What can unique communities that develop on deep-sea wood falls tell us about how productivity drives diversity

1. TESTING ENERGETIC THEORY WITH
EXPERIMENTAL DEEP-SEA WOOD FALLS
CRAIG R MCCLAIN
National Evolutionary Synthesis Center

2. WOOD FALL
Dead Wood Tell Tales
@DrCraigMc
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@DrCraigMc

3. Biodiversity
Productivity Diversity Relationship
Productivity

4. THEORIES
OF
COMMUNITY
ASSEMBLY AND
ENERGETIC
THEORY

5. The Species Energy Theory (More Individuals Hypothesis)
(Srivastava & Lawton 1998), originally
proposed by Wright (1983)
!
As productivity decreases, abundances
of species also decrease.
!
Rare species at low productivities are
thus at increased risk of stochastic
extinction, i.e. Allee effects.
!
With increased productivity Allee
effects are diminished and coexistence
increases (Wright et al. 1993).
Abundance
Productivity

6. Additional energy may elevate the
amount of rare resources, allowing
rare or absent niche-specialists to
become abundant and raise overall
community diversity, e.g. Niche
Position Hypothesis (Evans et al. 1999;
Evans et al. 2005).
!
At high productivities, this theory also
predicts that greater specialization is
allowable and prevents competitive
exclusion (Schoener 1976; DeAngelis
1994).
Niche Position Hypothesis
Productivity
Species
Unique Traits

7. Increased energy may increase the
amount of preferred resource, and
species may decrease their
consumption of less optimal
resources. This would reduce niche
breadth in high energy areas and
allow for greater coexistence, e.g.
Niche Width Hypothesis (Evans et al.
1999).
Niche Width Hypothesis
Productivity
Niche Breadth

8. The food web is predicted
to become more complex
with increased energy;
sustenance to higher trophic
levels results in longer food
chains (Post 2002a; Takimoto
& Post 2012).
One More Trophic Level Hypothesis
Productivity
Trophic Level

9. Nonequitable Distribution of Energy Hypothesis
An energetic optimum size exists for a
community that maximizes multiple
energetic constraints that correlate with
body size, e.g. metabolism, life history,
foraging efficiency, starvation resistance
(Rex & Etter 1998; Sebens 2002). Species
of this optimum size are more efficient in
procuring resources and translating them
into growth and reproduction.
!
More energy allows decreases
competitive interactions based on size,
i.e. species don’t have to be the perfect
size
Productivity
Body Size

10. WOOD FALLS
are an IDEAL
test system
for theories about
COMMUNITY ASSEMBLY
AND ENERGETIC THEORY

11. During the Typhoon Morakot in 2009,
a total of 8.4*1012 g of total woody debris
was transported to the oceans of Asia

13. The total amount of energy
can be precisely controlled
to the wood fall community.

14. Discrete habitat boundaries allow for the easy quantification
of standing stock, trophic structure, and diversity.
!
Easily collected allowing for the whole community to be quantified as
opposed to just the collection of a subset.

15. 39/43 of the species found on the wood fall were endemic
of these endemic species all were represented by ~10-10,000
individuals, non-endemics have 1-4 individuals
Deep-sea wood falls host an almost
completely endemic fauna
covering a broad taxonomic composition.

16. Accurate tracking of energy through the community via stable isotope analysis.
!
Stable isotope compositions of animals that rely energetically on wood
are isotopically distinct from animals that rely energetically on phytodetritus.

17. Wood falls in deep sea, especially at the depths investigated here,
are also energetically isolated from the surrounding deep sea.

18. WOOD
FALLS
the IDEAL
EXPERIMENT

26. WOOD FALLS
the
RESULTS

28. Xylophaga

33. -1.0 -0.5 0.0 0.5
-0.8 -0.6 -0.4 -0.2 0.0 0.2 0.4 0.6
NMDS1
NMDS2
Absent
Light
Present
Weight (kg)
0
5
10
15
MDS: a matrix of item–item
similarities, then assigns a
location to each item in N-dimensional
space. Distance in
plot correlates with differences in
communities!
!
1. Abundance!
2. Composition
McClain & Barry, Biology Letters, 2014

34. Xyloskenea sp. nov.
32
30
Xyloskenea sp. nov.
large medium small
Absent Light Present
-30 -20 -10 0 10
0 10 20 30 40
CAP1
CAP2
Provanna sp. 1
Hyalogyra sp. 1
Polynoidae sp. A.
Protanais sp. nov.
3
65
7
10
1113
18
19
21
22
26 27
35
Weight
Absent
Present
Light
Occurence of Halo
200
100
400
200
200
100
500
400
300
200
100
0
Abundance Per Wood Fall
Protanais sp. nov.
0
0
0
Abundance Per Wood Fall
Wood Weight Group
Hyalogyra sp. 1
Provanna sp. 1
McClain & Barry, Biology Letters, 2014

35. Protanais sp. nov.
Dillwynella (Ganesa) panamesis

36. Set 1
Set 2
November 2006-October 2011 (5 years)
multiple successional stages
November 2006-October 2013 (7 years)
post halo stage

37. Species are targeted to a specific log size and successional state
Species Energy/Niche Position
P
−1.5 −1.0 −0.5 0.0 0.5 1.0
−1.0 −0.5 0.0 0.5
NMDS1
NMDS2
1
2
Log Size
MDS: a matrix of item–item
similarities, then assigns a
location to each item in N-dimensional
space. Distance in
plot correlates with differences in
communities!
!
1. Abundance!
2. Composition

38. Presence/Absence
−1.5 −1.0 −0.5 0.0 0.5
Species are targeted to a specific log size and successional state
Niche Position Hypothesis
−0.8 −0.6 −0.4 −0.2 0.0 0.2 0.4
NMDS1
NMDS2
1
2
MDS: a matrix of item–item
similarities, then assigns a
location to each item in N-dimensional
space. Distance in
plot correlates with differences in
communities!
!
1. Composition

39. Biodiversity
Productivity Diversity Relationship
Productivity

40. 1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
24
18
19
20
21
22
23
26
27
28
29
30
31
32
35
20
15
10
5
0.0 0.5 1.0
Log10 Weight (kg)
Richess
Set
a
a
1
2
Species Richness Increases With Wood Fall Size
Wood Fall Size and Richness Weaker In Second Set
Smaller Wood Falls Become More Diverse

41. Hyalogyra sp. 1 Dillwynella (Ganesa) panamesis Xyloskena sp. nov
Provanna pacifica Provanna sp. 1 Provanna sp. 1
Hyalogyra sp. 1
Cephalaspidea sp.???

42. 1
2
3
4
5 6
7
8
9
10
11
12
13
14
15
16
17
24
18
19
20
21
22
23
26
27
28
29
31 30
32 35
2500
2000
1500
1000
500
0
0.0 0.5 1.0
Log10 Weight (kg)
Abundance
Set
a
a
1
2
743
1078
Abundance Increases with Wood Fall Size

43. 1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
35
16
17
18
19
20
21
22
24
23
26
27
28
29
30
31
32
20
15
10
5
1.5 2.0 2.5 3.0
Log10 Abundance
Richess
Set
a
a
1
2
Richness of Wood Falls Correlated With Abundance
More Individual Hypothesis

44. 1
2
3
4
5
6
7
8
12
13
11 9 10
14
15
16
17
18
19
20
21
22 23 24 26
27
28
2930
31
32
35
8
6
4
2
0.0 0.5 1.0
Log10 Weight (kg)
Singletons
Set
a
a
1
2
1
2
3
4
16
5
6
7
8
9
10
11
12
13
14
15
17
18
19
20
21
22
23 24
26
27
28
29
30
31
32
35
15
10
5
0
0.0 0.5 1.0
Log10 Weight (kg)
No. of Species w/ Abundance Less Than 5
Set
a
a
1
2
Number of Rare Species Increases With Wood Fall Size
More Individual Hypothesis/Niche Position

45. Gastropod.1 Gastropod.2 Gastropod.3 Gastropod.4 Gastropod.5 Gastropod.7 Gastropod.8
1.5
1.0
2.0
1.5
1.0
0.5
1.5
1.0
0.5
1.50
1.25
1.00
0.3
0.2
0.1
0.10
0.05
0.00
0.0 0.5 1.0 0.0 0.5 1.0 0.0 0.5 1.0 0.0 0.5 1.0 0.0 0.5 1.0 0.0 0.5 1.0 0.0 0.5 1.0
Gastropod.9 Gastropod.10 Anemone1 Anemone2 Crinoid Ophiuroid.1 Ophiuroid.2
0.9
0.6
0.3
0.6
0.4
0.2
0.05
0.04
0.03
0.02
0.01
0.9
0.6
0.3
0.6
0.4
0.2
0.06
0.04
0.02
0.0 0.5 1.0 0.0 0.5 1.0 0.0 0.5 1.0 0.0 0.5 1.0 0.0 0.5 1.0 0.0 0.5 1.0 0.0 0.5 1.0
Ophiuroid.3 Bivalve.4 Bivalve.1 Bivalve.2 Bivalve.3 Polychaete.1 Polychaete.2
0.050
0.025
0.000
0.4
0.3
0.2
0.1
0.3
0.2
0.1
0.06
0.04
0.02
1.2
0.8
0.4
1.5
1.0
0.5
0.0 0.5 1.0 0.0 0.5 1.0 0.0 0.5 1.0 0.0 0.5 1.0 0.0 0.5 1.0 0.0 0.5 1.0 0.0 0.5 1.0
Polychaete.3 Polychaete.4 Polychaete.6 Polychaete.7 Polychaete.8 Polychaete.9 Polychaete.10
1.2
0.8
0.4
0.6
0.4
0.2
0.3
0.2
0.1
0.12
0.08
0.04
0.20
0.15
0.10
0.05
0.100
0.075
0.050
0.025
0.0 0.5 1.0 0.0 0.5 1.0 0.0 0.5 1.0 0.0 0.5 1.0 0.0 0.5 1.0 0.0 0.5 1.0 0.0 0.5 1.0
Polychaete.11 Polychaete.16 Polychaete.17 Tanaid.1 Galatheid.1 Galatheid.2 Chiton
0.15
0.10
0.05
0.04
0.02
2.0
1.6
1.2
0.8
0.6
0.4
0.2
0.3
0.2
0.1
0.100
0.075
0.050
0.025
0.0 0.5 1.0 0.0 0.5 1.0 0.0 0.5 1.0 0.0 0.5 1.0 0.0 0.5 1.0 0.0 0.5 1.0 0.0 0.5 1.0
Asteroid.1 WTF.1 WTF.2 Amphipod1 Amphipod2 Amphipod3 Pycno1
0.075
0.050
0.025
0.05
0.0 0.5 1.0 0.0 0.5 1.0 0.0 0.5 1.0 0.0 0.5 1.0 0.0 0.5 1.0 0.0 0.5 1.0 0.0 0.5 1.0
Iso1 Limpet1 Limpet2
2.0
1.5
1.0
0.5
0.0
0.5
0.0
0.0
0.75
0.0
−0.05
0.15
0.10
0.05
0.00
0.0
0.0
0.00
0.0
0.0
0.00
0.100
0.075
0.050
0.025
0.000
−0.025
0.0
0.0
0.00
0.0
0.0
0.75
0.50
0.25
0.00
0.0
0.0
0.0
0.00
0.00
0.000
0.100
0.075
0.050
0.025
0.000
0.00
0.00
0.8
0.0
0.0
0.000
0.06
0.04
0.02
0.00
0.000
0.00
1.2
0.9
0.6
0.3
0.0
1.00
0.75
0.50
0.25
0.00
0.5
0.4
0.3
0.2
0.1
0.0
0.075
0.050
0.025
0.000
0.100
0.075
0.050
0.025
0.000
1.0
0.5
0.0
1.00
0.75
0.50
0.25
0.00
0.0 0.5 1.0 0.0 0.5 1.0 0.0 0.5 1.0
Log10 Weight (kg)
Abundance
Set
1
2
Responses of Individual Species Vary

46. The food web is predicted
to become more complex
with increased energy;
sustenance to higher trophic
levels results in longer food
chains (Post 2002a; Takimoto
& Post 2012).
One More Trophic Level Hypothesis
Productivity
Trophic Level

49. Conclusions
• Species richness increases with increasing wood fall size
• With greater time the relationship becomes weaker
• With time, smaller logs add species with greater magnitude that larger logs
• Abundance increases with increasing log size and in second set (more time)
• Richness is a function of abundance among wood falls (Species Energy)
• But more species for same abundance in second set
• Second set is more even (adding more species without increasing abundance)
• Addition of rare species (Island biogeography, Niche Position)
• Number of singletons more pronounced in smaller logs (Allee Efffects, Species
Energy)
• However, rare species seem to contribute to overall all richness in both sets with
increasing wood size (Niche Position)
• Abundance of all species do not increase at the same rate (Niche Position)

50. Acknowledgments
Jim Barry (MBARI), Jenna Judge (UC
Berkeley), David Honig (Duke U),
Janet Voight (Field Museum), Tammy
Horton (NOC), Doug Eernisse (UC
Fullerton), Keiichi Kakue (Hokkaido U)
!
Funding: National Evolutionary
Synthesis Center (NSF Grant
#EF-0905606)
!
Funding and Ship Support: Monterey
Bay Aquarium Research Institute
(Packard Foundation)
!
Artwork by Immy Smith
Visiting Artist, Herbarium RNG

51. Deep Sea News
http://deepseanews.com
@DrCraigMc
Deep Sea
News
DSN
http://craigmcclain.com

52. More Individuals Hypothesis
Abundance of all species is expected to increase with increasing wood-fall size.
!
Wood-fall size is predicted to be a significant predictor of abundance.
The size*species interaction term should not be statistically significant, i.e. different relationships—
negative and positive—between size and abundance for each species
Df Sum Sq Mean Sq F value Pr(>F)
Weight 1 46950 46950 26.0946 3.717e-07 ***
Species 44 815908 18543 10.3063 < 2.2e-16 ***
Set 1 10825 10825 6.0162 0.0143 *
Weight*Species 44 432523 9830 5.4635 < 2.2e-16 ***
Residuals 1349 2427164 1799

53. Niche Position Hypothesis
Additional energy may elevate the amount of rare resources, allowing rare or absent niche-specialists
to become abundant and raise overall community diversity
!
Abundance of rare species only increases with increasing wood-fall size.
!
The abundance rank order, a metric of dominance/rarity, is expected to show a significant
interaction effect with size, i.e. high rank order species have slopes near zero and low rank order
species have positive slopes.
Df Sum Sq Mean Sq F value Pr(>F)
Weight 1 46950 46950 21.3099 4.256e-06 ***
Set 1 10825 10825 4.9131 0.02681 *
Rank 1 414815 414815 188.2776 < 2.2e-16 ***
Weight:Rank 1 99176 99176 45.0142 2.807e-11 ***
Residuals 1435 3161605 2203

54. Species Rank
Species Abundance
1 2 5 10 20 50 100
1 2 3 4 5 6 7 8 9 10 11 12
Species Rank
Species Abundance
1 2 5 10 20 50
2 4 6 8 10 12 14 16
3
5
26
24
21 19
6
7
10
18
22
11 13
27
30
32
35
1
2
4
8
9
12
14
15
16
17
20
23
28
29
3.0
2.5
2.0
1.5
1.0 31
0.0 0.5 1.0
Log10 Weight (kg)
Coefficient from Zipf Fit
Set
a
a
1
2
3
5
27 26
6
7
10
11
13
18
19
21
22
30
32
35
24
1
2
4
8
9
12
14
15
16
17
20
23
29 28
31
0.8
0.6
0.4
0.2
0.0 0.5 1.0
Log10 Weight (kg)
K from Geometric Series
Set
a
a
1
2
Log 32
Log 35