Leafing Patterns and Drivers across Seasonally Dry Tropical Communities

Author(s)

Alberton, Bruna ^[1] ; Torres, Ricardo da Silva ^[2] ; Sanna Freire Silva, Thiago ^[3] ; da Rocha, Humberto R. ^[4] ; Moura, Magna S. B. ^[5] ; Morellato, Leonor Patricia Cerdeira ^[1]

Affiliation

^[1] Univ Estadual Paulista Unesp, Inst Biociencias, Lab Fenol, BR-13506900 Rio Claro, SP - Brazil

^[2] Univ Estadual Campinas, Inst Comp, BR-13083852 Campinas, SP - Brazil

^[3] Univ Stirling, Biol & Environm Sci, Stirling FK9 4LA - Scotland

^[4] Univ Sao Paulo, Inst Astron Geofis & Ciencias Atmosfer, BR-05508090 Sao Paulo - Brazil

^[5] Embrapa Semiarido, Empresa Brasileira Pesquisa Agr, BR-56302970 Petrolina, PE - Brazil

• Document type: Journal article
• Source: REMOTE SENSING; v. 11, n. 19 OCT 2019.
• Web of Science Citations: 0

Abstract

Investigating the timing of key phenological events across environments with variable seasonality is crucial to understand the drivers of ecosystem dynamics. Leaf production in the tropics is mainly constrained by water and light availability. Identifying the factors regulating leaf phenology patterns allows efficiently forecasting of climate change impacts. We conducted a novel phenological monitoring study across four Neotropical vegetation sites using leaf phenology time series obtained from digital repeated photographs (phenocameras). Seasonality differed among sites, from very seasonally dry climate in the caatinga dry scrubland with an eight-month long dry season to the less restrictive Cerrado vegetation with a six-month dry season. To unravel the main drivers of leaf phenology and understand how they influence seasonal dynamics (represented by the green color channel (Gcc) vegetation index), we applied Generalized Additive Mixed Models (GAMMs) to estimate the growing seasons, using water deficit and day length as covariates. Our results indicated that plant-water relationships are more important in the caatinga, while light (measured as day-length) was more relevant in explaining leafing patterns in Cerrado communities. Leafing behaviors and predictor-response relationships (distinct smooth functions) were more variable at the less seasonal Cerrado sites, suggesting that different life-forms (grasses, herbs, shrubs, and trees) are capable of overcoming drought through specific phenological strategies and associated functional traits, such as deep root systems in trees. (AU)

• FAPESP's process: 14/00215-0 - Remote phenology and leaf exchange patterns towards a sazonality gradient
• Grantee: Bruna de Costa Alberton
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 09/54208-6 - Multi-User Centralized Laboratory at the São Paulo State University Center for Biodiversity Studies
• Grantee: Célio Fernando Baptista Haddad
• Support Opportunities: Multi-user Equipment Program
• FAPESP's process: 15/50682-6 - Climate-smart watershed investments in the montane tropics of South America (ClimateWise)
• Grantee: Humberto Ribeiro da Rocha
• Support Opportunities: Research Program on Global Climate Change - Thematic Grants
• 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)
• FAPESP's process: 10/52113-5 - e-phenology: the application of new technologies to monitor plant phenology and track climate changes in the tropics
• Grantee: Leonor Patricia Cerdeira Morellato
• Support Opportunities: Research Program on Global Climate Change - Regular Grants
• FAPESP's process: 16/01413-5 - Using leaf phenology patterns to investigate net ecosystem exchange controls in tropical vegetations
• Grantee: Bruna de Costa Alberton
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate