Ecologie et Dynamique des Systèmes AnthropisésFRE 3498 CNRS-UPJVwww.u-picardie.fr/edysan

Ali Almoussawi, Jonathan Lenoir, Tarek Hattab, Emilie Gallet-Moron, Carol Garzon, Ahmad Kobaissi, Guillaume Decocq

Email: ali.almoussawi@etud.u-picardie.fr

A Multiscalar Assessment of Plant Species Richness in Small Forest Patches

Embedded in Agricultural Landscapes

Alpha-Gamma Relationship

20

Gamma

5

Alpha

20

5

Local:Regional Richness

EXAMPLE

The Case of the Botanist The Case of the Microbiologist

OBJECTIVES

a) Relation between alpha and gamma diversity at different spatial scales

(local-regional richness relationship)

b) Effect of habitat fragmentation on the alpha-gamma relationship:

proportional sampling (type I in Cornell & Lawton) vs. community

saturation (type II in Cornell and Lawton)

HYPOTHESIS

Proportional sampling

Community saturation

FOR

EST

OP

ENFI

ELD

METHOD

SLOPEln(SL/(SR-SL))

ln(SR)

The local-regional species richness relationship: new perspectives on the null-hypothesis (Robert C. Szava-Kovats , Martin

Zobel and Meelis Pärtel).

EXPLANATION

P-value ≥ 0.05 linear SL- SR relation

(no significance)

P-value < 0.05 curved SL- SR relation

(significance)

Significant negative slope (slope<0)

curvature to the right

Significant positive slope (slope>0)

curvature to the left

X = ln(SR)

X = SR

Y=

SL

Y=

ln

(SL

/(S

R-S

L))

Map Design

9 windows

3 open fieldsOB-OC-OT (highly

isolated)15 patches of

each

3 farm landsBB-BC-BT

(fragmented)15 patches of

each

3 unfragmented lands

FB-FC-FT (fake patches)

15 patches of each

ORGANIZATION

135 Total Patches

9 WINDOWS

10 STUDIED PAIRWISE COMPARISONS IN

EACH WINDOW

9*10= 90 COMPARISONS

For every patch

Total

1000m2

100m210m2

1m2

ORGANIZATION

Parameters

Parameters

Area

Age

Shape Length

Region

pH

Habitat

Nitrogen

Phosphorous

Table of Significance

α γ BOCAGE

slope aB

FOREST

slope aF

OPENFIELD

slope aO

BOCAGE

aB curvature

FOREST

aF curvature

OPENFIELD

aO curvature

1 10 -0.3039 0.0193 0.4405 Linear Linear Linear

1 100 -0.03557 0.09473 -1.07757 Linear Linear Linear

1 1000 -0.1023 -0.0515 0.1791 Linear Linear Linear

1* Total -0.04242 0.11218 -1.350 Linear Linear Curvilinear to the right

10 100 0.329 -0.25 0.5343 Linear Linear Linear

10 1000 0.0719 -0.4038 -0.3507 Linear Linear Linear

10* Total 0.1514 -0.2019 -1.2736 Linear Linear Curvilinear to the right

100 1000 -0.243 -0.15438 -0.5474 Linear Linear Linear

100* Total -0.1019 0.0042 -1.5859 Linear Linear Curvilinear to the right

1000* Total -0.03486 -0.09957 -2.1488 Linear Linear Curvilinear to the right

SIGNIFICANCE

Openfield

Bocage

Forest

Significance

Non-Significance

CONCLUSIONS

- Fragmentation affects the relation between local (alpha) and regional (gamma) diversity of species.

- The representation of this relationship turns from being a linear to a curvilinear pattern due to the effect of fragmentation of patches (Open-field).

- This relationship appears in cases of large difference between local and regional area.

PERSPECTIVES

PHYLOGENETIC

DIVERSITY

BETA DIVERSITY

DARK DIVERSITY