Transcript Fig phenology:correlation to climate factors As in many other studies

Phenological characteristics
of Ficus microcarpa
under climate change
Shuling Lin
School of Geographical Sciences,
Guangzhou University

Relationship between plant phenology
and climate change has become an
important topic under global climate
warming.

Phenology is a plant growth progress that is
largely driven by meteorological conditions.

Phenological changes are vital indicators for
changes in climate and other enviromental
conditions.
750 fig species



Africa
America
Asia-Oceania
Weiblen 1999
Syconium

Urn-shaped and enclosed
infloresences

Highly specific fig wasps for
polliation
Fig and fig wasp life cycle

Figs rely on fig wasps for transmission
of their pollen, and also rely on birds
for seed dispersal.

The impact of climate change on fig
tree phenology and population
dynamics of fig wasps and birds.
Ficus microcarpa

Wide geographic distribution in tropical and
subtropical areas

Native to India,South China, Malaysia,
Melanesia,and Australia

Northern edge, Guangzhou, China

Southern edge, Townsville, Australia
Phenological studies conducted in different
locations provide an opportunity for a
comparsion
Phenology studies on F.microcarpa
Study site
Seasonality
Crop produced
per year
Crop
duration
reference
Hong Kong
Continuous production
1-5 crops,
most 1-3
1-4 months
Hill 1967
Singapore
No clear pattern
2-6 crops
(mean 4.4)
30 days
Corlett 1984
Taipei
Continuous production with
main peaks
0-4 crops,
Most 2-3
26 days in
Hsieh 1992
Sao Carlos
(Brazil)
Continuous production
2.26±0.81 crops
110.75days
Figueiredo
et al. 1995
Brisbane
(Australia)
Female phase:late spring peak No records
Male phase:more present in
warmer months
No records
Mcpherson
2005
Taipei
Continuous production with
main peaks
5-10 weeks
Huiwen
Yang 2011
5.4±2.7 crops,
(mean 4.7)
Why flowering phenology variation
in different study sites?
•
•
•
•
Temperature
Precipitation
Sunlight hours
……
The two edges of its range
40
300
35
Temperature ( ℃ )
200
25
20
150
15
Rainfall (mm) 1
250
30
mean max temperature
mean min temperature
Guangzhou
mean monthly precipitation
100
10
50
5
0
0
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Month
40
300
35
250
200
25
20
150
15
Rainful (mm)
Temperature(℃)
30
mean max temperature
mean min temperature
mean momthly precipitation
Townsville
100
10
50
5
0
0
Jan
Feb
Mar
Apr
May
Jun
Jul
Month
Aug
Sep
Oct
Nov
Dec
Climatic change in the
last three decades
Methods

8-10 individual trees

1-2 weeks

the stage of syconium Develpoment and the duration of
phases

50 ripe figs collected randomly per fruiting trees

flowering patterns of F.microcarpa in different environments

the correlation between climate factors and syconia quantity
1-4crops
Crop length 1-2months
Intra-tree asynchronous flowering
Fig.1 The flowering phenology for ten individuals of
F.microcarpa over 18 months growing in Guangzhou.
1-3crops
Crop length 30 days
Intra-tree asynchronous flowering
rarely occurred
The relative proportion of each phase 1
on sampling trees (%)
70
60
A
B
50
D
E
C
40
30
20
10
2007
F-30
J-30
D-30
N-30
O-30
S-30
A-30
J-30
J-30
M-30
A-30
M-30
0
2008
Fig.2 The flowering phenology for eight individuals of
F.microcarpa over 11 months growing in Townsville.
Table 1 Correlation between the number of syconia of five de
velopmental phases of F.microcarpa and climatic factors
Crops
Average
temperature
Rainfall
sunlight hours
A phase
0.334
0.136
0.178
B phase
0.268
0.198
0.142
C phase
0.252
-0.263
0.165
D phase
0.702*
0.055
0.379
E phase
0.502
-0.118
0.271
An asterik (*) denotes mean differents is significant at 0.05 level.
Table 2 Correlation between temperature and the relative pr
oportions of each stage on trees at different times.
Crops
Average
Average
Max.temperature min.temperature
A phase
-0.596 *
-0.558 *
B phase
-0.522 *
-0.458 *
C phase
-0.488 *
-0.433 *
D phase
-0.249
-0.053
E phase
-0.373
-0.206
An asterik (*) denotes mean differents is significant at 0.05 level.
Fig phenology:correlation to climate factors

As in many other studies, temperature played a
determinant role in fig phenology. The number of
syconia in each phase showed a positive correlation
with temperature, especially male phase.

Male phase was correlated with sunlight hours.
This indicates that a temperate climate seems
favorable for wasp dispersal.
Fig phenology:correlation to climate factors

The proportion of A, B, C fig stages was
significantly related to low temperature
(Table 2), indicating the these stages of fig
development were prolonged in the cool and
dry months.
Fig phenology:correlation to climate factors

Rainfall is also important for syconia
development.

There was not direct correlation between
male phase and rainfall. Ficus might avoid
growing into male phase during heavy
rainfall to benefit wasp dispersal.
Fig phenology:correlation to climate factors

This study found a positive correlation between receptive
syconia and rainfall.

Response of receptive phase to rainfall seems disadvantageous
for pollinator arrival. However, unpollinated syconia remain
receptive for one to two weeks. Overlap between male- and
female-phase might reduced both the pollen waste and
abortion probability of receptive syconia.
Hypothesis was presented

Janzen's hypothesis of adaptations to
seasonality was tested and criticized.

Within-tree asynchronous flowering was
adaptation to adverse conditions，including
low temperature，heavy rainfall，gale etc.
Style length
Style length
(mm)
the ovipositor length of
pollinating wasps (mm)
Guangzhou
0.85±0.38
1.02±0.05
Townsville
0.95±0.32
1.11±0.06
300
250
Frequency
200
Guangzhou
Townsville
150
100
50
0
0.0
0.2
0.4
0.6
0.8
1.0
1.2
Style length (mm)
1.4
1.6
1.8
2.0
Foundress
120
2.7
100
Guangzhou
Townsville
Frequency
80
1.6
60
40
20
0
0
1
2
3
4
5
6
Foundress
7
8
9
10
11
12
Table 3 Comparison of syconium characteristics in
F.microcarpa in two sampling sites
Diameter
Female
flowers
Male
flowers
Seeds
(%)
Wasps
(%)
Nonpollinators
(%)
Guangzhou
10.37±0.55 262.58±46.69
24.09±9.86 16.58
24.22
11.98
Townsville
11.48±0.79
29.23±6.22 24.35
32.57
0.25
310.57±40.13
Table 4 The mean number of seeds and wasps produced per
syconium in different months (±SD)
Guangzhou
Townsville
December
March
June
September
May
Novembe
r
seeds
5.15±6.37
4.09±6.68
10.63±8.16
28.77±19.28**
89.38±10.08
72.93±34.55
wasps
40.13±22.57*
28.24±18.94*
59.95±26.16*
86.20±24.46**
74.10±17.03
118.06±44.9
9
Note:*and**indicates significant different at 0.05 and 0.01 level, respectively.


The phenology of F.microcarpa can be
influenced by biotic and abiotic factors,
other climatic factor may also play a part.
Seed and wasp development are
temperature dependent.


The phenology of F.microcarpa can be
influenced by biotic and abiotic factors,
other climatic factor may also play a part.
Seed and wasp development are
temperature dependent.