Tropical forest response to temperature: a pantropical synthesis of elevation gradients, and leaf thermoregulation studies


Tropical forest response to temperature: a pantropical synthesis of elevation gradients, and leaf thermoregulation studies

Part 1: Tue, July 12, 10:30 - 12:30 hrs, Room: Barahona 4

Part 2: Tue, July 12, 14:00 - 16:00 hrs, Room: Barahona 4


Lina Mercado, Patrick Meir, Eric M Dusenge

This session synthesizes new research on the response of tropical forest trees to temperature with particular focus on new elevation gradient studies in tropical montane and lowland forests in Costa Rica, Puerto Rico, Panama, Colombia, Peru, Brazil, Rwanda, and Australia and leaf thermoregulation studies.

Tropical forests play a crucial role in the global carbon budget, accounting for more than half of terrestrial net primary production and storing around 40% of plant biomass, yet unprecedented climate shifts are predicted this century in tropical regions. Tropical forests around the world are increasingly experiencing significantly warmer climates relative to their recent historical climate regimes. Despite this urgent climate change context we have little understanding of what current temperatures are experienced by leaves, the temperature at which the main processes controlling productivity such as photosynthesis and respiration occur, and in particular the limits of thermal tolerance for tropical forest species still relatively unknown. This knowledge is needed to predict response to climate change in these forests over the coming decades. Current and predicted temperature rises are far more rapid than experienced in the recent past and currently-established trees will experience these new climatic conditions. Therefore, the performance and persistence of existing tropical forest trees over this century depends on their ability to either tolerate warmer climates, acclimate their physiology to higher temperatures or, via dispersal, migrate to new climates. Elevation gradients provide ideal natural laboratories for investigating temperature responses of montane forest species. There is now a set of elevation gradient studies set up across the global tropics to study temperature responses of tropical forest trees. Here we report on early findings from these key studies, focusing on the fundamental energy balance of tropical leaves, on plant growth, physiology and survival and on plant-soil interactions. The aims of this symposium are -To synthesize and integrate ongoing research on elevation gradients across the global tropics in order to assess current and future tropical forest responses to changes in temperature at different locations, for plants of different ages, successional stages and across a wide range of species. Particular focus will be given to temperature responses of tree growth, both mature and juveniles, photosynthesis, respiration, leaf temperature and thermal tolerance, with some integrated studies also addressing soil and plant processes together. -To gather members of the scientific community currently investigating temperature responses of tropical forest in order to share findings, methodologies, challenges and developments within this community, with a view to better fundamental understanding and improved model-based prediction under future climate scenarios.

Using transplant experiments to understand the effects of climate change on trees and crops in the tropical Andes
Kenneth Feeley*, Heraldo Vasconcelos and Richard Tito Leon

Andean dominant tree species respond differently to global warming: Insights from field experiments
Zorayda Restrepo*, Lina Mercado, Iain Hartley, Sebastian Gonzalez-Caro and Juan Camilo Villegas

Water-use strategies under heat stress and their impact on growth and mortality of Rwandan tropical trees
Maria Wittemann*, Myriam Mujawamariya, Bonaventure Ntirugulirwa, Etienne Zibera, Donat Nsabimana, Göran Wallin and Johan Uddling

Photosynthetic thermal acclimation capacity of tropical montane rainforest trees in Rwanda and in the Colombian Andes
Mirindi Eric Dusenge*, Maria Wittemann, Myriam Mujawamariya, Lasse Tarvainen, Etienne Zibera, Bonaventure Ntirugulirwa, Danielle Way, Donat Nsabimana, Johan Uddling, Göran Wallin, Lina Mercado, Zorayda Restrepo, Sebastian Gonzalez-Caro, Patrick Meir and Adriana Sanchez

Physiological acclimation and leaf temperature proximities to thermal thresholds across a Puerto Rican forest
Kelsey Carter*, Tana Wood, Sasha Reed, Kaylie Butts and Molly Cavaleri

Diurnal variation of photosynthetic rate on tropical montane tree species
Sebastian Gonzalez-Caro*, Lina Mercado, Eric M Dusenge, Andrew Cox and Mirindi Eric Dusenge

Leaf thermoregulation in the world’s hottest tropical rainforest
Sean Michaletz*, Sandra Duran, Vanessa Buzzard, Steven Leavitt, Nate McDowell, Scott R. Saleska, Joost van Haren, Peter Troch and Brian Enquist

Long-term drought effects on the thermal sensitivity of Amazon Forest trees
Emma Docherty*, Emanuel Gloor, Daniela Sponchiado, Martin Gilpin, Carlos Pinto, Haroldo Junior, Ingrid Coughlin, Leandro Ferreira, João Junior, Antonio da Costa, Patrick Meir and David Galbraith

Investigating the effects of higher temperatures on Cerrado tree reproduction
Georgina Werkmeister*, David Galbraith, Milene Alves, Márcia Cardoso da Silva, Jairo Matos da Rocha, Paulo Alves da Silva, Bruno Gonçalves Lopes, Daniel Ferreira de Oliveira, Regiane Batista Santos, Denilson Mendes Santos, Beatriz Marimon, Ben Hur Marimon Júnior, David Ashley, Santiago Clerici, Oliver Phillips and Emanuel Gloor

Photosynthetic thermal optima controlled by stomatal conductance in six subtropical species and do not acclimate across an urban thermal gradient.
Alyssa Kullberg*

The importance of tree species traits for leaf temperature regulation – observations from three forest types in China
Sophie Fauset*