Flowering and fruiting phenology of a subtropical rain forest, Fushan, Taiwan 張楊家豪 1 、呂佳陵 1 、孫義方 2 、謝長富 1 1 臺灣大學生態學與演化生物學研究所 2 東海大學熱帶生態學與生物多樣性研究中心

Introduction Phenology is the study of the recurrent biological events, the causes of the timing with regard biotic and abiotic forces, and the interralation among phases of the same species or different species. (Lieth 1974) Plant reproductive patterns have a major impact on the temporal structure of a community. (Bawa 1983; Herrera 1986) The activity of pollinators, frugivores, and flower and fruit predators The timing of seed dispersal, seed germination The breeding periods of many animals

Introduction In seasonal environments the timing of fruiting and flowering is usually correlated with climatic conditions. Photoperiod (Heinrich 1976) Temperature (Arroyo et al 1981; Smith-Ramirez and Armeto 1994) Precipitation (van Schaik et al 1993) Irradiance (van Schaik et al 1993; Hamann 2004; Zimmermann 2007) Few records exist for Taiwan and no attempts have been made to evaluate reproductive phenology at the community level over an extended period of time.

Introduction The climate in Fushan exhibits a clear seasonality in temperature and irradiance but not in precipitation. average temperature: 18.2 ℃ annual precipitation: 4271 mm The objectives of this research: Understand the flowering and fruiting patterns of the subtropical rain forest in Fushan Evaluate the relationship between reproductive activity and climatic factors (irradiance and temperature)

Data Collection 87 seed traps in the Fushan Forest Dynamics Plot Established in Aug Surface area: 0.5 m 2 Trap mesh: 1.6 mm All reproductive parts (flowers, fruit, seeds) were sorted, counted, and identified to species each week Sept – Aug (260 weeks)

The locations of 106 seed traps

Quantitative phenological records Flower production No. of traps with flower collected in each month for each species Seed production No. of seeds collected in each month for each species All analyses were restricted to species with ≥ 10 records and encountered in ≥ 5 traps.

Data analysis Flowering and fruiting phenology Circular vector algebra (Batschelet 1981; Wright and Calderon 1995) Relationship between reproductive activity and climatic factors Time series cross correlation (Zar 1999; Zimmerman et al 2007) Correspondence analysis

Flowering and fruiting phenology Mean flowering and fruiting dates Vector algebra (Batschelet 1981; Wright and Calderon 1995) mean vector

Periodicity of flowering (fruiting) phenology Autocorrelation analyses ( Zimmerman et al, 2007) lag = 0 r = 1 lag = 1 r = lag = 6 r = lag = 12 r = 0.712

Periodicity of flowering (fruiting) phenology Autocorrelation analyses (Zimmerman et al, 2007) annual biannual supra-annual continuous

Regularity of flowering (fruiting) phenology vector length = 0.99 Second mean vector (Hamann 2004) Annual and supra-annual Irregular intervals: vector length < 0.7

Mean flowering dates n = 44 species

annual: 41 species annual but irregular: 1species biannual: 2 species

Mean fruiting dates n = 28 species

annual: 19 species continuous: 1species supra-annual & regular : 4 species irregular: 4 species

Relationship between the reproductive activity and climatic variables Cross correlation analyses (Zar 1999; Zimmerman et al 2007) Community-level reproductive patterns No. of species with peak reproductive activity Fewest months comprised ≥ 75% of total records Climatic variables (1992 – 2006) Temperature Growing Degree Index (GDI) T avg – T base 1, 3, 6-month GDI

Community-wide peak months of reproductive activity Flowering Fruiting

Cross-correlation: Flowering vs 1-month GDI

Cross-correlation: Flowering vs Temperature change

Cross-correlation: Fruiting vs 1-month GDI

Cross-correlation: Fruiting vs 3-month GDI

Cross-correlation: Fruiting vs 6-month GDI

Glochidion acuminatum (Euphorbiaceae) Machilus thunbergii (Lauraceae)

Pyrenaria shinkoensis (Theaceae) Myrsine seguinii (Myrsinaceae)

Correspondence Analysis

Summary The flowering and fruiting phenology exhibit a clear seasonality. Most species are annual flowering and fruiting. No. of species peak flowering are positively correlated with monthly temperature changes. No. of species peak fruiting are positively correlated with 6-month growing degree index. Frost occurring in 2005 affected the fruit production of many species.

Acknowledgements 2004 – 2005 林試所林業科技委辦計畫 福山亞熱帶雨林永久樣區設置與幼苗更新狀態之研究 2006 林務局委託研究計畫 台灣北部福山地區亞熱帶雨林種子雨之研究 2006 林務局委託研究計畫 台灣北部福山地區亞熱帶雨林小苗短期動態之研究 2007 林務局委託研究計畫 台灣北部福山地區亞熱帶雨林種子雨與喬木小苗動態之研究 林試所 蘇聲欣 先生 林試所福山研究中心 福山樣區調查團隊 臺灣大學 黃思博 黃雅怡 林均雅 族繁不及備載的調查義工們

Mean flowering and fruiting dates Vector algebra (Batschelet 1981) mean vector angle mean vector length

Cross correlation: Flowering vs Irradiance

Temperature vs Irradiance