Rapid Shifts of Peak Flowering Phenology in 12 Species under the Effects of Extreme Climate Events in Macao

Jianhao Zhang,Tou I Chan,Dongming Liu,Ian Ian Ng,Chunyan Tang,Hongfeng Chen,Qifei Yi,Wen Ye,Fuwu Xing,Lin Wang

doi:10.1038/s41598-018-32209-4

Abstract

Plant phenology is sensitive to climate change; the timing of flowering has served as a visible indicator of plant phenology in numerous studies. The present study used phenological records from a manual monitoring program to characterize the flowering phenology of 12 species in Guia Hill, Macao. The mean peak flowering dates (PFDs) of these species ranged from March to September, 41.7% of which occurred in May. The earliest or latest PFDs of nine species occurred in 2013, a year with extremely heavy rain events in early spring. In addition, we found that, in the 5-year period, the monthly mean temperature or monthly precipitation in two periods, specifically 1) during November to December of the previous year and 2) during 0–2 months before the PFDs of each species, were significantly correlated with the PFD of eight species. The result showed that, even though complex species-specific responses to the characteristics of climate widely exist, most species in the present study responded to shifts in climate shifts in these two periods. In addition, some species were extraordinarily sensitive to extreme climate events. Precipitation was more effective in altering flowering date than temperature, especially among the late-flowering species in Guia Hill, Macao.

Highlights

Flowering events is observable, especially in southern subtropical forests where fully expanded leaves remain on many plants almost all year round, and senescence is not as distinct as happens in temperate areas
The peak flowering date (PFD) of two species (L. monopetala and Sterculia lanceolata) did not vary significantly in 2013 and lacked significant correlation with monthly precipitation (MP) or mean temperature (MMT) in the 5-year study period. This suggests that their PFDs are relatively insensitive to precipitation or temperature; perhaps a complex mechanism with genetic controls that is controlled by other environmental factors, such as photoperiod, etc
The PFDs of M. paniculatus and S. jambos were negatively and significantly correlated with both MMT and MP, but their PFDs did not advance significantly in 2013. This implies their PFDs could be advanced by abundant rainfall and warm weather within a certain range, but could be regulated and constrained by other biotic and abiotic factors; as a result, their PFDs were relatively stable under abnormal climatic conditions

Summary

Introduction

Flowering events is observable, especially in southern subtropical forests where fully expanded leaves remain on many plants almost all year round, and senescence is not as distinct as happens in temperate areas. In contrast with the gradual warming that is occurring along with climate change, extreme climate events are not necessarily a part of long-term climatic trends, such as heavy rainfall events, heat waves, or abnormal drought within several days or weeks; relatively few previous reports have addressed the effects of such events on phenology[31]. Both et al believed short-term extreme events had a more powerful effect on disturbing the synchronization of activities and phenology among organisms than gradual warming[32]. Some climate-sensitive species will be filtered out in the present study

Methods

Results

Conclusion