Shiyatov Stepan Grigorevich

Shiyatov Stepan Grigoryevich, Doctor of Biological Sciences, Professor, Leading Research Worker of Institute of Plant and Animal Ecology of the Ural Branch of the Russian Academy of Sciences, Honored Science Worker of the Russian Federation.

He was born on 24.12.1933 in the village of Vladimirovka, Zilairsky area of the Bashkir Autonomous Soviet Socialist Republic, in the family of peasants. Mr Shiyatov graduated from primary school in 1945, and from secondary school – in 1951. He spent the years of his childhood and youth in the area which is distinguished by beauty and rich in biological resources – that is the Zilair plateau. A border of an area of distribution of plants and animals of broad-leaved, steppe and taiga complexes goes in this place. I often went to the forest and river, and during these walks I observed the life of animals and peculiarities of distribution of plants with great interest. Therefore I decided to get biological education and go in for studying complex ecological systems.

I entered Ural Forestry Engineering Institute, the Faculty of Forestry in 1952. Such outstanding Professors as N.A. Konovalov, V.N. Petri, P.L. Gorchakovsky, L.I. Vigorov and etc. were teaching there at that time. We mastered fundamentals of forestry sciences and understood an important biospheric role of forests on the planet thanks to the aforementioned lecturers. During the period of my studying at the Institute, the Professor P.L. Gorchakovsky (later he became the Academician of the Russian Academy of Sciences) was researching the flora and vegetation of high-mountain areas of the Urals. He organized expeditions with participation of students every year. I had an opportunity to take part in work of such expeditions. In 1954-1955 I took part in field works in the Nether-Polar Urals (Sablya Ridge, Manaraga and Narodnaya Mountains), and in 1956 – to Konzhakovsky Stone Mountain (the Northern Urals). During these trips, I was greatly impressed by specific light forests and crooked forests which grew at the upper border of the forest in extreme soil-climatic conditions and played an important water and soil protection role. On the proposal of P.L. Gorchakovsky, I made my graduation paper which was devoted to studying of the composition, structure and altitudinal distribution of high-mountain forests in the Northern Urals.

After my graduation from the Institute, I was sent for work as the Supervisor of the area of soft resin extraction at the Katav-Ivanovsky Chemical Forestry Enterprise (Chelyabinsk region), where I worked for a year. In spring 1958, I won a competition to the position of the Junior Research Worker at the Ural Forestry Experimental Station organized in the city of Sverdlovsk. I was included into members of a research group, the goal of which was to study reafforestation and assess the fire risk of concentrated cutting. In 1959 the Prof. P.L. Gorchakovsky (who had already changed his place of work for Institute of Biology of the Ural Branch of the Academy of Sciences of the USSR by this time) offered me to go to full-time postgraduate study and make a qualification paper on research of the dynamics of the upper border of the forest in the Polar Urals.

When I completed postgraduate study, I was employed by the same Institute where I made my career from the Junior Research Worker to the Head of the Laboratory. I defended my Candidate’s thesis in 1964, and then my Doctor’s thesis in 1981. In 1985 I organized the dendrochronology laboratory which was the first one in our country. This laboratory was aimed at solution of problems of the forest ecology. I headed this laboratory until 2009. In 1997 I was confirmed in an academic rank “Professor”, and in 1999 an honorary degree “Honored Science Worker of the Russian Federation” was conferred to me. I have been a member of the editorial board of “Ecology” journal from 1993 until the present time.

Interest to studying reactions of ground and water ecosystems to the climate warming which has begun in the XX^th century has increased significantly starting from the middle of the last century. It has been found that the greatest climate warming occurs in northern and high-mountain regions. Therefore a task to assess the reaction of high-mountain and northern ecosystems to changes in the climate appeared. The first works carried out by us in the Polar Urals showed that starting from the 1920s intensive expansion of tree vegetation to mountain tundras has been seen due to improvement of the climatic conditions. The dendrochronology laboratory was created at the Institute for quantitative assessment of such changes in the Urals and Siberian Subarctic zone. And the task of this laboratory was retrospective studying of the conditions of the environment and spatio-temporal dynamics of forest stands using forest-study, dendrochronological, radiocarbon, distance, cartographic and photographic methods, as well as GIS-technologies. The dendrochronological method was chosen as the main one, i.e. it is analysis of changeability of radial growth of woody plants under the influence of climatic factors and calendar dating of the time of formation of each annual ring of the wood. This method enables to determine exactly the period of life of alive and dead trees, to extend the woody-ring chronologies as long as centuries back, to reconstruct the climatic conditions of the last centuries and even thousand years accurate within a year. Moreover, analysis of anatomical anomalies in annual rings of the wood enables to date the time and intensity of such catastrophes as forest fires, massive outbursts of reproduction of injurious insects and extreme weather conditions (spring and summer frosts, snowbreaks, windbreaks, high and continuous levels of spring floods in rivers, landslides).

The most important scientific results of the laboratory are as follows:

1. Theoretical and methodological fundamentals of phitoindication of conditions of the environment and natural processes in highlands (snow cover, wind situation, thermal regime, changes of the climate, fires, snowbreaks, mud flows, anthropogenic activity) are worked out.

2. The role of climatic, edaphic and anthropogenic factors which determine the composition, morphological and age structure of forest stands growing at the upper border of the forest in the Polar, Nether-Polar, Northern and Southern Urals is studied.

3. Reconstruction of the spatio-temporal dynamics of larch forest stands in the Polar Urals for the last 1550 years under the influence of secular changes of the climate is performed. A continuous warm period which lasted from the VIII^th to the XIV^th centuries, when the upper border of the forest increased higher into the mountains for 60-80m, was revealed for the first time. A cold period from the XIV^th to the XIX^th centuries, when massive drying of forest stands and decrease of the upper border of the forest were seen, followed the warm period. During the last 110-120 years, intensive expansion of tree vegetation to mountain tundras was observed in all high-mountain areas of the Urals.

4. It is shown that radial growth of trees growing at the upper and polar borders of the forest is determined mainly by the temperature regime of summer months. Per-year reconstruction of variability of the summer temperature for the last 200-1350 years for different high-mountain provinces of the Urals and areas of the European and Asian Subarctic zone is performed on this basis. The longest per-year reconstruction of the summer temperature (7.350 years) is made for southern areas of Yamal. The cycles of different length (intra-secular, secular and even super-secular) are revealed well in radial growth of woody plants and in changeability of the climatic factors.

5. The system of dendroecological monitoring is created in all high-mountain areas of the Urals with the purpose of monitoring changes in the composition, structure and spatial position of forest-tundra, forest-field and forest ecosystems. It includes permanent plots and altitudinal profiles, morphological structure of forest stands, radial growth of forests, seed-bearing, microclimatic observations within summer and winter periods, cartographic and photographic materials.

At the present time, the staff of the laboratory continue to study the spatio-temporal dynamics of high-mountain forests in the Urals, paying special attention to exploring of the processes of seed-bearing and reafforestation, use of historical landscape and distance photos, cartographic materials and GIS-technologies.