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 siteSeasonalityCrop produced per year Crop duration reference Hong KongContinuous production1-5 crops, most monthsHill 1967 SingaporeNo clear pattern2-6 crops (mean 4.4) 30 daysCorlett 1984 TaipeiContinuous production with main peaks 0-4 crops, Most days inHsieh 1992 Sao Carlos (Brazil) Continuous production2.26±0.81 crops110.75daysFigueiredo et al Brisbane (Australia) Female phase:late spring peak Male phase:more present in warmer months No records Mcpherson 2005 TaipeiContinuous production with main peaks 5.4 ± 2.7 crops, (mean 4.7) 5-10 weeksHuiwen Yang 2011

Why flowering phenology variation in different study sites? Temperature Precipitation Sunlight hours ……

Guangzhou Townsville Climatic change in the last three decades The two edges of its range

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 Methods

Fig.1 The flowering phenology for ten individuals of F.microcarpa over 18 months growing in Guangzhou. 1-4crops Crop length 1-2months Intra-tree asynchronous flowering

Fig.2 The flowering phenology for eight individuals of F.microcarpa over 11 months growing in Townsville. 1-3crops Crop length 30 days Intra-tree asynchronous flowering rarely occurred

Table 1 Correlation between the number of syconia of five de velopmental phases of F.microcarpa and climatic factors CropsAverage temperature Rainfall sunlight hours A phase B phase C phase D phase0.702* E phase 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. CropsAverage Max.temperature Average min.temperature A phase * * B phase * * C phase * * D phase E phase 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

Foundress

DiameterFemale flowers Male flowers Seeds (%) Wasps (%) Non- pollinators (%) Guangzhou 10.37± ± ± Townsville 11.48± ± ± Table 3 Comparison of syconium characteristics in F.microcarpa in two sampling sites

GuangzhouTownsville DecemberMarchJuneSeptemberMayNovembe r seeds 5.15± ± ± ±19.28**89.38± ±34.55 wasps 40.13±22.57*28.24±18.94*59.95±26.16*86.20±24.46**74.10± ±44.99 Table 4 The mean number of seeds and wasps produced per syconium in different months (±SD) 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.