ENSO and frost codetermine decade‐long temporal variation in flower and seed production in a subtropical rain forest

Abstract

Summary Flower and seed production of plants can be greatly influenced by both natural climatic oscillations and local weather extremes. However, owing to the rarity of long‐term monitoring studies conducted at a sufficient temporal scale to capture climatic oscillations and the unpredictability of extreme weather events, evidence that demonstrates how these two external forcings act in concert to drive plant reproduction remains scarce. In addition, considerable variation in species' phenological responses to the external climatic forcings was often observed. Phylogenetic relationships may mediate this interspecific variation, but previous studies yielded inconsistent results when testing this hypothesis. We monitored the flower and seed production in a subtropical rain forest, Fushan, Taiwan (24°45′N, 121°35′E), for over 10 years (since September 2002). In March 2005, a record low temperature (−1.3 °C) occurred at Fushan and caused great frost damage to plants. We used weekly phenological records and long‐term meteorological data to assess the effects of climatic fluctuations and extreme weather event on plant reproductive output. We show that the El Niño Southern Oscillation (ENSO) indices, which integrated local climatic variables at Fushan over several months, were strongly associated with flower and seed production. The 2005 spring frost also had long‐lasting effects on the flower and seed production of several species. In particular, we detected phylogenetic signals in the relationships between phenological responses of flowering production and several climatic variables (maximum temperature, irradiance and ENSO34 index). By contrast, the relationships between seed production and climatic variables, as well as phenological responses to the frost event, did not exhibit a phylogenetic signal. Synthesis. Our findings add to the growing evidence that together the natural climatic oscillation (ENSO) and the extreme weather event (frost) determined the temporal variation in flower and seed production. In addition, phylogenetically closely related species resembled each other in their flowering responses to abiotic variation in this subtropical rain forest. Improved understanding of these abiotic and biotic interactions may help predicting population‐ and community‐level phenological responses under future climate changes.

Effects of hurricanes and climate oscillations on annual variation in reproduction in wet forest, Puerto Rico

“…Similar studies from Panama (Wright and Calderón ) and Taiwan (Chang‐Yang et al. , ) both showed direct effects of temperature, rainfall, and irradiance. Pau et al.…”

“…Reproduction is resource intensive and pollen and seed dispersal could be negatively influenced by unusual weather‐related disturbance events (e.g., Augspurger , Chang‐Yang et al. ). This is especially true of cyclonic storms, which severely damage forests and alter successional dynamics to leave legacies on forest structure and composition (Lugo , Brokaw et al.…”

Variation and synchrony of tree species mast seeding in an old‐growth temperate forest

“…; Chang‐Yang et al. ). In addition, further fieldwork on measuring more related parameters for flower production and seed predation rate could benefit our conclusions and understanding of mast seeding ecology.…”

“…; Chang‐Yang et al. ). Among the 71 mast‐seeding papers we reviewed, 57 (80.3%) focused on single species or a few phylogenetically closely related species, while only 14 (20%) studied multiple species, but in no more than five families (e.g.…”

Effects of El Niño on the population dynamics of the Malay civet east of the Wallace line

“…fruit or small mammal abundance) so we do not know how El Niños actually affected food resources on Buton. However, given that El Niño events have been linked to community‐wide increases in fruit production in other parts of the wet tropics, not only just in the dipterocarp forests of Peninsular Malaysia and Borneo (Ashton et al ., ; Curran & Leighton, ) but also on Barro Colorado Island (BCI) in Panama (Wright et al ., ; Wright & Calderón, ), and Taiwan (Chang‐Yang et al ., ) increased food availability is a plausible explanation for our results. The low capture rates we observed in surveys immediately following El Niño events is also consistent with the hypothesis of higher food availability.…”