Phytomass Production Research Articles

No detrimental effects of delayed mowing or uncut grass refuges on plant and bryophyte community structure and phytomass production in low-intensity hay meadows

To maintain European semi-natural grasslands, agri-environment schemes (AES) have been established in many countries but their biodiversity benefits have remained limited. We tested the effects of three new mowing regimes designed to benefit biodiversity in extensively managed meadows across the Swiss lowlands. Our experimental treatments mimicked easily implementable farming practices. We previously showed that invertebrates benefit from delayed mowing and leaving an uncut grass refuge. Here we focus on the effects on plant and bryophyte communities.We compared the standard AES practice (earliest mowing on June 15, no fertilizer input, but no restriction on number of cuts) to three alternative mowing regimes: (i) earliest mowing delayed by one month, (ii) maximum of two cuts per year with at least eight weeks in between, and (iii) leaving an uncut refuge on 10–20% of the meadow area in 12 study areas in the Swiss lowlands. We also tested for the interactive effects of ambient temperature, precipitation, elevation, meadow size, local forest cover, time since AES registration, and phytomass production.After five years of application, we found no difference in the effects of mowing regimes on vascular plant or bryophyte species richness, community composition, phytomass, flowering phenology or average plant height (the latter two indices were derived from the literature). However, cutting frequency and hay nutritional quality (C:N and Ca:P ratios) were lower under delayed mowing. Vascular plant and bryophyte species richness as well as forage quality were negatively related to phytomass, while the latter was positively related to mean summer temperature and negatively to time since AES registration.We conclude that supporting invertebrate biodiversity with alternative mowing regimes has no detrimental effects on the vascular plants and mosses, while the reduced forage quality calls for additional financial compensation of the farmers adopting these agri-environment schemes.

Evaluacion de la frecuencias de corte del pasto guinea mombaza (Megathyrsus maximus, Jacq), en condiciones de sol y sombra natural en el municipio de Sampués, Sucre-Colombia

El presente estudio tuvo como objetivo realizar un comparativo de diferentes frecuencias de corte en pasto guinea mombaza (Megathyrsus maximus), bajo sol y sombra natural influenciada por el dosel del árbol de campano (Pithecellobium saman), en condiciones de la Subregión Sabanas de Sucre. Este estudio se llevó a cabo en la granja Los Pericos de la Universidad de Sucre. La siembra del pasto se realizó con semillas de guinea mombaza certificadas, la cual fue trasplantada en suelo un mes después. Los factores analizados correspondieron a tres frecuencias de corte (25 días, 35 días y 45 días) a única altura de 30 cm y dos condiciones (luminosidad y sombreado). Los datos fueron analizados de acuerdo con un diseño de bloque completamente al azar en arreglo de parcelas dividas. La luminosidad tuvo influencia significativa sobre la variable altura de planta, número de macollas por planta, número de tallos verdes/planta, perímetro de la planta, diámetro de la planta, producción de fitomasa verde (Aforo). La materia seca influenció el índice de área foliar y al número de tallos secos por planta con respecto a la variables largo de la hoja, ancho de la hoja, y número de hojas por planta, quienes no mostraron diferencia significativa. Los resultados obtenidos en el presente estudio permiten concluir que la especie de pasto Megathyrsus maximus cv. mombaza mostró una variabilidad morfológica que permite su adaptación a las condiciones de luz plena y sombra natural.

Short communication: Effects of summer rainfall variations on sheep body state and farming sustainability in sub-Mediterranean pastoral systems

In sub-Mediterranean climate the grassland aboveground phytomass production peaks in late spring and drops in summer, when the decrease of the pasture feed value may lead to the worsening of the animal welfare. Our goal was to define the summer rainfall values leading to a decrease of semi-extensive farming system sustainability in sub-Mediterranean regions. Summer rainfall variations reflect in the aboveground phytomass production and on the sheep body state. Differences of body condition score (BCS) among years were significant in late summer, which is the mating period for sheep. In the driest year the BCS of end August drops down to 2.1, largely below the value considered sufficient to ensure the animal breeding/milking performances (2.5). Reduction of summer rainfall greater than 15–20% compared to the normal average value (thus less than expected by the scenario of climate change) might be detrimental for semi-extensive rearing sustainability in sub-Mediterranean climate.

Efecto del envase y del riego en vivero en el establecimiento de Pinus cooperi Blanco en dos condiciones de sitio

Se evaluó en campo, en dos sitios con características climáticas contrastantes: El Carmen, Durango y Santa Lucía, Pueblo Nuevo, Durango, el efecto de la calidad de planta de Pinus cooperi Blanco producida en vivero en envases de 80 cm3 y 170 cm3 de volumen y regada en la fase de preacondicionamiento cada 48, 96 y 168 horas. Los tratamientos se distribuyeron en un diseño experimental de bloques al azar, con un arreglo en parcelas subdivididas. Durante 18 meses se evaluó supervivencia, crecimiento en diámetro y altura, así como producción de fitomasa. La planta producida en el envase de 170 cm3 resultó superior estadísticamente (p<0,05) en diámetro, con 9,26 mm y en producción total de fitomasa con 19,0 g. Por otro lado, la planta regada cada 96 horas resultó superior estadísticamente (p<0,05) en diámetro, con 9,17 mm y en producción de fitomasa con 17,9 g. El tamaño de envase y la frecuencia de riegos no influyeron estadísticamente (p>0,05) en la supervivencia y crecimiento en altura de las plantas. El factor sitio de plantación sólo tuvo diferencias significativas (p<0,05) en la supervivencia y en el crecimiento en altura de las plantas. La supervivencia fue superior estadísticamente (p<0,05) en el sitio El Carmen, Durango, con 85,6 %, mientras que el crecimiento en altura sobresalió en Santa Lucía, Pueblo Nuevo, Durango con 18,5 cm.

Increase of forage dryness induces differentiated anatomical response in the sheep rumen compartments.

The aim of this study was to investigate how the Surface Enlargement Factor (SEF) and the epithelial keratinization degree of sheep rumen change in response to phytomass production, and to forage fiber and water content during the pasture vegetative cycle. The study used eighteen sheep nourished with dry hay and cereals during the winter season and with fresh hay during the pasture vegetative cycle. We collected samples from rumen indicative regions for two consecutive years characterized by different rainfall and pasture productivity values. We evaluated the densities (D) of rumen papillae to estimate the rumen SEF, and the keratinization percentage of the epithelial lining; these parameters showed differentiated modifications in the four ruminal analyzed compartments in response to pasture seasonal conditions. In addition, we performed Canonical Redundancy Analysis (RDA) on the "keratinization and SEF" matrix constrained by phytomass, water, and crude fiber contents of pasture at different time in the two considered years to highlight how rumen features answer to pasture conditions. Atrium (A) and ventral sac (VS) keratinization showed a strict positive correlation to crude fiber, while SEF of VS was positively related to phytomass and forage water content. The degree of keratinization of the rumen VS epithelium proved to be a useful parameter for evaluating anatomical variations in the short term period related to pasture features; in addition, its monitoring could be carried out through biopsy, thus avoiding the killing of animals. The study also leads to the application of the 3Rs (Replacement; Reduction; and Refinement). Microsc. Res. Tech. 79:738-743, 2016. © 2016 Wiley Periodicals, Inc.

Nitrogen fertilization on palisadegrass: phytomass decomposition and nutrients release

ABSTRACT Topdressing or pre-seeding nitrogen (N) application increases phytomass production, providing a higher nutrients accumulation and indirectly favoring the subsequent crop. However, N fertilization can alter the dry matter decomposition and nutrients release dynamics. This study aimed at evaluating the decomposition rate, cellulose, lignin and nutrients release speed from palisadegrass as a function of N fertilization. The experimental design was randomized blocks with four replications, in a factorial scheme constituted by two N fertilization levels and six sampling times after desiccation [0, 14, 34, 41, 51 and 68 days after management (DAM)]. The topdressing N fertilization on palisadegrass increases the dry matter production and N accumulation, but does not alter the decomposition and release speed. N fertilization reduces the C/N ratio, but it does not change the contents of cellulose and lignin and the decomposition and release of N, K, Ca, Mg, C and Si. The amounts of P and S accumulated in the plant and released into the soil increase with N fertilization. The maximum release rates occur within 0-14 DAM, being more intensive for P and S when N is applied. These results demonstrate the high potential of this species for crop-livestock integration systems, with some advantages that can be potentialized with higher N doses.

Carbon storage of anthropoid’s vegetation on the Ngaoundere escarpment (Adamawa, Cameroon)

A study carry out on carbon storage of anthropoid’s vegetation on the Ngaoundere escarpment on four vegetaltypes (fallow, farms, shrub savanna and woody savanna) with the aim of fighting against climate change. Dendrometricdata to determine phytomass and carbon storage were carried out on plot of 20m x 50m. Data analysis with the aid of software programs like excel, Stat graphics plus S.O and XLSTAT showed the most anthropoid vegetation (fallow and farms)present a low production of phytomass and carbon storage as compared to natural vegetation (shrub and woodysavannas). Carbon credit is proportional to the quantity of carbon storage in the different vegetation formations to alleviatethe effect of human activities of the vegetation of the escarped the subvention of the local population through carbonshould be encouraged.

The Effect of Varying Speed Release of Nutrients from Fertilizers on Growth-production Process of Turf

The aim of this experiment was to compare the influence of fertilizers with different speed of nutrients release on growth–production indicators of turf under non–irrigated conditions. The experiment was carried in warm and dry conditions in area Nitra (Slovak Republic). In the experiment were followed 5 treatments (1. without fertilization, 2. Nitre with dolomite, Superphosphate, Potassium salt, 3. Turf fertilizer Travcerit®, 4. Slow release fertilizer SRF NPK 14–5–14 (+ 4CaO + 4MgO + 7S), 5. Controlled release fertilizer Duslocote® NPK (S) 13–9–18 (+6S)). The highest gain of height reached variant fertilized by fertilizer SRF NPK 14–5–14 (+ 4CaO + 4MgO + 7S). Comparison of the individual treatments for the whole period showed significantly lower average daily gains of height on control treatment compared to fertilizing treatments Nitre with dolomite, Superphosphate, Potassium salt, SRF NPK 14–5–14 (+ 4CaO + 4MgO + 7S) and Duslocote® NPK (S) 13–9–18 (+6S). During the reported period the highest gain of weight reached treatment by application fertilizer Duslocote® NPK (S) 13– 9–18 (+ 6S). Comparison of the individual treatments for the whole period, were found significantly lower average daily production of phytomass on control treatment in comparison with fertilization turfs by Travcerit® and Duslocote® NPK (S) 13–9–18 (+6S).

Effects of Irrigations with Treated Municipal Wastewater on Phenological Parameters of Tetraploid Cenchrus ciliaris L.

This study was conducted to investigate the use of treated municipal wastewater (TWW) in agriculture. Experiments have been carried out from July 2013 to July 2014, irrigating Cenchrus ciliaris with TWW or tap water (TW). The study, conducted under greenhouse conditions, compared the effect of TWW with the water normally used in irrigation, on the growth, phenological and phytomass production of C. ciliaris a species with high pastoral value. Firstly, our results evidenced that all the chemical parameters of TWW fell in the range of values permitted by Tunisian regulation except chloride. Additionally, TWW increased plant growth during the growth cycle, producing taller plant with respect to TW. All plants irrigated with TWW showed a better performance than plants irrigated with TW only. Similarly, TWW irrigations had positive impacts on flowering parameters during the reproductive cycle. Therefore, treated wastewater can be used as an alternative water resource in irrigation of annual fodder species, with the dual purpose of preserving fresh water and of increasing soil fertility as well as crop productivity.

Evaluation of the effect of microorganisms in Arachis pintoi roots on the potential of copper absorption in land

The research was carried out to evaluate the potential phytoextraction and phytostability of perennial peanut (Arachis pintoi) and to determine the influence of the isolated microorganisms from the root nodules of Arachis pintoi on coppercontaminated soil to improve the ability of treatment metal in soil pollution. Perennial peanuts were planted in the experimental pots which had unsterilized and sterilized soil. Different quanlities of CuSO4.5H2O were directly homogenized into sieved soil to formulate mixtures containing Cu in concentrations (mg/kg) of 200, 400 and 600. In addition, sterilized soil was contaminated by adding Cu with 400 mg/kg. The other pots had copper- contaminated sterilized soil and was added the isolated microorganisms from the root nodules of Arachis pintoi. Our results showed that the perennial peanut had high phytomass production and grew normally in the soil with 200 mg/kg of Cu. The copper accumulation was determined of 668.2, 107 and 561.2 mg/kg in the whole plant, roots and shoots, respectively in plants which were cultivated in the soil with 200 mg/kg of Cu. In the soil with 400 mg/kg and 600 mg/kg of Cu, the plants showed low biomass production and the plants had been poisonous. Both bioconcentration factors (BCF) and translocation factors (TF) were used to estimate a plant’s potential for the purpose of phytoremediation. The highest BCF and TF for Cu concentrations were 3.341 and 5.24 with 200 mg/kg of Cu, respectively. Both factors were higher than 1 therefore Archis pintoi is a potential plant for copper phytoextraction in copper contaminated sites at the concentration of 200-400 mg/kg. The isolated microrganism from the root nodules of Arachis pintoi on copper- contaminated soil was Burkholderia kururiensi PR1, which was a species of proteobacteria and stimulated plant growth. However, the result showed that Burkholderia kururiensi is unable to resistant to concentration of copper (25 mg/L). More research on the other isolated microorganisms of the root system to enhance the Cu accumulation in plants should be carried. Finally, these results showed the potential of the heavy metal phytoextraction of the perennial peanut in contaminated soil. It is easy to apply because of the low cost.

Evaluation of two Brazilian indigenous plants for phytostabilization and phytoremediation of copper-contaminated soils.

Indigenous plants have been grown naturally and vigorously in copper contaminated soils. Thus, the aim of this study was to evaluate the phytoremediation ability of two indigenous plants naturally grown in two vineyard soils copper contaminated, and in a copper mining waste. However, it was evaluated the macro and micronutrient uptake and the potential of phytoremediation. So, a greenhouse study was carried out with Bidens pilosa and Plantago lanceolata in samples of vineyard soils (Inceptisol and Mollisol) copper contaminated, and in a copper mining waste. Plant growth, macro and micronutrient up take, tolerance index (TI), translocation factor (TF), metal extraction ratio (MER), bioaccumulation factor (BCF), plant effective number of the shoots (PENs), and plant effective number of the total plant (PENt) were analyzed. Both plants grown in vineyard soils showed high phytomass production and TI. P. lanceolata plants cultivated in the Inceptisol showed the highest copper concentrations in the shoots (142 mg kg-1), roots (964 mg kg-1) and entire plants (1,106 mg kg-1). High levels of copper were phytoaccumulated from the Inceptisol by B. pilosa and P. lanceolata with 3,500 and 2,200 g ha-1 respectively. Both B. pilosa and P. lanceolata plants showed characteristics of high copper hyperaccumulator. Results showed that both species play an important role in the natural copper phytoaccumulation in both vineyard soils contaminated with copper, being important to its phytoremediation.

Drivers of Setaria pumila (Poir.) Roem. et Schult growth and impact on forage quality in lowland Switzerland meadows

AbstractInvasive grasses (especially Setaria pumila (Poir.) Roem. et Schult) increasingly threaten meadows and pastures as a consequence of human impact and climate change. We conducted a study in 2012 and in 2013 to better understand the growing cycle and the influence of S. pumila on forage quality of lowland meadows. We observed a rapid increase of S. pumila presence and phytomass on the southern side of the Alps across the growing season. We measured (i) above‐ground phytomass, with a modified Corral‐Fenlon method; (ii) botanical composition using the linear point quadrat method; and (iii) grassland chemical composition by NIRs (near‐infrared spectroscopy) analyses. To test the hypothesis that S. pumila summer growth is related to specific climatic conditions, meteorological data (temperature, precipitation and evapotranspiration) were collected from meteorological stations near the study sites. Total phytomass was sorted into S. pumila and other species. We used a generalized linear mixed models (GLMM) and found the abundance of S. pumila to be inversely correlated with rainfall and the presence of other species, but positively correlated with temperature increase. The increase of S. pumila above‐ground phytomass production was linked to a reduction of forage quality.

Simulated heat waves affected alpine grassland only in combination with drought.

The Alpine region is warming fast, and concurrently, the frequency and intensity of climate extremes are increasing. It is currently unclear whether alpine ecosystems are sensitive or resistant to such extremes. We subjected Swiss alpine grassland communities to heat waves with varying intensity by transplanting monoliths to four different elevations (2440-660 m above sea level) for 17 d. Half of these were regularly irrigated while the other half were deprived of irrigation to additionally induce a drought at each site. Heat waves had no significant impacts on fluorescence (Fv /Fm , a stress indicator), senescence and aboveground productivity if irrigation was provided. However, when heat waves coincided with drought, the plants showed clear signs of stress, resulting in vegetation browning and reduced phytomass production. This likely resulted from direct drought effects, but also, as measurements of stomatal conductance and canopy temperatures suggest, from increased high-temperature stress as water scarcity decreased heat mitigation through transpiration. The immediate responses to heat waves (with or without droughts) recorded in these alpine grasslands were similar to those observed in the more extensively studied grasslands from temperate climates. Responses following climate extremes may differ in alpine environments, however, because the short growing season likely constrains recovery.

Linking floral biodiversity with nitrogen and carbon translocations in semi-natural grasslands in Lithuani

Abstract The aim of the present study is to evaluate the long-term effects of long-term piggery effluent application on semi-natural grassland ecotop-phytotop changes (above- and below-ground phytomass production, and carbon and nitrogen allocation in grassland communities) in relation to changes (or variability) in topsoil properties. Analysis of phytomass distribution in piggery effluent irrigated grassland communities showed that dry biomass yield varied from 1.7−5.3 t ha-1. Variability in soil and plant cover created a unique and highly unpredictable site specific system, where long-term anthropogenic influences established successor communities with specific characteristics of above- and below-ground biomass distribution. These characteristics depend more on grassland communities than on soil chemical properties. Families of grasses (Poaceae) dominated the surveyed communities and accumulated most carbon and least nitrogen, while legumes accumulated most nitrogen and lignin and least carbon. Carbon concentrations in above-ground biomass had minor variations, while accumulation of nitrogen was strongly influenced by species diversity (r = 0.94, n = 10, p <0.001) and production of above-ground biomass

Soil water erosion under different cultivation systems and different fertilization rates and forms over 10 years

The action of rain and surface runoff together are the active agents of water erosion, and further influences are the soil type, terrain, soil cover, soil management, and conservation practices. Soil water erosion is low in the no-tillage management system, being influenced by the amount and form of lime and fertilizer application to the soil, among other factors. The aim was to evaluate the effect of the form of liming, the quantity and management of fertilizer application on the soil and water losses by erosion under natural rainfall. The study was carried out between 2003 and 2013 on a Humic Dystrupept soil, with the following treatments: T1 - cultivation with liming and corrective fertilizer incorporated into the soil in the first year, and with 100 % annual maintenance fertilization of P and K; T2 - surface liming and corrective fertilization distributed over five years, and with 75 % annual maintenance fertilization of P and K; T3 - surface liming and corrective fertilization distributed over three years, and with 50 % annual maintenance fertilization of P and K; T4 - surface liming and corrective fertilization distributed over two years, and with 25 % annual maintenance fertilization of P and K; T5 - fallow soil, without liming or fertilization. In the rotation the crops black oat (Avena strigosa ), soybean (Glycine max ), common vetch (Vicia sativa ), maize (Zea mays ), fodder radish (Raphanus sativus ), and black beans (Phaseolus vulgaris ). The split application of lime and mineral fertilizer to the soil surface in a no-tillage system over three and five years, results in better control of soil losses than when split in two years. The increase in the amount of fertilizer applied to the soil surface under no-tillage cultivation increases phytomass production and reduces soil loss by water erosion. Water losses in treatments under no-tillage cultivation were low in all crop cycles, with a similar behavior as soil losses.

Phytomass production and nutrient accumulation by green manure species

Green manuring is recognized as a viable alternative to improve nutrient cycling in soils. The aim of this study was to evaluate the phytomass production and nutrient accumulation in shoots of the summer green manures jack bean [Canavalia ensiformis (L.) DC.], dwarf pigeon pea (Cajanus cajanvar var. Flavus DC.), dwarf mucuna [Mucuna deeringiana (Bort) Merr] and sunn hemp (Crotalaria juncea L.), under nitrogen fertilization and/or inoculation with N-fixing bacteria. A split plot design was arranged with the four Fabaceae species as main plots and nitrogen fertilization (with and without) and inoculation with diazotrophic bacteria (with and without) as the subplots, in a 2² factorial. The experiment was arranged as a randomized complete block design with four replications. In the conditions of this trial, the sunn hemp had the highest production of shoot phytomass (12.4 Mg ha-1) and nutrient accumulation, while the dwarf mucuna had the lowest production of shoot phytomass (3.9 Mg ha-1) and nutrient accumulation. The results showed no effect of nitrogen fertilization or inoculation with N-fixing bacteria on the production of shoot phytomass and nutrient accumulation, except for inoculation without nitrogen fertilization, resulting in greater P accumulation (p <0.05) in the sunn hemp and greater Zn and Mn accumulation in the dwarf mucuna. These findings indicate that N fertilization or inoculation with N2-fixing bacteria for Fabaceae are low efficiency practices in the edaphoclimatic conditions of this study.

Phytoremediation of Vineyard Copper-Contaminated Soil and Copper Mining Waste by a High Potential Bioenergy Crop (Helianthus annus L.)

Phytoremediation is a helpful technique to remediate copper-contaminated areas. The aim of this study was to evaluate sunflower phytoremediation capacity in two vineyard copper-contaminated soils (Inceptisol and Mollisol) and a copper mining waste. Nutrient uptake, copper phytoaccumulation, translocation factor (TF), and bioaccumulation factor (BCF) of sunflower were evaluated after 57 days of growth. Plants grown in both the Mollisol and Inceptisol soils showed high plant height. Fresh biomass was high in the Mollisol in the shoots and roots and also demonstrated the highest values on the tolerance index (TI). The BCF after growth in all three of the copper contaminated soils as Inceptisol, Mollisol, and copper mining waste showed reduction of this index value to 0.19, 0.24, and 0.03, respectively against native soil (Mollisol under natural conditions (4.71). Sunflowers have some important characteristics such as high phytomass production, copper phytoaccumulation, and potential use to biofuel. Thus, sunflower is a potential candidate to phytoremediation of vineyard copper-contaminated soils.

Organic carbon fluxes in the system soil-phytocenosis of bilberry-sphagnum spruce forest in the middle taiga zone of the Komi republic

Quantitative characteristics of organic carbon stock and distribution in the main ecosystem blocks and production-destruction processes in the soil-phytocenosis system have been evaluated in wet oldgrowth bilberry-sphagnum forest. It has been shown that equivalent amounts of carbon are accumulated in the soil and plant reservoirs of the ecosystem and that atmospheric carbon fixation for phytomass production prevails over carbon release in the course of necromass decomposition.

Management strategies of saline water on morphometric characteristics of melon cultivars

It was to aimed it to investigate effects of various saline water use strategies on melon production and quality of two cultivars (Cucumis melo L., Sancho - C1 and Medellín - C2. The plants were irrigated with water of low (S1 = 0.61 dS m-1) and high (S2 = 4.78 dS m-1) salinity levels, during each crop stage: S1S1S2S2 - T1; S2S1S2S2 - T2; S2S2S1S2 - T3. The 1st, 2nd, 3rd and 4th terms of these sequences correspond to initial growth, flowering, fruit ripening and harvest phenological stages, respectively. Additionally, there was irrigation rotation during all cycle, with water S1 during two days followed by S2 for one day (S1 2 dias + S2 1 dia - T4) and irrigation with non-salt water S2 during all cycle - T5. Moreover, we used as control, the irrigation water at 3.2 dS m-1 resulting from water mixture of S1 and S2 - T6 (farm used irrigation management). The experiment was carried out in Pedra Preta Farm, in Mossoró, RN, using an entire randomized block statistical design in a 6x2 subdivided plot scheme with four replications. Saline water irrigation at initial growth stage reduces leaf area and shoot dry phytomass of Sancho and Medellín melon cultivars. The irrigation by T4 provided the highest phytomass production of fruits at 48 DAS, reducing in 33% of good quality water in irrigation.

Dynamics of structure and biological productivity of post-fire larch forests in the Northern Mongolia

Peculiarities of forming and growth of post-fire larch (Larix sibirica Ledeb.) forests at the southern range of their distribution in the Northern Mongolia were studied. Regularities of the stand structure and dynamics of biological productivity are analyzed and discussed in the paper. It has been proved that the structure of the organic mass of the post-fire herb-carex type larch tree stands at the southern border of forest vegetation distribution is closely related to their biometric indices as-age, density, and productivity. In comparison with tree stands from the other areas of forest vegetation, the total phytomass stock of larch phytocenoses appropriately increases by zonal gradient from forest-tundra border to the Transbaikalian southern taiga and northern regions of Mongolia. Regeneration of forest cover by edificator and formation of the original larch coenopopulation is a positive trend from an environmental point of view, because the Siberian larch in young and middle-age period in the area has a sufficiently high growth energy and rate of phytomass production, with more than twice exceeding mature forests in fixed carbon of the atmosphere and has positive values of carbon balance and total destruction of organic matter by the “input-output” parameters.