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Transcript
Species conservation strategies
Shorea lumutensis: genetic
variation and conservation
David Boshier, and SL Lee
Balau Putih – White Balau
© SL Lee
Shorea lumutensis
Sub-sessile fruits with three outer
and two inner wings
© SL Lee
Small hermaphrodite flowers
© SL Lee
© SL Lee
Endemic to Peninsular Malaysia
Shorea lumutensis is
restricted to Manjung
District, Peninsular
Malaysia, and confined to
five forest reserves.
Endangered as distribution
restricted & habitat
potentially threatened by
human activities.
Dry coastal hill dipterocarp forests
on moderate-fertility soils, in
microclimates where drainage is
good or where high soil moisture
levels cannot be permanently
maintained
© SL Lee
The number of large trees was estimated to be < 500 for these five populations
Threat – logging activities
(Segari Melintang FR)
© SL Lee
Threat – excavation of stone (quarry) & conversion
to oil palm plantation (Teluk Muroh FR)
© SL Lee
Threat – Land development for tourism
(Pangkor Selatan & Sg. Pinang FRs)
© SL Lee
Need for research
• Little was known about the biology of S.
lumutensis
• Research aimed to assess the
population ecology and population
genetics to elucidate specific
ecological and genetic requirements for
the species’ existence …
• … In order to subsequently develop
conservation strategies
Population
dynamics
Relatedness among
population
Demographic
structure
Gene flow &
mating system
Ecological
studies
Genetic
studies
Population survey
Flowering biology
Germination &
seedling studies
Effective breeding
unit
Minimum viable
population size
• Total of 416 individuals >1 cm dbh recorded within 8ha plot
200
160
(m)
120
80
40
0
0
40
80
120
160
200
240
280
320
360
400
(m)
• Density of S. lumutensis >30 cm dbh within plot, 4.4 trees/ha
Large number
of seedlings
scattered
around the
mature tree
© SL Lee
© SL Lee
Short-term population dynamics (2001-2004)
• 75 trees died over the 3-year study period
• Mortality was detected only at the two lowest-sized classes
• Growth was slow - 0.3mm/yr to 2.4 mm/yr
Seedling performance
One-year old
© SL Lee
Two-year old
© SL Lee
Conservation alternatives
• Preservation of actual diversity
• Conservation of evolutionary
potential
• Mantain options for future
generations, while satisfying present
needs
How big is “big enough”?
• 50/500 rule (Franklin 1980)
• 50 - inbreeding depression to acceptable level
• 500 - sufficient for new variation from mutation to
replace that lost by genetic drift
• refers to effective population size (Ne) rather than
survey numbers (N) – so may need many more!
• in trees Ne smaller than N due to: overlapping
generations, dioecy, asynchronous flowering,
fecundity differences between individuals
Where should we conserve?
In situ - Ex situ
In situ - reserve system of undisturbed,
protected areas within natural distribution
(ecosystem based)
Ex situ - artificial maintenance of populations
outside natural distribution (species based)
15
Conservation of biodiversity
in situ : trees as a paradigm
Ideal reserve model
Emphasis: large, continuous, protected areas
Limitations: location, size, security, biology:
–
–
–
–
Movement of animals
Extensive distribution of many species
Gene flow between populations
Upland, non agricultural areas
Essential but not sufficient
16
Conservation of biodiversity ex
situ : methods and limitations
seed banks - problems of regeneration
plantations - changes in gene frequencies, few
populations
botanical gardens - deficiencies for gene pool
conservation
17
© RBG Kew
© RBG Kew
Conservation of biodiversity ex
situ : methods and limitations
- useful, but resources limit application to few
species (usually commercial)
- last gasp holding for highly endangered species
- complementary to other approaches
Conservation of alleles
• common - rare
what proportion?
• widespread - localised
what scale?
common
rare (<0.05)
widespread
easy
sample size
localised
key
luck
Widespread vs locally common alleles
Allele a
b
c
d
Pop 1
0.500
0.250
0.230
0.020
frequency
2
3
0.320 0.450
0.030 0.050
0.400 0.450
0.250 0.050
4
0.550
0.050
0.350
0.050
Figure 2: Dendrogram of genetic similarities between the five populations of Shorea
lumutensis (bootstrap % values on branches based on 1000 replications).
Table 3. Geographic distance (in km) for the five S. lumutensis populations.
How many conservation areas are
required?
Exists in five
populations
<500 large trees
High levels of
genetic diversity
Low population
differentiation
Conservation strategies: in situ conservation?
• Selection of in situ gene conservation areas
• How many conservation areas are required?
• How large does each conservation area need to be?
• How should conservation areas be designed?
• Monitoring?
• Management?
Conservation strategies: ex situ conservation?
• How?
• Where?
• Who?
Shorea lumutensis
each group summarize on wall chart paper
or PowerPoint
Remember
need a conservation objective
prioritise actions – resources are limited
list the localised but common alleles?
list problems by type
- genetic, which pops. too small? which are different?
- other types of problems
which conservation methods - in situ, ex situ?
who? will do, what? where?
how will you pay for it?
© SL Lee
© SL Lee
© SL Lee
Ghazali Jaafar, Yahya Marhani, Mariam Din and Sharifah Talib for
field and technical assistance.
The late Baya Busu, Ramli Punyoh, Mustapa Data, Ayau Kanir,
Apok Kassim and Angan Atan for field assistance
Pn. Hamidah Mamat (FRIM) helped draw the maps.
© SL Lee
© SL Lee
© SL Lee