NASA scientists find tundra vegetation will be taller and greener by 2100

Global warming changed the structure of vegetation in the forests of the far northA trend that, according to NASA researchers, will continue at least until the end of this century.

The change in forest structure could be more carbon dioxide (CO2), a greenhouse gas, from the atmosphere Recording Or increase the thawing of permafrostwas to Release of old carbon Millions of data points from the Ice, Cloud, and land Elevation Satellite 2 (ICESat-2) and Landsat missions contributed to this latest research, which will be used to refine computer models for climate predictions.

The tundra landscapes are becoming higher and greener.

With the warming of the climate The vegetation in the forests of the far north is changing as more trees and shrubs appearThese changes in the vegetation structure of the boreal forests and tundra will continue for at least the next 80 years, NASA scientists said in a recently published study.

Boreal forests generally grow between 50 and 60 degrees north latitude and cover large parts of Alaska, Canada, Scandinavia, and Russia. Evergreen trees such as pines, spruces, and firs grow in this habitat. Further north, the permafrost and short growing season of the tundra biome have historically made the growth of large trees or dense forests difficult. Vegetation in these regions consists instead of shrubs, mosses, and grasses.

The boundary between the two biomes is difficult to determine. Previous studies have shown that Plant growth increases in high latitudes and extends northwards in are relocatedthat were previously sparsely covered with tundra shrubs and grasses. The new NASA-led study now finds that these tundra areas and the adjacent transition forests, where the boreal regions and the tundra meet, are experiencing increased tree and shrub abundance, and are expected to remain so at least until the end of the century.

“The results of this study are a further step towards a growing body of work that shows a change in vegetation patterns in the boreal forest biome“, said Paul MontesanoLead author of the study and researcher at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.

“We have used satellite data to track the increase in vegetation growth in this habitat since 1984 and found that it corresponds to what computer models have predicted for the next few decades. This paints a picture of sustained change over the next 80 years or so, which is particularly pronounced in the transition forests.

The scientists found predicted over“positive changes in the average height” in all tundra and transitional forest landscapes (boreal to tundra) included in this study. This suggests that Trees and shrubs in rural areas where they are currently rare will grow larger and more numerous.

“The increase in vegetation that accompanies the change can offset some of the effects of increased CO₂ emissions by absorbing more CO2 through photosynthesis“, said the study’s co-author Chris NeighScientists at NASA’s Landsat 8 and 9 project in Goddard. The carbon absorbed through this process would then be stored in trees, shrubs and soil.

The change in forest structure can also lead to Permafrost areas are thawing because the dark-colored vegetation absorbs more sunlight, which creates CO₂ and methane could be releasedthat have been stored in the soil for thousands of years.

In her in Nature Communication Earth & Environment In published work, NASA scientists describe the combination of satellite data, machine learning, climate variables and climate models they used to model and predict forest structure over the next few years. Specifically, they analyzed nearly 20 million data points from NASA’s ICESat-2.

They then compared these data points with tens of thousands of scenes of North American boreal forests from 1984 to 2020 from Landsat, a joint mission of NASA and the US Geological Survey. To create models with such large amounts of data, known as“Big data“-Projects require advanced computing capabilities.

The ICESat-2 mission uses a laser instrument called a lidar to measure the height of features on the Earth’s surface (such as ice sheets or trees) from space. In the study, the authors examined these measurements of vegetation height in the far north to understand what the current structure of the boreal forest looks like.

The scientists then modeled several future climate scenarios, considering different temperature and precipitation scenarios, to show what forest structure would look like in response to these changes.

“Our climate is changing, and these changes affect almost everything in nature“, said Melanie FrostRemote sensing scientist at NASA’s Goddard Center. “It’s important that scientists understand how things are changing and use that knowledge to inform our climate models.”.

Source reference:

Paul M. Montesano et al., A shift in transition forests in the boreal zone of North America will continue until 2100, Communications Earth & Environment (2024). DOI: 10.1038/s43247-024-01454-z