Investigating the linkage between
biodiversity and ecosystem functions
in coastal areas
Masahiro Nakaoka1,2), Akihito Aizawa1), Teruko Demise1),
Takuya Era1), Shuko Kato1) and Kentaro Watanabe1)
1) Chiba University
2) Current address: Akkeshi Marine Station, Field Science
Center for Northern Biosphere, Hokkaido University
E-mail: [email protected]
Adaptive management of biodiversity
and functions of coastal ecosystems
Q: Where to conserve?
A1: A site with highest biodiversity
(for conservationists)
A2: A site with highest productivity
(for fishermen)
Are the answers the same?
Biodiversity enhances ecosystem functions
BD-EF relationship
Positive link between biodiversity
and ecosystem functions revealed
by manipulative experiments
Tillman (2000)
plant species richness
co
m
m
un
ity
b
io
m
as
s
Questions and problems
1. Which measures of biodiversity should be used?
2. Does the rule hold at larger spatial scales?
Fewer research has been done in marine ecosystems.
Which measure of biodiversity ?
1. Definition at different biological levels
Genetic diversity at population level
Species diversity at community level
Landscape diversity at ecosystem level
2. Spatial scale of biodiversity
α diversity: diversity within a patch
β diversity: difference between patches
γ diversity: diversity of whole area
P
P
P
BD-EF relationship changes among regions
Hector et al (1999)
species loss
bi
om
as
s
Environmental factors interfere with BD-EF
relationship at broad spatial scales.
Purpose of the present study
Investigating possible relationships among environmental factors,
biodiversity and ecosystem functions in coastal habitats
Adaptive management of biodiversity,
ecosystem functions and services
Environmental gradients
Resource availability
Modulators (temp, pH)
Disturbance regime
Biodiversity
Composition
Richness and evenness
Species interactions
Ecosystem functions
Productivity
Resistance and Resilience
Stability
Case studies at two different habitats
Rocky intertidal community
along the Pacific coast of Japan
Seagrass beds in
Tokyo Bay
Known as most productive habitats in the world
(annual productivity exceeding tropical rain forest)
Harbor diverse plant and animals species, forming
“hot spot” of biodiversity in marine ecosystems
What is seagrass bed?
A unit of coastal landscape
consisting of seagrasses, i.e.,
“flowering plants living in the sea”
(Do not confuse with seaweeds!)
Study sites
Tokyo Bay
17 stations in 5 areas
established in a nested
design (although not
perfectly designed)
Seagrass bed in Futtsu
Analysis of genetic diversity of eelgrass
using microsatellite DNA
Collection of
eelgrass
DNA estraction by
CTAB method
Calculation of genetic diversity
115 117
98 107
98 121
(bp)
PCR amplification
Determionation of
genotypes
Electrophoresis
Analysis of genetic diversity of eelgrass
using microsatellite DNA
0 .0
0 .2
0 .4
0 .6
0 .8
1 .0
KK1 KK2 FT1 FT2 FT3 TK1 TK2 YH YE TT1 TT2 TJ
Fr
eq
o
f h
et
er
oz
yg
oc
ity
(H
)
Remote sensing analysis on long-term
changes in seagrass beds
Remote sensing analysis on long-term
changes in seagrass beds
0
5 x 103
1985 1990 1995 2000 2005 2010
Se
ag
ra
ss
a
re
a
(m
2 )
TK3
TK2
TT34 x 103
3 x 103
2 x 103
1 x 103
Analyses on animal community
Analyses on animal community
0
20
40
60
80
KK FP1 FP2 FF1 FF2 TKT TKU TKS TTH TTN TTO
Sp
ec
is
ri
ch
ne
ss
0
1
2
3
4
5
KK FP1 FP2 FF1 FF2 TKT TKU TKS TTH TTN TTO
D
en
si
ty
(m
-2
)
Relationships among environmental factors,
biodiversity and ecosystem functions
Positive correlation between
nutrient concentration and
density of benthic animals
（r=0.921, p=0.001）
Positive correlation between
seagrass bed area and genetic
diversity of eelgrass
（r=0.892, p=0.042）
2.5
3.0
3.5
4.0
0.0 0.2 0.4 0.6 0.8 1.0
N concentration (mg/l)
lo
g
(i
n
fa
u
na
d
e
ns
it
y
)
4.5
5.0
5.5
6.0
6.5
2 3 4 5 6 7
log (seagrass bed area)
A
lle
le
r
ic
h
n
e
ss
o
f
e
e
lg
ra
ss
Relationships among environmental factors,
biodiversity and ecosystem functions
Seagrass
species
diversity
Species
diversity
of epifauna
Nutrient
concentration
Water
transparency
Water
temperature
Stability of
seagrass bed
Sediment
composition
Seagrass
genetic
diversity
Species
diversity
of infauna
Abundance
of epifauna
Abundance
of infauna
Seagrass
bed areaPositive
Negative
What is rocky intertidal community?
Community on marine hard bottom which is
exposed to severe stress when emerged at low tide
Strong environmental gradient creates characteristic
zonation pattern of organisms.
Species interactions were strongly influenced by
competition over space.
Known as ideal system for experimental studies on
population and community ecology (such as classic
studies by Joseph Connell and Robert T. Paine)
Hierarchical census along
the Pacific coast of JapanDoto
Donan
Sanriku
Boso
Nanki
Osumi
6 regions
6 regions * 5 coasts * 5 plots
=150 plots
Chikura
Emi
Kominato
Nishikawana
Mera
5 coasts
01
02
0304
05 5 plots
0 50m25
vertical rock wall
Field census
100ｃｍ
Census plot Succession plot
Simultaneous monitoring at all sites since 2002
Monitoring of environment (temperature, nutrient, chlorophyll a
concentration, wave exposure, geology and geography of rocks)
Measurement of BD and EF (see next page)
mean tide level
50ｃｍ
Biodiversity at different spatial scales
Species richness of sessile organisms appeared at census plots
between 2002 and 2005
α1 : plot species richness
α2 : coastal species richness
γ : regional species richness
αα11
γγ
αα22Mera
Emi
Chikura
Nishikawana
Kominato
Ecosystem functions
1: Coverage
- indicator of biomass and productivity
(average between 2002 and 2005)
2: Temporal variation in coverage
- indicator of stability
(C.V. of coverage between 2002 and 2005)
3: Recovery speed from disturbance
- indicator of resilience
(coverage of the succession plot in 2004, i.e,
one year after the removal of organisms)
Results of path analysis
Nanki Osumi
Coverage Coverage
Water
temperature
α1
diversity
Chl. a
Rock
irregularity Water
temperature
Chl. a
.52
.59
.35 .40
-.35
-.56
α1
diversity .67
.34
.36
R2=0.70 R2=0.69
BD-EF relationship at different scales
0+000+Osumi
++0-++Nanki
000000Boso
+00000Sanriku
0++000Donan
00+000Doto
--0000--0All
γα2α1γα2α1γα2α1BD
ResilienceStabilityCoverageEF
Discussion from the rocky shore study
Effects of BD on EF were negative by analysis using
data from all regions, but positive for each region.
BiodiversityBiodiversity
Ec
os
ys
te
m
F
un
ct
io
n
Ec
os
ys
te
m
F
un
ct
io
n
Plot diversity (α1) affects ecosystem functions more
frequently than coastal diversity（α（α22））..
Conclusion
Biodiversity measured at different spatial and biological levels is
related to functions of coastal ecosystem.
The observed BD-EF relationship varied among regions and
among measures of biodiversity, suggesting importance of
considering spatial scale of observation and the effects of
environmental gradient.
Combined approaches using long-term monitoring data and
experimental approaches are promising to elucidate causal
mechanisms for the observed relationships, which is necessary
for planning adaptive management strategy for conservation of
coastal ecosystem.
Acknowledgements
Seagrass team: T. Yamakita, K. Yamada, N. Whanpetch, M. Hori, Y.
Tanaka, N. Tanaka, M. Ishii, A. Kondoh,
Rocky intertidal team : T. Noda, T. Yamamoto, M. Hori, T. Okuda, M.
Tsujino, T. Hagino, N. Ito, T. Maruyama
