Aboveground Phytomass Research Articles

Productivity of plant genotypes of species Galega L. genus during introduction in the Right-Bank Forest-Steppe of Ukraine

To establish the features of the formation of productivity elements of plant of the genus Galega species, depending on the genotypic characteristics and conditions of vegetation during the introduction in the Right-Bank Forest-Steppe of Ukraine. Methods. In 2004–2020 in labo­ratory and field conditions, six plant varieties of the genus Galega of the M. M. Gryshko National Botanical Garden selection were studied. The following methods were used: general scientific, biological and morphological, laboratory, field and statistical. Morphometric parameters such as plant height, number of shoots, leaves, inflorescences per plant, fruit size, length of the root system, as well as productive potential, nitrogen-fixing ability of plants, mass of productive shoots, heat capacity, yield of aboveground mass, yield of dry matter per unit area were assessed. Results. It was found that the genotypes of G. orientalis Lam. (‘Kavkazkyi Branets’, ‘Saliut’, ‘NBS-75’, ‘Riabchyk’) and G. officinalis L. (‘Harant’, ‘Flaminho’), when introduced in the Right-Bank Forest-Steppe of Ukraine, are characterized by high productivity of aboveground phytomass (from 28.6 to 62.4 t/ha), as well as by the yield of dry matter (from 7.12 to 16.5 t/ha). In the structure of the aboveground mass of genotypes, stems accounted for 37.0–44.2%, leaves – 40.9–51.4%, inflorescences – 11.6–14.9%. The heat capacity of the raw material of G. orientalis plants was 4051–4275 kcal/ha. The total energy output reached 30.44–67.85 Gcal/ha. Conclusions. It was revealed that plants of species of the genus Galega have a high bioproductive potential, and are able to provide raw materials for biogas production. The best of the six studied genotypes were ‘Flamingo’, ‘NBS-75’, and ‘Riab­chyk’.

Динаміка вмісту 137Сs у тканинах і органах сосни звичайної (Pinus Sylvestris L.) у вологих суборах Полісся України після аварії на ЧАЕС

Based on multiyear monitoring observations, dynamics of 137Сs intake into the main tissues and organs of aboveground phytomass of Scots pine (Pinus sylvestris L.) during 30 years from the Chornobyl accident was determined as well peculiarities of their radioactive contamination. Empirical (observations), radioecological and statistical methods were used. It was found that for the wood increase of values of transfer factor was observed between 1991 and 2002 yrs with the further monotonous decrease of this value up to 2020; in internal bark, 1-year shoots, 2-year shoots, 1-year needles, 2-year needles, twigs thick and twigs thin multiyear dynamics was similar – an increase of values of transfer factor in the period of 1991 - 2002 yrs with further decrease of it up to 2020. At external bark, monotonous decrease of values of transfer factor was found during the whole observation period 1991 - 2020.

GEOGRAPHICAL PRINCIPLES OF DISTRIBUTION OF INVASIVE FLORA OF RAILWAYS IN KIROVOHRAD REGION

Development of transport capable to overcome distances of the planetary level, was caused to more intensive, than early, expansion allied, especially invasive, species of plants that become concurrent for aboriginal flora. Phytoinvasions are one of the most important geoecological problems of our time, as they disrupt the species composition and structure of natural phytocenoses, ultimately leading to the impoverishment of the plant component of landscapes and the reduction of biodiversity. One of leading factors in the spread of adventitious and, in particular, invasive species is rail transport, as a result of which seeds and organs of plants capable of taking root and gradually displacing the aboriginal flora get in the way.
 Although among the invasive flora of Kirovohrad region there are representatives of different systematic groups and life forms of plants, still clearly dominated by angiosperms and - at the same time - herbaceous plants. Main peculiarities of the space differentiation are described by the examples of railway stations of Holovanivsk and Znamianka situated consequently in the West and the East of the Kirovohrad region. The most common representative of the invasive flora of the railways of the studied region is ragweed, also widespread grindelia spread (in the west of the Kirovograd region) and sweet silique (in the east of the region). Of the families of flowering plants, the most widely represented are Aster (Compositae), a significant place is occupied by Cabbage (Cruciferous), Thin-legged (Cereals), Legumes and others.
 Factors contributing to the naturalization of invasive species and their rapid displacement of aboriginal flora are various. The main ones are eurybiont, unpretentious to the conditions of the habitat, the significant size of the aboveground phytomass.
 The internal diversity in the invasive flora of the region's railways is mainly due to the influence of the factor of the sectoral nature of natural conditions within the territory rather elongated from west to east. Therefore, in the presence of clear common features characterizing the invasive flora of the region, the differences associated with predominance of moisture-loving plants in the western part of the region and drought-resistant plants in the eastern part are noticeable.
 The practical use of the study results is associated with the possibility of improving the system of measures to combat phytoinvasions, taking into account the geographical features of the spatial distribution of individual species.
 Results of the investigation may be used during realizing tasks of ecologization of land using, especially defining priorities in the struggle with invasive species of the plants of railways. Discovered internal differentiation in expansion different allied species in Kirovohrad region gives a ground for defining the most important factors of distortion natural biodiversity in its different parts. Studying space peculiarities of expansion allied flora has a significance for create concrete actions directed to renewing initial space composition of phytocenosis and landscapes distorted by invasions.
 Key words: invasive flora, railway tracks, Kirovohrad region, adventitia, ragweed, grindelia spread, itching eastern.

Vertical-Fractional Structure of Aboveground Phytomass of the Tree Layer of Pine Forests in the Northern Ural Foothills (Komi Republic)

Vertical-Fractional Structure of Aboveground Phytomass of the Tree Layer of Pine Forests in the Northern Ural Foothills (Komi Republic)

Biomass and mortmass of woody vegetation in metal-contaminated areas (Southern Urals, Russia).

BackgroundSince the mid-2000s, long-term monitoring of various components of natural ecosystems under conditions of industrial pollution has been carried out in the Southern Urals. As a part of these monitoring programmes, the data on various components of biota in different biotopes, collected with different methods and in different time intervals, continue to be gathered. In addition, data collected through these monitoring programmes can also be used to study the local biodiversity of non-polluted areas.In 2012, in the vicinity of the Karabash Copper Smelter, a study of communities of small mammals was carried out, considering the heterogeneity of their habitats. Within the framework of this project, we presented a detailed description of the state of woody vegetation in the study area.New informationThe dataset (available from the GBIF network at https://www.gbif.org/dataset/61384edd-2d0a-437b-8cf0-ff4d2dfcc0da) includes the results of an assessment of the woody vegetation biomass at seven habitats (pine, birch and floodplain forests, reed swamp, sparse birch stand, marshy meadow and dump of household waste) of areas with different levels of industrial pollution in the vicinities of the Karabash, the Southern Urals. Karabash Copper Smelter (KCS) is one of Russia’s most significant point polluters; the main components of its emissions are heavy metals, dust and sulphur dioxide. Parameters of woody vegetation (diameter at breast height, diameter at root collar level and biomass) were estimated for seven forest elements (forest stand, subcanopy (undergrowth and underwood), half-dead tree of a forest stand and four types of coarse woody debris (downed bole, fragment of downed bole, standing dead tree and stump)) at 41 sampling plots (20 at unpolluted and 21 at polluted areas) and 165 subplots (81 and 84, respectively). The dataset includes 411 sampling events (estimation events of the forest elements at sampling plots and subplots), corresponding to 5786 occurrences (estimations of the woody vegetation components) observed during July 2012. For most woody vegetation components (72%), an estimate of the above-ground phytomass is given. For each sampling event, information on the presence or absence of woody vegetation species at the considered habitats is provided (a total of 1479 occurrences with status "absent"). The dataset can be used for environmental monitoring, sustainable forest management, modelling forest productivity considering global changes, studying the structure and biodiversity of forest cover and assessing forests’ carbon-sequestration capacity. In addition, the dataset provides information about different forest ecosystems under the influence of strong industrial pollution.

Seasonal development of aboveground phytomass of evergreen introduced plants on the Southern Coast of the Crimea

For the Southern Coast of Crimea, the problem of park communities’ productivity, due to the high recreational load on the environment and climate change, is of particular relevance. The aim of the research was to study the features of the introduced park communities evergreen aboveground phytomass formation and seasonal growth in the conditions of the Southern coast of the Crimea. A comparative assessment of vegetative shoots seasonal growth features of plants Laurus nobilis L., Prunus laurocerasus L., Viburnum tinus L., Aucuba japonica Thunb and Nerium oleander L. was performed. It was found that the time of renewal of shoot growth in spring after winter dormancy in V. tinus and A. japonica began at 459-462 °C, P. laurocerasus - 649 °C, and L. nobilis - 886 °C and N. oleander - 990 °C amounts of active air temperatures above 5 °C. The largest growth (49.3 cm) and the accumulation of leaf phytomass (42.3 cm3) differ in annual shoots of N. oleander. P. laurocerasus has a great potential with a phytomass volume an annual shoot of 24.5 cm3. The increase of shoots phytomass in V. tinus, A. japonica, and L. nobilis is 7-8 times less than that in N. oleander.

ПОКАЗАТЕЛИ ХЕМОДЕСТРУКЦИОННОГО ФРАКЦИОНИРОВАНИЯ ОРГАНИЧЕСКОГО ВЕЩЕСТВА ПОЧВ ПРИРОДНЫХ И АНТРОПОГЕННО ПРЕОБРАЗОВАННЫХ ЛАНДШАФТОВ ЮГА ПРИМОРЬЯ

The differences in the qualitative composition of organic matter in the soils of natural and anthropogenically transformed landscapes in the south of Primorye were established by the method of chemodestructive fractionation (CDF). The lowest indices of the easily oxidizable part (EOP) in the organic matter are typical for soils of technogenic landscapes (embryozems) with very low humus content due to low reserves of aboveground phytomass and the supply of fresh organic matter of plant origin. Embryozems are characterized by a low supply of humus with nitrogen. Higher EOP values are characteristic of soils of natural landscapes (burozems) with average humus content. In burozems, oxidative and eluvial processes are balanced by humus formation. In the soils of agrogenic landscapes (agro-dark-humus podbeles, agro-dark-humus gley soils) with low humus content, the proportion of EOP decreased and, at the same time, the proportion of the hardly oxidized part in the composition of soil organic matter increased. Some increase in EOP was recorded in agro-dark-humus gley soils with rump crops, which is associated with the intensification of the transformation processes of organic matter and the transition of organic matter from the difficult-to-oxidize to the easily oxidized part. Based on the data obtained on the qualitative composition of organic matter, the CDF method implies that in the soils of natural landscapes (burozems), the proportion of EOP exceeded that in comparison with soils of agrogenic (agro-dark-humus podbely, agro-dark-humus gley) and technogenic landscapes (em-briozems). This indicates differences in the conditions of soil formation and the ongoing oxidative and humus-forming processes.

Tuning Potassium and Magnesium Fertilization of Potato in the South of West Siberia

Imbalance of nutrients limits crop yields. Although K fertilization receives sufficient attention in research and practice, Mg supply is rather neglected. The effect of Mg fertilization (0, 5 and 10 g Mg/m2), combined with two K fertilization rates (10 and 15 g K/m2), on potato production and soil exchangeable K and Mg was studied in a three-season microplot field experiment in the Novosibirsk region, Russia. Tuber yield did not respond to the increased K fertilization, but increased at 5 and decreased at 10 g Mg/m2. Total Mg concentration in tubers increased at 15 g K/m2, whereas N, P and K were not affected by fertilization. The tuber yield was maximal (3.6 kg/m2) at 10 g K/m2 and 5 g Mg/m2. Soil exchangeable Mg increased by the year, resulting in preferential development of the aboveground phytomass due to apparently increased Mg availability and K/Mg imbalance. Potato production depended on the year, strongly implicating weather conditions. Therefore, the weather and the chemical nature of K and Mg fertilizers (as pertinent to their release mode from fertilizer in soil), are important for balancing their proportions and amounts while assessing interactions among nutrients in potato production and adjusting regional fertilization strategies.

The Korean pine aboveground phytomass determination in the Far East south conditions

The forest stands phytomass purposeful studies in the Far East have not been carried out enough. Phytomass determination was mainly carried out as a necessary element for assessing physiological, hydrological and silvicultural processes in the forest. Phytomass largely determines the carbon sequestration, the litter amount, fire hazard, etc. (ibid.), its organic matter contributes greatly to the overall carbon and nitrogen cycle in the forest ecosystem. Research has been carried out to analyse the age 100-70 years pine plantations aboveground phytomass, growing in the Vladivostok agglomeration green zone. On the Vladivostok agglomeration green zone territory, four test plots were laid to assess the Korean pine phytomass according to the Atkin A.S. method, the size of the test plots was 0.4 hectares, the samples were laid in forest 3 types: rhododendral oak forests, shrub-forb oak forests, sedge ash forests - forbs. The Korean pine aboveground phytomass was calculated based on the Vladivostok forestry (stock) taxation description data. The presented materials’ analysis indicates that the Korean pine aboveground phytomass is characterized by high variability even within a specific forest type, it ranges from 7 to 35 t/ha (forest type D4). The data on any species’ trees aboveground phytomass reserves from the trial plots allow us to calculate the aboveground phytomass reserves on all trial plots and per 1 forest hectare.

Growth, development, morphology and biochemical characteristics of <i>Solidago canadensis</i> L. plants when introduced in the middle taiga subzone of the Komi Republic

The paper presents the results of a long-term study of four samples of Canadian goldenrod (Solidago canadensis L.) of different geographic origin introduced in the middle taiga subzone of the Komi Republic. Under cultural conditions, the species is highly resistant and longevity (up to 18 years). It has been established that with the introduction in the North, reproduction of the Canadian goldenrod is possible by vegetative means, as well as from seeds of foreign origin. The mass transition of plants grown by seedlings to the generative period occurs in the third year of life. According to the flowering rhythm (July 31 September 25), the species is classified as a mid-summer-mid-autumn plant. Fruiting of plants is interrupted by frost, full-fledged seeds are not formed. The morphological features of the generative shoot have been studied. The plant height in culture reaches 143155 cm. The number of leaves on the stem is 63101. The floral part of the shoot (inflorescence) 3039 cm long is formed from the axils of 4149 leaves and consists of 2141 paracladia 813 cm long. The number of baskets on one shoot in different specimens of Canadian goldenrod varies from 2700 to 4200. The content of nitrogen mass fraction (1,83,0%) in the aboveground raw phytomass of Canadian goldenrod has been studied for the first time and the quantitative and qualitative composition of amino acids in plant proteins has been determined. The total content of amino acids in the plant raw material of Canadian goldenrod has varied from 7,9 to 15,1% over the years. In the aboveground phytomass of plants, 17 amino acids have been found and determined, including 7 irreplaceable ones. The share of essential amino acids has averaged 37% of the total. The highest rates of equity participation have been noted for the following amino acids: proline, glutamic, aspartic, lysine, leucine, valine, alanine, arginine and glycine 13,2; 11,0; 10,8; 8,4; 8,0; 5,9; 5,8; 5,7 and 5,2%, respectively. In the conditions of the North, biochemical studies of this species have been carried out for the first time. The content of flavonols in the aboveground raw phytomass of Canadian goldenrod have been 4,55,7% and met the requirements for medicinal raw materials (more than 3%). The yield of essential oil and its component composition have been determined. The EO content in the aboveground phytomass of plants has varied from 0,85 to 1,7% in terms of absolutely dry raw material. In the composition of EM, 39 components have been reliably identified, nine of which have been attributed to the main ones. The dominant compounds are: -pinene (up to 43,9%), myrcene (up to 18,2%), limonene (up to 13,2%), -3-carene (up to 12,0%); from sesquiterpenoids: germacrene D (up to 54,3%), bornyl acetate (up to 5,8%), geranyl acetate (up to 2,4%), cadinadiene (up to 2,0%), sesqui-fellandrene (up to 1,4%).

Сравнительный анализ биоэнергетической продуктивности культурфитоценозов сосны обыкновенной европейского севера

The bioenergetic productivity of artificial pine stands is considered. It was found that in 30-year-old artificial pine coenoses, the lowest amount of energy associated with the tree layer is observed in the lichen type of growing conditions (443,1 GJ/ha), the highest — in the blueberry (1915,1 GJ/ha). Bioenergetic productivity occupies an intermediate position (1210,7 GJ/ha) in the cranberry-type forest culture phytocenoses. It is shown that the accumulated energy reaches the highest relative value in such a component of aboveground phytomass as trunk wood. For this fraction, the variation is observed from 50.2% in the lichen type of growing conditions to 65.8% in the blueberry type, based on the total stock of phytomass of forest crops. It is established that the secondary position relative to this indicator is occupied by woody greens. The share of the energy productivity of needles in the total aboveground phytomass decreases with the improvement of forest growing conditions. An approximately equal ratio of energy deposition in the studied types of artificial pine forests by the fractions of bark and live branches (7,2...11,7%) was determined, and the smallest share of accumulated energy falls on the fraction of dry branches (5,3...7,0 %).

Phytodiversity and bioproductivity of the Leymus chinensis steppes in eastern Transbaikalia

The research objective is caused by wide spread of leymus communities in the southeastern Transbaikalia and gaps in studying their species composition, structure, and phytomass accumulation; it is to give a phytocenotic characteristics of leymus communities in the steppe zone of eastern Transbaikalia, and to determine the level of their biological productivity using standard geobotanical, agrochemical and soil methods. The paper studies monodominant Leymus chinensis communities growing on various soil types of meadow steppe, steppe floodplain meadows and haloxerophytic steppe of the south-eastern Transbaikalia. The species composition of communities is represented by 21 families, 45 genera, 62 species. Halophytes account for 11.3 % (7 species), halotolerant – 29 % (18 species), glycophytes – 59.7 % (37 species). The species of the families Asteraceae – 30.6 %, Poaceae – 17.7 %, Rosaceae – 8 % form the largest share in the projective cover of communities. The rest families are of 1 – 2 species. The species composition of Leymus is represented mainly by the steppe complex with xerophytes different variants belonging to the Asian type of area. The main part belongs to rhizome species in the biomorph composition, and the share of annuals and biennials is significant as well. The similarity between communities is within the range from low to medium, which is due to the great participation of single-species families and genera. The authors have assessed the contribution to aboveground phytomass of a dominant species, Leymus chinensis, other species and died grass. The greatest contribution of ears to the aboveground phytomass is marked only in Descriptions 4 and 5. The primary production of Leymus chinensis communities is estimated as high, 2105 – 3189 g/m2 a year. Underground phytomass is 84 – 94 % of the total productivity. The underground and aboveground phytomass ratio is 1:5 – 15, that is determined by various soil and environmental conditions of growing the communities.

Steppe felt accumulation in Leymus chinensis communities of eastern Transbaikalia and transformation of its chemical composition

The study objective is to determine stocks and chemical composition of died phytomass and felt in Leymus coenoses in southeastern Transbaikalia. Using standard field geobotanical tools, the authors have determined macroelement composition by generally accepted techniques, calculated indicators of litter-fall index (LFI), C/N, C/P, C:N:S:P, Ca/K ratios. Statistical data processing has been carried out in Microsoft Excel. At present, the felt stock is 54 – 107 g/m2. Died phytomass content depends on the species composition in the coenoses, soil and environmental conditions of their growth, and the grazing load degree. The coefficient of correlation between died phytomass and felt content shows moderate value. The steppe litter-fall index indicates a low rate of felt decomposition. The felt chemical composition is defined by soil and environmental conditions (supply of nutrients and moisture). For the first time study has revealed that died phytomass and felt are highly resistant to decomposition and mineralization according to C/N, C/P, C:N:S:P and Ca/K ratio values in the aboveground phytomass of coenoses. However, the resistance can be adjusted once the species composition, climatic (drought, heavy rainfall) and anthropogenic conditions (spring burnings and steppe fires) change.

Effects of fire on production and destruction processes in steppe phytocenoses of Burtinskaya Steppe, Orenburg Nature Reserve

The paper deals with the production and destruction process in burned and unburned (control) steppe phytocenoses. The fire occurred in August 2014, after which a monitoring network consisting of 6 sites was laid out. During two vegetation seasons (2015 – 2016), we surveyed above-ground and below-ground phytomass stocks and on their basis production and destruction amounts in phytocenoses were calculated. Comparative analysis of control and burned communities revealed higher production and destruction of above-ground phytomass components in both years. With the general tendency for most phytocenoses to reduce above-ground production and increase litter in the second year of the survey, the first process was more intense in burned phytocenoses that were exposed to anthropogenic load in the past, and the second process occurred in almost all burned communities. In the below-ground sphere, mineralization processes were more intense during the entire survey period on control sites, and an increase in the mass of living and dead below-ground organs was more determined by the phytocenoses specifics, rather than their damage by fire.

Формування відпаду дерев у насадженнях парку-пам’ятки садово-паркового мистецтва загальнодержавного значення «Феофанія»

Tree stand mortality in urban ecosystems indicates the influence level of biotic and abiotic factors primarily on their life state. The significance of these processes lies in the knowledge of the forest stands patterns development and their use for forecasting and assessing ecosystem services. The territories of the nature reserve fund have been taken as research sites, as significant indicators of anthropogenically altered territories. The structure of biomass and forest stands species composition was found to be associated with the growth and development of living trees and the formation of dead trees. Biotic and abiotic factors, intraspecific competition and peculiarities of local formation condition and stands growth are determined to affect the life state of the main forest-forming species directly and indirectly. It was revealed that in the medieval oak plantation, the loss of trees during the research period (2016-2020) prevailed over the increase in the stand ground phytomass. It was found that the carbon deposited amount in the forest stands aboveground phytomass reflects the unusual dynamics for the overwhelming number of territory indicators. The litter formation caused the changes in the deposited carbon structure of the research stands phytomass by tree species. It also led to an increase in the deadwood carbon pool and the onset of carbon emissions from the detritus decomposition.

Рекультивированные земли как резерв кормовой базы животноводства

Abstract. The purpose is to establish the possibility of using mined brick clay pits for grazing livestock and preparing animal feed. The paper deals with the investigation of the above ground phytomass field layer (Fh) being formed dusing the natural growth of mined brick clay pits. Methodology. Species composition of the projective cover and aboveground phytomass were established on the counting areas of 0.5 × 0.5 sizes evenly spaced on the bottom and slopes of pit. At each of the quarry elements at least 30 registration sites were laid. In addition a similar number of registration sites were laid next to the quarry where clay was not mined. Researches were carried out in the district of pine-birch pre-forest steppe forests of the Trans Urals plain province, the west Siberian plain forest region. Results. It was found that the soil of mined out pits does not contain heavy metal and other chemical elements hazardous to animals. The total aboveground phetomass of Fh at the bottom and slopes of the quarry is 1101.1 and 812.6 kg/ha in absolutely dry, state, respectively. The total projective cover at the bottom of the quarry 3 years after the technical stage of reclamation is 64.7 % and on the slopes 42.5 %. The presence of meadow species in the composition, in particular of legumes family (Vicia cracca L.; V. hybridum L.; V. sativa L.; V. vernus L.; V. sylvatica L.; Trifolium pretense L.; T. lupinaster L.; T. repens L.; T. hybridum L.; T. medium L.; Lathyrus pratensis L.; Melilotu salbus Medikus; M. officinalis L. Pall.; Medicago lupulina L.) indicates a high feed value of FR. Scientific novelty. The transfer of mined out brick clay pits for temporary agricultural use will contribute at the formation of soil on the bottom and slopes of the quarry and ultimately, increase the productivity of future plantations.

Productivity of a promising forage species Poterium polygamum Waldst. & Kit. in the conditions of North Ossetia-Alania

The article presents the results of a long-term study of Poterium polygamum Waldst. & Kit. when introduced into culture in the collection nursery of plants of the Research Institute of Biotechnology in the Botanical Garden of the Gorsk State Agrarian University (Republic of North Ossetia-Alania) with the participation of the staff of the Botanical Garden of the Belgorod State University. The morphological features of P. polygamum are described: the structure of vegetative and generative organs. An assessment of the dynamics of the formation of aboveground phytomass, indicators of photosynthetic activity, productivity of the aboveground mass and seed productivity during the cultivation of P. polygamum under the conditions of culture is given. It has been established that the species P. polygamum, which is promising for fodder production, has a high bioresource potential under the conditions of North Ossetia-Alania and in culture can ensure the maintenance of the stability of cenopopulations throughout all the years of cultivation. The leaf area on average over four years of research was 48.5 thousand m2 (ha−1), photosynthetic potential-1.3 million m2 (ha−1), net productivity of photosynthesis-4.7 g (m−2) per day, yield of aboveground phytomass-321 q (ha−1) (r = 0.39-0.91). On average, when cultivated in culture, individuals of P. polygamum formed generative shoots-843.9 pcs. (m−2) per day; heads on 1 shoot-3.7 pcs.; seeds in 1 head-10.1 pcs.; seeds from 1 shoot-1.0 g; have a mass of 1000 seeds-8.6 g; seed yield-862.6 kg (ha−1). Seed productivity of P. polygamum varied from 773.3 to 947.8 pcs. per 1 m2. At the same time, the coefficient of seed productivity varied from 19.5 to 40.9%. Such stable productivity allows individuals of P. polygamum in natural conditions to withstand competition with other plants, and in culture makes the species promising for cultivation as a forage species.

PLANT MATTER OF THE KHAKASIA CATENA

The article presents the material on the species composition and biological productivity of grass ecosystems along the catena to Lake Utichye on the territory of the Iuso-Shirin steppe of Khakasia. Describs pattern of below-ground and above-ground components in stepр ecosystems 30% of the living phytomass is located in the soil and no then 60 % is allocated in below-ground organs. The productivity of the steppes varies depending on the type of ecosystem. In the ecosystem of the desert steppe, the vegetation cover has a minimum number of species, aboveground phytomass, a maximum number of underground organs, and the fraction of dead roots prevails, up to 50%. The richer and more humid ecosystems, the greater the diversity of species in the vegetation cover, the more reserves of aboveground phytomass and living underground organs. Dead root stocks are reduced to 20-35%.

Растительность и ее значение в формировании лугово-коричневых почв

The studied meadow-brown soils of moderately dry subtropics of Azerbaijan are formed under thinned forest-bush and lacustrine — grass vegetation. In meadow-brown and other types of meadow soils, vegetation development and phytomass formation are influenced by soil and surface moistening. Aboveground phytomass which plays an important role in humus formation of natural and cultural cenoses of meadow soils creates plant biomass of 32–60–76 cwt/ha and 55–110–119 cwt/ha.

Изменение кормовых запасов оленьих пастбищ в южных субарктических тундрах Ямала

Abstract. The relevance of the research is related to the need to monitor the resource potential of the vegetation in the southern subarctic tundra. The Yamal tundra has been experiencing a high grazing pressure since 1990. As a result of the increase in the number of private farms and the number of domesticated reindeer in Yamal, pasture degradation occurs (trampling of forage mass, shredding vegetation, disappearance of lichen cover, increased soil deflation). Purpose of the research is compare the forage stocks of reindeer pastures in the southern subarctic tundra of Yamal in 2017–2018 and in the 1990s. In the course of the study, estimates of the amount and structure of forage stocks in plant communities of the southern subarctic tundra of the Yamal Peninsula was assessed in the vicinity of the Payutayakha river. The stock of aboveground phytomass was determined by the mowing method. In 2017, degraded areas of the tundra were studied, and in 2018 undisturbed and intact areas were investigated. Scientific novelty. The data obtained are compared with the estimates published for the southern subarctic tundra in the 1990s. Results. Forage stocks in degraded areas, compared to stocks in the southern subarctic tundra in the 1990s, decreased 14 times; while in on undisturbed areas they decreased 3 times. In the structure of forage stocks in 2017–2018, compared to the situation at the end of the 20th century, the proportions of shrubs, lichens and grasses has decreased; the proportion of dwarf shrubs in degraded areas increased 4 times, while in undisturbed areas it increased 6 times. The study confirms the existence of overgrazing and a shortage of forage resources on pastures in the zone of the southern subarctic tundra of Yamal.