Biodiversity influences on mangrove forest ecosystem ... · Biodiversity influences on mangrove...
Transcript of Biodiversity influences on mangrove forest ecosystem ... · Biodiversity influences on mangrove...
Biodiversity influences on mangrove
forest ecosystem services delivery
Clare Duncan1,2, Jurgenne H. Primavera3,4,
Heather J. Koldewey3,5, Julian R. Thompson2, Nathalie Pettorelli1
1 Institute of Zoology, ZSL, Regent’s Park, London NW1 4RY UK
2 UCL Department of Geography, Gower Street, London WC1E 6BT UK
3 ZSL Conservation Programmes, Regent’s Park, London NW1 4RY UK
4 ZSL-Philippines, 43-E Burgos Street, Barangay Magdalo, La Paz, 5000 Iloilo City, Philippines
5 Centre for Ecology and Conservation, University of Exeter, Penryn, Cornwall TR10 9EZ UK
Current state of play…
• Mangroves are in global decline
FAO (2005).
Richards & Friess (2016).
• Loss of climate change
mitigation & adaptation
(CCMA) ES
Martine Perret.
International Labour.
Current state of play…
• Diversity is also declining
Polidoro et al. (2010).
DISTRIBUTION OF THREATENED SPECIES
• Mid- to upper-intertidal; selective cutting
Current state of play…
• Rehabilitation efforts often
species-poor or monoculture
Jurgenne H. Primavera.
Current state of play…
What does this mean for mangrove ES?
Does floristic diversity drive climate change
mitigation and adaptation ecosystem
services (ES) of mangrove forests?
• Terrestrial forests: flora richness can increase ecosystem functioning
• Mechanism = functional
differences
(complementarity in
resource use or
facilitation)
• Species richness not
important?
Gamfeldt et al. (2013).
Biodiversity & ES
• Terrestrial forests: saturating or mixed relationships
• Mechanism = functional
identity of the most
dominant species
• Could these mechanisms
= ES trade-offs?
Gamfeldt et al. (2013).
Biodiversity & ES
Complementarity in Mangroves…?
1: Leitão (2016).
• Species-poor systems – complementarity/facilitation may be strong?1
Complementarity in Mangroves…?
1: Leitão (2016).
• Species-poor systems – complementarity/facilitation may be strong?1
Lang’at et al. (2011).
1: Leitão (2016).
Complementarity in Mangroves…?
• Species-poor systems – complementarity/facilitation may be strong?1
• Many forests monospecific & still function fine – dominant species?
Huxham et al. (2010).
1: Leitão (2016).
Complementarity in Mangroves…?
• Species-poor systems – complementarity/facilitation may be strong?1
• Many forests monospecific & still function fine – dominant species?
• Narrow niche space & water constraints = morphological convergence
1: Leitão (2016).
Complementarity in Mangroves…?
• Species-poor systems – complementarity/facilitation may be strong?1
• Many forests monospecific & still function fine – dominant species?
• Narrow niche space & water constraints = morphological convergence
• Species-poor mangroves: genetic diversity - plasticity?
1: Leitão (2016).; 2: Balun (2011).
Complementarity in Mangroves…?
• Species-poor systems – complementarity/facilitation may be strong?1
• Many forests monospecific & still function fine – dominant species?
• Narrow niche space & water constraints = morphological convergence
• Species-poor mangroves: genetic diversity - plasticity?
• Hyperdiverse mangroves: functional traits vary between and within
zones2
CCMA ES in Diverse Mangroves…
• Does species richness matter for C stocks & storm surge
attenuation?
• Does complementarity or dominant functional identity
drive these?
• Are there mechanism- or functional trait-based trade-offs
between delivery of different mangrove CCMA ES?
Methodology - Which Traits?
RESOURCE USE STRATEGY
Specific leaf
area (SLA)
Wood density
Aerial roots Growth form
Maximum height
Methodology - Which Traits?
Specific leaf
area (SLA)
Wood density
Aerial roots Growth form
Maximum height
STRUCTURAL
RESOURCE USE STRATEGY
Methodology – Study Sites
Methodology – Study Sites
19 species
75.5 ha
7 species
7.8 ha
9 species
7.7 ha
9 species
27.5 ha
6 species
3.2 ha
Methodology – Study Sites
27 species
72 ha
19 species
75.5 ha
7 species
7.8 ha
9 species
7.7 ha
9 species
27.5 ha
6 species
3.2 ha
1: Kauffman & Donato (2010); 2: Komiyama et al. (2005); 3: Fu & Wu (2011); 4: Mazda et al. (1997); 5: Kattge et al. (2011);
6: Zanne et al. (2009); 7: Primavera et al. (2004); 8: Laliberté & Legendre (2010); 9: Conti & Díaz (2013).
• Temporary field plots – N = 79
• C stock & veg structure1-3
• Storm surge attenuation = Le4 at 2.7 m
• Species-specific wood density, SLA,
max height, growth form, aerial roots5-7
• SR & functional trait indices8,9
• Control for site & zonation
• Model averaging – relative variable importance
Methodology – Field + Lab
Results
• DOMINANCE of taller species = increased carbon stock
VEGETATION CWi = 1.00
R2 M = 0.21
R2 C = 0.45
SEDIMENT CWi = 0.83
R2 M = 0.07
R2 C = 0.56
Results
Wi = 0.51
R2 M = 0.30
R2 C = 0.49
Wi = 0.49
R2 M = 0.25
R2 C = 0.41
• DIVERSITY of height & all traits = increased storm surge
attenuation potential
Results
Wi = 0.51
R2 M = 0.30
R2 C = 0.49
Wi = 0.49
R2 M = 0.25
R2 C = 0.41
• DIVERSITY of height & all traits = increased storm surge
attenuation potential
Results
• No correlation between
storm surge attenuation
potential & C stocks
• Real trade-off in
mechanisms driving
CCMA ES?
Summary
IMPLICATIONS:
• No evidence species richness is important for mangrove CCMA ES
Summary
IMPLICATIONS:
• No evidence species richness is important for mangrove CCMA ES
• Functional diversity in structural traits may be key for coastal protection
Summary
IMPLICATIONS:
• No evidence species richness is important for mangrove CCMA ES
• Functional diversity in structural traits may be key for coastal protection
• Monoculture may be sufficient for high C stocks?
Summary
IMPLICATIONS:
• No evidence species richness is important for mangrove CCMA ES
• Functional diversity in structural traits may be key for coastal protection
• Monoculture may be sufficient for high C stocks?
• Trade-off between C stocks & storm surge attenuation due to traits?
Summary
IMPLICATIONS:
• No evidence species richness is important for mangrove CCMA ES
• Functional diversity in structural traits may be key for coastal protection
• Monoculture may be sufficient for high C stocks?
• Trade-off between C stocks & storm surge attenuation due to traits?
• Greenbelt rehabilitation to maintain functional diversity (MIT focus?)
Summary
IMPLICATIONS:
• No evidence species richness is important for mangrove CCMA ES
• Functional diversity in structural traits may be key for coastal protection
• Monoculture may be sufficient for high C stocks?
• Trade-off between C stocks & storm surge attenuation due to traits?
• Greenbelt rehabilitation to maintain functional diversity (MIT focus?)
QUESTIONS:
• Are these the right traits?
Summary
IMPLICATIONS:
• No evidence species richness is important for mangrove CCMA ES
• Functional diversity in structural traits may be key for coastal protection
• Monoculture may be sufficient for high C stocks?
• Trade-off between C stocks & storm surge attenuation due to traits?
• Greenbelt rehabilitation to maintain functional diversity (MIT focus?)
QUESTIONS:
• Are these the right traits?
• Plasticity in low diversity mangroves?
Summary
IMPLICATIONS:
• No evidence species richness is important for mangrove CCMA ES
• Functional diversity in structural traits may be key for coastal protection
• Monoculture may be sufficient for high C stocks?
• Trade-off between C stocks & storm surge attenuation due to traits?
• Greenbelt rehabilitation to maintain functional diversity (MIT focus?)
QUESTIONS:
• Are these the right traits?
• Plasticity in low diversity mangroves?
• Wider trophic interactions?
Thanks!
Municipalities of Dumangas, Ajuy, Panay, Ivisan, Kalibo and Ibajay
Field assistants
Bureau of Soils & Water Management, Cebu
TRY Initiative Global Database on Plant Traits – DIVERSITAS/GBP & Max Planck
ZSL-Philippines
Funding: The Rufford Foundation & The Darwin Initiative