The Indicative Potential of the Forest-Tundra Landscape Component

In order to expand the possibilities of soil-cover remote monitoring and improve prognostic models of active-layer depth dynamics in connection with global climatic changes, the verification of correspondence between plant and soil components of subarctic landscapes is necessary. This is most relevant for the forest-tundra zone,where the variety and mosaicity of soils and vegetation is great due to its ecotonic position. The purpose of this work was to study the relationship of vegetation with the characteristics of cryogenic soils and the dynamics of the active layer in forest-tundra landscapes. Data were obtained during monitoring studies at key sites in diverse landscapes of forest-tundra in the vicinity of Labytnangi. It was revealed that the thickness of the organogenic horizons, as well as the value of the moss phytomass, determine the active-layer thickness. A close connection with relief and soils allows the use of vegetation as an indicator of the soil texture and the depth of active-layer occurrence and features. Keywords: plant communities, cryogenic soils, active layer, landscape, forest-tundra, Western Siberi

Ornamental grasses breeding activity in the botanical garden of ural federal university

This paper described the importance of ornamental grasses in modern landscape design; the use of new non- traditional plant species and the need for new modern varieties in order to improve plant breeding under challenging climatic conditions in the region. Methods were tested and developed in the botanical garden of the Ural Federal University at different stages of plant breeding. It is an Anatomo-morphological method (test) of rapid selection of initial seed production according to the principle of correlation relationship between floral and vegetative traits. The main and typical features of future cultivar of wide-spread Leymus divaricatus (Drobow) Tzvelev are presented by an identity card of future cultivar. © 2021 Author(s).Ministry of Education and Science of the Russian Federation, Minobrnauka, (FEUZ-2020-0057)This work was supported by the Ministry of Science and Higher Education of the Russian Federation as part of the state assignment ʋ FEUZ-2020-0057

The Indicative Potential of the Forest-Tundra Landscape Component

In order to expand the possibilities of soil-cover remote monitoring and improve prognostic models of active-layer depth dynamics in connection with global climatic changes, the verification of correspondence between plant and soil components of subarctic landscapes is necessary. This is most relevant for the forest-tundra zone,where the variety and mosaicity of soils and vegetation is great due to its ecotonic position. The purpose of this work was to study the relationship of vegetation with the characteristics of cryogenic soils and the dynamics of the active layer in forest-tundra landscapes. Data were obtained during monitoring studies at key sites in diverse landscapes of forest-tundra in the vicinity of Labytnangi. It was revealed that the thickness of the organogenic horizons, as well as the value of the moss phytomass, determine the active-layer thickness. A close connection with relief and soils allows the use of vegetation as an indicator of the soil texture and the depth of active-layer occurrence and features. Keywords: plant communities, cryogenic soils, active layer, landscape, forest-tundra, Western Siberi

BIOLOGICAL CHARACTERISTICS ОF SEEDS ОF AMARANTHUS L. DURING INTRODUCTION IN THE BOTANIC GARDEN ОF URAL FEDERAL UNIVERSITY

In the botanic garden of Ural Federal University introduction of different species of Amaranthus L. is carried out for thirty years. We studied the sowing qualities of seeds belonging to 11 amaranth samples. The study showed that amaranth seeds are homogeneous. Germinative energy and germinating capacity of amaranth seeds remain at a high level up to 8–9 years of storage. The lightest seeds of A. powellii subsp. bouchonii and A. retroflexus lost laboratory germinating capacity after six years of storage. Seeds of other amaranth species lost germination after 12–13 years of storage.Работа выполнена при финансовой поддержке Министерства образования и науки РФ в рамках государственного задания № 6.7696.2017/8.9

Simulating hydrology with an isotopic land surface model in western Siberia: what do we learn from water isotopes?

International audienceImprovements in the evaluation of land surface models would translate into more reliable predictions of future climate changes, as significant uncertainties persist in the quantification and representation of the relative contributions of soil and vegetation to the water and energy cycles. In this paper, we investigate the usefulness of water stable isotopes in land surface models studying land surface processes. To achieve this, we implemented 18O and 2H and the computation of the oxygen (δ18O) and deuterium (δD) stable isotope composition of soil and leaf water pools in a~recent version of the land surface model ORCHIDEE. We performed point-wise simulations with this new model and evaluated its performance on vertical profiles of soil water isotope ratios measured in summer 2012 at four experimental sites located in a boreal region of the Artic zone of western Siberia. The model performed relatively well in simulating some features of the δ18O soil profiles, but poorly reproduced the d-excess profiles, at all four stations. The response of the simulated δ18O profiles to variations in key hydrological parameters revealed the importance of the choice of a correct infiltration pathway in ORCHIDEE. Our results show also that the strength of the evaporative enrichment signal plays a role in shaping the profiles, too and, therefore, the relevance of the vegetation and bare soil characterization. We investigated furthermore to which extent we are able to determine the relative contribution of the evaporation to the evapotranspiration. This study's results confirm that the use of water stable isotopes measurements helps constrain the representation of key land surface processes in land surface models

Testing the capability of ORCHIDEE land surface model to simulate Arctic ecosystems: Sensitivity analysis and site-level model calibration

Journal of Advances in Modeling Earth Systems, 2017International audienceThe ORCHIDEE land surface model has recently been updated to improve the representation of high-latitude environments. The model now includes improved soil thermodynamics and the representation of permafrost physical processes (soil thawing and freezing), as well as a new snow model to improve the representation of the seasonal evolution of the snow pack and the resulting insulation effects. The model was evaluated against data from the experimental sites of the WSibIso-Megagrant project (www.wsibiso.ru). ORCHIDEE was applied in stand-alone mode, on two experimental sites located in the Yamal Peninsula in the northwestern part of Siberia. These sites are representative of circumpolar-Arctic tundra environments and differ by their respective fractions of shrub/tree cover and soil type. After performing a global sensitivity analysis to identify those parameters that have most influence on the simulation of energy and water transfers, the model was calibrated at local scale and evaluated against in situ measurements (vertical profiles of soil temperature and moisture, as well as active layer thickness) acquired during summer 2012. The results show how sensitivity analysis can identify the dominant processes and thereby reduce the parameter space for the calibration process. We also discuss the model performance at simulating the soil temperature and water content (i.e., energy and water transfers in the soil-vegetationatmosphere continuum) and the contribution of the vertical discretization of the hydrothermal properties. This work clearly shows, at least at the two sites used for validation, that the new ORCHIDEE vertical discretization can represent the water and heat transfers through complex cryogenic Arctic soils-soils which present multiple horizons sometimes with peat inclusions. The improved model allows us to prescribe the vertical heterogeneity of the soil hydrothermal properties