Органопедогенез – незамеченный базовый процесс почвообразования

The territory of the Republic of Karelia is latitudinally elongated and traversing two boreal subzones such as the northern and middle taiga. Pine and spruce stands predominate in the northern taiga, while forests in middle taiga are more diverse, represented by secondary stands, and often dominated by deciduous species. These factors define the foraging behaviour of beavers and their role in alteration of riparian forests. Dispersing in the northern taiga, beavers tend to choose waterside areas with a higher proportion of deciduous species. However, such habitats occupy less than 1% of the forested area in this subzone, so the overall effect of beaver foraging on forest stands would be minor. On the other hand, inside beaver colonies, stand alteration is far more pronounced than changes in colonies in the middle taiga, and the effects are the following: 1) waterside forests in the northern taiga lose 2.5 times more deciduous trees than those in the middle taiga (61.4 and 26.3 %, respectively); 2) in waterside stands, aspen is totally removed, the share of conifers is doubled, and the share of birch is reduced (in the middle taiga, the share of birch around beaver colonies slightly increases, and the share of aspen is reduced by a factor of 1.5); 3) beavers in the north of Karelia consume thick birch trees more often than in the south of the region; 4) the regeneration capacity of damaged trees in the north is lower than in the south of Karelia.
 Key words: beavers, foraging activities, waterside forests, northern and middle taiga, tree stands

Relatively little work has been published about soils in northwestern Russia, and soil-parent material-vegetation relationships are not well established for this region. Seven pedons developed on late-Pleistocence glacial deposits in the northern, middle, and southern taiga zones of northwestern Russia were described and classified according to the official classification systems of both the United States and Russia. Morphological descriptions and laboratory data that included pH, particle size distribution, selective dissolution analysis, and carbonate equivalent were used for classification. Psamments (Podzols) with Bs and Bhs horizons are most common in the northern taiga, where parent materials are dominated by felsic till and glacial outwash, and vegetation is mostly evergreen conifers. Parent material heterogeneity in the middle taiga promotes soil diversity. Soils on thin calcareous till over limestone are Rendolls (Soddy-calcareous soil); soils on thick calcareous till are Cryalfs (Podzolic soil), and those on slightly calcareous glacial-lacustrine deposits are Psamments (Podzol), with much weaker spodic character than the soils of the northern taiga. Vegetation in the middle taiga varies from broadleaf, deciduous trees on highly calcareous soils, to evergreen conifers on the weakly calcareous soils. The southern taiga region soil formed on calcareous two-layer till is a Cryept (Soddy-podzolic soil) under evergreen conifer forest. Soil properties are clearly linked to the composition of the glacial deposits and to the forest vegetation. We also show that strongly podzolized soils, as indicated by albic horizons and significant subsoil accumulations of carbon and oxalate-extractable Al and Fe, nonetheless fail U.S. taxonomic criteria for spodic material and Spodosols, primarily on the basis of soil color.

The Chronicles of Nature (Letopis Prirody) kept in the nature reserves of the Russian Federaton aggregate a wide spectrum of systematic field records. Information of particular interest therein is the timing of ripening of berries and their yields across years, since berries are an important food for many wildlife species, including brown bear (Ursus arctos), a core species in boreal European Russia. Such trophic links are most explicit and interesting in the autumn during fattening or hyperphagia period in bears, when the animals depend on berry availability for storing up fat. We aimed to identify the ecological relationships of brown bear applying integrated analysis of field data on the carnivore diet and of records from the Chronicles of Nature of the Kivach Nature Reserves (the middle taiga) and the Pinega Nature Reserve (the northern taiga). We have determined the prevalence (%) of the certain foods in brown bear scats sampled from transects along forest roads and paths. The number and productivity of fruit-bearing rowan trees (Sorbus aucuparia) were determined along permanent transects. Bilberry (Vaccinium myrtillus) and cowberry (Vaccinium vitis-idaea) berries dominate in brown bear diet. Berry ripening dates (19-43 days) and the average yield (scores 1.3 to 5.0) vary greatly over years. Trends in ripening onset dates follow a vector towards earlier dates. In the Pinega NR, the rate of this process is faster in bilberry. The coefficient of rank correlation between the number of fruit-bearing rowans along dirt roads and rowan prevalence in scats was r=1. The same significant correlation was found between the number of fruit-bearing rowan trees and rowan berry yield. The prevalence of different foods in brown bear scats during the hyperphagia period shows the high dietary plasticity of species. A reliable strong correlation was detected in the Pinega NR between the last sighting of brown bear tracks in autumn and the onset of berry ripening in bog bilberry and rowan. The relatively stable food supply for brown bear in the middle and northern taiga of European Russia is one of the factors defining the high numbers and wide distribution of the species. Keywords: Chronicles of Nature, nature reserves, middle and northern taiga subzones, fattening foods, berry fruiting, trophic links, dietary plasticity, Ursus arctos.

A significant part of carbon assimilated by forest is deposited in tree trunks. Growth and development of tree stands is accompanied by accumulation of standing dead trees (snags) due to natural tree mortality and as a result of the impact of exogenous factors. Carbon accumulated in these dead trunks is excluded from the fast turnover due to low rate of wood decomposition, so that snags can be considered as a pool of organic carbon with a slow rate of its return to the atmosphere. We estimated stock of snags on 54 sample plots, which represent the main types of forest ecosystems in the northern and middle taiga of Central Siberia. In the middle taiga, stock of snags varied from up to 7 m3 ha-1 in Siberian spruce forests to 20-42 m3 ha-1 in Scots pine forests. Larch forests in the northern taiga had the similar stock of snags as larch forests in the middle taiga despite significantly higher growing stock in the later. Snags contributed from 4 to 19% to the total stock of woody biomass in studied forests. This study indicated the significance of snags and can be used to estimate carbon budget of forest ecosystems of the region.

In the course of studies in typical forest ecosystems of the northern, middle, and southern taiga of Western Siberia performed at the peak of the growing season, the spatial variation of soil CO2 emissions and their relationships with the content of extractable and microbial soil carbon and soil hydrothermic parameters were estimated. The studied parameters of the soil carbon cycle are characterized by the high spatial variability in all the studied ecosystems. This fact indicates the need for a detailed investigation of the greenhouse gas soil emission in all ecosystems typical of a given natural zone. There is a statistically significant difference between the soils of the green-moss pine forests and the soils of the lichen pine forest of the northern taiga. In the green-moss pine forest, the carbon content of microbial biomass is 1.5 times higher (195 ± 24 and 127 ± 16 mg C/kg soil, respectively), the content of extractable carbon is 4 times higher (157 ± 25 and 41 ± 5 mg C/kg of soil, respectively), and the CO2 emission is 1.7 times higher (324 ± 20 and 190 ± 10 mg CO2/(m2 h), respectively) than those in the lichen pine forest. In the northern taiga zone, carbon dioxide emissions from soils in the green-moss pine forests are largely determined by the soil temperature; the role of soil moisture is less significant. In the soils of lichen pine forests, the CO2 emission is mainly controlled by the content of extractable carbon. Significant factors influencing the soil СО2 emission in forest ecosystems of the taiga zone are the content of extractable and microbial carbon and hydrothermic parameters of the soils.

The “standard model” consist on a) typical empirical distributions of CH 4 emission for main wetland landscapes in each natural zone of Western Siberia; b) durations of “period of CH 4-emission” (Tundra - 103 days, Forest-Tundra - 120 days, Northern Taiga - 138 days, Middle Taiga - 166 days, Southern Taiga - 172 days, Subtaiga - 193 days, and Forested steppe - 201 days); c) areas of different wetland types in each zone. For accounting future improvements we denominate this model by the code, for example: “Aa1” (first letter denominate the used period of CH 4-emission, second letter - the used areas of wetlands, and third - typical values of methane flux). New estimation of the regional methane emission from West Siberian wetlands (4.9 ± 2.3 Тg/year or 3.7 ± 1.7 ТgС/year) was calculated from “standard model” Aa1.

This article deals with the peculiarities of distribution of ixodid ticks on small mammals in the northern, middle, southern taiga and subtaiga of the West Siberian Plain. Representatives of 7 species of ixodid ticks were found to inhabit the area:Ixodes persulcatus,I.apronophorus,I.trianguliceps,I. pavlovskyi,Dermacentor reticulatus,D.marginatus,D.silvarum. Species diversity decreases from south to north. In the northern taiga and middle taiga subzones, populations of two species were found –I.persulcatusandI.apronophorus. In addition to these two species, the larva ofI.triangulicepswas found in the southern taiga. The sub-taiga subzone is characterized by the presence of seven species of ixodid ticks. In general,I.persulcatuswas the most abundant within the taiga zone, and its proportion in different subzones ranged from 41 to 85%. In some areas of the middle taiga, its dominance could reach 99% in the structure of ixodid communities. Cases of hyperinvasion by ticks were observed in individual host individuals – their number varied from 52 to 195 individuals. Such significant infestations were most often observed in representatives of the background species of small mammals – northern red-backed vole, common shrew, and occasionally on the common hamster.

Species with continuous distribution area will be impacted by climate change in different ways. That is related to the population’s geographical position and climate features of the population formation. Short-term response of Scots pine (Pinus sylvestris L.) was studied with taken into consideration intraspecies features of populations. Provenance tests in the Arkhangelsk (62.60 N, 39.98 E) and Vologda (62.60 N, 39.98E) regions located in the north of the Russian Plain were used. Provenances collection (23 provenances from the northern, middle, and southern taiga subzones and mixed forest zone) from areas with different climate characteristics was considered. Clinal variability and a reaction norm of vegetative and generative response to various levels of temperature change and seed transfer were studied. Average actual height and diameter values for 31-year provenances and calculated values for provenances were compared using ‘latitudinal growth coefficient’ proposed by I.V. Volosevich (1984) for the north of the Russian Plain. Provenance reproductive ability response was assessed using seed-bearing trees’ numbers in provenances of the 1st class of age. Pine growing in the north of the Russian Plain would respond to warming by productivity increasing more significantly than pine growing in the south. Response of pine from the northern and middle taiga subzones on climate warming can be expected on 1.01 m and 1.12 cm to temperature rise by 100°C for height and diameter, and 0.85 m and 0.93 cm for seeds transfer to 1 degree of northern latitude to southward. Probable reaction norm for pine reproduction potential under temperature change by 100°C of the sum of the temperatures above 10ºС and seed transfer by 1 degree of northern latitude can be expected about 6%.

The article highlights the issues of studying the structure of indigenous forests of different ages as a model of sustainable forest formations. The research purpose is to study the patterns of horizontal structure formation of indigenous virgin spruce forests of the northern, middle and southern taiga subzones of European Russia. We consider the nature of the horizontal structure as one of the most important signs of sustainability of forest communities developed over the evolution. Indigenous virgin spruce forests in each of the taiga subzones of European Russia were adopted as research objects: spruce forests of the Severodvinsk forestry of the Arkhangelsk region in the northern taiga subzone; spruce forests of the Vepsky forest reserve in the middle taiga subzone; spruce forests of the Central Forest Nature Reserve in the southern taiga subzone. Sample plots were laid out in biogeocenoses, where we studied the age, horizontal, and pathological characteristics of spruce forests. Continuous tree drilling was carried out to determine the age of trees and their infestation by wood-destroying fungi of the biotrophic complex. The mosaics of age generations were identified on the plans of sample plots; the area of each of them, the volume of trees in the mosaics and the homogeneity by age, and the amount of natural regeneration were determined. Indigenous spruce fir forests of the taiga of European Russia have a different age structure with a different number of age generations in the age series and various dynamic indicators of biogeocenoses. All of them have a mosaic arrangement of trees grouped by different age generations, growing in different sized areas and distinguished by an unequal degree of homogeneity in terms of age. This defines a complex age horizontal and vertical structure of biogeocenoses; the most important condition for sustainability of forest communities. Accounting of spruce natural regeneration showed significant differences in the number of undergrowth in spruce forests of different taiga subzones, which refers to a variety of horizontal structures of such forests. The ratio of the number of spruce undergrowth growing on decaying trunks of woody debris and on the ground is as follows: the number of 0.5 m high undergrowth in both growing conditions is almost equal, the number of over 3 m high undergrowth on deadwood trunks is less compared to the number of undergrowth of this height category on the ground.

The carbon pool and its fluxes were studied in Karelian pine forests of automorphic sites for the characterization of the regional carbon cycle. On the permanent sample plots arranged in pine stands (dominant forest types) of the middle and northern taiga, the structure and dynamics of the phytomass, as well as the composition of the soil organic matter, were investigated. The contribution of different components of the forest ecosystems to the regional carbon budget was studied. The carbon pools in the soils of the middle and northern taiga subzones were 330–440 × 102 and 440–550 × 102 kg/ha, respectively. The share of soil carbon in the total carbon pool of the forest biogeocenoses studied amounted to 46–35 and 33–24%, respectively. The period of considerable carbon fixation in the pine ecosystem (nearly 20 × 102 kg/ha/yr) turned out to be limited to the middle-aged stands. In the mature and overmature pine forests, only 4 × 102 kg of C/ha/yr were fixed. The main part of carbon in the soil (65–75%) was contained in the illuvial horizons, although its content there was less that 1% as compared to 30–50% in the forest litters. On industrial harvesting of wood, the main reserves of soil carbon are not spent; only the fund of mobile carbon in organic horizons of poor soils is exhausted or carbon accumulates intensely due to the development of continuous plant cover on fertile soils.

Forest fires alter the trophic structure of soil nematode communities

<p>Wetland ecosystems play a significant role in organic carbon conservation; one meter layer of peat soils store over 30 percent of terrestrial organic carbon (Lal, 2008). Ecosystems have different sensitivity to climate change in different nature zones (IPCC, 2014) due to various moisture and temperature regime.</p><p>The aim in this work is to define effect of temperature and moisture on mineralization rate in peat soils in Northern and Southern taiga.</p><p>The samples of Cryic Histosol (WRB, 2014) were taken from Northern Taiga (65°18'52" N, 72°52'32" E). The samples of Fibric Histosol (WRB, 2014) were taken from Southern Taiga (55°40'04" N 36°42'49" E). In laboratory conditions, samples were brought to certain soil moisture (SM): 30, 60, 80, 100 % (Gritsch, 2015), temperature of incubation was ranging from 5 to 25 ◦C (equal-time method).</p><p>In all the cases basal respiration (BR) was growing with increasing of temperature. Samples of Cryic Histosol are more sensitive to changes both in temperature and moisture. BR varies from 0.58 ±0.26 (30% SM and 5 ◦C) to 13.53±0.22 mg C-CO<sub>2</sub>/g/h (100% SM and 25 ◦C). Q<sub>10</sub> coefficient varies from 4.64 to 2.82 respectively (this coefficient demonstrates differences in the temperature sensitivity of soil respiration (Kirschbaum, 1995)). For samples of Fibric Histosol BR varies from 0.75±0.01 (30% SM and 5 ◦C) to 6.14±0.26 mg C-CO<sub>2</sub>/g/h (100% SM and 25 ◦C). Q<sub>10</sub> coefficient varies from 2.70 to 2.18 respectively.</p><p>Influence of moisture and temperature on biological activity in all of the cases was statistically confirmed, but interaction of factors is significant only for Cryic Histosol. According to the results, Cryic Histosol is more sensitive to temperature and moisture change, than Fibric Histosol. Peat soils in the northern area are subjected to more rapid organic carbon mineralization after a change of hydrothermal regime, than southern peat soils. In conclusion, Q<sub>10</sub> coefficient variation indicates that soils with low soil moisture are more sensitive to temperature changes.</p>

Целью исследования являлось определение закономерностей эволюции таежных экосистем Приенисейской Сибири в климатические периоды голоцена (по материалам базы данных). Климатические периоды голоцена – последнего межледниковья: современный (SOV), субатлантический (SA), суббореальный (SB), атлантический (AT), бореальный (BO), предбореальный (PB) – отличаются биоклиматическими характеристиками, зависящими от глобального изменения климата. Объектами исследования являются отложения геологических разрезов в долине Енисея и его притоков, в том числе с вмещающими горизонтами палеопочв в таежной зоне Приенисейской Сибири. Применен комплексный палеоэкологический метод исследования, представленный палеогеографическими, палеопедологическими, палинологическими, геоархеологическими, геоморфологическими, стратиграфическими исследованиями, материалы которых представлены в авторской базе данных «Эволюция природной среды голоцена Сибири» с дополнениями. Современная растительность представлена темнохвойными породами (пихта сибирская (Abies sibirica), елью сибирской (Picea obovata), а также сосной сибирской кедровой, или сибирским кедром (Pinus sibirica). В предбореальный период (PB) в начале потепления перигляциальный ландшафт сменился на лесной, например, в северной тайге основные лесообразующие породы – ель, береза, ольха. В бореальный период (ВО) биоклиматическая обстановка теплее, чем современная. Например, в средней тайге, по данным спорово-пыльцевых спектров, наблюдается абсолютный максимум березы и падение пыльцы ели, а в южной тайге – распространение лесостепного ландшафта (березовая лесостепь с лиственницей). В атлантический (АТ2) период голоцена (оптимкум потепления) в южной тайге лесные ландшафты представлены березово-еловым лесом с лиственницей и сосной. На открытых пространствах произрастали травяные сообщества, под которыми формировались черноземовидные почвы. В суббореальный период (SB) преобладание в спорово-пыльцевых спектрах пыльцы березы, а в заболоченных участках – лиственничные и еловые леса с березой. В субатлантический период (SА) формируются кедрово-сосновые леса (на дренированной поверхности) и елово-кедровые леса с березой (на заболоченных участках). То есть в климатические периоды голоцена существовала флуктуация природных подзон как во времени, так и в пространстве. The aim of the study was to determine the patterns of evolution of taiga ecosystems of Yenisei Siberia in the climatic periods of the Holocene (based on the information of the database). The climatic periods of the Holocene – the last interglacial period – modern (SOV), sub-Atlantic (SA), sub-boreal (SB), Atlantic (AT), Boreal (BO), pre-boreal (PB) differ in bioclimatic characteristics, depending on the global climate change. The objects of the study are deposits of geological sections of the valley of the Yenisei River and its tributaries, including the enclosing horizons of paleosols in the taiga zone of Yenisei Siberia. A comprehensive paleoecological research method was applied, represented by paleogeographic, paleopedological, palynological, geoarchaeological, geomorphological, stratigraphic studies, the materials of which are presented in the author’s database “Evolution of the natural environment of the Holocene of Siberia” with additions. Current vegetation is represented by dark coniferous species (Siberian fir (Abies sibirica), Siberian spruce (Picea obovata), as well as Siberian cedar (Pinus sibirica). During the pre-boreal period (PB), at the beginning of warming, the periglacial landscape was replaced by the forest one, for example, in the northern taiga, the main forest-forming species are spruce, birch, alder trees. In the boreal period (BO), the bioclimatic environment was warmer compared with the modern one. For example, in the middle taiga, according to the spore and pollen spectra, there is an absolute maximum of birch as well as presence of spruce pollen. In the southern taiga, there is the forest-steppe landscape (birch forest-steppe with larch trees). In the Atlantic (AT) period of the Holocene (a warming optimum) in the southern taiga, forest landscapes are represented by birch and spruce forests with larch and pine trees. Grass communities grew in open spaces, where chernozem-like soils were formed. Within the sub-boreal period (SB), in the southern taiga, the predominance of birch pollen in the spore and pollen spectra is observed, and in swampy areas there are larch and spruce forests with birch trees. During the sub–Atlantic period (SA), cedar and pine forests (on a drained surface) and spruce-cedar forests with birch trees (in swampy areas) are formed in the southern taiga. That is, during the climatic periods of the Holocene, there was a fluctuation of natural subzones both in time and in space.

Problems related to biological decomposition of wood and volumes of mycogenic emission of carbon dioxide and carbon in forests of Western Siberia are considered. Annual C-CO2 emission in the region reaches 31 million tons of carbon, which is equivalent to 116 million tons of carbon dioxide. With respect to the volume of emission, natural zones may be arranged in the following descending series: southern taiga (38%), middle taiga (29%), subtaiga (16%), forest-steppe (10%), northern taiga (6%), and forest-tundra (1%).

The paper considers the modern network of protected natural areas in the Perm region. The study determines the current status of the network and the priorities of its geographical formation; investigates representation of six natural areas in the network; identifies the role of protected areas in biodiversity conservation. Based on the regional method, the degree of the protected areas natural environment degradation has been established. The network of protected areas consists of 361 objects of federal, regional and local significance. The total area reaches 10.7% of the Perm region‘s territory. The main component of the network is represented by 257 protected areas of regional importance. In the region, 6 natural areas have been identified: middle taiga, southern taiga, mixed coniferous-deciduous forests, Kungur forest-steppe, Western Urals, Northern Urals. Theinternational level of the protected areas network development has only been achieved in the Northern Urals. The share of protected areas in the middle taiga is higher than the average Russian level; for mixed coniferous-deciduous forests, it is close to the average Russian level. The least protected are southern taiga (4.8%) and forest-steppe ecosystems (3.8%). The most disastrous is conservation of the natural environment of the Kungur forest-steppe. There is a very small number of forest-steppe areas suitable for creating full-fledged protected areas. 89 rare species of biota inhabit the protected areas. All mammals, reptiles, amphibians, fish and invertebrates that are rare for the Perm region are covered with complete protection. Outside the network of protected areas, there are habitats of 7 species of birds, 21 species of angiosperms, 1 species of the fern-like, lycopods and lichen. On this basis, it is possible to develop territorial protection measures. The average environmental degradation of regional protected areas in the Perm region as a whole is 1.45 points. The degradation of protected areas is increasing in the series: middle taiga – Northern Urals – southern taiga – Western Urals – mixed coniferous-deciduous forests – Kungur forest-steppe.