Phylogenetic Diversity in Rock Outcrop Plant Communities in Southeastern Brazil
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Transcript of Phylogenetic Diversity in Rock Outcrop Plant Communities in Southeastern Brazil
Phylogenetic Diversity in Rock Outcrop Plant Communities in Southeastern Brazil
Colmenares S.L.T.1, Rosado B.H.P.2, de Mattos E.A.31 Universidade Federal do Rio de Janeiro – Programa de Pós Graduação em Ecologia
2 Instituto de Pesquisa Jardim Botânico do Rio de Janeiro , 3 Universidade Federal do Rio de Janeiro – Departamento de Ecologia
Community Ecology & Function
Symposia DNA barcodes and beyond: Developing and utilizing community-wide DNA sequence data to understand
ecology and evolution of tropical biodiversity
Analysis of the phylogenetic structure of communities provide insights into the ecological processes that
organize them (Webb, 2000)
(Vamosi, et al. 2009)
…
ROCKY OUTCROPS OR INSELBERGS“Xeric islands in a tropical matrix”
great environmental heterogeneity
Vegetation is found forming elliptical soil-islands or patches of varying size
and soil depth
These islands exhibit a clearly defined border, enabling precise delimitation of area and species composition
Increases in area and substratum depth contain an apparent gradient on water and nutrient
availability, which may restrict establishment of some plant species
Smaller patches provide harsher
environmental conditions than
larger ones, probably filtering the species
according to their ability to deal with
environmental stresses
Thus, we postulated that species’ patch composition will vary according to size
variation and species’ phylogenetic relatedness
A set of 26 vegetation patches of varied sizes (between 0.5
m2 and 30 m2) was censed to construct a presence/absence
species vs. patch area matrix
PHYLOGENETIC COMMUNITY STRUCTURE
22 species - 7 families
PHYLOGENETIC COMMUNITY STRUCTURE
Com 1
Com 2
Clustered
Evenly dispersed
We aim to explore if co-occurring species
within each vegetation patch are phylogenetic evenly
dispersed or clustered
The Mean Phylogenetic Distance (MPD) and the Mean Nearest Taxon Phylogenetic Distance (MNTD) were calculated and tested against null
distribution of 999 null communities to obtain the standardized indexes:
Net Related Index (NRI) and Nearest Taxon Index (NTI)
NRI or NTI ≥ +1.96 Clustered
Evenly dispersed
NRI or NTI ≤ - 1.96
When:
R² = 0.256
0
2
4
6
8
10
12
14
-5 5 15 25 35
RIC
HN
ESS
AREA
RICHNESS vs. AREA
We observed a significantly relationship
between richness and patch area
NRI and NTI values were not significantly different from randomly generated
null communities
Thus, we have some evidence that the presence of species of
species in each vegetation patch presents random
phylogenetic distribution
-2.5
-2
-1.5
-1
-0.5
0
0.5
1
1.5
2
0 10 20 30 40
NRI
NRI
-2.5
-2
-1.5
-1
-0.5
0
0.5
1
1.5
2
0 10 20 30 40
NTI
NTI
Further studies are necessary to test whether the above results can remain when variation in
abundance of species and functional trait diversity are
included on the analysis
So… What can we expect ?
?
?
Webb et al., 2002
ACKNOWLEDGMENTS
TO PROF.LÚCIA G. LOHMANN
TO MY MOTHER
PARQUE ESTADUALSERRA DA TIRIRICA –
NITERÓI, RJ
y = 3.334x + 484.4R² = 0.175
0100200300400500600700
0 5 10 15 20 25 30 35
MP
D
Area
MPD
y = -5.503x + 503.6R² = 0.093
0
200
400
600
800
1000
0 5 10 15 20 25 30 35
MN
TD
Area
MNTD
MPD was positively, but weak related to the patch area and number of taxa respectively
(r2=0.18, pvalue=0.026; r2=0.30, pvalue=0.0024), whereas MNTD decreased with increasing
number of taxa (r2=0.509, pvalue=0.000020).
0
100
200
300
400
500
600
700
0 5 10 15 20 25 30 35
MP
D
Area
MPD
-3
-2
-1
0
1
2
0 5 10 15 20 25 30 35NR
I
Area
NRI
-3
-2
-1
0
1
2
0 5 10 15 20 25 30 35NTI
Area
NTI
0
200
400
600
800
1000
0 5 10 15 20 25 30 35
MN
TD
Area
MNTD
AND WHAT ABOUT PHYTLOGENETIC RELATEDNESS BETWEEN CO-OCURRING SPECIES AT EACH VEGETATION PATCH?