Limiting similarity among coexisting species
Limiting similarity among coexisting species
Body size ratios: the ‘1.3 rule’���(Hutchinson, 1959)
hypothesized patterns: 1) minimum size ratios 2) constant size ratios across an
entire assemblage
Diamond 1975
Nature, 270: 660-661, 1977
Community AssemblyPool
(many species)
Local community
(a subset of species)
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www.aguilaharpia.org���
Cornwell and Ackerly 2009 Ecol. Mon.
Community trait statistics
• Given a set of trait values for a community, and a larger set of values for the regional species pool:
• What statistic could you use to ask whether the species in the community were more similar to each other overall, compared to a randomly assembled community?
• What statistic could you use to ask whether the species were evenly spaced along a trait axis, compared to a randomly assembled community?
10 20 30 40
05
10
15
20
sla
rep(0
, 54)
one community species pool
Cornwell and Ackerly 2009 Ecol. Mon.
10 20 30 40
05
10
15
20
sla
rep
(0,
54
)
10 20 30 40
05
10
15
20
sla
rep
(0,
54
)
results of null
sla range
Frequency
5 10 15 20 25 30 35 40
050
100
150
200
250
300
350
obs = 14.2 p = 0.074
Cornwell and Ackerly 2009 Ecol. Mon.
Cornwell and Ackerly 2009 Ecol. Mon.
SLA had significant even spacing – evidence of non-random ecological differentiation
Phenotypic even dispersion
modified from Cavender-Bares et al. 2004 American Naturalist
Phylogenetic even dispersion
% Soil Moisture Vol. H20 [Vol. Soil]-1
Q. hemispherica
Q. michauxii
0.0
0.3
0.6Q. chapmanii
0.00.30.60.9
Q. shumardii
10 20 30
0.00.30.60.9Q. geminata
10 20 30
0.0
0.3
0.6 Q. nigra
10 20 30
Q. laevis
Q. margaretta
Q. laurifolia
0.0
0.3
0.6
Q. virginiana
10 20 30
Q. myrtifolia
0.00.30.60.9
Q. austrina
Q. hemispherica
Q. michauxii
0.0
0.3
0.6Q. chapmanii
0.00.30.60.9
Q. shumardii
10 20 30
0.00.30.60.9Q. geminata
10 20 30
0.0
0.3
0.6 Q. nigra
10 20 30
Q. laevis
Q. margaretta
Q. laurifolia
0.0
0.3
0.6
Q. virginiana
10 20 30
Q. myrtifolia
0.00.30.60.9
Q. austrina
Q. hemispherica
Q. michauxii
0.0
0.3
0.6Q. chapmanii
0.00.30.60.9
Q. shumardii
10 20 30
0.00.30.60.9Q. geminata
10 20 30
0.0
0.3
0.6 Q. nigra
10 20 30
Q. laevis
Q. margaretta
Q. laurifolia
0.0
0.3
0.6
Q. virginiana
10 20 30
Q. myrtifolia
0.00.30.60.9
Q. austrina
Soil Moisture
Oaks of northern Florida (J. Cavender-Bares et al.
2004a, Amer. Nat.; 2004b Ecol. Monogr.)
courtesy J. Cavender-Bares, Univ. Minnesota
Cavender-Bares et al. 2004
modified from Cavender-Bares et al. 2004 American Naturalist
+ +
Phylogenetic even dispersion
Valiente-Banuet and Vérdu 2007 Ecology Letters
Valiente-Banuet and Vérdu 2007 Ecology Letters
facilitated niche non-facilitated niche
Cavender-Bares et al. 2004 Amer. Nat.
BARRO COLORADO ISLAND, PANAMA
BCI 50 ha plot
Swenson et al. 2006 Ecology
20 x 20 m subplot 50 ha ‘pool’ (entire plot)
Münkemüller et al. 2014 Glob Ecol Biogeogr.
Swenson et al. 2006 Ecology
Swenson et al. 2006 Ecology
20 x 20 m subplot 0.36 ha ‘pool’ 1 ha ‘pool’ 50 ha ‘pool’ (entire plot)
Swenson et al. 2006 Ecology
Graham and Fine 2008 Ecol Lett
Two communities that share no species
Phylobetadiversity
High Low