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(a) (b) (c) Figure 2 The percentages of species in Australia that are not threatened (all), endangered or extinct for (a) habit, (b) sex system and (c) fruit type. Percentages add to 100 for each extinction risk. 0 10
30 40 50 Herb Vine
Liane Shr
ub Tree
Intro Native
0 20 40 60 80 100 Short-lived Long-lived 0 20
60 80 100 Bise xual
Dioecious Monoecious 0 20
60 80 Dry-indeh Dry-deh Fleshy
% of species % of species % of species (a) (b) (c) (d) Figure 1 The percentages of species in Australia that are native or introduced for (a) habit, (b) life span, (c) sex system and (d) fruit type. Percentages add to 100 for total species. Life-history characters in the Australian flora Journal of Biogeography 33, 271–290 283 ª 2006 The Authors. Journal compilation ª 2006 Blackwell Publishing Ltd flora. In each of three trees (Asterids 550–577 genera; Core Eudicots 454–529 genera; Commelinids 534 genera), character mapping showed that the non-threatened status is the ancestral condition and that the conditions of endangered or extinct are derived characters. The analysis of character-state change in the three trees, compared with the randomized trees, showed that, for each tree, threat status (i.e., endangered or extinct) was significantly non-randomly clustered (Table 4); in other words, threat status occurs in some genera more often than expected by chance. To explore this further a concentrated changes test was used to look at the randomness of co-occurrence of traits (correlated evolution) such as threat status and genus size and threat status and sex system. Correlated evolution was found in the three trees and within them in several clades (Table 5). Threat status was significantly phylogenetically concentrated with genus size in some of the resolved polytomies but not conclusively so (Table 5). Threat status was significantly phylogenetically concentrated with unisexual sex systems (monoecy plus dioecy) in the Asteraceae, Thymelaeaceae, and within a clade comprising the Cyperaceae, Eriocaulaceae and Hydatellaceae. D I S C U S S I O N Australia is renowned for its unusual flora (e.g. Banksia, Grevillea, Eucalyptus), but less is known about whether this unusual biodiversity is concomitant with unusual life-history strategies. The evaluation of the life-history characters in the Australian flora shows that there are some interesting patterns. For example, monoecy is the predominant unisexual system (Table 6) – unlike the general trends found on islands (e.g. New Zealand and Hawaii, Table 6) and in worldwide assessments (Table 6). Renner & Ricklefs (1995) point out that non-random distributions of sex systems in floras may reflect phylogenetic influences rather than local selective factors. We found support for this, as the floras of South Africa and India, which have many botanical affinities with Australia, also have higher levels of 0 10 20 30 40 50 60 70 80 Ex Herb Vine Liane
Shrub Tree
Herb Vine
Liane Shrub
Tree En All Ex En All Ex En All Ex En All Ex En All Ex En All Ex En All Ex En All Ex En All Ex En All Bisexual
Monoecious Dioecious 0 10
30 40 50 60 70 80 Fleshy Dry-indeh Dry-deh
% of species % of species Figure 3 The percentages of species in Australia that are not threatened (all), endangered or extinct for habit with different (a) sex systems and (b) fruit types. Percentages add to 100 for each extinction risk. Table 2 Minimum adequate model describing the probability of occurrence of character traits in endangered species. The intercept refers to the baseline category of species with a shrub habit, flowers bisexual and fruit dry-dehiscent. Sign, coefficient and significance of the effects are all relative to levels included in the intercept Step Coefficient estimate SD Wald P (Intercept) )3.33 0.09
36.906 < 0.001*** Herbs
0.26 0.12
2.112 0.035*
Trees )0.27
0.20 )1.347
0.178 Monoecious )1.15 0.31
)3.680 0.002***
Dioecious )0.18
0.37 )0.484
0.628 Fleshy
)0.65 0.26
)2.482 0.013*
Dry-indehiscent )0.16
0.18 )0.914
0.361 Herbs : monoecious 0.58 0.47
1.235 0.217
Trees : monoecious 1.43
0.41 3.514
< 0.001*** Herbs : dioecious )0.48 0.63
)0.761 0.447
Trees : dioecious )0.65
0.71 )0.916
0.360 Herbs : fleshy )0.77 0.76
)1.008 0.313
Trees : fleshy 0.44
0.39 1.140
0.254 Herbs : dry-indehiscent )1.38 0.30
)4.681 < 0.001*** Trees : dry-indehiscent 0.02 0.63
0.031 0.976
Deviance explained (%) 84 Values are in the transformed (logit) scale. Table 3 The analysis of deviance table for the minimum adequate model for endangered species Term d.f.
Deviance Residual
d.f. Residual
deviance P (> |v|) Null 41 143.036 – – – Habit 2 0.383 39 142.653
0.826 Sex
2 26.874
37 115.779
< 0.001 Fruit
2 48.444
35 67.336
< 0.001 Habitat : sex 4 16.667
31 50.669
0.002 Habitat : fruit 4 27.354
27 23.315
< 0.001 A. Sjo¨stro¨m and C. L. Gross 284 Journal of Biogeography 33, 271–290 ª 2006 The Authors. Journal compilation ª 2006 Blackwell Publishing Ltd monoecy than of dioecy (Table 6). Gross (2005) identified high levels of monoecy in the tree flora of tropical Australia and hypothesized that inefficient insect pollination systems may be instrumental in maintaining monoecy. Hegde & Ellstrand (1999) point out that generalizations about rare and endangered species are important for the development of conservation management policy,
and moreover for understanding the nature of rarity. Our results, the first to incorporate all of the Australian flowering plants are complex – they show that the condition of endangered and extinction in Australian flowering species can be associated with a combination of life-history characters that can be correlated with phylogeny. We explore here the evolutionary and ecological significance of these findings; we are left with more questions than answers but hope that we generate interest to test our hypotheses. The association of habit with extinction Trees are absent from the Australian extinct list. Recently presumed extinct taxa in some locations outside Australia also show patterns among their life-history strategies. For example, a bias in the habit of species that have become extinct is evident in an isolated fragment of lowland rainforest in the Singapore Botanic Gardens (Turner et al., 1996). In over a century of isolation, proportionately fewer trees than other life forms have become extinct there. In another study, Robinson et al. (1994) investigated plant species losses and invasions during a period of 112 years (1879–1991) on Staten Island, New York. They found that trees exhibit higher levels of persistence than shrubs or vines, and woody plants in general appear to be less vulnerable to extirpation than herbaceous ones. From Robinson et al. (1994) and Turner et al. (1996), it appears that trees tend to persist in a variety of locations around the world, and in the face of possibly quite different threatening processes. This tendency, however, must be interpreted within the context of the relative longevity of Table 4 Results of the test for trait clustering (rare or not), where the observed number of steps of character-state change (trait gains) in each tree was compared with the random distribution of characters from 1000 tree resolutions Trait examined
Observed number
of steps Range of
steps in 1000
randomizations Rank of
observed relative to randomized Rarity – Asterid clade 21 46–50
1 Rarity – Core Eudicot clade 19 56–63 1
16 42–47
1 Figure 4 The proportion of (a) endangered species (odds ratio ¼ 1.131 with 95% confidence interval 1.099–1.163, t ¼ 4.37, P < 0.001; G 2 ¼ 19.17, d.f. ¼ 1, P < 0.001) or (b) extinct species (t ¼ )0.18; G 2 ¼ 0.61, d.f. ¼ 1, P ¼ 0.43) within a genus versus log(genus size) for all of the Australian genera (n ¼ 1978), and the proportion of endangered species or extinct species within a genus versus log(genus size) for only those genera with (c) endangered species (odds ratio ¼ 0.619 with 95% confidence interval 0.596–0.643, t ¼ )7.17; G 2 ¼ 169.53, d.f. ¼ 1, P < 0.001) (n ¼ 179) or (d) extinct species (odds ratio ¼ 0.365 with 95% confidence interval 0.318–0.420, t ¼ )7.24; G 2 ¼ )61.54, d.f. ¼ 1, P < 0.001) (n ¼ 26). t: Wald statistic. The outside lines are the 95% confidence intervals for the fitted curve (central line). Life-history characters in the Australian flora Journal of Biogeography 33, 271–290 285
ª 2006 The Authors. Journal compilation ª 2006 Blackwell Publishing Ltd Table 5 Examples of correlated evolution in two traits in clades from the angiosperm supertree Clade
Trait comparison Number of taxa P values Asterids
Rarity and genus size 550
0.00–0.00 Core Eudicots Rarity and genus size 454
0.00–0.006 Commelinids (monocots) Rarity and genus size 534
0.00–0.147 Asterales Rarity and genus size 168
0.00–0.514 Apiales
Rarity and genus size 44 0.00–0.551 Solanales Rarity and genus size 13 0.00–1.00 Lamiales Rarity and genus size 127 0.00–0.359 Asteraceae Rarity and genus size 140 0.00–0.508 Apiaceae Rarity and genus size 27 0.125–0.154 Asterids Rarity and sex system 577 0.00–0.00 Core Eudicots Rarity and sex system 529 0.00–0.00 Commelinids (monocots) Rarity and sex system 534 0.00–0.00 Asterales Rarity and sex system 162 0.001–0.006 Solanales Rarity and sex system 14 0.63–0.09 Asteraceae Rarity and sex system 145 0.001–0.010 Apiaceae Rarity and sex system 27 0.125–0.191 Thymelaeaceae Rarity and sex system 10 0.00–0.00 Sapindaceae Rarity and sex system 45 0.486–0.672 Sapindaceae Rarity and sex system (bisexual or not) 45 0.00–0.563 Euphorbiaceae Rarity and sex system 45 Unisexual or not 0.574–0.672 Bisexual or not 0.486–0.671 Cyperaceae, Eriocaulaceae and Hydatellaceae Rarity and sex system (unisexual or not) 50 0.00–0.02 Asterids Rarity and fruit type 564 Fleshy or not 0.00–0.00 Dry-indehiscent or not 0.00–0.00 Dry-dehiscent or not 0.00–0.00 Core Eudicots Rarity and fruit type 467
Fleshy or not 0.00–0.00 Dry-indehiscent or not 0.00–0.00 Dry-dehiscent or not >0.05
Commelinids (monocots) Rarity and fruit type 534 Fleshy or not 0.00–0.00 Dry-indehiscent or not 0.00–0.00 Dry-dehiscent or not 0.00–0.00 Liliaceae Rarity and fruit type (fleshy or not) 35 0.062–0.084 Zingiberaceae Rarity and fruit type (fleshy or not) 9 0.559–0.704 Triuridaceae, Stemonaceae and Pandanaceae Rarity and fruit type (fleshy or not) 4 0.00–0.00 Cyperaceae, Eriocaulaceae and Hydatellaceae Rarity and fruit type 44 Dry-indehiscent or not 0.98–0.993 Dry-dehiscent or not 0.007–0.014 Asterids
Rarity and fruit type 564
Fleshy or not 0.00–0.00 Dry-indehiscent or not 0.00–0.00 Dry-dehiscent or not 0.00–0.00 Apocynaceae Rarity and fruit type (fleshy or not) 31 0.007–0.025 Goodeniaceae Rarity and fruit type (dry-dehiscent or not) 13 0.045–0.087 Euphorbiaceae Rarity and fruit type (fleshy or not) 44 0.00–0.00 Myrtaceae Rarity and fruit type 76 Fleshy or not 0.00–0.00 Dry-indehiscent or not 0.00–0.001 Rutaceae
Rarity and fruit type (fleshy or not) 44 0.00–0.00 Sapindaceae Rarity and fruit type (dry-indehiscent or not) 31 0.013–0.020 P values are based on 10 random trees with resolved polytomies. No other clades gave significant P values. A. Sjo¨stro¨m and C. L. Gross 286 Journal of Biogeography 33, 271–290 ª 2006 The Authors. Journal compilation ª 2006 Blackwell Publishing Ltd Table 6 The distribution of life-history characters (%)
in 20 studies Study Bio.
region Number
of species
Habit Life
span Sex
Fruit Woody
N on-wdy
Sht L ng Mix H erm Dio Mono
M ix Flshy Dry Tr Sh Li He Vi Dry-indeh Dry-deh
This study
A ustralia
16,824 (total),
16,704 (habit),
16,702 (lfspan), 16,655 (sex),
16,802 (fruit)
17.3 40.8
2.1 38.5
1.2 10.1
89.9 76.3
5.5 18.1
13.0 28.0
59.0 Parsons
(1958) S. Australia 2102 89.0
4.2 5.9
1.0 McComb
(1966) W. Australia 3886 90.0
4.4 2.5
3.0 Godley
(1979) New
Z ealand
1813 76.0
15.0 9.0
Rogers & W alker (2002)
New Z ealand 2715 23.6
2.1 65.6
Steiner (1988)
South Africa
565 (habit,
fruit), 8497
(sex) 37.3
62.7 79.7
6.7 13.0
68.3 31.5
Flores & Schemske (1984) Caribbean 2036 (fruit),
2037 (habit,
sex) 22.7
15.7 10.7
50.9 78.9
6.2 14.9
35.3 64.7
McComb (1966)
British Isles
1594 80.7
3.1* 8.7
7.5 Hegde
and Ellstrand
(1999)
British Isles
860 12.4
87.6 30.9
69.1 6.2
4 4.8
49.1 Khedr
et al.
(2002) à Egypt 2340 (habit),
2376 (lfspan)
1.4 18.5
0.8 79.3
47.8 47.4
4.8 Fox
(1985) Alaska
1471 8.7
91.3 4.3
9 5.7
Fox (1985)
California 5421
14.2 85.8
6.6 9 3.4 Hegde & Ellstrand (1999) California 718 17.7
82.3 35.1
64.9 1.9
4 2.8
55.4 Conn
et al.
(1980) N + S C arolina 3274§ 5.3
8.6 83.0
3.1 20.6
79.4 Kaye
et al.
(1997) Oregon
338 – 0.3 7.1 92.6
16.9 83.1
Carlquist (1966)
Hawaii 1484
55.4 30.7
13.9 Sakai
et al.
(1995) Hawaii
844 (habit),
966 (fruit)
28.9 40.8
30.1 44.1
55.9 Sakai
et al.
(2002) Hawaii**
1159 (habit),
1045 (lfspan), 1040 (sex)
25.5 42.4
1.5 25.4
4.9 2.1
97.9 62.9
21.0 16.1
42.4 57.7
Robinson et al. (1994) Statten
Island-current 639
2.7 5.0
59.3 10.3
56.7 17.1
dng dng
Robinson et al. (1994) Statten
Island-historic 1082
8.7 8.9
79.8 15.5
81.8 26.5
dng dng
Turner et al. (1996) Singapore-current 314 38.5
8.9 20.1
3.8 Turner
et al.
(1996) Singapore-historic 448 63.8
8.5 23.2
3.1 Roy
(1974) India
13,988 79.4
6.7 13.7
Yampolsky & Yampolsky (1922) World
121,492 71.4
3.5 14.0
10.5 Tr:
tree, Sh:
shrub, Li:
liane, He:
herb, Vi:
vine, Non-wdy:
non-woody; lfspan:
life span,
Sht: short
duration, Lng:
long duration; Herm: hermaphrodi te, Dio:
dioecious, Mono:
monoecious; Flshy:
fleshy fruits,
Dry-indeh: dry-indehiscent fruits, Dry-deh:
dry-dehiscent fruits;
dng: data
not given.
*Kay & Stevens (1986) report
dioecy levels
of 4% (n ¼ 59).
Data
also from
S. Hegde,
pers. comm.
à Includes
introduced species;
parasites (n ¼ 36) omitted
from habit.
§Includes gymnosperms and introduced species. – Threatened species only.
**Endangered species
only. Life
span and
sex are
endangered endemics
only. Life-history characters in the Australian flora Journal of Biogeography 33, 271–290 287
ª 2006 The Authors. Journal compilation ª 2006 Blackwell Publishing Ltd trees and the observed low recruitment levels of trees in altered landscapes. There are, however, many tree species on the endangered list so complacency about this life form is unwar- ranted.
The association of sex system, fruit type and habit with rarity For the first time we have an overall picture of what the Kataloq: teaching teaching -> Oncological Emergencies Dr. Gary Harding md, frcpc teaching -> Chapter S: IV iv. Informed Search teaching -> Exploring a Protein Structure in the rcsb pdb: Insulin Learning Goals teaching -> Infertility, In Vitro Fertilization (ivf) and Genetic Testing Susan Sarajari, M. D., Ph. D teaching -> Java – gui graphical User Interface ine2720 Web Application Software Development teaching -> Exploring a Protein Structure in the rcsb pdb: Antibodies Learning Goals teaching -> Malrotation and volvulus teaching -> Pathogenic Bacteria/4 3rd Lab. Investigation Pathogenesis a microorganism is a pathogen teaching -> Another length Page of 1 1 metre = 1000 millimetres teaching -> Iteration 1 First real development iteration Yüklə 225,04 Kb. Dostları ilə paylaş:
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