Fir Forests Research Articles

Biotic and Abiotic Determinants of Soil Organic Matter Stock and Fine Root Biomass in Mountain Area Temperate Forests—Examples from Cambisols under European Beech, Norway Spruce, and Silver Fir (Carpathians, Central Europe)

Forest ecosystems significantly contribute to the global organic carbon (OC) pool, exhibiting high spatial heterogeneity in this respect. Some of the components of the OC pool in a forest (woody aboveground biomass (wAGB), coarse root biomass (CRB)) can be relatively easily estimated using readily available data from land observation and forest inventories, while some of the components of the OC pool are very difficult to determine (fine root biomass (FRB) and soil organic matter (SOM) stock). The main objectives of our study were to: (1) estimate the SOM stock; (2) estimate FRB; and (3) assess the relationship between both biotic (wAGB, forest age, foliage, stand density) and abiotic factors (climatic conditions, relief, soil properties) and SOM stocks and FRB in temperate forests in the Western Carpathians consisting of European beech, Norway spruce, and silver fir (32 forest inventory plots in total). We uncovered the highest wAGB in beech forests and highest SOM stocks under beech forest. FRB was the highest under fir forest. We noted a considerable impact of stand density on SOM stocks, particularly in beech and spruce forests. FRB content was mostly impacted by stand density only in beech forests without any discernible effects on other forest characteristics. We discovered significant impacts of relief-dependent factors and SOM stocks at all the studied sites. Our biomass and carbon models informed by more detailed environmental data led to reduce the uncertainty in over- and underestimation in Cambisols under beech, spruce, and fir forests for mountain temperate forest carbon pools.

Aboveground biomass and its biotic and abiotic modulators of a main food bamboo of the giant panda in a subalpine spruce–fir forest in southwestern China

AbstractAs one of the main food bamboo species of the giant panda (Ailuropoda melanoleuca), Fargesia denudata is widely distributed in the understory of spruce–fir forests in the mountainous area of southwestern China. However, the driving factors of its biomass and distribution in the forests are still unclear. We conducted a systematic investigation of the tree and shrub layers (including bamboos) of 209 subplots (20 m × 20 m) in a Forest Global Earth Observatory plot, the Wanglang Plot (25.2 ha), to explore the effects of abiotic (topographic and soil characteristics) and biotic (tree density, total basal area (TBA), shrub coverage, etc.) factors on the aboveground biomass of F. denudata (bamboo biomass hereafter). Bamboo biomass averaged 1.17 ton/ha, with a large variation from 0 to 4.88 ton/ha (95% confidence interval) among the 209 subplots. Bamboo biomass increased significantly with elevation, slope and mean diameter at breast height of trees, and decreased significantly with tree density, shrub coverage and soil pH. However, bamboo biomass was not significantly correlated with tree TBA, aspect, soil organic matter or total nitrogen content. The random forest model indicated that topographic factors and biotic factors had greater influences on the bamboo biomass than soil characteristics in general. Specifically, topographic factors mainly affected the bamboo biomass by changing tree density and soil characteristics. Our results can provide valuable guidance for the protection of giant pandas and the management of subalpine spruce–fir forests.

Aggregation distributions across stand age in provenances of Cunninghamia lanceolata (Lamb.) Hook

It is particularly important to select the provenance with better adaptability in the context of the counteracting potential adverse effects of climate change. However, the growth environment of trees and the length of breeding cycle determine the uncertainty of early selection. Thereby, it is advisable to provide information for provenance selection by analyzing the relationship between young, middle and mature forests. Chinese fir(Cunninghamia lanceolata (Lamb.) Hook.) is an evergreen coniferous tree species with rapid growth and high-quality timber, and it is an important reforestation and commercial tree species in South China. The provenance experimental forests of Chinese fir in Jiangxi and Guangxi were taken as the test object, the growth survey went by three stages of growth: young, middle and mature ages. The linear mixed model was used to evaluate the differentiation of different forest stage provenances in terms of growth. K-medoids clustering algorithm was used to group provenances, the geographical distribution characteristics of Chinese fir were evaluated based on the major groups, and the risk of early selection and the genetic gain of excellent provenances were calculated. The highest total variability was explained by the genotype effect (G) in the young, middle-aged and mature forest stage, the influence of genotype increased through time, while the influence of site was reduced and the G×E interaction changed in a small range. The differences in heritability were similar between young and middle-aged forests, but the heritability of growth traits was higher at Jiangxi than Guangxi in the mature forest stage. The provenances with excellent productivity Chinese fir showed aggregation distribution at the mature forest stage, and the provenances with worst growth were mainly distributed in the northern marginal production area.

Within-population genotype – Soil interactions drive phenotypic variation in a recovering fir forest from central Mexico

Within-population phenotypic variation can be used as a proxy for adaptive potential and individual performance in forest plantations and natural populations. Such variation can be viewed as the sum of genetic factors and their interaction with environmental variation (e.g., soil characteristics), which lead identical genotypes to produce contrasting phenotypes in different environments, and introduced individuals to perform differently from local trees in plantations and test trials. Predicting this variation is of great interest to foresters working with commercially important species. Such is the case of sacred fir (Abies religiosa), a species that is an important source of wood and resin for communities living above 2500 m asl in central Mexico. We determined the contribution of both genetic and soil factors for predicting phenotypic performance of local naturally regenerated (NR) and introduced by reforestation (RF) seedlings in a sacred fir trial test performed by local communities in the Nevado de Toluca National Park. In spite of a low genetic differentiation between plant sources, NR seedlings outperformed RF plants in terms of height, diameter and water use. According to our models, a large part of these differences could be explained by the interaction of genetic, management and edaphic factors within the trial site, with local genotypes using more efficiently the available soil nitrogen than the introduced ones; thus indicating that planting could be changing plant microenvironment and have a measurable phenotypic effect. Association studies between genetic and edaphic variation further suggested that local adaptation might also be occurring at small within-population scales. All such traits, when correctly integrated, may result in fair genome-based phenotypic predictions for small secluded natural populations, which could be at the base of better reforestation practices, and conservation and assisted migration programs.

Cumulative effects of spruce budworm and moose herbivory on boreal forest ecosystems

Abstract Ungulate herbivory is a key natural disturbance in many ecosystems. In forest ecosystems, ungulate herbivory often co‐occurs with other disturbances yet there are few studies looking at the cumulative impacts of ungulates and other natural disturbances on forest dynamics. We report on an 18‐year experiment to investigate the combined effects of introduced, non‐native moose and native spruce budworm herbivory on balsam fir forest recruitment and regeneration. Specifically, we measured inputs into early life‐history components of balsam fir dominant boreal forest ecosystems such as seed density, seedbed quality, seedling and sapling height and density, as well as adult density in eight paired moose exclosure and control sites across a spruce budworm disturbance gradient (i.e. no outbreak, recent outbreak, old outbreak) that resulted in closed, partially open and open canopies. Piecewise structural equation models (SEMs) revealed a strong negative effect of spruce budworm disturbance on balsam fir adult density and indirect effects of this budworm disturbance on balsam fir seedling and sapling density mediated through adult density. We observed a similar pattern of budworm disturbance effects on balsam fir seed density with the lowest densities in sites with open canopy, then partially open and closed canopies. As expected, the SEM showed a positive effect of bryophyte seedbed cover on balsam fir seedling density. The SEM showed support for a positive effect of moose exclusion on balsam fir sapling height and density. Specifically, saplings were on average taller and denser in exclosure than control plots and these differences are most pronounced at sites with partially open canopies created by spruce budworm disturbance and undisturbed or closed canopy sites. Overall, we show evidence for cumulative and interactive effects of spruce budworm and moose herbivory on all life stages of balsam fir and such effects are negatively affecting regeneration of balsam fir forests. Human activities are creating conditions that facilitate the expansion and increased impacts of herbivores on boreal ecosystem functioning. A greater understanding of how ungulate herbivory interacts with other disturbances is needed to improve our predictions of forest ecosystem dynamics under global change. A free Plain Language Summary can be found within the Supporting Information of this article.

Long-term effects of thinning and mixing on stand spatial structure: a case study of Chinese fir plantations

The regular planting and periodic harvesting of a single tree species are features of plantations, which are associated with a reduction of biodiversity. Such plantations are strongly encouraged to be converted into mixed forests. However, the spatial structure dynamics of plantations during the conversion process are poorly understood. In subtropical regions, thinned forest of Chinese fir (Cunninghamia lanceolata [Lamb.] Hook.) and mixed forest of Chinese fir and Michelia macclurei Dandy are considered two ideal modes of plantation management. In this study, we analyzed the spatial structure dynamics of two forest stands and their six main tree populations over a rotation of 27 years, using spatial point analyses. We found that Chinese fir and M. macclurei had a regular distribution pattern (scale, r = 0-1 m) in the early stages of planting (1993), and Chinese fir maintained this pattern after experiencing self-thinning and selective cutting. In addition, non-planted tree species (i.e., natural regeneration of late-seral species, NRLSS) displayed significantly intraspecific clumping, which resulted in the distribution patterns of the forest stands changing from regular to aggregated (r = 0-5.5, 1-20 m), and the species distribution of mixed forest changed from random to clumped (r = 0-20 m). Moreover, during the management period (1993-2018), individuals were significantly differentiated in terms of size, and some small trees in the thinned forest were aggregated together. For the NRLSS, the diameter at breast height was randomly distributed (r = 0-20 m). Furthermore, Chinese fir and M. macclurei were separated at r = 0-1 m in the planting stage, but any pair of the six main populations in the thinned forest and mixed forest were randomly correlated over a rotation. Finally, the nearest neighbor distance of the stands became shorter after conversion, while the values for Chinese fir increased. After 25 years, the mixed plantation and the thinned plantation had a complex spatial structure. They develop towards natural forests and could be used as a template for future plantation management.

Litter Production, Decomposition, and Nutrient Release in Silver Fir (<I>Abies pindrow</I>) and Spruce (<I>Picea smithiana</I>) Forests of Northwest Himalayas

Temperate forests of silver fir and spruce in western Himalayas meet high turnover of litter fall of 10393.97 ± 488.43 kg/ha/y and 9708.17 ± 1341.07 kg/ha/y, respectively. The decomposition rates (decay constant - k) are also very low (0.221 to 0.294) in both the species. Accordingly, a time period of 10 to 13 years is required for decomposing 95 per cent of total litter in these forests. Low concentration of N, P and K nutrients were observed in the month of April in which maximum needle fall was recorded in both the species. Nearly 35 per cent and 38 per cent of the nutrients may be withdrawn from the needles before leaf fall in silver fir and spruce, respectively. The mobility of different nutrients from decomposing needle litter is found as: K > Mg > P > N > Ca and K > Ca > N > P > Mg for silver fir and spruce, respectively. The annual nutrient return was observed as: Ca > N > K > Mg > Pin both these temperate coniferous species

Ранний - средний голоцен северного Сахалина

New palynological and radiocarbon data obtained from sections of two ancient peatbogs permitted to specify the landscape and climatic changes in the nature of the first half of the Holocene on the southern outskirts of North Sakhalin. The Early Holocene was generally colder and drier in comparison with modern climatic conditions. The vegetation cover was dominated by larch/birch forests with the shrub birch undergrowth. In the middle of the Boreal Period (9000-8400 yrs. BP / 10,100-9300 Cal. yrs. BP), the climate became significantly warmer and slightly wetter, yet remaining drier than the modern one. Birch forests with the presence of broad-leaved and dark coniferous tree species were widespread. In the initial phase of the Atlantic Period (probably 7800-7500 yrs. BP / 8800-8300 Cal. yrs. BP), in the climatic conditions warmer and much more humid than modern ones, the first expansion of spruce/fir forests occurred. The second half of the early and first half of the middle phase of the Atlantic Period (7500-6500 yrs. BP / 8300-7400 Cal. yrs. BP) were distinguished by decreased humidity and further warming of the climate, which resulted in dominating birch forests, subordinate spruce/fir taiga, and a lot of deciduous forests. There were two cold episodes at the beginning and in the middle of this stage. The first of them, about 7300 yrs. BP / 8100 Cal. yrs. BP, was dry and provided the return of birch/larch forests. The second, about 7100 yrs. BP / 7900 Cal. yrs. BP, had a more humid climate, which caused an increase in the role of dark coniferous taiga and a weakening of birch forests. In the second half of the middle and, possibly, the beginning of the late phase of the period (probably 6500-5400 yrs. BP / 7400-6200 Cal. yrs. BP), spruce/fir forests with participation of broad-leaved tree spread. They developed in a warmer and more humid climate, similar to the current climate in the south of the Sakhalin Island and close to the optimal climatic conditions of the post-glacial time. The middle of the Late Atlantic Period, about 5300 yrs. BP / 6100 Cal. yrs. BP, was marked by the second, maximum expansion of spruce/ fir forests, due to the onset of the cool and, possibly, the wettest episode in the Middle Holocene.

Comparison of tree diameter distributions in managed and unmanaged Kazdağı fir forests

Forest structural complexity affects tree growth, species diversity, understory seedling density, wildlife habitat and fire behaviour. Thus, defining the structural complexity of forest ecosystems would play a crucial role in their management. The vertical structure in stands of shade-tolerant tree species can be described by using the distribution of tree diameters. In this study, the main objective was to determine and compare the diameter distribution patterns of managed and unmanaged Kazdağı fir (Abies nordmanniana subsp. equi-trojani) forests in northern Turkey. Hierarchical clustering analysis was used to define the diameter distribution patterns. Three main diameter distribution patterns were examined in both managed and unmanaged forests. Two of the patterns in the managed forest did not possess the expected diameter structure of selection silviculture (i.e. reverse J-shape). The observed patterns in the unmanaged forest were mostly representative of the diameter structure of old-growth forests. Given the initial findings, it is likely that the small-scale disturbances created by selection methods may not be adequate to establish and recruit sufficient number of trees into small- diameter sizes in Kazdağı fir forests. The assessment of patterns of tree diameter distribution in these forests would create a basis for future research, aiming to enhance the structural complexity.

Stoichiometric traits (N:P) of understory plants contribute to reductions in plant diversity following long-term nitrogen addition in subtropical forest.

Nitrogen enrichment is pervasive in forest ecosystems, but its influence on understory plant communities and their stoichiometric characteristics is poorly understood. We hypothesize that when forest is enriched with nitrogen (N), the stoichiometric characteristics of plant species explain changes in understory plant diversity. A 13‐year field experiment was conducted to explore the effects of N addition on foliar carbon (C): N: phosphorus (P) stoichiometry, understory plant species richness, and intrinsic water use efficiency (iWUE) in a subtropical Chinese fir forest. Four levels of N addition were applied: 0, 6, 12, and 24 g m−2 year−1. Individual plant species were categorized into resistant plants, intermediate resistant plants, and sensitive plants based on their response to nitrogen addition. Results showed that N addition significantly decreased the number of species, genera, and families of herbaceous plants. Foliar N:P ratios were greater in sensitive plants than resistant or intermediate resistant plants, while iWUE showed an opposite trend. However, no relationship was detected between soil available N and foliar N, and soil N:P and foliar N:P ratios. Our results indicated that long‐term N addition decreased the diversity of understory plants in a subtropical forest. Through regulating water use efficiency with N addition, sensitive plants change their N:P stoichiometry and have a higher risk of mortality, while resistant plants maintain a stable N:P stoichiometry, which contributes to their survival. These findings suggest that plant N:P stoichiometry plays an important role in understory plant performance in response to environmental change of N.

Modeling of growth and development of spruce stands in the West Siberian South taiga plain forest region

Taxation standards, including growth tables, play an important role in the design of forestry activities and the organization of management in forest areas, but it still cannot be argued that they fully reflect all the features of the dynamics of forest stands in various forest growing conditions. The present work is devoted to filling in the gaps in the characteristics of the growth features of Siberian fir (Abies sibirica L.) stands within the West Siberian southern taiga plain forest region. The aim of the work was to develop models of growth and development of the most common types of forests of the fir formation within the boundaries of the study area. The work is based on the materials of the mass inventory of 3491 stands, while 1367 stands belonged to the stands of the forb group of forest types, and 2124 stands to the green moss. Modeling was carried out for average height (H), average diameter (D), stock (M) of stands. As a result of the study, mathematical models of the dynamics of the taxation indicators of Siberian fir stands of two most common groups of forest types in the study area - green moss fir forests and forb fir forests - were constructed. For practical use, tables of the course of growth of modal fir stands were developed, which were supplemented with information on the age dynamics of phytomass and carbon concentration.

Modeling the Effect of Different Forest Types on Water Balance in the Three Gorges Reservoir Area in China, with CoupModel

Precipitation, throughfall, stemflow, and soil water content were measured, whereas interception, transpiration, evaporation, deep percolation, and soil water recharge were estimated in three plots, including oak (Lithocarpus glaber), Chinese fir (Cunninghamia lanceolata) forestlands, and maize (Zea mays) farmland in the Three Gorges Reservoir in China. A physical process-based model (CoupModel) was set up with climatic measurements as input and was calibrated with throughfall and vertical frequency domain reflectometry measurements from January 2018 to December 2019. Simulated values of soil moisture were fairly consistent with measured ones, with a determination coefficient (R2) of 0.73–0.91. Evapotranspiration was the main output of water balance, with a percentage of up to 61%, and such output was ranked as follows: oak forest (720 mm/y) > Chinese fir forest (700 mm/y) > maize farmland (600 mm/y). Afforestation influenced water balance, and water recharge was generally less significant in oak forestland than in Chinese fir forestland. Annual simulated deep percolation decreased by 60 mm for oak and 47 mm for Chinese fir compared with that for farmland (452 mm/y) and even more significantly in wet years. This decrease was mainly attributed to increased interception (122–159 mm/y) and transpiration (49–84 mm/y) after afforestation. Simulations indicated that vegetation species significantly influenced the magnitude of water balance components, calling for further attention to the selection of regrown tree species in the planning for afforestation projects, particularly for such projects that aim to improve the quantity of water infiltrating groundwater. Soil and water conservation measures should also be applied scientifically when converting farmland to forest in this area, particularly in the oak forest stand.

Syntaxonomical revision of the order Fagetalia sylvaticae Pawłowski ex Pawłowski et al. 1928 in Slovakia

A complete syntaxonomical revision of beech, fir and mixed montane forest communities within the order Fagetalia sylvaticae was realised for the first time in Slovakia. We used all available phytosociological material and selected 3355 releves according to the dominance of Fagus sylvatica, Abies alba and/or Acer pseudoplatanus in the tree layer. The second criterion was the presence of diagnostic species of alliances. To classify vegetation at the association level, we ran Modified Twinspan separately within each alliance. Finally, we accepted 18 associations within the alliances Fagion sylvaticae, Symphyto cordati-Fagion, Lonicero alpigenae-Fagion and Sorbo-Fagion. The concept of narrow alliances within the narrowly defined Fagetalia sylvaticae order was used. Associations of fir forests were combined with floristically similar associations of beech and mixed montane forests into the common higher units. Communities of Carpathian calcicolous montane forests were clustered in the newly described suballiance Tanaceto clusii-Fagenion including Cicerbito alpinae-Fagetum ass. nov. Another new association of Teucryo chamaedrys-Fagetum was described for species-rich thermophilous beech forests on carbonates (in Sorbo-Fagion alliance). Delimitation of Western and Eastern Carpathian mesotrophic beech and fir forests was resolved at the levels of association and alliance as well. Diagnostic species combinations, nomenclatural types, and the original forms of names and synonymy are provided for all units, along with brief descriptions of their structure, ecology and distribution.

Arbuscular mycorrhizal fungal colonization and soil pH induced by nitrogen and phosphorus additions affects leaf C:N:P stoichiometry in Chinese fir (Cunninghamia lanceolata) forests

The aim of this study was to investigate the mechanisms by which nitrogen (N) and phosphorous (P) additions affect plant C:N:P stoichiometry via changes in AMF communities in a Chinese fir plantation. Experimental plots in a 10-year-old Chinese fir plantation were treated with N addition (LN, 30 kg•ha−1•yr−1, and HN, 60 kg•ha−1•yr−1) and P addition (LP, 20 mg•kg−1, and HP, 40 mg•kg−1) for 2 years starting from 2017. Soil properties, leaf C:N:P stoichiometry, and changes in AMF community composition and diversity were measured. N or P addition increased soil N availability, decreased P availability, and increased N:P in the leaves and soil. Changes in soil pH induced by N and P additions affected the colonization rate and spore density of AMF. AMF colonization rate was increased by N or P addition, and AMF diversity was increased by LN addition. N and P additions altered AMF species composition, and the dominant genus of the AMF in the soil was Glomus in all treatments. The interaction of N and P treatments had no significant effect on AMF diversity. AMF colonization rate and diversity, rather than its composition, affected leaf C:N:P stoichiometry. N and P additions affected colonization rate and diversity of AMF though changes in soil pH, which drove leaf C:N:P stoichiometry, and potentially affected forest productivity via the fungi-soil-plant system.

Principles for assessing forest management risks associated with natural hazards

Subject. This article examines the risks associated with the loss of ecological and resource potential of forests, and those affecting timber harvesting activities. Objectives. The article aims to develop and test methodological approaches and principles for assessing risks to certain forest management types associated with natural hazards. Methods. For the study, we used the methods of general scientific research, statistical, comparative, logical, and geoinformation analyses. Results. The article presents a developed method of calculating the environmental and economic damage to the fir forests of Western Siberia as a result of the invasion of bark beetles, Polygraphus proximus Blandford. It describes the main natural factors that disrupt the operation of special equipment and the conditions for harvested wood transportation and assesses the most likely risks of logging activities in winter. The testing of a comprehensive assessment of forest risks at the regional level shows the region's area differences in terms of risk both for individual natural hazard factors and in their totality. Conclusions. Forest management risk analysis can be successfully implemented through using methods based on general scientific principles. Specially designed approaches should be used to address narrowly focused industry challenges.

Effects of tree spacing and thinning on root reinforcement in mountain forests of the European Southern Alps

Root reinforcement is a mechanism through which forests contribute to the prevention and mitigation of shallow instabilities in soils, one of the main hazards in mountain areas. This study aims to assess how spatial tree distribution and whether thinning operations affect root reinforcement in the most common forest types of the European Southern Alps. We measured size and position of the trees of 119 stands, belonging to sweet chestnut, European beech, Norway spruce, and spruce-beech-silver fir forest types. We developed, calibrated and validated a model for estimating root reinforcement at the stand level, using the spatial distribution of tree diameter as the input variable. Finally, we simulated a thinning of 18% stand basal area, selecting removal trees from smaller diameter classes (low thinning) or from random clusters (random cluster thinning), and assessed its effect on root reinforcement. Root reinforcement statistically differed among forest types and the lowest values were found in the sweet chestnut forest type. Irrespective of the forest type, low thinning did not significantly modify root reinforcement, while random cluster thinning reduced it five-fold.

ВОЗМОЖНОСТИ ГИС ДЛЯ ИЗУЧЕНИЯ ПРОЦЕССОВ РАСПРОСТРАНЕНИЯ УССУРИЙСКОГО ПОЛИГРАФА В ПИХТОВЫХ ЛЕСАХ СИБИРИ

In recent decades, the Siberian fir forests have been seriously damaged by the invasive bark beetle of Far Eastern origin, the Ussuri polygraph Polygraphus proximus Blandf. The damage from the impact of the pest is expressed in monetary value and in the loss of many ecological functions of forest ecosystems. Technologies for organizing ground monitoring of the spread of the pest are successfully tested by Siberian scientists, and with the involvement of GIS technologies, they can provide a spatio-temporal analysis of the scale of the negative processes occurring. The purpose of this article is to show the capabilities of GIS technologies in combination with remote sensing in studying the processes of invasion of the Ussuri polygraph using the example of forest areas in the Tomsk region. It is shown that the geoinformation approach to the study of the fir forests state in the centers of mass reproduction of the pest makes it possible to create a series of thematic maps reflecting large-scale spatial and temporal changes in plantations and to give a short-term forecast of the development of the centers. The high efficiency of this approach is shown in the local analysis of the centers’ development and to assess the dynamics of mass reproduction of the pest at the forestry level. Based on the built-in analytical information and cartographic display, it becomes possible to predict the emergence of new centers, monitor and control their development.

ОСОБЕННОСТИ МЕСТООБИТАНИЙ И СОСТОЯНИЕ ПОПУЛЯЦИЙ РЕДКИХ ОРХИДЕЙ (ORCHIDACEAE) НАЦИОНАЛЬНОГО ПАРКА «НИЖНЯЯ КАМА» И СОПРЕДЕЛЬНЫХ ТЕРРИТОРИЙ НА СЕВЕРЕ ТАТАРСТАНА (ЕВРОПЕЙСКАЯ РОССИЯ)

The article examines the populations of rare species of orchids Cypripedium calceolus (L.), Epipactis helleborine L., Goodyera repens (L.) R.Br, Neottia nidus-avis (L.) Rich., Neottianthe cucullata (L.) Schlechter, Platanthera bifolia (L.) Rich. on the territory of the Republic of Tatarstan. The temperate continental climate prevails on the territory of Tatarstan, which is typical for the central part and northwestern regions of the Volga and Predkamye. In contrast, the north and northeast of Tatarstan are characterized by a moderately cool climate with a lot of precipitation during the growing season. Small fragments of the southern taiga complexes with green moss spruce and fir are formed in the north, in the Baltasi district. Dark coniferous species – spruce and fir are dominated in the north-east along the river Vyatka in Lubyanskoye forestry in coniferous-deciduous forests. Such habitats are characterized by the predominance of typically boreal and boreal-nemoral species of shrubs, grasses and mosses. Rare species have been recorded: Pyrola media Sw., P. chlorantha Sw., Diphasiastrum complanatum (L.) Holub, Hypopitys monotropa Crantz, Viola selkirkii Pursh ex Goldie. Orchid populations have some features. The development and flowering of Platanthera bifolia and Cypripedium calceolus occur 7–10 days later in comparison with central and northwestern regions of Tatarstan. Virginal and adult vegetative individuals predominate in the population structure. Generative individuals of C. calceolus in spruce-broad-leaved and pine-spruce with fir forests often do not form clones; their share is 72 % of all generative plants. The number of shoots of C. calceolus clones decreases and makes in average 3.2 shoots. On the contrary, the number of shoots in clones of the northwestern populations is equal to 6.5. The share of generative individuals of the studied populations of P. bifolia is 25 % on average and it significantly decreases in the populations of the recreational zone of the National Park. The species grows here in dry pine forests on compacted soil, and, probably, tourists pick flowers up for bouquets. Populations of N. cucullata and G. repens are found only in the protected and buffer zones of the National Park. The age structure is full-term though the share of generative plants is quite low and averages 34 % for N. cucullata, and only 15 % for G. repens. N. cucullata and G. repens have not been found yet in habitats with suitable abiotic and biotic conditions in the north and north-east of Tatarstan. This fact requires further research. The species composition of mosses is almost identical in the habitats of orchids (Pleurozium schreberi (Brid.) Mitt., dominates among mosses in all phytocenoses, but the projective cover and height of the moss tufts differ significantly. Typically boreal and hemiboreal species are registered: P. schreberi Dicranum polysetum Sw., Dicranum scoparium Hedw., Rhytidiadelphus triquetrus (Hedw.) Warnst, Rhodobryum roseum (Hedw.) Limpr., Hylocomium splendens (Hedw.) Bruch et al., Ptilium crista-castrensis (Hedw.) DeNot. A rare species – Plagiomnium drummondii (Bruch&Schimp.) T.J. Kop. is identified in the north of the Republic of Tatarstan. The abundance and development of mosses, as guarantors of humidity and preservation of microclimatic conditions, are important conditions for the growth of symbiotrophic fungi that contribute to the maintenance of orchids and many species of boreal forests on the southern border of their distribution.

Coleotteri del legno e microhabitat forestali nei boschi misti di abete bianco e faggio della Riserva di Vallombrosa

Forest biodiversity can be monitored trough ecological indicators, such as microhabitats and dead wood. Among the primary users of these small habitats there are arthropods, birds and mammals, but the most important component is represented by Coleoptera. In 2020, a study was launched in the mixed forests of silver fir and beech in the Nature Reserve of Vallombrosa in order to examine the saproxylic beetles present and the relationships between these species and indicators of forest biodiversity. In 47 plots, we sampled flying and crawling beetles, assessed the microhabitats and measured the volumes of dead wood and living trees. In this paper we report the first results obtained from the study. In the examined stands, we found threatened and endangered species included in the Red List of Italian Saproxylic Beetles and species protected under the Habitat Directive. A total of 2573 microhabitats were surveyed and proved to have ecological relationships with the sampled beetle species. The percentage ratio between the volume of dead wood and the volume of living trees was 39%. The results are discussed to describe the ecological role of the saproxylic beetles with respect to the biodiversity indicators. Saproxylic Beetles and microhabitats in mixed forests of silver firand beech in the Vallombrosa ReserveSaproxylic Beetles and microhabitats in mixed forests of silver firand beech in the Vallombrosa Reserve

Разнообразие лиственничных лесов и редколесий западного макросклона Приполярного и Северного Урала

Разнообразие лиственничных лесов и редколесий западного макросклона Приполярного и Северного Урала