Colin R. Maycock 1, Penny Gardner 1, Eyen Khoo 2, Chris Kettle 3, Jaboury Ghazoul 3 & David F.R.P....
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Colin R. Maycock 1 , Penny Gardner 1 , Eyen Khoo 2 , Chris Kettle 3 , Jaboury Ghazoul 3 & David F.R.P. Burslem 1 1 University of Aberdeen 2 Forest Research Centre, Sabah Forestry Department 3 ETH, Zurich Pollinator niche-partitioning among eight coexisting dipterocarp species in Sabah Linking life-history trade-offs to population genetic structure in tropical forest trees: implications for maintenance of species richness
Transcript of Colin R. Maycock 1, Penny Gardner 1, Eyen Khoo 2, Chris Kettle 3, Jaboury Ghazoul 3 & David F.R.P....
Colin R. Maycock1, Penny Gardner1, Eyen Khoo2, Chris Kettle3, Jaboury Ghazoul3 & David F.R.P.
Burslem11 University of Aberdeen2 Forest Research Centre, Sabah Forestry Department3 ETH, Zurich
Pollinator niche-partitioning among eight coexisting dipterocarp species in
Sabah
Linking life-history trade-offs to population
genetic structure in tropical forest trees:
implications for maintenance of species
richness
Background
• Coexisting dipterocarps partition available pollinators either in time (sequential flowering) or in space (differentiation of pollinator communities among dipterocarp species)
• Across dipterocarp species, pollinator body size correlates positively with flower size, pollinator foraging range and mean pollen dispersal distance
Key predictionsP
ollin
ator
bo
dy s
ize
Flower size
Specialized pollination systems
Methods
• Pollinator exclusion experiment
• Characterization of flower visitor communities
Location of study site• Trails
– 41 km of trails
• Plots– 68.5 ha Alluvial– 2 x 13.8 ha Sandstone– All reproductive Dipts
• 30 cm dbh canopy spp• 50 cm dbh emergent spp
Pollinator exclusion experiment• GPS trees with developing flower buds• Select trees
– maximize range of inter-tree distances– climbability (SRT & Doubled RT)
• 6 trees species (3 trees in 2006)• 3 treatments & a control
– Open pollination = all pollinators = control– 5 mm mesh bags ≠ large pollinators– 2 mm mesh bags ≠ medium & large pollinators – 0.2 mm mesh bags ≠ All pollinators = Apomixis
• 10 sets of bags per tree• Monitored weekly • 8 species
– S. xanthophylla, S. multiflora & S. leprosula = 2 flowerings
Flower visitors & pollinators• Flypaper traps• 24 hr sweep net
sampling• Flower collections• Direct observations• 3-5 trees/species
• Ordinal sorts• +/- pollen ongoing • Systematic descriptions
and an image library
a) At the end of anthesis
Calyx diameter (mm)
0 1 2 3 4 5 6 7 8 9 10 11 12
0.0
0.5
1.0
1.5
Pro
po
rtio
n o
f fl
ow
ers
rem
ain
ing
re
lati
ve t
o t
he
op
en t
reat
men
tS. multifloraS. xanthophyllaH. beccarianaS. leprosulaS. johorensisP. tomentellaS. smithianaD. grandiflorus
b) 1 month after the end of anthesis
Large flower visitors excluded
b) 1 month after the end of anthesis
Calyx diameter (mm)
0 1 2 3 4 5 6 7 8 9 10 11 12
0.0
0.5
1.0
1.5
Pro
po
rtio
n o
f fl
ow
ers
rem
ain
ing
re
lati
ve t
o t
he
op
en t
reat
men
tS. multifloraS. xanthophyllaH. beccarianaS. leprosulaS. johorensisP. tomentellaS. smithianaD. grandiflorus
a) At the end of anthesis
Large & moderate flower visitors excluded
Calyx diameter (mm)
0 1 2 3 4 5 6 7 8 9 10 11 12
0.0
0.5
1.0
1.5
2.0
Pro
po
rtio
n o
f fl
ow
ers
rem
ain
ing
re
lati
ve t
o t
he
op
en t
reat
men
tS. multifloraS. xanthophyllaH. beccarianaS. leprosulaS. johorensisP. tomentellaS. smithianaD. grandiflorus
All flower visitors excludeda) At the end of anthesis b) 1 month after the end of anthesis
Interpretation• 5 mm mesh
– D. grandiflorus & S. johorensis
• 2 mm mesh– D. grandiflorus, P. tomentella & S. smithiana,
& S. johorensis
• 0.2 mm mesh– D. grandiflorus, S. johorensis & P. tomentella– S. smithiana– Other spp.
• Why still getting seed set if excluding all flower visitors?
Calyx diameter (mm)
0 1 2 3 4 5 6 7 8 9 10 11 12
0.0
0.5
1.0
1.5
2.0
Pro
po
rtio
n o
f fl
ow
ers
rem
ain
ing
re
lati
ve t
o t
he
op
en t
reat
men
t
S. multifloraS. xanthophyllaH. beccarianaS. leprosulaS. johorensisP. tomentellaS. smithianaD. grandiflorus
b) 1 month after the end of anthesis
Thrips hawaiiensis
Ordinal sorts of sweep net samples
S. multi
flora
S. xan
thophyl
la
H. bec
caria
na
S. johore
nsis
S. lep
rosu
la
S. sm
ithia
na
P. tom
ente
lla0.0
0.2
0.4
0.6
0.8
1.0
Coleoptera Thrips Hymenoptera (excluding ants) Hemiptera Diptera Lepidoptera Other
Increasing flower size
Ideas• Dipterocarps probably have a generalized
pollination system– Thrips play a part, but so do other insects– Thrips are non-specific
• Different strategies in different species– S. leprosula
• Hand crossing suggests self-compatibility in this species • ~ 1.5 million flowers of S. leprosula receive pollen, but only
10,000s develop into fruit• Post-fertilization maternal selection?
– D. grandiflorus• Pre-fertilization self rejection?• E.g. Pollen-tube guidance mechanism
Acknowledgements• Forest Research Centre, Sabah Forestry Department • NERC - funding• EPU & EPUN – research permission
Jeisin teaching Chris HP techniques Anis and I practicing rescue techniques
Thank you - Any questions?
Most important outcome from the project;Marcolm DOB: 31st August 2007KK, Sabah
