Czech forest helps NASA scientists plot climate change

The Žofín forest in South Bohemia belongs among the oldest protected nature reserves in Central Europe. This unique woodland, which has been protected for more than 180 years, has now become a focus of research carried out by the US space agency NASA. They want to use the data collected in the forest to compare it with measurements taken from space. That could enable them to get a more accurate picture of the Earth’s surface.

Photo: Petr Kološ

The Žofín forest, located in Novohradské Hory near the border with Austria, was declared a protected area already in 1838. Its oldest trees, mostly giant spruces and firs, are up to 400 years old. The primeval forest has developed more or less without any human intervention for nearly 180 years and presents an ideal site for scientists who want to study the life cycle of plants.

The US space agency NASA has chosen to scan the Žofín forest as part of their global project called GEDI, or the Global Ecosystem Dynamics Investigation. The project aims to produce the first high-resolution laser ranging observations of the 3D structure of the Earth, which will enable scientists to better understand how the Earth behaves as a system.

Experts from NASA have chosen the Žofín forest not just because of its unique history, but also to cooperate with Czech scientists, who have been studying the location for many years now. Casey Koshwin is an expert from Brown University, who is cooperating on the research with NASA:

“The other reason why we chose the Žofín forest is to work with Czech scientists, who have been carrying out research here. They have data from laser scanning on the ground that provides very detailed measurements of the tree structures. It is useful for us to compare with data that we collect from the helicopter today.

Tomáš Vrška, photo: archive of Mendel University in Brno

“They have a lot of really novel methods using lasers to study tree structure. The software that they are developing is very unique: to be able to take this so-called point cloud with millions of laser measurements and to break it up into individual trees that allows us to measure the biomass of individual trees - that’s a very cutting edge thing that has been done here.”

NASA’s GEDI project has already been carried out in other parts of the world, including Alaska and Africa’s Gabon, but experts lacked the precise data from ground measurements which they could then compare with the satellite measurements. This is why they focused their attention on the Žofín forest.

The Czech 3D forestry-data software has been developed for several years now by experts from the Department of Forest Ecology at the Silva Tarouca Research Institute, just outside Prague. Tomáš Vrška, the head of the department, outlines more details about its development:

“Our advantage is that we started to collect the data early and we started to produce the 3D Software. Our colleagues are currently making some amendments to the software along with our US colleague from Brown University.

“If everything goes according to plan, this software could be used to measure tree parameters for the whole GEDI project. That means NASA could use our software, and that is something that doesn’t happen every day.”

Last week, Czech experts from the Silva Tarouca Research Institute, along with their colleagues from Brown University and a Swiss company from Luzern specializing in terrain mapping, met in the midst of the Žofín forest to start gathering the data for NASA’s GEDI project.

Photo: Petr Kološ

The data was collected both on the ground as well as from the air, with the help of a special helicopter. Tomáš Vrška was one of the people in the field:

“This pilotless helicopter is operated by the company Aeroscout from Switzerland’s Luzern. It has a scanner attached to the underframe which is mapping the forest from a height of about 100 meters.

“It scans all the trees in the forest with a preciseness of 5000 points per square meter, which is a really unique density. So the data will be really valuable, because they will enable us to create a very precise 3D picture.”

The measurements collected at the Žofín forest will be processed afterwards both by Czech and US experts. The data from the ground scanner will be analysed by scientists at the Silva Tarouca Institute, while the measurements from the air will be processed at Brown University in the US.

The results will then be compared with the data acquired by NASA from the International Space Station, 410 kilometres above the Earth. That will determine the extent of inaccuracies connected with measurements from space and will enable experts to make their future measurements more precise.

So what will be the practical use of the data collected in the Žofín Forest in South Bohemia? Tomáš Vrška once again:

“As for our territory, we will acquire new data about the primeval forest and about the whole structure of the nature reserve. We will get answers how a mixed forest with a prevalence of oaks functions in Central European conditions. Until now, we couldn’t answer these questions, because we didn’t have the necessary data. So this is really unique.”

On the global level, GEDI aims to produce the first high-resolution observations of the Earth’s surface structure, which will be useful for weather forecasting, forest management, and monitoring of glaciers and snow layers in high altitudes. Casey Koshwin, an expert from Brown University, outlines more details:

Photo: Petr Kološ

“The end goal hopefully is to learn more how much carbon is stored in forests around the world and also how forests respond to climate change. It’s very important for understanding global climate and climate change.

“We make a lot of carbon when we burn fossil fuels and we think that a lot of that is currently being stored and taken back from the atmosphere by forests. However, we don’t know exactly where that’s happening and we also don’t know how long this will continue.

“It’s important to monitor forests around the world to learn more about tree growth and tree death and all of these other processes.”

Another scanning of the Žofín forest is planned for the summer, when the trees have already grown leaves. Using the know-how from the Czech Republic, the experts would then like to move their research in rainforests. The complete software that enables precise forest measurements from space is expected to be available in about five years’ time.