Landslides: long-term effects on tundra vegetation

Date:
September 28, 2020
Source:
University of Eastern Finland
Summary:
Landslides have long-term effects on tundra vegetation, a new study
shows. Conducting the study in North West Siberia, the researchers
found that tundra vegetation regenerated rapidly after a major
landslide event in 1989.



FULL STORY ========================================================================== Landslides have long-term effects on tundra vegetation, a new study shows.

Conducting the study in North West Siberia, the researchers found that
tundra vegetation regenerated rapidly after a major landslide event in
1989. Two decades later, differences in the vegetation of the landslide
area and the areas surrounding it have evened out, but even after 30
years, the vegetation of the landslide area is nowhere close to the
vegetation of the surrounding areas.


========================================================================== Several studies have reported changes in the Normalized Difference
Vegetation Index (NDVI) in Arctic regions. So far, remote sensing data
that is used to calculate the NDVI hasn't been able to discern, in detail, landscape level factors that have an effect on, e.g., greening.

"Landslides caused by the thawing of permafrost will become
increasingly common in North West Siberia and elsewhere in the Arctic,
too. These are caused by climate change and they also have an effect on vegetation. However, the exact effect of landslides on NDVI is difficult
to discern from low-resolution satellite data," Professor Timo Kumpula
from the University of Eastern Finland says.

The researchers point out that permafrost thawing also has implications
for all construction. Indeed, the Bovanenkovo gas field, one of Russia's largest gas fields in the Arctic, is located in the study site. Permafrost thawing can cause structural collapses and put infrastructure at
risk. This, in turn, could lead to various types of environmental damage.

VHR satellite data sheds detailed light on regional changes in vegetation Published in Environmental Research Letters, the study was conducted
in collaboration between the University of Eastern Finland, Northern
Arizona University and the University of Lapland. In addition to data from
the Landsat satellite, the researchers used very high resolution (VHR) satellite data from the QuickBird-2 and WorldView-2 and 3 satellites
to analyse post-landslide changes in vegetation. The study site on the
Yamal Peninsula covers 35 square kilometres.

"VHR satellite images allow us to see very small changes in the land
cover, such as temporary degradation of vegetation or new landslides
that can be very small, even less than 0.1 hectares in size. We can also
see sites where existing permafrost thawing expands," Researcher Mariana Verdonen from the University of Eastern Finland says.


========================================================================== Story Source: Materials provided by University_of_Eastern_Finland. Note: Content may be edited for style and length.


========================================================================== Journal Reference:
1. Mariana Verdonen, Logan T Berner, Bruce C Forbes, Timo Kumpula.

Periglacial vegetation dynamics in Arctic Russia: decadal analysis
of tundra regeneration on landslides with time series satellite
imagery.

Environmental Research Letters, 2020; DOI: 10.1088/1748-9326/abb500 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2020/09/200928125042.htm

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