The circular nature of recurrent life cycle events: a test comparing tropical and temperate phenology

Author(s)

Staggemeier, Vanessa Graziele ^{[1, 2]} ; Gutierrez Camargo, Maria Gabriela ^[1] ; Felizola Diniz-Filho, Jose Alexandre ^[3] ; Freckleton, Robert ^[4] ; Jardim, Lucas ^[3] ; Cerdeira Morellato, Leonor Patricia ^[1]

Affiliation

^[1] Univ Estadual Paulista UNESP, Grp Fenol Dispersao Sementes, Inst Biociencias, Dept Bot, Rio Claro - Brazil

^[2] Univ Fed Rio Grande do Norte, Dept Ecol, Ctr Biociencias, BR-59078970 Natal, RN - Brazil

^[3] Univ Fed Goias, Dept Ecol, Lab Ecol Teor & Sintese, Goiania, Go - Brazil

^[4] Univ Sheffield, Dept Anim & Plant Sci, Sheffield, S Yorkshire - England

• Document type: Review article
• Source: JOURNAL OF ECOLOGY; v. 108, n. 2, p. 393-404, MAR 2020.
• Web of Science Citations: 4

Abstract

1. The high diversity of plant species in the tropics has revealed complex phenological patterns and reproductive strategies occurring throughout the year. Describing and analysing tropical plant phenology, and detecting triggers, demands to consider the circular nature of recurrent life cycle events and the use of appropriated statistical metrics. 2. Here, we explore analytical pitfalls potentially affecting results of studies that do not consider the circular nature of phenology data when comparing resting and non-resting systems, especially when accounting for phylogeny. We discuss definitions of the widely used first flowering date and revisit the literature on phylogenetic signal in plant phenology. We compare statistical analyses for tropical and temperate phenology by simulating communities with known phenological and phylogenetic structures. 3. We demonstrate that ignoring the circular nature of phenological data underestimates the phylogenetic signal in plant phenology. Using the proposed circular transformation for non-resting tropical ecosystems and resting temperate systems prevented errors, yielding precise comparisons. 4. Synthesis. The analysis of both non-resting and resting systems must consider the circularity of phenological events. Circular statistics is the appropriate approach to calculate phenological parameters, identify phylogenetic signal and assess drivers, allowing accurate cross-comparisons of phenology across environments at large spatial scales. (AU)

• FAPESP's process: 16/02312-8 - Combining plant distribution and phenology to predict the potential effects of climate change in the tropics
• Grantee: Vanessa Graziele Staggemeier
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor
• FAPESP's process: 14/13899-4 - Phenology and phylogenies as tools to understand the effects of climate changes in the tropics
• Grantee: Vanessa Graziele Staggemeier
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 15/10754-8 - Spatio-temporal variations in the flower-color spectra according to the pollinators' visual systems
• Grantee: Maria Gabriela Gutierrez de Camargo
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 18/14118-7 - Phenology 2018: One Planet, Two Hemispheres, Many regions
• Grantee: Leonor Patricia Cerdeira Morellato
• Support Opportunities: Research Grants - Meeting - Abroad
• FAPESP's process: 13/50155-0 - Combining new technologies to monitor phenology from leaves to ecosystems
• Grantee: Leonor Patricia Cerdeira Morellato
• Support Opportunities: Research Program on Global Climate Change - University-Industry Cooperative Research (PITE)