In this week’s Video of the Week, an automatic weather station (AWS) is installed on Yala Glacier in Nepal, one of the world’s most studied glaciers. In the video shared by the International Centre for Integrated Mountain Development (ICIMOD) on October 16, a young researcher, Anushilan Acharya, is identified with the hashtag #girlsonice.
The installation is part of a push by ICIMOD to increase data collection on glaciers in the Hindu Kush Himalaya. Of the 54,252 identified glaciers in the HKH, only seven are monitored by ICIMOD researchers. The information is essential to understanding how climate change might affect the region’s water resources.
The weather stations provide data points for glacier monitoring. Last year, GlacierHub reported on a study which found approximately 21 percent of Yala’s annual snowfall was returned to the atmosphere via sublimation, a rate higher than most glaciers on Earth’s tallest mountain ranges.
Fieldwork on Yala is notoriously difficult. The glacier is a four-day hike from the start of the Langtang Valley, which is a day’s drive from Kathmandu. In the sublimation study, an eddy covariance system was installed to measure the rate of snow loss to the atmosphere. The instruments required so much energy to power that the team had to lug a car battery up the glacier to ensure it would have sufficient energy to run during the research.
The stonefly is the largest animal inhabiting the glaciers of Patagonia. What the inch-long insect eats and excretes on the ice is central to the overall glacier ecosystem. Also known as the Patagonian Dragon, the stonefly occupies a near-apex position in the truncated glacier food chain. Stonefly larvae develop in glacial meltwater pools, where the larvae spends most of its life as a waterbound nymph, consuming algae, fungi, and other small inhabitants found in cryoconite sediments. The wingless adults wander the ice surface in search of food and mating opportunities. Despite their significant influence on glacier biogeochemical cycles, glacier invertebrates like the stonefly and their associated bacteria remain understudied. New research published in the journal Environmental Microbiology provided the first look at the genetics underlying the gut microbiome of stonefly nymphs.
The research team, comprised of Japanese and Chilean scientists, traveled by horseback and camped at Tyndall Glacier in Chile, collecting samples for analysis in a Tokyo laboratory. The team were surprised to find some bacteria in the stonefly gut were not present on the glacier surface. Not only was the bacteria absent from the surface of the Tyndall Glacier, but they were also distinct from bacteria catalogued in other glacier environments, indicating a symbiotic relationship between the Patagonian stonefly nymph host and its gut bacteria. The stonefly nymph provides an enriching gut environment and in turn the bacteria aids in the insect’s nutrition and material cycle of the glacier environment.
Insects and animals, including humans, host a variety of microorganisms in their digestive tracts. These microorganisms and other bacteria, called gut flora, help perform a variety of functions critical to the health of their host. For example, humans lack enzymes necessary to break down certain fibers, starches, and sugars. Our gut flora keeps us healthy and enables us to ingest a wide range of foods we would otherwise be unable to digest. Similarly, the stonefly’s gut community enables it to benefit from seemingly nutritionless cryoconite sediments.
According to Takumi Murakami, from Japan’s National Institute of Genetics and principal author of the study, glacier stonefly nymphs and their gut bacteria likely drive the decomposition of organic materials on the glacier. The gut bacteria-invertebrate symbiosis may even be a common phenomenon in glacier ecosystems beyond Patagonia. Understanding the role of high trophic level invertebrates, like the stonefly, and their bacteria in glacier ecosystems is key to understanding the big picture of glacier nutritional networks.
Japanese scientists have compiled a significant body of research on invertebrates and their gut flora, particularly those inhabiting glaciers. In 1984, Japanese researcher Shiro Kohshima documented a novel discovery on a visit to the Yala Glacier in Nepal; a cold-tolerant midge. Later he visited Patagonia to examine the glacier-indigenous insects of the region. Kohshima enlisted collaborators, who in turn brought their students, which has resulted in the present day team of glacier-insect specialists, including Murakami. Their diligence in studying glacier ecosystems has produced a prolific body of published work, helping fill knowledge gaps at the headwaters of organic decomposition.
Further underscoring the importance of the research, Murakami told GlacierHub, “Recent studies suggested that glacier ecosystems are the source of nutrition for downstream soil, river, and ocean ecosystems.” Were it not for the bacteria inhabiting the gut of the Patagonian Dragon, the organic matter would not be processed, and thus would not contribute to the glacier or downstream ecosystems.
Murakami adds, “Since glacier environments are susceptible to climate change, it is essential to accumulate the knowledge on the current glacier ecosystems for future studies, otherwise we will lose the opportunity.” Murakami’s concern is not unfounded. In the U.S., the stonefly is the poster child of understudied species that are quickly disappearing due to rapidly changing habitats. Petitions listing two species of stonefly under the Endangered Species Act are under consideration.
The Importance of Snow Sublimation on a Himalayan Glacier
From Frontiers in Earth Science: “Snow sublimation is a loss of water from the snowpack to the atmosphere. So far, snow sublimation has remained unquantified in the Himalaya, prohibiting a full understanding of the water balance and glacier mass balance. Hence, we measured surface latent heat fluxes with an eddy covariance system on Yala Glacier (5,350 m a.s.l) in the Nepalese Himalaya to quantify the role snow sublimation plays in the water and glacier mass budget. Observations reveal that cumulative sublimation is 32 mm for a 32-day period from October to November 2016, which is high compared to observations in other regions in the world.”
Hydropower Production in India under Climate Change
From Nature: “Hydropower is a valuable renewable energy resource in India, which can help in climate change mitigation and meet the increasing energy demands. However, the crucial role of climate change on hydropower production in India remains unexplored. Here using the observations and model simulations, we show that seven large hydropower projects experienced a significant (p-value < 0.05) warming and a decline in precipitation and streamflow during the observed period of 1951–2007.”
From Molecular Ecology: “Primary succession on bare ground surrounded by intact ecosystems is, during its first stages, characterized by predator‐dominated arthropod communities. However, little is known on what prey sustains these predators at the start of succession and which factors drive the structure of these food webs. As prey availability can be extremely patchy and episodic in pioneer stages, trophic networks might be highly variable. Moreover, the importance of allochthonous versus autochthonous food sources for these pioneer predators is mostly unknown. To answer these questions the gut content of 1832 arthropod predators… were screened molecularly to track intraguild and extraguild trophic interactions among all major prey groups occurring in these systems. ”
How do wild yaks respond to glacier melt and past exploitation?
“To explore how mammals of extreme elevation respond to glacial recession and past harvest, we combined our fieldwork with remote sensing and used analyses of ~60 expeditions from 1850–1925 to represent baseline conditions for wildlife before heavy exploitation on the Tibetan Plateau. Focusing on endangered wild yaks (Bos mutus), we document female changes in habitat use across time whereupon they increasingly relied on steeper post-glacial terrain, and currently have a 20x greater dependence on winter snow patches than males. Our twin findings—that the sexes of a cold-adapted species respond differently to modern climate forcing and long-past exploitation—indicate that effective conservation planning will require knowledge of the interplay between past and future if we will assure persistence of the region’s biodiversity.”
“Snow algae in shallow ice cores (7 m long) from Yala Glacier in the Lang-tang region of Nepal were examined for potential use in ice-core dating. Ice-core samples taken at 5350 m a.s.l. in 1994 contained more than seven species of snow algae. In a vertical profile of the algal biomass, 11 distinct algal layers were observed. Seasonal observation in 1996 at the coring site indicated most algal growth occurred from late spring to late summer. Pit observation in 1991, 1992 and 1994 indicated that algal layer formation takes place annually.”
“Abundance and habitat requirements of nivicolous myxomycetes were surveyed over 4 yr at the northwestern Greater Caucasus ridge (Russia). An elevational transect spanning 3.66 km from 1 700 to 3 000 m a.s.l. was established at the summit Malaya Khatipara situated within the Teberda State Biosphere reserve. Between 2010 and 2013 1177 fructifications of nivicolous myxomycetes were recorded, with 700 of these determined to 44 species, varieties, and forms. Virtually all fructifications developed near or at the margin of a snow field. Abundance of myxomycete fructifications varied extremely between years, ranging from near zero to hundreds of colonies. At sites with known myxomycete occurrences 16 data loggers were installed in the years 2011 and 2012, measuring relative humidity and temperature at the soil surface. Together with weather data recorded on the nearby Klukhor pass and experiments with myxamoebae cultured on agar, these data explain the observed extreme fluctuations in myxomycete abundance.”