African forests phytogeography, (phylo)diversity and extinction risks:

Insights from a mega database on the distribution of tropical African vascular plants

Gilles Dauby

Thomas Couvreur & RAINBIO consortium

African forests phytogeography, (phylo)diversity and extinction risks:

Insights from a mega database on the distribution of tropical African vascular plants

tropics

Gilles Dauby

Thomas Couvreur & RAINBIO consortium

African forests phytogeography, (phylo)diversity and extinction risks:

Insights from a mega database on the distribution of tropical African vascular plants

tropics

Gilles Dauby

Thomas Couvreur & RAINBIO consortium

Gilles Dauby

Thomas Couvreur & RAINBIO consortium

African forests phytogeography, (phylo)diversity and extinction risks:

Insights from a mega database on the distribution of tropical African vascular plants

tropics

Biodiversity synthesis centre

RAINBIO project

African RAIN forest community dynamics: implications for tropical BIOdiversity

conservation and climate change mitigation

AIM 1: up-to-date comprehensive plant occurrences DATABASE

A near-comprehensive standardized database

Records density

> 580,000 georeferenced records

> 24,000 species

RAINBIO database

The largest ever in its kind for Tropical Africa

RAINBIO database

Proportion of herb species

20 %

80 %

‘Basic’ statistics important for biodiversity management and conservation

Species richness

Objectives

1. Document phytogeographical regions Characterize their floristic/phylogenetic affinities & diversity Understand their origins

Objectives

1. Document phytogeographical regions Characterize their floristic/phylogenetic affinities & diversity Understand their origins

2. Evaluate conservation status, regions with high concentration of potentially threatened species

Objectives

1. Document phytogeographical regions Characterize their floristic/phylogenetic affinities & diversity Understand their origins

2. Evaluate conservation status, regions with high concentration of potentially threatened species

3. Species climatic niche modelling

Objectives

1. Document phytogeographical regions Characterize their floristic/phylogenetic affinities & diversity Understand their origins

2. Evaluate conservation status, regions with high concentration of potentially threatened species

3. Species climatic niche modelling

Phytogeographical delimitation

Phytochorological delimitation of White (1983)

Linder (2011) Fayolle (2014)

Phytogeographical delimitation

Phytochorological delimitation of White (1983)

Linder (2011) Fayolle (2014)

Will RAINBIO bring new insights?

Network approach to delimitate floristic bioregions

Bipartite network with species and localities as nodes Clustering with map equations algorithm into bioregions Efficient method for delineate biogeographical regions

Vilhena & Antonelli 2014 nature com.

Network approach to delimitate floristic bioregions

http://bioregions.mapequation.org/

Bioregions in African tropics

Many bioregions identified

Bioregions in African tropics

Many bioregions identified

Several highlands regions

Bioregions in African tropics

Many bioregions identified

Several highlands regions

Striking contrast between West and East Africa

Bioregions in African tropics

Many bioregions identified

Several highlands regions

Striking contrast between West and East Africa

Bioregions in African tropics

Focus on Guineo-Congolese region

Focus on Guineo-Congolian region

Upper Guinea

Lower Guinea

Congolese

Focus on Guineo-Congolian region

Upper Guinea

Lower Guinea

Congolese

Transition areas

Transition areas

Floristic relationships among bioregions?

How bioregions patterns be explained?

Floristic relationships among bioregions?

How bioregions patterns be explained?

Geographical distance

Ecological (climatic) distance

Floristic relationships among bioregions?

Example with Upper Guinea

Floristic relationships among bioregions?

Floristic distance

well correlated with both

ecological and geographical

distances

R = 0.78 R = 0.72

Example with Upper Guinea

Floristic relationships among bioregions?

Example with Cameroon highlands

Floristic relationships among bioregions?

Example with Cameroon highlands

R = 0.12 R = 0.42

Well correlated with

ecological distance

Floristic relationships among bioregions?

Floristic relationships reflect

recent dispersal events

and

environmental gradients

Floristic relationships among bioregions?

Floristic relationships reflect

recent dispersal events

and

environmental gradients

Floristic relationships among bioregions?

Floristic relationships reflect

recent dispersal events

and

environmental gradients

Floristic relationships among bioregions?

Floristic relationships reflect

recent dispersal events

and

environmental gradients

Floristic relationships among bioregions?

Floristic relationships reflect

recent dispersal events

and

environmental gradients

Floristic relationships among bioregions?

Should reflect

• Ecological similarity if niche conservatism occurs

• Biogeographical events (vicariance, dispersal,

diversification)

Phylogenetic relationships among bioregions?

Dated mega phylogeny available

ca. 4000 species represented

Other species are grafted

randomly within their genus

(>90% of all RAINBIO species)

Phylogenetic relationships among bioregions?

Assessing lineages turnover

Phylogenetic relationships among bioregions?

1

0 0

0 10

6

7

7

8 1

Bio

regi

on

1

4

2

2

0

9 7

Bio

regi

on

2

Bio

regi

on

3

Bio

regi

on

4

Sp. 1

Sp. 2

Sp. 3

Sp. 4

Sp. 5

Sp. 6

0

1

5

2

0 3

6 8

Assessing lineages turnover Cut at a

given age

Phylogenetic relationships among bioregions?

1

0 0

0 10

6

7

7

8 1

Bio

regi

on

1

4

2

2

0

9 7

Bio

regi

on

2

Bio

regi

on

3

Bio

regi

on

4

Lineage 1

Lineage 2

Lineage 3

Lineage 4

1

0 0

0 10

6

7

7

8 1

Bio

regi

on

1

4

2

2

0

9 7

Bio

regi

on

2

Bio

regi

on

3

Bio

regi

on

4

Sp. 1

Sp. 2

Sp. 3

Sp. 4

Sp. 5

Sp. 6

0

1

5

2

0 3

6 8

Cut at 40 Millions years

Phylogenetic relationships among bioregions?

Phylogenetic relationships among bioregions?

Highligh

ancient biogeographical

events

Cut at 40 Millions years

Floristic turnover Lineages turnover (40 Millions years)

Floristic turnover Lineages turnover (40 Millions years)

Evidence of niche

conservatism

Conclusions

• RAINBIO do provide new insights into phytogeographical delimitations of

African tropics

Lineages vs. floristic turnover highlight different biogeographical/ecological

processes for explaining biogeographical patterns

• RAINBIO + megaphylogeny improve our understanding of

phytogeographical patterns

Take home message

Collect plant specimens

This is useful !!

field

Take home message

© Leonid Schneider

Share your data

This is a win-win action

Take home message

Share your data

This is a win-win action RAINBIO

© Ainsley Seago

Vincent Droissart

Olivier J. Hardy

Steven Janssens

All contributors to RAINBIO database