Roundup: Swedish Mountain, Glacier Retreat and Glacier Forelands

Hot Weather Melts Sweden’s Highest Peak

From Bloomberg: “This summer’s exceptionally hot weather has seen the south peak of Kebnekaise lose the crown as Sweden’s highest point… The south peak measured 2,097 meters (6,879 feet) above sea level on July 31, down from 2,101 meters on July 2, according to data from the Tarfala research station. The north peak is 2,096.8 meters high, and the research station estimates that it overtook the south peak as Sweden’s highest point on Aug. 1 as the melting has continued.”

Find out more about glacier melting on Sweden’s highest mountain here.

Kebnekaise Mountains on GlacierHub
Kebnekaise Mountains (Source: Swedish Tourist Association).

Melting of Maliy Aktru Glacier Reveals Primary Ecological Succession

In Wiley’s Journal for Ecology and Evolution: “Plants, microorganisms (bacteria and fungi), and soil elements along a chronosequence in the first 600m of the Maliy Aktru glacier’s forefront (Altai Mountains, Russia) were surveyed… Plant succession shows clear signs of changes along the incremental distance from the glacier front. The development of biological communities and the variation in geochemical parameters represent an irrefutable proof that climate change is altering soils that have been long covered by ice.”

Read more about glacier retreat in the Altai Mountains here.

Maliy Aktru glacier’s forefront on glacierhub
Maliy Aktru Glacier’s Forefront (Source: Alexi Rudoy/World Glacier Monitoring Service).

 

Anthropogenic Influence on Primary Succession in Alps

From the 6th Symposium for Research in Protected Areas: “Glacier forelands are ideal ecosystems to study community assembly processes… This study focuses on possible anthropogenic influences on these primary successions. Floristic data of three glacier forelands show that anthropogenic influences in form of (i) grazing sheep and (ii) hiking trails are creating patterns, visible in the floristic community composition and in change of species numbers. (iii) Additionally, it was found that the special protected area ‘Inneres Untersulzbachtal,’ where grazing has been absent for decades didn’t show any of these patterns, underlining the importance of process-protection in glacier forelands, as one of the last truly wild ecosystems in central Europe.”

Discover the anthropogenic influences on primary successions in glacier forelands here.

Alps Glacier Foreland (Source: Brigitta Erschbamer/ Resrach Gate).

Worms Contribute to Soil Ecology After Glacier Retreat

Nematodes under a microscope, courtesy of snickclunk/flickr.
Nematodes under a microscope, courtesy of snickclunk/flickr.

The rock, gravel, sand and fine particles that are trapped under glaciers for millennia undergo major changes as glaciers retreat. Once they are exposed to the atmosphere, they are colonized by a variety of organisms and develop soils. They shift from having relatively few species of bacteria to developing more complex ecosystems.

Studying nematodes — or roundworms — communities in these soils can provide insight into the stages of ecosystem development as the worms respond differently to vegetative changes from grasslands to forested areas, a recent study from the Chinese Academy of Sciences found. The types of nematodes found in soil can also give insights about soil health, the authors found.

Though they may not look very impressive, nematodes are complex creatures. More than 25,000 species have been identified and have been known to adapt to a large variety of environments — from terrestrial to watery ecosystems, from salty to fresh habitats, and from northern to southern longitudes.

Collecting samples in glacier forelands (source: LTERNET)
Collecting samples in glacier forelands (source: LTERNET)

The Hailuogou Glacier on the southeastern Tibetan Plateau in China has retreated 1.8 kilometers in the 20th century, according to glaciologist Mauri Pelto. Because of the glacier’s rapid retreat, researchers from the Chinese Academy of Sciences were able to observe 120 years of plant regeneration in seven different stages. In phase one–the first 3 years after soil is initially exposed–mosses, small plants and grasses begin to grow. During phases two, three and four, or years 3 through 40, grasses eventually become replaced by shrubs and low trees. In phases five, six and seven, from 40 to 120 years after exposure, mature forests develop. Samples of these phases were taken from seven different sites and analysed for pH balance, phosphorus and nitrogen content. Nematodes were extracted from the samples.

The researchers found that while all these changes were occurring above ground, dynamic changes were also occurring beneath the surface. As the soils first developed, levels of soil phosphorous increased, and fungi-eating nematodes were dominant. In later stages, these nematodes were replaced with bacteria-eating nematodes; this shift is likely a response to the improvement of soil quality.

Hailuogou Glacier, courtesy of Mykle Hoban/Flickr.
Hailuogou Glacier, courtesy of Mykle Hoban/Flickr.

But by the seventh phase, soil health began to decrease, and the researchers noticed the return of fungi-eating nematodes, species that survive well in poor soil conditions. Nutrient availability at this later phase began decreasing, suggesting that the ecosystem was entering a retrogressive phase.

“Further research should be conducted to determine the most efficient approach to integrate plant succession, nutrient availability, and soil bacterial and invertebrate community dynamics into models of ecosystem development and succession,” the researchers concluded. “These models would be helpful for prediction and management of nutrient limitation during long-term soil development.” It will be interesting to see whether the patterns of changing nematode populations in the glacier forelands in China are similar to those in other areas. It will also be of importance to framing climate change policy, since the expansion of vegetation in areas formerly covered by glaciers has the potential to sequester carbon dioxide.