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Doctor of Philosophy Programs in Human Biology, Degree Programs in Comprehensive Human Sciences D4 Natalia Gogoleva

Have you heard of “Arctic Amplification”? It's a phenomenon where the Earth's northernmost region is experiencing the impacts at least three times faster than the rest of the planet. Among the regions experiencing Arctic amplification, my Homeland stands out as one of the most vulnerable areas to climate change. The Sakha Republic, also known as Yakutia, is home to almost 1 million people, including dozens of indigenous groups such as Sakha. It is the largest republic in the Russian Federation and boasts one of the lowest population densities in the world. 

Yakutia is predominantly covered by permafrost and has a unique yet delicate ecosystem. Most of its territory is occupied by the taiga (boreal forest) and tundra. However, several threats have been a growing concern for both Sakha and international scientific communities. What exact threats are we currently facing? To address this, I have interviewed two scientists from Yakutia about this question.

From permafrost to lakes and soil degradations

Nearly a decade ago, as I peered through the aircraft’s window after the plane took off from Yakutsk for Japan, the landscape below unfolded before me, revealing a quilt of countless lakes scattered across the terrain of Sakha land, their proximity striking me with wonder. Could it be that the same piece of land has transformed, now with an even greater number of water bodies? This alteration might well be attributed to the thawing of permafrost which is the subterranean ground layer housing frozen water, preserved microorganisms, and massive storage of greenhouse gases.

Dr. Luidmila Pestryakova from North-Eastern Federal University, is an esteemed and charismatic scientist with nearly five decades of research under her belt, is a pioneering researcher of limnology, blazing a trail in the study of ancient lakes through palaeobotanical research. Throughout her illustrious career, she has lent her expertise to over 40 local and international research expeditions spanning the lakes of Yakutia and the broader Siberian region. Her focus lies particularly on diatomic algae inhabiting lake sediments, serving as a key to unlocking the histories of these individual water bodies. Remarkably, Dr. Pestryakova's findings reveal that, despite Yakutia boasting an abundance of nearly 800 thousand lakes, most of them are very young, born of the thawing permafrost known as thermokarst-originated lakes. Thermokarst refers to forest and land depression caused by the repeated thawing and freezing of the permafrost layer, which will eventually turn to lake (Photos 1 and 2). 

Particularly, Dr. Pestryakova has shared that the active progression of thermokarst formation in Yakutia was observed over the past three decades. Areas of permafrost subject to anthropogenic disturbances or development, including cultivated lands, settlements, clearings, and technogenic infrastructures, are particularly susceptible to thermokarst formations. Despite the effect on local peoples’ quality of life, it is important to note that thermokarsts possess the potential to wield substantial influence over the entire ecosystem of Yakutia.

The spread of thermokarst serves as a stark indicator of global climate change within permafrost landscapes. In simpler terms, rising temperatures have led to the widespread degradation of soil on a considerable scale and it is actively ongoing year by year. This will eventually lead to the formation of more thermokarst lakes, as demonstrated by Yukechi lake example (Figure 1). Then, imagine what will happen in the next century if climate change continues at the current pace. 

Photo 1. Young “Alaas” or Thermkarst  (Credit: L. Pestryakova, A.N. Fedorov) 

Photo 2. Degradation of Syrdakh arable land in Central Yakutia (Credit: L.Pestryakova, A.N. Fedorov) 

Figure 1. Monitoring of Yukechi Lake in Central Yakutia, which is the thermokarst-originated lake. (Credit Lyudmila Pestryakova, A.N. Fedorov )

Taiga forest vulnerability to climatic changes

Yakutia is predominantly blanketed by the vast taiga forest, dominated by coniferous trees. These trees play a pivotal role as significant carbon reservoirs, actively participating in the global carbon cycle. Now, let us ponder what will happen if these forests are damaged or vanished.

Figure 2. Diagram of effects of singular extreme wet event on Spasskaya Pad forest near Yakutsk (Credit: Dr.Nogovitcyn) 

Dr. Aleksandr Nogovitcyn, an up-and-coming researcher hailing from Sakha, has recently earned his Ph.D. in Earth System Science from Hokkaido University. His doctoral work delved into the response of the boreal forest to environmental disturbances. Sakha Republic is known for its continental climate, and experienced a remarkable deviation in 2007, a consequence of unusually high precipitation. Subsequent evaluations of the forests’ well-being unveiled a concerning decline, attributable to overly saturated soil. In addition to visible changes such as high tree mortality,Dr. Nogovitcyn detected signs of decreased nitrogen availability, likely due to damage to tree roots (Figure 2). Such discoveries may hold implications for how taiga forests might react to ongoing climatic shifts.

To summarize, forests rely heavily on essential nutrients and moisture liberated from the annual thawing of permafrost layers. However, as annual temperatures continue to increase, there exists a strong likelihood that permafrost will thaw at an accelerated pace, potentially significantly altering the whole dynamics of Sakha’s forest ecosystems and currents in global carbon circulation. 

More ecological threats and call for international cooperation

Photo 3. Yakutia forests are prone to forest fires and their occurrences are expected to escalate every year (Credit: Oleg Gogolev)

Yakutia has been experiencing annual forest fires, with the affected area expanding each year. Recently scientists from USA have discovered that these forest fires are contributing to the accelerated formation of thermokarsts. In addition to these, there is a fear of losing numerous animal species and the potential introduction of harmful new species that could disrupt the fragile balance of Sakha's environment. These problems have been also mentioned by both Dr. Pestryakova and Dr. Nogovitcyn during our interviews. 

Collectively, these complex, interconnected developments underscore the concept of "Arctic Amplification", highlighting the profound impact on the Sakha region, the rest of the Circumpolar Region, and later the whole planet.

Despite these concerns, a glimmer of hope may persist, assuming that this may be a temporary phase. Sakha's scientists have maintained close partnerships with colleagues from Japan, Germany, the USA, and various other nations for many decades. The outcomes of these collaborations have been nothing short of highly productive, leading to a deeper understanding of our present ecological circumstances and the ability to foresee future developments. There is a hope that more such collaborative efforts will emerge. For, without united endeavors, no single nation can confront Mother Nature. 

Dr. Luidmila A. Pestryakova, Professor of Paleogeography at the North-Eastern Federal University, Yakutsk, Russia. 
She is the pioneer of paleobotany, specializing in the history of lakes. She has an enormous experience of more 30 years of having participated in and organized more than 40 fieldwork all around the Siberian terrain. She currently resides in Yakutsk and is a full-time professor in the Institute of Natural Sciences of North-Eastern Federal University.

Dr. Aleksandr Nogovitcyn, a researcher in Hokkaido University.
He got PhD degree in Earth Environmental Science from Hokkaido University and his research focuses on studying of effects of climatic events on the boreal forest ecosystems. Now Aleksandr works as a researcher in the institute of Earth and Environmental Sciences at Hokkaido University. 

References:
- Chen, Y., Lara, M. J., Jones, B. M., Frost, G. V., & Hu, F. S. (2021). Thermokarst acceleration in Arctic tundra driven by climate change and fire disturbance. One Earth, 4(12), 1718-1729.

- Nogovitcyn, A., Shakhmatov, R., Morozumi, T., Tei, S., Miyamoto, Y., Shin, N., ... & Sugimoto, A. (2023). Historical variation in the normalized difference vegetation index compared with soil moisture in a taiga forest ecosystem in northeastern Siberia. Biogeosciences, 20(15), 3185-3201.