Study suggests some resilience, but physiological responses need more study
By Summit Voice
FRISCO — Tropical forests may show resilience in the face of global warming, losing less biomass in response to greenhouse gas emissions than may previously thought, according to a new study published online this week in Nature Geoscience.
The results suggest that, while the risk of climate-induced damage to tropical forests will be relatively small, a lot more research is needed to quantify the physiological response of tropical forest ecosystems to climate change. The study was aimed in part at determining the future evolution of tropical rainforests — including the role they play in the global climate system and carbon cycle.
The research team included climate scientists and tropical ecologists from the UK, USA, Australia and Brazil and was led by Dr. Chris Huntingford, with the Centre for Ecology & Hydrology in the UK. The research team looked at computer simulations with 22 climate models to explore the response of tropical forests in the Americas, Africa and Asia to greenhouse-gas-induced climate change.
They found loss of forest cover in only one model, and only in the Americas. The researchers found that the largest source of uncertainty in the projections to be differences in how plant physiological processes are represented, ahead of the choice of emission scenario and differences between various climate projections.
“The big surprise in our analysis is that uncertainties in ecological models of the rainforest are significantly larger than uncertainties from differences in climate projections,” Huntingford said. “Despite this we conclude that based on current knowledge of expected climate change and ecological response, there is evidence of forest resilience for the Americas (Amazonia and Central America), Africa and Asia.”
“This study highlights why we must improve our understanding of how tropical forests respond to increasing temperature and drought,” said Leeds University professor David Galbraith.
“Different vegetation models currently simulate remarkable variability in forest sensitivity to climate change. And while these new results suggest that tropical forests may be quite resilient to warming, it is important also to remember that other factors not included in this study, such as fire and deforestation, will also affect the carbon stored in tropical forests. Their impacts are also difficult to simulate. It is therefore critical that modelling studies are accompanied by further comprehensive forest observations,” Galbraith said.