the Sky’ - Tepuis ‘Islands in the Sky’ - Tepuis

• tepuis basis for Sir Arthur Conan Doyle’s “The Lost • tepuis basis for opening scene of Arachnophobia World”

• actually home to one of the world’s largest set of plant “carnivores”

Heliamphora - sun pitcher

‘Islands in the Sky’ - Tepuis ‘Islands in the Sky’ - Tepuis

• Pantepui - biogeographic province proposed by the Phelps for high • Pantepui - biogeographic province proposed by the Phelps for high elevation “island” portion over 1500 m elevation “island” portion over 1500 m • characterized by a combination of extreme conditions: cool weather, heavy rainfalls, dense clouds, strong winds, high solar radiation, and extremely infertile substrates

Pantepui

2 ‘Islands in the Sky’ - Tepuis

• Pantepui - biogeographic province proposed by the Phelps for high elevation portion over 1500 m • Distinctive biota

Tepui vireo Rana manakin

Redbanded fruiteater

Asteraceae

Tepui Flora Tepui Flora

• Pantepui - island like species/area relationship Riki Olivares - M.S. thesis

Do the tepuis function as islands?

P < 0.0001 Ricarda Riina M.S. thesis (2003)

Log Summit Area

3 Tepui Flora Tepui Flora •Pantepui - island like endemism • Floristic relationships among tepuis Overall plant richness and endemism Pantepui Shield Pantepui Single tepui • Is there a biogeographical taxa endemics endemics endemics pattern? Families 156 2 0 0 – vicariance formed by river erosion? Genera 626 80 23 13 (4%) (2%) Species 2447 1517 1034 617 (42%) (25%)

Riki Olivares - M.S. thesis Vicki Funk - Smithsonian

Tepui Flora

Cluster Analysis based on floristic composition Guayana Shield - pantepui area

eastern tepuis

western tepuis

4 Tepui Flora

Guayana Shield - pantepui area • positive significant (P = 0.001) correlation between the floristic distance matrix and the among-tepuis geographic distance matrix (Mantel Test)

eastern tepuis

western tepuis

‘Islands in the Sky’ - Paramo, Afroalpine

• convergent types across high elevation areas of the tropics • depending on elevation, often occur as ‘islands’

5 ‘Islands in the Sky’ - Paramo, Afroalpine ‘Islands in the Sky’ - Paramo, Afroalpine

• South American paramo and East African afroalpine (‘Ethiopian’) • ecology is harsh and unvarying: ‘winter by night, summer by day’ best studied floristically as islands

‘Islands in the Sky’ - Paramo, Afroalpine ‘Islands in the Sky’ - Paramo, Afroalpine

• Convergent life forms occur in both areas as a response to • Convergent life forms occur in both areas as a response to these ecological conditions these ecological conditions Hypericum (sclerophyll) Afroalpine

Erica Dendrosenecio (Asteraceae) Lobelia (Lobeliaceae) (sclerophyll)

Viola (cushion)

Acaena (rosette) tussock grass

6 ‘Islands in the Sky’ - Paramo, Afroalpine Radiation in Andean Puya () • Convergent life forms occur in both areas as a response to Rachel Schmidt Jabaily these ecological conditions Paramo

Puya (Bromeliaceae)

Espeletia (Asteraceae) Puya raimondii, Ancash, Peru

Radiation in Andean Puya Radiation in Andean Puya “mapping” on latitude & (Bromeliaceae) (Bromeliaceae) elevation on DNA tree Direction of latitudinal and elevation shifts?

latitude elevation

Jabaily&Sytsma 2013

7 Radiation in Andean Puya ‘Islands in the Sky’ - Paramo, Afroalpine (Bromeliaceae) • Biogeography of afroalpine flora – adaptive radiation of Dendrosenecio Relative rates of movements (Asteraceae)

in latitude and elevation ! !

!

! !

Jabaily&Sytsma 2013 !

‘Islands in the Sky’ - Paramo, Afroalpine ‘Islands in the Sky’ - Paramo, Afroalpine

• Biogeography of afroalpine flora – adaptive radiation of Dendrosenecio • Biogeography of afroalpine flora – adaptive radiation of Dendrosenecio (Asteraceae) Which pattern? 1. Inter-island dispersal followed by (Asteraceae) Which pattern? 1. Inter-island dispersal followed by elevation shifts elevation shifts 2. Multiple dispersals from similar • Convergence of species adapted 2. Multiple dispersals from similar to similar elevations! elevations Mt. Kenya elevations Mt. Kenya

8 species adapted to 4 life zones (in color)

Eric Knox

root

Phylogeny superimposed on biogeography

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