saltmarsh ecosystem services under multiple stresstemporal change in average winter...
TRANSCRIPT
Saltmarsh ecosystem services under multiple stress
Carl Van Colen
Joanne Wong, Steven Degraer, Laura Airoldi, Magda Vincx
Context-dependent effects of sediment deposition
& increased inundation
Email from Ewoud Monballiu • who am I? • who is involved? • which challenge(s) faced us? (stressors) • what was our assumption in order to tackle this challenge(s)? (research hypotheses) • what happened: interventions, processes, applications, discoveries, (un)expected barriers, pivotal moments or breakthrough moments? (results) • where we are now & what principles of working can be gleaned from this?
• my proposition is …
Outline
Coastal habitats and ecosystems are affected by multiple stressors
Who am I (and what do I study)?
Coastal benthic habitats are affected by multiple stressors •Broad scale phenomena
Mora et al. 2013 PloS Biology. Predicted changes by 2100 due to greenhouse gas emissions
•Local disturbances and environmental change
Multiple stressors interact and result in changes in the intrinsic dynamics of ecosystems that may predispose the system to critical shifts Disentangling local vs. broad-scale drivers of change & potential interaction effects
Methods
Study context-dependency in ecological interactions that determine BDEF relationships & support resilience
•Spatial and temporal context-dependency •Evolutionary adaptation
Coastal habitats: estuaries, coastal lagoons, salt marshes, continental shelf seas
Benthic communities: microbial communities benthic invertebrates (macrobenthos) nekton
Ultimate research goal... Moving from hindsight to a more predictive science that is able to assist in the implementation of ecosystem-based management
Who am I (and what do I study)?
Macrobenthos as a bio-indicator of environmental change
Well suited for long-term comparative investigations since many of the constituent species are
sessile or have low mobility relatively long-lived integrate effects of environmental change over time
Macrobenthos-mediated ecosystem services Production services: food provisioning (direct, e.g. shell
fish; indirect: provision of food/nutrients to higher trophic groups); raw materials (e.g. shells) Regulating services (removal of pollutants) Supporting services (nutrient cycling, biologically-mediated habitat)
Saltmarsh vegetation provide habitat & ecosystem services
provide erosion control, sediment accretion and carbon sequestration
Who is involved?
M. Alsebai Long-term variability and regime shifts in
benthic communities
S.Mestdagh Estuarine benthic-pelagic coupling
V. Lo Salt marsh biodiversity
and functioning: human pressures & Recovery pathways
J. Wong Management options
of cumulative stressors in salt
marshes
E. Ong Stressors & benthos
behavior
X. Fang Estuarine benthic
ecosystem functioning: Biogeochemical
modelling
Case study 1: Sediment-benthos relationships in the Zwin
coastal lagoon
2003: 95 samples + seasonal survey 12 stations (Tricolor study)
158 ha - Ramsar list - Natura 2000 – Dunes, salt marsh and creeks, tidal flats, salt pans, tidal pond. To be enlarged in the future (+120 ha).
Case study 1: Sediment-benthos relationships in the Zwin
coastal lagoon
2010: 60 samples (BEMONA and ZTAR project)
Case study 1: Sediment-benthos relationships in the Zwin
coastal lagoon
2013: 60 samples (ZTAR project)
0%
25%
50%
75%
100%
0 100 200 300 400 500
0
2
4
6
8
10
12
14
Pro
ba
bil
ity
of
occ
urr
en
ce
Bio
ma
ss (
g A
FDW
.m-2
)
H. diversicolor
0%
25%
50%
75%
100%
0 100 200 300 400 500
0
1
2
3
4
Pro
ba
bil
ity
of
occ
urr
en
ce
Bio
mas
s (g
AFD
W.m
-2)
H. filiformis
0%
25%
50%
75%
100%
0 100 200 300 400 500
0
20
40
60
80
100
120
Pro
ba
bil
ity
of
occ
urr
en
ce
Median grain size (µm)
Bio
mas
s (g
AFD
W.m
-2)
S. plana
0%
25%
50%
75%
100%
0 100 200 300 400 500
0
1
2
3
4
5
Pro
ba
bil
ity
of
occ
urr
en
ce
Median grain size (µm)
Bio
mas
s (g
AFD
W.m
-2)
M. balthica
• Habitat preference: identification of critical thresholds modelling occurrence and biomass of benthos as a function of sediment
Van Colen C. et al. (2014) Sediment-benthos relationships as a tool to assist in conservation practices in a coastal lagoon subjected to sediment change. Biodiversity and conservation
- Highest probability of occurrence < 200 µm
- Biomass optima for Hediste and Scrobicularia < 150 µm
- Biomass optimum for Macoma @ 300 µm probability of occurrence < 200 µm
0%
25%
50%
75%
100%
0 100 200 300 400 500
0
2
4
6
8
10
12
14
Pro
ba
bil
ity
of
occ
urr
en
ce
Bio
ma
ss (
g A
FDW
.m-2
)
H. diversicolor
0%
25%
50%
75%
100%
0 100 200 300 400 500
0
1
2
3
4
Pro
ba
bil
ity
of
occ
urr
en
ce
Bio
mas
s (g
AFD
W.m
-2)
H. filiformis
0%
25%
50%
75%
100%
0 100 200 300 400 500
0
20
40
60
80
100
120
Pro
ba
bil
ity
of
occ
urr
en
ce
Median grain size (µm)
Bio
mas
s (g
AFD
W.m
-2)
S. plana
0%
25%
50%
75%
100%
0 100 200 300 400 500
0
1
2
3
4
5
Pro
ba
bil
ity
of
occ
urr
en
ce
Median grain size (µm)
Bio
mas
s (g
AFD
W.m
-2)
M. balthica
B
N
200 m
SPATIO-TEMPORAL DYNAMICS IN BENTHIC COMMUNITIES AND SEDIMENT PROPERTIES 2003 – 2010
IN TWO CONTRASTING HABITATS
Van Colen C. et al. (2014) Sediment-benthos relationships as a tool to assist in conservation practices in a coastal lagoon subjected to sediment change. Biodiversity and conservation
150
175
200
225
250
275
300
325M
ed
ian
gra
in s
ize
(µ
m)
0
5
10
15
20
25
Mu
d c
on
ten
t (%
< 6
3µ
m)
0
0.5
1
1.5
2
2.5
3
3.5
2003 2010 2003 2010
Inlet channel High intertidal
Org
anic
mat
ter
(%)
0
5
10
15
20
25
30
35
2003 2010 2003 2010
Inlet channel High intertidal
Bio
mas
s (g
AFD
W m
-²)
Scrobicularia plana
Macoma balthica
Heteromastus filiformis
Hediste diversicolor
Total biomass
A B
C D
Temporal variability in sediment composition, (a) median grain size, (b) mud content, (c) organic matter content; and (d) biomass of macrobenthos in the inlet channel and intertidal habitat surrounding the tidal pond. The top of the stacked bar represents the total biomass and the biomass of the four most dominant species in terms of biomass are depicted in different colors (see inset). Error bars are 95 % confidence intervals (note that mud content = 0 in 2010)
Context-dependent
sedimentological change (spatial segregation)
- Coarsening of the inlet
channel - Finer sediment in the high
intertidal Benthos response to
sediment change
- Gradual infilling of the floodplain
Increased access for
ground predators Overall decrease in
sediment organic matter, macrobenthos biomass & thus food supply for shorebirds and nekton foraging in the intertidal creeks
0
50
100
150
200C. alpina
30
40
50
60
70
80
90
100
20
03
-20
04
20
04
-20
05
20
05
-20
06
20
06
-20
07
20
07
-20
08
20
08
-20
09
20
09
-20
10
20
10
-20
11
P. squatarola
40
60
80
100
120
140R. avosetta
0
10
20
30
40
50
60
70
80
90
20
03
-20
04
20
04
-20
05
20
05
-20
06
20
06
-20
07
20
07
-20
08
20
08
-20
09
20
09
-20
10
20
10
-20
11
T. tadorna
Ab
un
da
nce
(a
vera
ge
mo
nth
ly t
ota
l co
un
ts)
TEMPORAL DYNAMICS IN SHOREBIRD ABUNDANCES IN THE ZWIN COASTAL LAGOON
2003 - 2010
Temporal change in average winter (November-February) abundances of Calidris alpina (Dunlin), Pluvialis squatarola (Grey Plover), Recurvirostra avosetta (Avocet), and Tadorna tadorna (Shelduck) in the Zwin nature reserve between 2003 and 2011. Solid lines represent running average fits (n=2) through the average counts. Data are obtained from monthly density censuses of shorebirds performed during high tide for the complete nature reserve in November-February between November 2003 and February 2011. Survey counts for R. avosetta were occasionally missing for February 2006 and January 2007. Population densities significantly declined over time for T. tadorna (simple linear regression: F(1, 6) = 16.95; R² = 0.74; p = 0.006; Durbin-Watson test of serial correlation over time = D = 1.52, correlation = 0.10)
Shellduck feeding traces on microbial biofilm
Further actions: Monitoring nekton and benthos responses to restoration management in the Zwin coastal lagoon
Case study 2: Interactive effects of increased inundation and
nutrient loading on Spartina maritima in the NE Adriatic Sea
Deegan et al. (2012) Coastal eutrophication as a driver of salt marsh loss. Nature 490: Excess in nutrients cause saltmarsh deterioration
9 years of
Testing the joint effect of excess nutrients and increased inundation on Spartina
Experiment using field mesocosms
Stressors: excess nutrients & increased inundation
Other factor: soil type
Wong J. et al. (2015) Sediment-benthos relationships as a tool to assist in conservation practices in a coastal lagoon subjected to sediment change. Marine environmental research
8 scenarios of orthogonal combinations of two levels of:
1) Inundation → low (ambient) vs. high (+10 cm = 20% more inundation: i.e. 2020 scenario, Theseus 2009)
2) Nutrient → low (ambient) vs. high (Osmocote fertiliser NPK: 1.5 mg/L)
3) Soil type → low (~2%) vs. medium (~10%) organic
Study site: Vallona lagoon
Replication: n=8
Growth season July-September
Vallona Lagoon
- Dominant negative inundation effects on plant properties - Root growth worse when increased inundation is coupled with high nutrients Reduced vertical growth keep up with sea level rise Impact on erosion control?
Summary of the two case studies
• Sediment deposition and increased inundation affect saltmarsh ecosystem services
- habitat quality for e.g. shorebirds - plant biomass carbon sequestration & erosion control - benthos & salt marsh mediated effects on regulating and supporting services BUT • The magnitude and direction of stressor impact can be site-specific
depending on environmental conditions - hydrodynamics - nutrient loading
PROPOSITION
With current delays and limitations on the mitigation of global stressors, it is crucial to identify which factors can maintain ecosystem resilience at
local scales.
Investigating interactive effects of global and local stressors (or management actions, i.e.
removal/reduction of a local stressor) across gradients in space and time can therefore assist in
the implementation of conservation strategies.
"The single most important problem is our misguided focus on identifying the single most important problem!”
- Jared Diamond
Acknowledgments Thank you for your attention! MARBIOL and UNIBO colleagues Research funded by the Research Foundation Flanders (FWO) Mares doctoral programme, ANB Contact: [email protected]