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Lignicolous macromycetes are of great importance for the functionality of forest ecosystems. These fungi work as the main carbon reintegrating agents in the soil or as keepers of forest vitality. Under the biotic and abiotic changes, fungi species reacts differently, the main effects being seen at the level of numbers and composition structure of fungal communities. In the context of human actions on forest ecosystems, numerous studies show the detrimental effects on lignicolous mycodiversity, at both European and local levels. In order to protect mycodiversity, it is vital to understand the way the relation between fungi and forest works.

The present study aimed to assess four forest stands, Fagus orientalis Lipsky-Carpinus betulus L.-Acer velutinum Boiss. (FO-CB-AV), Fagus orientalis Lipsky-Carpinus betulus L. (FO-CB), Fagus orientalis Lipsky-Acer velutinum Boiss. (FO-AV), and Pure Fagus orientalis Lipsky (FO) on basis of some soil quality indices in Mazandaran Province, northern Iran. Five samples per stand were taken (0-30 cm), the physical, chemical, and biological characteristics of soil were determined. Nine criteria were selected according to Principal Component Analysis as Minimum Data Set. According to the results, the highest value of litter Ca, density and biomass of earthworm, and C microbial biomass were found in FO-CB-AV. After applying the analytical hierarchy process, the calculated overall priority based on nine criteria showed that the FO-CB-AV stand had a higher ecological potential compared to the other stands. Therefore, the FO-CB-AV stand had more of appropriate conditions for improving soil quality in degraded forest regions compared to the other stands under current conditions.

Abstract The dramatic climate fluctuations of the late Quaternary have influenced the diversity and composition of macroorganism communities, but how they structure belowground microbial communities is less well known. Fungi constitute an important component of soil microorganism communities. They play an important role in biodiversity maintenance, community assembly, and ecosystem functioning, and differ from many macroorganisms in many traits. Here, we examined soil fungal communities in Chinese temperate, subtropical, and tropic forests using Illumina MiSeq sequencing of the fungal ITS1 region. The relative effect of late Quaternary climate change and contemporary environment (plant, soil, current climate, and geographic distance) on the soil fungal community was analyzed. The richness of the total fungal community, along with saprotrophic, ectomycorrhizal (EM), and pathogenic fungal communities, was influenced primarily by the contemporary environment (plant and/or soil) but not by late Quaternary climate change. Late Quaternary climate change acted in concert with the contemporary environment to shape total, saprotrophic, EM, and pathogenic fungal community compositions and with a stronger effect in temperate forest than in tropic–subtropical forest ecosystems. Some contemporary environmental factors influencing total, saprotrophic, EM, and pathogenic fungal communities in temperate and tropic–subtropical forests were different. We demonstrate that late Quaternary climate change can help to explain current soil fungal community composition and argue that climatic legacies can help to predict soil fungal responses to climate change.

Atmospheric pollution produced by anthropogenic activities has detrimental effects on humans but also on plants. When forests are affected by exposure to pollutants such as nitrogen oxides, particles (with size ≤ 10 µm), and ozone, they in turn act as sentinels towards pollutant emission and at the same time provide ecosystem services when they scavenge pollutants form the atmosphere. In order to move towards levels of air quality not giving rise to significant negative impacts and risks to human health and the environment, the revision of the National Emission Ceilings Directive (2016/2284/EU) sets limits on the amount of pollutants that can be emitted by each Member States per year. By recognizing the negative impacts of pollution on forest ecosystems, the Directive also invites member states to monitor the impacts of pollution on forest ecosystems encouraging the continuation of long-term monitoring networks such as the ICP-Forests network. We discuss here opportunities for Italy to attain the directive thanks to a revitalized activity based on existing monitoring networks and the synergies with other newly established monitoring programs.

In the past few decades, industrialization has caused a large number of pollutants to be released into the atmosphere. Forest ecosystems play an important function in regulating the biogeochemistry and the circulation of metal ions pollutants. Forest ecosystems affect the absorption of pollutants and dissolution of nutrients from the atmosphere and vegetation canopy, thereby influencing the content and composition of forest floor leachate and soil solution. This study examined changes in acid anions (NO3−, SO42−, Cl−) and metal cations (K+, Ca2+, Na2+, Mg2+, Fe3+, Pb2+, Cu2+, Cd2+) in rainfall, throughfall, stemflow, and forest floor leachate for five different forests (Larix principis-rupprechtii, Picea wilsonii, Picea crassifolia, Betula platyphylla and Rhododendron communities). The results showed that the enrichment capacity of acid anions and metal cations in the vegetation canopy of the coniferous forests (L. principis-rupprechtii, P. wilsonii, P. crassifolia) was stronger than that of the broad-leaved forests (B. platyphylla and Rhododendron communities). The content of acid anions and metal cations in stemflow of coniferous forests were 3.7–5.6 times and 0–9.3 times higher than those of broad-leaved forests, respectively. Corresponding values in throughfall were 1–1.4 times and 0.3–2.4 times, respectively. The contents of NO3−, Cl−, K+, Mg2+, Fe3+, Pb2+, Cu2+, and Cd2+ in leachate filtered from the soil layers that are deepening gradually showed consistent decreasing trend for all the forest stands. In addition, NO3−, Cl−, K+, Mg2+, Fe3+, and Pb2+ were also concentrated in the topsoil, except for Cu2+ and Cd2+. Nevertheless, SO42− and Na+ were concentrated in the subsoil, whereas Ca2+ was concentrated in the upper soil layers. Soil organic carbon (SOC) and total nitrogen (TN) contents in coniferous forest stands were 20–37% and 34–63% higher than those in broad-leaved forest stands, respectively. This results also shown that the contents of OC and TN has a strong correlation with the content of partial metal cations in soil and litter, indicating that coniferous forest stands had stronger ion scavenging and adsorption capacity in soil layer and litter layer than broad-leaved forest stands. Therefore, L. principis-rupprechtii, P. wilsonii, P. crassifolia had higher air pollutant adsorption and soil pollution remediation capacities than the other two forests. Thus, we recommend planting coniferous tree species (L. principis-rupprechtii, P. wilsonii and P. crassifolia) for eco-rehabilitation and water purification to improve the ecological service function of forest ecosystems.

Soil fungi predominate the forest topsoil microbial biomass and participate in biogeochemical cycling as decomposers, symbionts, and pathogens. They are intimately associated with plants but their interactions with aboveground and belowground plant traits are unclear. Here, we evaluated soil fungal communities and their relationships with leaf and root traits in nine forest ecosystems ranging from tropical to cold temperate along a 3,700-km transect in eastern China. Basidiomycota was the most abundant phylum, followed by Ascomycota, Zygomycota, Glomeromycota, and Chytridiomycota. There was no latitudinal trend in total, saprotrophic, and pathotrophic fungal richness. However, ectomycorrhizal fungal abundance and richness increased with latitude significantly and reached maxima in temperate forests. Saprotrophic and pathotrophic fungi were most abundant in tropical and subtropical forests and their abundance decreased with latitude. Spatial and climatic factors, soil properties, and plant traits collectively explained 45% of the variance in soil fungal richness. Specific root length and root biomass had the greatest direct effects on total fungal richness. Specific root length was the key determinant of saprotrophic and pathotrophic fungal richness while root phosphorus content was the main biotic factor determining ectomycorrhizal fungal richness. In contrast, spatial and climatic features, soil properties, total leaf nitrogen and phosphorus, specific root length, and root biomass collectively explained >60% of the variance in fungal community composition. Soil fungal richness and composition are strongly controlled by both aboveground and belowground plant traits. The findings of this study provide new evidence that plant traits predict soil fungal diversity distribution at the continental scale.

Oomycetes (Stramenopiles, protists) are among the most severe plant pathogens, comprising species with a high economic and ecologic impact on forest ecosystems. Their diversity and community structures are well studied in terrestrial habitats, but tree canopies as huge and diverse habitats have been widely neglected. A recent study highlighted distinct oomycete communities in the canopy stratum compared to the ground region of three temperate deciduous trees (Quercus robur, Tilia cordata, Fraxinus excelsior). While the communities from the two strata were distinct when taking oomycete abundances into account, they were rather similar when only OTU presence/absence was considered. It remains, however, unknown if this homogeneity in the OTU presence also leads to a functional homogenisation among microhabitats within the two strata ground and canopy. In this study, we supplemented functional traits to oomycete communities in the tree microhabitats, which were determined over a time period of 2 years with a metabarcoding approach. Our results showed that even though most oomycetes occurred in all microhabitats, a strong discrepancy between the strata and correspondingly the distribution of oomycete lifestyles could be observed. This pattern was constant over several seasons. Obligate biotrophic species, exclusively feeding on living host tissue, dominated the canopy region, implying tree canopies to be a hitherto neglected reservoir for parasitic protists. OTUs assigned to the genus Hyaloperonospora—parasites highly specialised on hosts that were not sampled—could be determined in high abundances in the canopy and the surrounding air, challenging the strict host dependencies ruled for some oomycetes. Our findings further contribute to the understanding of oomycete ecosystem functioning in forest ecosystems.

A new cleistanthane nor-diterpenoid, named olicleistanone (1), was isolated as a racemate from the culture filtrates of Diplodia olivarum, an emerging pathogen involved in the aetiology of branch canker and dieback of several plant species typical of the Mediterranean maquis in Sardinia, Italy. When the fungus was grown in vitro on Czapek medium, olicleistanone was isolated together with some already known phytotoxic diterpenoids identified as sphaeropsidins A, C, and G, and diplopimarane (2-5). Olicleistanone was characterized as 4-ethoxy-6a-methoxy-3,8,8-trimethyl-4,5,8,9,10,11-hexahydrodibenzo[de,g]chromen-7(6aH)-one. When D. olivarum was grown on mineral salt medium it produced (-)-mellein (6), sphaeropsidin A and small amounts of sphaeropsidin G and diplopimarane. Olicleistanone (1) exhibited strong activity against the insect Artemia salina L. (100% larval mortality) at 100 μg mL-1 but did not exhibit phytotoxic, antifungal or antioomycete activity. Among the metabolites isolated (1-6), sphaeropsidin A (2) was active in all bioassays performed exhibiting strong phytotoxicity on leaves of Phaseolus vulgaris L., Juglans regia L. and Quercus suber L. at 1 mg mL-1. Sphaeropsidin A (2) also completely inhibited mycelium growth of Athelia rolfsii, Diplodia corticola, Phytophthora cambivora and P. lacustris at 200 μg per plug, and was active in the Artemia salina assay. Also in this assay, diplopimarane (5) and sphaeropsidin G (4) were active (100% larval mortality). Diplopimarane also showed antifungal and antioomycete activities. Athelia rolfsii was the most sensitive species to diplopimarane. Sphaeropsidin C (3) and (-)-mellein (6) were inactive in all bioassays. These results expand knowledge on the metabolic profile of Botryosphaeriaceae, and embody the first characterization of the main secondary metabolites secreted by D. olivarum.

We estimated the carbon (C) stored in the total aerial biomass of native forests of the Espinal (Ñandubay District, Entre Ríos Province, Argentina) and the reduction of CO2 emissions by avoided deforestation. In this work, it was used the information reported in the First National Inventory of Native Forests from 2007. The forests from the evaluated area stored a total of 54.48 Tg C, with an average of 38.82 Mg.ha-1. In a zero deforestation scenario from 2020, an emission reduction of the order of 17.7 Tg CO2 would be achieved by 2030, representing 3.7% of the national goal proposed by Argentina not to exceeding, the net emission of 483 Tg CO2 (Nationally Determined Contribution). The Espinal forests conservation also constitutes a mechanism with great potential to generate and commercialize C credits according to the standards of the REDD + mechanism. [ABSTRACT FROM AUTHOR]

Aims: The interaction between plants and soil is an important internal driver of ecosystem evolution. Many studies have reported the unidirectional effects of soil nutrients on plant diversity and species turnover. However, there are still many gaps in our knowledge about how plant diversity and species turnover feedback to soil nutrients. Methods: In the present study, three forest plots with different species composition and diversity were created through artificial disturbance in the same stand origin forest, and their long-term dynamics were observed. We identified underlying mechanisms of how plant diversity (Shannon-Wiener index) and species turnover (Bray-Curtis dissimilarity) affect soil total nitrogen (TN), total phosphorus (TP), available nitrogen (AN), and available phosphorus (AP). Results: Plant diversity was associated with soil TN, TP, AN, and AP concentrations (P < 0.01). Species turnover was negatively correlated with the log-response ratio of TP (LRR TP) (P < 0.001), but not correlated with LRR AP. Species turnover had significant positive correlations with LRR TN and LRR AN (P < 0.001). The structural equation model supports hypotheses that plant diversity and species turnover influenced soil N and P availability by affecting forest community growth (total tree basal area, TBA), litter quantity and quality, and soil physical and chemical properties (soil organic carbon, SOC; soil exchangeable base cations). Conclusions: Collectively, our results highlighted the co-regulation of plant diversity and species turnover on soil N and P availability by "complementary" and "mass" effects during the long-term dynamics of forest ecosystems. [ABSTRACT FROM AUTHOR]

Tree canopies are colonized by billions of highly specialized microorganisms that are well adapted to the highly variable microclimatic conditions, caused by diurnal fluctuations and seasonal changes. In this study, we investigated seasonality patterns of protists in the tree canopies of a temperate floodplain forest via high-throughput sequencing with group-specific primers for the phyla Cercozoa and Endomyxa. We observed consistent seasonality, and identified divergent spring and autumn taxa. Tree crowns were characterized by a dominance of bacterivores and omnivores, while eukaryvores gained a distinctly larger share in litter and soil communities on the ground. In the canopy seasonality was largest among communities detected on the foliar surface: In spring, higher variance within alpha diversity of foliar samples indicated greater heterogeneity during initial colonization. However, communities underwent compositional changes during the aging of leaves in autumn, highly reflecting recurring phenological changes during protistan colonization. Surprisingly, endomyxan root pathogens appeared to be exceptionally abundant across tree canopies during autumn, demonstrating a potential role of the canopy surface as a physical filter for air-dispersed propagules. Overall, about 80% of detected OTUs could not be assigned to known species—representing dozens of microeukaryotic taxa whose canopy inhabitants are waiting to be discovered. [ABSTRACT FROM AUTHOR]

The association between ectomycorrhizal (ECM) fungi and trees is at the heart of forest ecosystems. Nowadays, this association is increasingly facing pressures resulting from anthropogenic activities, impacting the structure, biodiversity and functions of ECM fungal communities and their hosts. Here, we review some of the most common anthropogenic activities (i.e. enrichment of atmospheric carbon dioxide, increase of global temperature, atmospheric pollution, nitrogen deposition, use of pesticides, land use management, introduction of invasive species and biodiversity loss) affecting ECM fungi (i.e. species richness, abundance, taxonomy, production of spores and carpophores, and enzymatic activities) and their tree hosts. The review was conducted at different scales, from species to populations and ecosystems and whenever possible, example including boreal, temperate and tropical forests were reported. To conclude, we discussed about the present challenges hindering a better holistic understanding of our future forest ecosystems hosting ECM fungi. Overall, climate change is expected to affect ECM fungi through an alteration of plant metabolism and spatial distribution of trees. Although industrial pollutants and pesticides effects remains less clear at large scale, N-deposition and/or fertilization could induce ECM shifts and alter nutrient cycling. Regarding other anthropogenic parameters (e.g. land use, invasive species), they may affect ECM fungal communities by impacting their diversity, abundance and richness. [ABSTRACT FROM AUTHOR]

The raising concentration of atmospheric CO2 resulted in global warming. The forest ecosystem in Tibet played an irreplaceable role in maintaining global carbon balance and mitigating climate change for its abundant original forest resources with powerful action of carbon sink. In the present study, the samples of soil and vegetation were collected at a total of 137 sites from 2001 to 2018 in Tibet. Based on the field survey of Tibet's forest resources and 8th forest inventory data, we estimated the carbon storage and carbon density of forest vegetation (tree layer, shrub, grass, litter and dead wood) and soil (0–50 cm) in Tibet. Geostatistical methods combined with Kriging spatial interpolation and Moran's I were applied to reveal their spatial distribution patterns and variation characteristics. The carbon density of forest vegetation and soil in Tibet were 74.57 t ha−1 and 96.24 t ha−1, respectively. The carbon storage of forest vegetation and soil in Tibet were 344.35 Tg C and 440.53 Tg C, respectively. Carbon density of fir (Abies forest) was 144.80 t ha−1 with the highest value among all the forest types. Carbon storage of spruce (Picea forest) was the highest with 99.09 Tg C compared with other forest types. The carbon density of fir forest and spruce forest both increased with the rising temperature and precipitation. Temperature was the main influential factor. The spatial distribution of carbon density of forest vegetation, soil, and ecosystem in Tibet generally showed declining trends from western Tibet to eastern Tibet. Our results facilitated the understanding of the carbon sequestration role of forest ecosystem in the Tibet. It also implied that as the carbon storage potential of Tibet's forests are expected to increase, these forests are likely to serve as huge carbon sinks in the current era of global warming and climate change. [ABSTRACT FROM AUTHOR]

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A climatic modelling program was used in order to see the extent of changes in future climatic conditions. This can realize prognosis for certain climatic factors that cause extreme climatic phenomena concerning forest ecosystems. The program was applied for forest ecosystems comprised of Scots pine, installed and inventoried on sample surfaces from Transylvania. Simulations were then created within two future climatic scenarios. Two scenarios were chosen: the climatic scenario in which the increase of greenhouse gases would be moderate (rcp-4.5) and the climatic scenario in which the increase would be accentuated (rcp-8.5). The data was then processed, resulting in an analysis focused on the results of future climatic changes on forest ecosystems located in the studied area. By analyzing all three pine stands, we can conclude that the Lechinta stand is the most vulnerable one if the two climatic parameters change. It is necessary to verify and use future climatic scenarios for other areas that have the same species, as well as for other species, in order to see how they will be affected. These results can be used for applying the best management measures for current stands as well as for establishing decisions for installing future stands at a national level. [ABSTRACT FROM AUTHOR]

Soil fungi predominate the forest topsoil microbial biomass and participate in biogeochemical cycling as decomposers, symbionts, and pathogens. They are intimately associated with plants but their interactions with aboveground and belowground plant traits are unclear. Here, we evaluated soil fungal communities and their relationships with leaf and root traits in nine forest ecosystems ranging from tropical to cold temperate along a 3,700-km transect in eastern China. Basidiomycota was the most abundant phylum, followed by Ascomycota, Zygomycota, Glomeromycota, and Chytridiomycota. There was no latitudinal trend in total, saprotrophic, and pathotrophic fungal richness. However, ectomycorrhizal fungal abundance and richness increased with latitude significantly and reached maxima in temperate forests. Saprotrophic and pathotrophic fungi were most abundant in tropical and subtropical forests and their abundance decreased with latitude. Spatial and climatic factors, soil properties, and plant traits collectively explained 45% of the variance in soil fungal richness. Specific root length and root biomass had the greatest direct effects on total fungal richness. Specific root length was the key determinant of saprotrophic and pathotrophic fungal richness while root phosphorus content was the main biotic factor determining ectomycorrhizal fungal richness. In contrast, spatial and climatic features, soil properties, total leaf nitrogen and phosphorus, specific root length, and root biomass collectively explained >60% of the variance in fungal community composition. Soil fungal richness and composition are strongly controlled by both aboveground and belowground plant traits. The findings of this study provide new evidence that plant traits predict soil fungal diversity distribution at the continental scale. [ABSTRACT FROM AUTHOR]

Soil fauna communities are major drivers of many forest ecosystem processes. Tree species diversity and composition shape soil fauna communities, but their relationships are poorly understood, notably whether or not soil fauna diversity depends on tree species diversity. Here, we characterized soil macrofauna communities from forests composed of either one or three tree species, located in four different climate zones and growing on different soil types. Using multivariate analysis and model averaging we investigated the relative importance of tree species richness, tree functional type (deciduous vs. evergreen), litter quality, microhabitat and microclimatic characteristics as drivers of soil macrofauna community composition and structure. We found that macrofauna communities in mixed forest stands were represented by a higher number of broad taxonomic groups that were more diverse and more evenly represented. We also observed a switch from earthworm-dominated to predator-dominated communities with increasing evergreen proportion in forest stands, which we interpreted as a result of a lower litter quality and a higher forest floor mass. Finally, canopy openness was positively related to detritivore abundance and biomass, leading to higher predator species richness and diversity probably through trophic cascade effects. Interestingly, considering different levels of taxonomic resolution in the analyses highlighted different facets of macrofauna response to tree species richness, likely a result of both different ecological niche range and methodological constraints. Overall, our study supports the positive effects of tree species richness on macrofauna diversity and abundance through multiple changes in resource quality and availability, microhabitat, and microclimate modifications. [ABSTRACT FROM AUTHOR]

The forest ecosystems of Tibet function as important carbon sinks. However, previous estimates of carbon budgets have included large uncertainties owing to the limitations of data acquisition and the method of estimation. In this study, IPCC and model estimation methods have been used to calculate all the sectors of carbon stocks in typical forest vegetation of Tibet and explore the biogeographical patterns and potential drivers of these pools. The results showed that the total carbon pools of biomass and dead organic matter in six typical forest ecosystems in Tibet was 457.67 Tg C, of which 10.52–164.85 Tg C (76.53%) was stored in aboveground biomass, 1.87–59.37 Tg C (22.07%) in belowground biomass, 0.01–2.75 Tg C (0.73%) in the forest understory, 0.02–1.57 Tg C (0.53%) in litter, and 0.01–0.27 Tg C (0.14%) in dead wood. These carbon reserves are primarily distributed in mature and over mature forests, comprising 48.89% and 31.58%, respectively. Geographical location and natural conditions affect the carbon sequestration capacity of the Tibetan forest ecosystems that decreases from southeast to northwest. An analysis also suggests that the canopy and tree densities have some effect on the carbon sequestration efficiency in different carbon pools. This is primarily because these two indicators have a greater impact on the growth of trees. In addition, it was found that the forests of Abies fabri and Platycladus orientalis had the highest and lowest degrees of carbon fixation, respectively. [ABSTRACT FROM AUTHOR]

Forest ecosystems are shaped by internal dynamics and external factors like forest management. A modified physical appearance of ecosystems may affect the short- and long-term provision of ecosystem goods and services (EG&S) from forests. Ecosystem functioning research provides powerful tools for both, the mechanistic description of ecosystem dynamics and the normative assessment of the value of ecosystems. Holistic insights into the functioning of ecosystems require interdisciplinary projects. However, disciplinary differences in terminology and implicit underlying assumptions about relationships between descriptive ecosystem characteristics and their relevance for society may lead to misunderstandings hindering conceptual integration of disciplines. This highlights the need for a common language in ecosystem functioning research. Here, we provide a classification scheme of different types of ecosystem characteristics applicable across disciplines. We introduce a terminology that unambiguously differentiates between normative and descriptive uses of the terms 'ecosystem function', 'ecosystem functioning' and 'ecosystem goods and services'. Based on this terminology, we propose a framework facilitating the explicit communication of hypotheses, underlying assumptions, analyses and conclusions belonging to three different aspects of ecosystem functioning: (1) mechanistic ecosystem functioning, (2) supplying ecosystem functioning and (3) ecosystem integrity. 'Mechanistic ecosystem functioning' addresses relationships and interactions between purely descriptive ecosystem characteristics and their dependence on external factors. 'Supplying ecosystem functioning' translates descriptive ecosystem characteristics into benefits for society in providing EG&S. 'Ecosystem integrity' assesses the capabilities of ecosystems to provide EG&S in the long term. We further propose the use of a mathematical interpretation of the term 'ecosystem function' as 'characteristic A is the function of characteristics B, C, ..., X'. This definition clearly accounts for complex relationships between ecosystem characteristics and avoids ambiguity inherent in the discrimination of 'ecosystem-functions' and other ('non-functional') ecosystem characteristics. Our approach will increase understanding across disciplines and foster joint syntheses by providing a unified framework for interdisciplinary studies. [ABSTRACT FROM AUTHOR]

ABSTRACT Forests accumulate and store large amounts of carbon (C), and a substantial fraction of this stock is contained in deadwood. This transient pool is subject to decomposition by deadwood-associated organisms, and in this process it contributes to CO2 emissions. Although fungi and bacteria are known to colonize deadwood, little is known about the microbial processes that mediate carbon and nitrogen (N) cycling in deadwood. In this study, using a combination of metagenomics, metatranscriptomics, and nutrient flux measurements, we demonstrate that the decomposition of deadwood reflects the complementary roles played by fungi and bacteria. Fungi were found to dominate the decomposition of deadwood and particularly its recalcitrant fractions, while several bacterial taxa participate in N accumulation in deadwood through N fixation, being dependent on fungal activity with respect to deadwood colonization and C supply. Conversely, bacterial N fixation helps to decrease the constraints of deadwood decomposition for fungi. Both the CO2 efflux and N accumulation that are a result of a joint action of deadwood bacteria and fungi may be significant for nutrient cycling at ecosystem levels. Especially in boreal forests with low N stocks, deadwood retention may help to improve the nutritional status and fertility of soils. IMPORTANCE Wood represents a globally important stock of C, and its mineralization importantly contributes to the global C cycle. Microorganisms play a key role in deadwood decomposition, since they possess enzymatic tools for the degradation of recalcitrant plant polymers. The present paradigm is that fungi accomplish degradation while commensalist bacteria exploit the products of fungal extracellular enzymatic cleavage, but this assumption was never backed by the analysis of microbial roles in deadwood. This study clearly identifies the roles of fungi and bacteria in the microbiome and demonstrates the importance of bacteria and their N fixation for the nutrient balance in deadwood as well as fluxes at the ecosystem level. Deadwood decomposition is shown as a process where fungi and bacteria play defined, complementary roles.

A new cleistanthane nor-diterpenoid, named olicleistanone (1), was isolated as a racemate from the culture filtrates of Diplodia olivarum, an emerging pathogen involved in the aetiology of branch canker and dieback of several plant species typical of the Mediterranean maquis in Sardinia, Italy. When the fungus was grown in vitro on Czapek medium, olicleistanone was isolated together with some already known phytotoxic diterpenoids identified as sphaeropsidins A, C, and G, and diplopimarane (2-5). Olicleistanone was characterized as 4-ethoxy-6a-methoxy-3,8,8-trimethyl-4,5,8,9,10,11- hexahydrodibenzo[de,g]chromen-7(6aH)-one. When D. olivarum was grown on mineral salt medium it produced (-)-mellein (6), sphaeropsidin A and small amounts of sphaeropsidin G and diplopimarane. Olicleistanone (1) exhibited strong activity against the insect Artemia salina L. (100% larval mortality) at 100 µg mL-1 but did not exhibit phytotoxic, antifungal or antioomycete activity. Among the metabolites isolated (1-6), sphaeropsidin A (2) was active in all bioassays performed exhibiting strong phytotoxicity on leaves of Phaseolus vulgaris L., Juglans regia L. and Quercus suber L. at 1 mg mL-1. Sphaeropsidin A (2) also completely inhibited mycelium growth of Athelia rolfsii, Diplodia corticola, Phytophthora cambivora and P. lacustris at 200 μg per plug, and was active in the Artemia salina assay. Also in this assay, diplopimarane (5) and sphaeropsidin G (4) were active (100% larval mortality). Diplopimarane also showed antifungal and antioomycete activities. Athelia rolfsii was the most sensitive species to diplopimarane. Sphaeropsidin C (3) and (-)-mellein (6) were inactive in all bioassays. These results expand knowledge on the metabolic profile of Botryosphaeriaceae, and embody the first characterization of the main secondary metabolites secreted by D. olivarum. [ABSTRACT FROM AUTHOR]

The purpose of this study was to ascertain the stocks of coarse woody debris (CWD) in bilberry pine forests in the southern part of the Republic of Karelia (the middle taiga subzone) and evaluate age-related changes in CWD abundance, stocks, and structure and reveal patterns in their dynamics. Analysis of data from 160 sample plots has shown that the amount of CWD decreases with age: on average, from 1525 (SE ± 12) pcs/ha in young stands to 805 (SE ± 13) pcs/ha in premature ones and 507 (SE ± 7) pcs/ha in overmature stands. On the contrary, the stocks of wood detritus increase from 21 (SE ± 2.6) m3/ha in young stands to 32 (SE ± 2.9) m3/ha in premature stands and 69 (SE ± 6.8) m3/ha in overmature stands. CWD stocks differ in the composition of components: with respect to the number of trunks, standing deadwood prevails in young and middle-aged stands, with the proportion of downed deadwood gradually increasing over time; with respect to the stock, downed deadwood prevails in all age groups except middle-aged stands. The degree of CWD decay gradually increases with stand aging. [ABSTRACT FROM AUTHOR]

Modern approaches to the development of nature management are focused on the formation of a system of sustainable development of regions. Forest territories act as an edifier, which has a global impact on the state of all ecosystems under the conditions of increasing anthropogenic pressure, reducing biodiversity and reducing the productivity of natural ecosystems When creating the ecological frameworks of territories, various research methods are proposed: information-analytical, comparative-geographical, the method of route survey of the territory, and cartographic. The reduction in the area of natural ecosystems leads to a significant reduction in the biodiversity of the most diverse groups of organisms. The extinction and significant reduction of species (very often even background for certain territories) leads to a decrease in genetic biodiversity, and, as a consequence, a disruption to evolutionary processes.

Tree canopies provide habitats for diverse and until now, still poorly characterized communities of microbial eukaryotes. One of the most general patterns in community ecology is the increase in species richness with increasing habitat diversity. Thus, environmental heterogeneity of tree canopies should be an important factor governing community structure and diversity in this subsystem of forest ecosystems. Nevertheless, it is unknown if similar patterns are reflected at the microbial scale within unicellular eukaryotes (protists). In this study, high-throughput sequencing of two prominent protistan taxa, Cercozoa (Rhizaria) and Oomycota (Stramenopiles), was performed. Group specific primers were used to comprehensively analyze their diversity in various microhabitats of a floodplain forest from the forest floor to the canopy region. Beta diversity indicated highly dissimilar protistan communities in the investigated microhabitats. However, the majority of operational taxonomic units (OTUs) was present in all samples, and therefore differences in beta diversity were mainly related to species performance (i.e., relative abundance). Accordingly, habitat diversity strongly favored distinct protistan taxa in terms of abundance, but due to their almost ubiquitous distribution the effect of species richness on community composition was negligible.

Abstract Significantly more carbon (C) is stored in deep soil than in shallow horizons, yet how the decomposition of deep soil organic C (SOC) will respond to rising temperature remains unexplored on large scales, leading to considerable uncertainties to predictions of the magnitude and direction of C‐cycle feedbacks to climate change. Herein, short‐term temperature sensitivity of SOC decomposition (expressed as Q10) from six depths within the top 1 m soil from 90 upland forest sites (540 soil samples) across China is reported. Results show that Q10 significantly increases with soil depth, suggesting that deep SOC is more vulnerable to loss with rising temperature in comparison to shallow SOC. Climate is the primary regulator of shallow soil Q10 but its relative influence declines with depth; in contrast, soil C quality has a minor influence on Q10 in shallow soil but increases its influence with depth. When considering the depth‐dependent Q10 variations, results further show that using the thermal response of shallow soil layer for the whole soil profile, as is usually done in model predictions, would significantly underestimate soil C‐climate feedbacks. The results highlight that Earth system models need to consider multilayer soil C dynamics and their controls to improve prediction accuracy.

Soil appears to play a key role in the response of the forest ecosystems to N deposition. Twenty years of experimental moderate N addition in a sub-alpine forest increased nitrate leaching, but the soil immobilized most of the N input, gradually decreasing the C:N ratio. Exchangeable and microbial N were only slightly affected, but denitrification and N2O production were increased and soil respiration tended to be reduced while soil microbial communities were remarkably resistant. It is assumed that these changes at the process level are related to the soil microbiome, but soil microbial communities have not been assessed so far at lower taxonomical resolution in this long-term experiment. The aim of this study is to understand the underlying causes of the results obtained so far by assessing how N treatment affects the soil microbiome at different soil depths. We analyzed bacterial and fungal diversity and community structures using Illumina MiSeq sequencing and quantified the responses of the N cycling communities to elevated N loads by quantitative PCR. The microbial functions were assessed by respiration, N mineralization, and potential nitrification. Bacterial and fungal α-diversity, observed richness and Shannon diversity index, remained unchanged upon N addition. Multivariate statistics showed shifts in the structures of fungal but not bacterial communities with N load, while the changes were minor. Differences in the community compositions associated with the N treatment were mainly observed at a lower taxonomical level. We found several fungal OTUs in particular genera such as the ectomycorrhizal fungi Hydnum, Piloderma, Amanita, and Tricholoma that decreased significantly with increased N-loads. We conclude that long-term moderate N addition at this forest site did not strongly affect the soil microbiome (which remained remarkably resistant) and its functioning.

Background. The research of the content of toxic chemical elements in various components in natural ecosystems is one of actual issues of the biosphere ecology. The purpose of the work was to study the background concentrations of cadmium in vascular plants in forest ecosystems of the Volga Upland in Penza region. Materials and methods. The research material was a number of samples of organs and tissues of the most common types of vascular plants of various life forms. They were selected during the period of time from September, 2015 to December, 2019. The samples were analyzed with the use of the MGA-915 MD atomic absorption spectrometer. Statistically calculated in Past 3. Results and conclusions. As a result of measurements, the quantitative content of cadmium in the biomaterial of woody and herbaceous plants has been determined. The processing of the statistical data allowed drawing the following conclusions. Trees accumulate the largest amount of the element in question, while grasses accumulate the smallest. On this indicator, bushes occupy a middle position. The species specificity is manifested in the nature of the cadmium accumulation by vascular plants. The content of the element in the vegetative organs and tissues of woody plants is not uniform. The minimum values were determined for the roots and the wood tissue of the trunk, the average values were determined for leaves, and the maximum values were determined for bark. The medicinal and edible vegetable raw materials, procurement of which is possible in the researched forest communities of Penza region, are safe with respect to the cadmium content. In protected areas, the entire supply of toxic elements coming from atmospheric precipitation is held therein. In this regard, they have the same – or even higher – rates of cadmium content in the soil and the biological objects than in the forest areas where fellings take place.

Abstract Improved knowledge of biological diversity patterns associated with elevation and their driving factors is indispensable for developing ecological theories. However, the results for the elevational distribution patterns of soil fauna are not consistent due to differing climates and vegetation. Here, we present a comprehensive analysis of soil macroinvertebrate composition and structure among different forests at three elevations on the eastern Tibetan Plateau, China. A total of 16,559 individuals belonging to 24 orders and 100 families were collected, and the macroinvertebrate individual abundance, family richness, and diversity apparently increased with increasing elevation. Moreover, remarkable seasonal dynamics were observed for both the composition and functional structure of soil macroinvertebrates among forest types and were inconsistently affected by different environmental factors. The structural equation model suggested that elevation indirectly affected soil macroinvertebrate abundance by modulating climate (e.g., temperature) and soil quality (e.g., soil organic carbon and total nitrogen). Additionally, although vegetation had minor direct effects on soil macroinvertebrate abundance, it might indirectly influence soil macroinvertebrate abundance by regulating plant litter input. Our results indicate that temperature and soil nutrients are critical factors of soil macroinvertebrate elevational distributions and highlight the importance of plant litter input in determining the composition and structure of soil macroinvertebrates at different elevations.

The study of vegetation phenology has great relevance in many fields since the importance of knowing timing and shifts in periodic plant life cycle events to face the consequences of global changes in issues such as crop production, forest management, ecosystem disturbances, and human health. The availability of high spatial resolution and dense revisit time satellite observations, such as Sentinel-2 satellites, allows high resolution phenological metrics to be estimated, able to provide key information from time series and to discriminate vegetation typologies. This paper presents an automated and transferable procedure that combines validated methodologies based on local curve fitting and local derivatives to exploit full satellite Earth observation time series to produce information about plant phenology. Multivariate statistical analysis is performed for the purpose of demonstrating the capacity of the generated smoothed vegetation curve, temporal statistics, and phenological metrics to serve as temporal discriminants to detect forest ecosystems processes responses to environmental gradients. The results show smoothed vegetation curve and temporal statistics able to highlight seasonal gradient and leaf type characteristics to discriminate forest types, with additional information about forest and leaf productivity provided by temporal statistics analysis. Furthermore, temporal, altitudinal, and latitudinal gradients are obtained from phenological metrics analysis, which also allows to associate temporal gradient with specific phenophases that support forest types distinction. This study highlights the importance of integrated data and methodologies to support the processes of vegetation recognition and monitoring activities.

We analyzed impacts of interannual disturbance on the water balance of watersheds in different forested ecosystem case studies across the United States from 1985 to 2016 using a remotely sensed long-term land cover monitoring record (U.S. Geological Survey Land Change Monitoring, Assessment, and Projection (LCMAP) Collection 1.0 Science products), gridded precipitation and evaporation data, and streamgaging data using paired watersheds (high and low disturbance). LCMAP products were used to quantify the timing and degree of interannual disturbance and to gain a better understanding of how land cover change affects the water balance of disturbed watersheds. In this paper, we present how LCMAP science products can be used to improve knowledge for hydrologic modeling, climate research, and forest management. Anthropogenic influences (e.g., dams and irrigation diversions) often minimize the impacts of land cover change on water balance dynamics when compared to interannual fluctuations of hydroclimatic events (e.g., drought and flooding). Our findings show that each watershed exhibits a complex suite of influences involving climate variables and other factors that affect each of their water balances differently when land cover change occurs. In this study, forests within arid to semi-arid climates experience greater water balance effects from land cover change than watersheds where water is less limited.

Abstract Background Stemflow is an essential hydrologic process shaping the soil of forests by providing a concentrated input of rainwater and solutions. However, the transport of metazoans by stemflow has yet to be investigated. This 8-week study documented the organisms (

Seasonal changes in the content of 137Cs in the soil and vegetation of forest ecosystems in the territory of the Chernobyl exclusion zone have been studied. Samples were selected during 2013 from January till March one time per month, and from April till December – one time per two weeks. The study subjects were forest litter and the upper layers of the humus-eluvial horizon of soils, one- and two-year-old needles and branches of P. sylvestris. The 137Cs content was measured by gamma spectrometry methods. Dependences of changes in 137Cs concentrations from the season of the year in the soils were not revealed. The leaping increase in the content of 137Cs in the soil layers throughout the year is likely to be related to changes in the quantity of pedobiota and the intensity of the processes of its vital activity. In the needles and branches of P. sylvestris the maximum values of 137Cs concentration are noted in the summer. Minimum values of 137Cs content in the studied organs of P. sylvestris are characteristic for the autumn-winter period. As a result of the studies, linear relationship was found between seasonal changes in 137Cs concentration in needles and branches of P. sylvestris in testing areas with different levels of contamination. Changes of the 137Cs content in the studied organs of P. sylvestris, which coincide in time at different testing areas, indicate common regularities of 137Cs redistribution at the soil-vegetation chain in forest ecosystems throughout the year.

Forest ecosystems provide a variety of environmental, economic, social and cultural goods and services crucial to sustaining human societies such as food, raw material, carbon sequestration, water purification, soil formation and habitat for millions of species. Due to excessive demand stemming from economic growth, demographic changes and individual choices, ecosystem services are under pressure and they are degraded. That is why it becomes more crucial to prevent these ecosystems and ecosystem services. In this study it is aimed to review the relationship between forest resources and ecosystem services for the Turkish forestry sector. Within this scope, after a brief examination of forest ecosystem services and the current situation of payment for ecosystem services (PES) mechanisms in Turkey, the forestry sector plans and documents are analyzed and how ecosystem services and PES mechanisms are handled in these plans and programs are evaluated. It is determined that there is no detailed purposes or actions on forest ecosystem services, their importance and PES in forestry sector plans in Turkey. Although emerging mechanisms such as PES offer good alternatives for financing forestry sector projects, Turkish forestry sector does not benefit from these resources yet already. [ABSTRACT FROM AUTHOR]

Tree canopies provide habitats for diverse and until now, still poorly characterized communities of microbial eukaryotes. One of the most general patterns in community ecology is the increase in species richness with increasing habitat diversity. Thus, environmental heterogeneity of tree canopies should be an important factor governing community structure and diversity in this subsystem of forest ecosystems. Nevertheless, it is unknown if similar patterns are reflected at the microbial scale within unicellular eukaryotes (protists). In this study, high-throughput sequencing of two prominent protistan taxa, Cercozoa (Rhizaria) and Oomycota (Stramenopiles), was performed. Group specific primers were used to comprehensively analyze their diversity in various microhabitats of a floodplain forest from the forest floor to the canopy region. Beta diversity indicated highly dissimilar protistan communities in the investigated microhabitats. However, the majority of operational taxonomic units (OTUs) was present in all samples, and therefore differences in beta diversity were mainly related to species performance (i.e., relative abundance). Accordingly, habitat diversity strongly favored distinct protistan taxa in terms of abundance, but due to their almost ubiquitous distribution the effect of species richness on community composition was negligible. [ABSTRACT FROM AUTHOR]

The paper considers the problems of utilizing forest resources and proposes a way to close the resource loop in the forest industry via processing forestry waste into carbon nanomaterials, which can be further used as a basis for biological preparations stimulating forest restoration. [ABSTRACT FROM AUTHOR]

Forest ecosystems are an important sink for terrestrial carbon sequestration. Hence, accurate modeling of the intra‐ and interannual variability of forest photosynthetic productivity remains a key objective in global biology. Applying climate‐driven leaf phenology and growth in models may improve predictions of the forest gross primary productivity (GPP). We used a dynamic non‐structural carbohydrates (NSC) model (FORCCHN2) that couples leaf development and phenology to investigate the relationships among photosynthesis and environmental factors. FORCCHN2 simulates spring and autumn phenological events from heat and chilling, respectively. Leaf area index data from satellites along with climate data estimated localized phenological parameters. NSC limitation, immediate temperature, accumulated heat, and growth potential comprised a daily leaf‐growth model. Functionally, leaf growth was decoupled from photosynthesis. Leaf biomass determined overall photosynthetic production. We compared this model with outputs of the other six terrestrial biospheric models and with observations from the North American Carbon Program Site Interim Synthesis in 18 forest sites. This model improved the predicted performance of yearly GPP with a 57%–210% increase in correlation (median) and up to a 102% reduction in biases (median), compared to three prognostic models and three prescribed models. At the North America continental scale, the model predicted the average annual GPP of 7.38 Pg C/year from forest ecosystems during 1985–2016. The results showed an increasing trend of GPP in North America (1.0 Pg C/decade). The inclusion of climate‐driven phenology and growth has a significant potential for improving dynamic vegetation models, and promotes a further understanding of the complex relationship between environment and photosynthesis. [ABSTRACT FROM AUTHOR]

Many terrestrial orchid species are known to grow in forest ecosystems, but the patterns of their diversity and habitat specialization have not been sufficiently explored. Niche parameters and factors influencing the distribution, abundance and composition of forest orchids in the central Balkans were investigated in the present study. Outlying mean index (OMI) analysis was used to explore ecological niches of orchids and environmental factors affecting the patterns of their distribution. Indicator species analysis was performed to identify species presenting strong affinity for specific forest and bedrock types. In addition, similarity profile analysis was applied to classify orchid taxa into meaningful groups, whereas the multi-response permutation procedure was used to analyse differences of orchid composition between forest types. Out of a total of 40 orchid species and subspecies analysed, 29 showed significant niche marginality. The first three axes of the OMI analysis explained 68.13% of total variability. Light, temperature, moisture, nitrogen and altitude were found to be the factors most effectively influencing the distribution and abundance of orchids. Seven orchids had statistically significant strong affinity for specific forest types, whereas eight orchids were statistically significantly correlated with specific bedrock types. Overall, six ecological groups of orchids were distinguished. The results suggest that specialist orchids occur at the extreme ends of the light, temperature, soil pH, moisture and altitude gradients. Moreover, most specialist orchid species were found from low to middle elevations. The results provide a useful basis for the successful design of strategies for the conservation of forest orchids. [ABSTRACT FROM AUTHOR]

Modeling the carbon cycle in forests is often restricted by modeling the main components, including emissions (respiration of soils and debris) and production (deposition of carbon in plants and soils). In this study we examine the applicability of various versions of the T&P model to estimate monthly, seasonal, and annual fluxes of CO2 from the sod-podzolic soil in the mixed forest of the Prioksko-Terrasny Nature Reserve, Moscow oblast. The model is parameterized and verified, and the accuracy is tested using a database of 20 years of monitoring CO2 emissions from soils and independent weather variables, including mean monthly air temperature and monthly precipitation. Numeric experiments show that all versions of the T&P model (both initial and parameterized by training sets at different temporal intervals) satisfactorily describe the long-term dynamics of mean monthly respiration of the sod-podzolic soil under forest cover (SRm). Parameterization of the T&P model with experimental data as a training set practically does not improve the quality of modeling in any of the test intervals. The use of weather data averaged over 20 years for the calculation of SRmod-mean and estimates of seasonal and annual soil fluxes of CO2 on their basis (SeSRmod-mean) in most cases overestimates the corresponding experimentally obtained values (SeSRexp). SeSRmod-mean for annual, summer, and winter soil CO2 fluxes are on average 4.5–6.7% higher than SeSRexp, and SeSRmod-mean for the warm season shows an overestimation of approximately 3%. The largest discrepancy of calculated estimates to experimental data is found for the spring period: the overestimation amounts to ~22%. Thus, the use of weather data averaged over 20 years has shown the applicability of an ensemble of versions of the T&P model for estimating seasonal and annual fluxes of CO2 from soil in a humid continental climate. [ABSTRACT FROM AUTHOR]

This article dwells upon the current understanding of the multifunctionality of forest ecosystems and links between multifunctionality and biodiversity, as well as the trade-offs and synergy between the ecosystem functions (EFs) and services of forests. The relevance of studying ecosystem services (ES's) is determined by the modern societal needs that have emerged as a result of global economic and population growth. Forest ecosystems provide multiple services simultaneously; i.e., they possess a multifunctionality trait. The majority of studies, however, focus on the relationships between biodiversity and individual ES's. Therefore, the impact of biodiversity loss on ES's is greatly underestimated due to the underdeveloped methodology and tools taking into account the multifunctionality of ecosystems. We propose a conceptual scheme of the linkages among biodiversity, multiple functions, and multiple services, including the factors affecting these links. The interdisciplinary concept of links and their introduction to support administrative decision-making necessitates addressing the following: identifying informative indicators of the links and assessing the synergies and trade-offs between various EFs. Reaching those objectives will allow us not only to obtain new fundamental knowledge about processes involved in the functioning of forest ecosystems, but also create markets for ES's that have not been considered marketable previously and ensure steady, sustainable forest use. [ABSTRACT FROM AUTHOR]

How, where, and why carbon (C) moves into and out of an ecosystem through time are long‐standing questions in biogeochemistry. Here, we bring together hundreds of thousands of C‐cycle observations at the Harvard Forest in central Massachusetts, USA, a mid‐latitude landscape dominated by 80–120‐yr‐old closed‐canopy forests. These data answered four questions: (1) where and how much C is presently stored in dominant forest types; (2) what are current rates of C accrual and loss; (3) what biotic and abiotic factors contribute to variability in these rates; and (4) how has climate change affected the forest's C cycle? Harvard Forest is an active C sink resulting from forest regrowth following land abandonment. Soil and tree biomass comprise nearly equal portions of existing C stocks. Net primary production (NPP) averaged 680–750 g C·m−2·yr−1; belowground NPP contributed 38–47% of the total, but with large uncertainty. Mineral soil C measured in the same inventory plots in 1992 and 2013 was too heterogeneous to detect change in soil‐C pools; however, radiocarbon data suggest a small but persistent sink of 10–30 g C·m−2·yr−1. Net ecosystem production (NEP) in hardwood stands averaged ~300 g C·m−2·yr−1. NEP in hemlock‐dominated forests averaged ~450 g C·m−2·yr−1 until infestation by the hemlock woolly adelgid turned these stands into a net C source. Since 2000, NPP has increased by 26%. For the period 1992–2015, NEP increased 93%. The increase in mean annual temperature and growing season length alone accounted for ~30% of the increase in productivity. Interannual variations in GPP and NEP were also correlated with increases in red oak biomass, forest leaf area, and canopy‐scale light‐use efficiency. Compared to long‐term global change experiments at the Harvard Forest, the C sink in regrowing biomass equaled or exceeded C cycle modifications imposed by soil warming, N saturation, and hemlock removal. Results of this synthesis and comparison to simulation models suggest that forests across the region are likely to accrue C for decades to come but may be disrupted if the frequency or severity of biotic and abiotic disturbances increases. [ABSTRACT FROM AUTHOR]

Aims: Vertical fine-root distribution determines the potential for acquisition of resources throughout soil profiles; yet, variation among forest types and changes in vertical distribution with environments are poorly understood. We examined vertical root distributions of different forest communities to determine how belowground strategies shift across different forest types and along edaphic gradients. Methods: Specific root length and diameter of fine roots as well as fine-root biomass, length and area densities were measured in sequential soil layers at 10 cm depth increments across 118 forest plots representing five subalpine forest types. Results: Evergreen forest types, including evergreen oaks, were more deeply rooted than birch forests. Differences in rooting depth were due to the dominant tree species identity, not to variations in shrub or herbaceous components. Within forest types, soil nutrients and physical properties contributed to shifts rooting depth but not root morphology. Conclusions: Vertical distributions of fine roots represent critical inputs of plant carbon into soils as well as different capacities for the acquisition of soil resources. Our findings identify consistent patterns of rooting distributions among forest types that may be predictable based on more easily measured root and soil properties and can improve efforts to model rooting depth profiles in forest communities. [ABSTRACT FROM AUTHOR]

Significantly more carbon (C) is stored in deep soil than in shallow horizons, yet how the decomposition of deep soil organic C (SOC) will respond to rising temperature remains unexplored on large scales, leading to considerable uncertainties to predictions of the magnitude and direction of C‐cycle feedbacks to climate change. Herein, short‐term temperature sensitivity of SOC decomposition (expressed as Q10) from six depths within the top 1 m soil from 90 upland forest sites (540 soil samples) across China is reported. Results show that Q10 significantly increases with soil depth, suggesting that deep SOC is more vulnerable to loss with rising temperature in comparison to shallow SOC. Climate is the primary regulator of shallow soil Q10 but its relative influence declines with depth; in contrast, soil C quality has a minor influence on Q10 in shallow soil but increases its influence with depth. When considering the depth‐dependent Q10 variations, results further show that using the thermal response of shallow soil layer for the whole soil profile, as is usually done in model predictions, would significantly underestimate soil C‐climate feedbacks. The results highlight that Earth system models need to consider multilayer soil C dynamics and their controls to improve prediction accuracy. [ABSTRACT FROM AUTHOR]

The aim of this study was to show the detailed properties of Technosol formed from the remains of an old lime kiln in Western Pomerania as a habitat of a rare protected plant - the lady's-slipper orchid (Cypripedium calceolous). Additionally, an attempt was made to establish the relationship between soil properties and the occurrence of the lady's slipper orchid. The study was conducted in the area of the Polanów Forest District in the Żydowo forestry, near Lake Kwiecko (northern Poland). In the middle of the patch of the lady's-slipper orchid (Cypripedium calceolous), a soil pit was dug, in which numerous artifacts in the form of brick rubble and enamel were found, which testify to the anthropogenic material from which the studied soil developed. Soil samples were taken from each soil horizon and basic physicochemical properties were determined. Additionally, a grid of points from which samples were taken from the humus horizon was established in the lady's-slipper orchid occurrence patch. The grid was used to check the surface properties of Technosol horizons in the whole range of the examined species occurrence. The occurrence of Humic Technosol was found in the patch of lady's-slipper orchid. The conducted study confirms that in forest areas of the remains of lime kilns, fertile Technosols are formed by as a result of natural succession of forest vegetation. As a result of these processes, in a short period of time (400 years) a soil profile of Humic Technosols with a deep, structural, biologically active humus horizon developed. Statistical analyzes showed that pH, high abundance of organic carbon and high biochemical activity of the soil studied are conducive to the development of the lady's-slipper orchid. [ABSTRACT FROM AUTHOR]

Radioactive contamination of the aboveground phytomass of marsh Labrador tea (Ledum palustre L.) in different periods after the Chernobyl accident was studied. Marsh Labrador tea is widely used in official and folk medicine. The studied species grows in over-moistened pine (less mixed) forests and open oligotrophic and mesotrophic marshes. It was found that in the first four years since the beginning of observations (1991), the magnitude of the specific activity of 137Cs in above-ground vegetative phytomass of marsh Labrador tea, depending on a permanent sample area (PSA), decreased by 1.2–1.4 times. After 10 years, it decreased by 1.6–1.7 times, after 16 years by 1.9–2.1 times, after 21 years by 2.7– 3.1 times, and after 27 years by 3.1–6.5 times. An increase in the magnitude of transitions factors was also observed on all PSA over time. Thus, the minimal increase within 1991–2018 was recorded in PSA 11 – by 1.2 times and on PSA 13 – by 1.4 times. The maximum decrease in the magnitude of transition coefficient was observed in PSA 16 – by 2.7 times, in PSA 15 – by 3.0 times, and in PSA 18 – by 2.0 times. It was found that marsh Labrador tea belongs to the group of plants that are characterized by the high content of 137Cs in the above-ground vegetative phytomass. Within the observation period (1991–2018), this content significantly exceeds the admissible levels of radionuclide content in plant medicinal raw materials that are used for manufacturing medical preparations. In the PSA with maximum magnitudes of soil contamination density (400.5±50.73 kBk·m-2) this excess made up 158.4 times in 1991, and 33.7 times (166.9±23.56 kBk·m-2) in 2018. For 27 years of observations, there has been a decrease in the density of radioactive soil contamination by 2.1– 2.7 times, which is due to radionuclide decomposition, its vertical migration in the soil, and towards the components of forest ecosystems [ABSTRACT FROM AUTHOR]

The improved version of simulation model EFIMOD 2 was used for the estimation of forest ecosystem dynamics and analysis of basic linkages between stand structure, environment, and external factors, such as cuttings, forest fires, increased nitrogen deposition, which were considered both separately and in combination, in different boreal forest types of European Russia. According to the simulation results, increasing role of Norway spruce during the undisturbed development resulted in enrichment of forest floor and mineral soil by nitrogen by 5 and 10%, respectively. In contrast, fires promoted increase in Scots pine portion in stand composition, decrease in forest floor pool by 31%, in comparison with undisturbed development. Cuttings had the impact on stocks of soil organic matter through the decreased litter fall input that resulted from partial removal of tree biomass. The combined effect of fires and cuttings on ecosystem carbon pools was about 17% smaller than could be expected from the simple sum of the effects of both factors, which means that impact of one factor reduces (by affecting the same components of ecosystems) the possibility for negative influence of another one. The gradual increase in nitrogen deposition from 1.5 to 3.0 kg ha−1 year−1 for northern taiga and from 3.0 to 4.5 kg ha−1 year−1 for middle taiga by the end of 100-year simulation period had a positive influence on the carbon and nitrogen accumulation in trees' biomass and soil organic matter (35% higher than in scenario without disturbances), thus partly overwhelming the impact from fires and cuttings. The important feature of the study is that the quantitative differences of stand and soil parameters between forest site types were revealed as well. [ABSTRACT FROM AUTHOR]

Forest ecosystems are complex areas in terms of rehabilitation of radioactively contaminated areas, so conducting an up-todate examination of these areas for radioactive contamination is relevant. The paper considers the improvement of methods of soil sampling for obtaining representative materials in the estimation of vertical migration of 137Cs in the soil profile and the level of soil contamination with 137Cs. The density of radioactive soil contamination was studied by reducing the number of selected samples from 30 to 3 in the layers of 10, 20, and 30 cm. The results show that when the number of soil samples decreases, the average magnitudes of soil contamination with 137Cs are not significantly different within each analyzed layer. It was noted that at sampling in the 10-centimeter layer, the studied indicator was 1.3-1.4 times lower than in the layers of 20 and 30 cm, and there is no difference between the latter. To obtain reliable levels of radioactive contamination of the territory, it is necessary to perform 10-time repeated sampling in the forest soil layer of 30 cm. At a decrease in the number of soil samples from 10 to 3, the fluctuation of average values of the specific activity of 137Cs in different layers of soil profile is low. To obtain representative magnitudes of 137Cs content in each layer of the soil profile, it is necessary to make various samplings. Thus, for 4-time repeated sampling, is sufficient for all layers of forest litter, and 6-time repeated sampling is enough for the humus-eluvial horizon. It is necessary to perform 8-time repeated sampling for the eluvial and illuvial horizon, and 10-time repeated sampling for illuvial sand and parent rock. The obtained results make it possible to carry out up-to-date examination of forests for radioactive contamination based on the updated methodology and using the obtained data on 137Cs migration in forest soils. [ABSTRACT FROM AUTHOR]