Galina Zdorovennova, Head of Hydrophysics Laboratory, Northern Water Problems Institute KarRC RAS:
– The ice situation is now unraveling differently on the large Lake Onego, on medium-sized lakes, and on forest lakelets. This is largely due the conditions during the fall and winter freeze-up period rather than an early warm-up. Small lakes were the first to get frozen, but as the weather in December was relatively warm, they were predominantly covered in white, brittle ice. It has now grown porous and very dangerous. Medium-sized lakes did not experience this situation, but it seems the frost in January and February was still insufficient – the ice on them now is not very thick. Ice on Lake Onego is still mostly quite strong and dry, but within Petrozavodsk, the Ministry of Emergencies has already banned going out onto lakes. It is crucial to follow these recommendations and not take risks under any circumstances. As our long-term research confirms, regional climate fluctuations have been altering the ice conditions, and even if you have been going out onto familiar bodies of water in the spring for many years, things can be very different today.
As for life under ice, aquatic organisms – phytoplankton – in small forest lakes, where the porous white ice blocks sunlight, are still dormant. In Lake Onego, light penetrating through the clearer, crystalline ice heats the water and induces vertical mixing (convection), which lifts nutrients from the bottom layers into the well-lit photic zone. This process awakens microorganisms. However, it would be too hasty to forecast an early algae bloom: it is difficult to predict the weather in April, which may be overcast with snowfall, potentially slowing these processes down again.
Read more about changes in ice on the Northern Water Problems Institute webpage.
Ice measurements in Petrozavodsk Bay, Lake Onego. Photos: R. Zdorovennov / NWPI KarRC RAS
High organic matter content accounts for the intense reddish color of lake water spilling over ice on a forest lakelet. R. Zdorovennov / NWPI KarRC RAS
Valeria Smirnova, Junior Researcher, Hydrobiology Laboratory, Northern Water Problems Institute KarRC RAS:
– Due to early ice-off, and provided the spring will be warm, we expect an earlier development of spring diatom phytoplankton in our water bodies. The main representative of diatoms here is the psychrophilic species Aulacoseira islandica (O. Müll.) Sim. Diatom cells sink to the bottom to serve as food for relict crustaceans. Intensive, early development of diatoms will increase their contribution to the annual phytoplankton production. For laymen, these processes will go largely unnoticed. However, in areas of water bodies with a higher trophic status, phosphorus loading additionally stimulates phytoplankton development. Active decomposition of algae on the bottom of such water bodies may entail oxygen deficiency (hypoxia) in summer.
Furthermore, algal blooms may develop in water bodies undergoing eutrophication. A bloom in this case means explosive proliferation of certain algae, including cyanobacteria. As a rule, this is visible to the naked eye. The water becomes less transparent and a slimy, oozy smelling film covers the surface. So, changes in the thermal regime call for closer constant monitoring of the state of aquatic ecosystems.
Mammals and Birds
Danila Panchenko, Senior Researcher, Zoology Laboratory, Institute of Biology KarRC RAS:
– This season stands out not only for the early warm-up but also in terms of atypical snow conditions. There was little snowfall in northern forests this year, and the snow was very loose, making it easier, e.g. for moose, to move around. In this sense, this winter was not so tough for many ungulates as in previous years. The rapid snowmelt exposes food sources for the animals: reindeer can forage on lichens on thawed patches without wasting energy on digging. The low-snow winter and early spring have also influenced animal movements. We are tracking collared wild forest reindeer females: one of them, who previously used to migrate far out of her summer pastures, this time remained within a relatively small area nearby all winter. Indirect evidence also suggests that the poaching pressure on reindeer was lower – illegal hunting usually peaks in late winter and early spring, when there is a dense snow cover good for snowmobiles. This year, however, snow remained loose and shallow throughout the winter and then began to melt quickly. Moving over lakes is also difficult due to the ice thawing. So, the early spring has generally been positive for reindeer and moose.
For reindeer, shallow snow cover means higher food availability. Photo:D. Panchenko / IB KarRC RAS
Alina Yakimova, Senior Researcher, Zoology Laboratory, Institute of Biology KarRC RAS:
– For small mammals, the conditions during transitional periods (spring and autumn) are critically important. This is a time of profound physiological transformation, making the animals particularly sensitive to adverse externalities.
An early, warm, and moderately humid spring can stimulate early start of breeding in these animals. However, this period needs to be sufficiently long to ensure a plentiful food supply, allowing the animals to gain enough weight to begin breeding. Conversely, a rainy and cold spring delays breeding and raises mortalities. Cold snaps recurring later on are also devastating for the animals, especially if they result in the formation of ice crust on snow in earlier spring or rainy and cold weather in mid-spring. So, apart from the timing of spring's arrival, the course of natural phenomena in spring is a critical factor. Since Karelia is a region with highly unstable weather, it is impossible to predict the specific conditions that will develop later this year.
Alexander Artemyev, Leading Researcher, Zoology Laboratory, Institute of Biology KarRC RAS:
– Birds are adapted to the standard timing of the spring and to minor weather fluctuations within a few days. But when the spring arrives far ahead of schedule, it is not very beneficial for many avians.
Many of the birds overwintering in our region are insectivores, such as kinglets and treecreepers, omnivores, like tits, or herbivores: bullfinches, greenfinches. For many of them, an early spring is a boon due to higher food availability: insects awaken, snowmelt exposed the ground, and herbage sprouts. Other birds of the locally overwintering population suffer from an early spring. The willow ptarmigan remains white until the end of April, and with no snow around, it becomes readily visible to predators. In March, black grouse, capercaillie, and hazel grouse burrow under the snow for shelter, but a hard crust formed by alternating thaws and frosts is an obstacle. Owls are also affected by this phenomenon – voles and mice cannot break through the overly hard crust to reach the surface.
The return of migratory birds is not always aligned with the time warmth actually sets in. Photo: I. Georgievsky / KarRC RAS
The same applies to migratory birds. The climate in our region is highly unstable - early thaws are almost always followed by a return of cold weather. A rapid, warm spring prompts short-distance migrants to fly in sooner. Rooks, starlings, skylarks, lapwings, and gulls have already arrived. While larger birds are more cold-tolerant – the neutral temperature region for geese and swans starts at zero degrees Celsius, skylarks, lapwings, and other small to medium-sized birds are not so well-adapted to frost. Most importantly, if snow covers farmlands again after it had thawed away, they may starve to death. For small birds, even five days without food is perilous.
Long-distance migrants, such as swallows, swifts, and cuckoos, live by their own internal clocks, which they synchronize to changes in daylight duration at their wintering grounds. They depart from there and arrive here at roughly the same time each year. It is only as they approach that they react to the current weather conditions, and can halt for a little longer in southerner regions to wait out on bad weather.
Plants in the woods and on farmlands
Nadezhda Genikova, Senior Researcher, Laboratory for Boreal Forest Dynamics and Productivity, Forest Research Institute KarRC RAS:
– It’s true that snow is meting actively in the city, with thawed patches appearing on lawns and puddles forming on paved surfaces. However, winter still reigns in the forest. Snow has only just begun to sag. All plants are still dormant and it is too early to speak of spring. Specifically, forest dwarf shrubs (bilberry and lingonberry) remain covered in snow, its depth being close to the long-term average.
Weathermen predict an early spring this year. If this turns out true, we can expect early snowmelt, ground being freed from snow, soil warming, and onset of the growing season ahead of the long-term averages. For now, we have seen a few days with above-zero temperatures, but cold days can still return. Spring frosts do not pose a threat to the well-adapted Karelian plants.
The spring is taking over rapidly. Photo: I. Georgievsky / KarRC RAS
Alexandra Kamova, Junior Researcher, Vilga Agrotechnology Laboratory, Department for Multidisciplinary Research KarRC RAS:
– It is always great joy for people of Karelia to welcome an early spring with its first warm days and sunshine, which trigger rapid snowmelt and induce growth in plants: buds begin to swell, and tips of the first spring flowers emerge. Gardeners and second-homers increasingly cast an interested eye on seeds and shop for new gardening tools, anticipating the upcoming season. However, the early arrival of warmth has not only positive but also several negative consequences for farmers.
On one hand, for agricultural enterprises, every day counts, especially in northern regions. As the saying goes, "one day feeds the year". If the weather gives a chance for an earlier start of operations, many would leap to it – early sowing can provide an earlier harvest. They just need to have machines and land ready for the season in time. However, one must always keep in mind the region's climatic conditions; southern districts always begin field work earlier than northern ones.
On the other hand, near-instant snowmelt and high temperatures in March are uncommon in our region and may be of short duration – the anomalous warmth would be replaced by temperatures more typical for the season, but awakening in plants has already been launched. Currently, fields are freeing of snow ahead of time, moisture evaporates before the start of massive herbage growth, causing soil moisture deficit, which will ultimately affect the formation of swards and potentially lower the yields of both forage and grain crops. Furthermore, frosts may recur, which could be ruinous for the winter crops not covered in snow.
What we do in this situation is welcome the rooks, monitor long-term and short-term weather forecasts, and be prepared to start spring fieldwork ahead of schedule.