3D 'cyberforests' created to predict effects of climate change

Washington, Feb 26: Scientists have created 'cyberforests' - computer simulation that grows realistic 3D forests down to the branches, leaves and roots of individual trees - to determine how drought, wildfires and other climate-related changes may affect real forests.

The model, called LES, uses computing power to grow 100x100-metre stands of drought and shade tolerant trees that can then be scaled up to actual forest size.

"It is a tool that forest managers can use to create 3D representations of their own forests and simulate what will happen to them in the future," said Nikolay Strigul, assistant professor at Washington State University (WSU) Vancouver in US.

It is the only forest-growing simulator that creates intricate root systems and canopy structures for each tree. Previous forest simulators could either grow one or the other. Below ground, the roots of different trees in LES compete for water resources in each pixel of the model.

Above ground, the leaves in each tree's canopy compete for sunlight in a similar fashion. Over time, the trees' canopies change shape to expose their leaves to more sunlight.

The researchers used a combination of data from the US Department of Agriculture's Forest Inventory and Analysis Programme and other forestry databases, as well as aerial reconnaissance from Unmanned Aerial Vehicles (UAV) or drones, to customise their model to particular forests.

The simulator lets scientists project how changing climate conditions will impact forests over thousands of years.

"In cooperation with the US Forest Service, we developed a method where we fly drones around a forest and take pictures and gather other imaging information," said Jean Lienard, a postdoctoral researcher at WSU. "We use this data to develop 3D models that have real distributions of space and ecological features," Lienard said.

For large parts of North America, climate change is leading to more frequent drought, warmer weather and other varying natural conditions, researchers found.

The researchers plan to use LES to help forest managers determine which species of trees and other ecological factors are necessary for forests to reestablish themselves after being destroyed by wildfires and other disturbances.

"The fear is that drier conditions in the future will prevent forests in places like Washington from reestablishing themselves after a clear-cut or wildfire. This could lead to increasing amounts of once-forested areas converted to desert," Strigul said. "Our model can help predict if forests are at risk of desertification or other climate change-related processes and identify what can be done to conserve these systems," he said.

The study was published in the journal Royal Society Open Science.

PTI