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Stable isotopes are increasingly being used in many scientific fields, including environmental sciences. In this study we measured the variation in the stable hydrogen and oxygen isotope composition of fog water, rain water (in the form of bulk falling precipitation) and throughfall water in the Sumava (the Bohemian Forest), Krkonose (the Giant Mts.) and Jizerske hory (the Jizera Mts.) Mts. in October-November 2017. In total, 46 cumulative two-week samples were collected and analysed. Our results indicate that the overall stable hydrogen and oxygen isotope composition of fog and rain samples differed significantly, fog being isotopically enriched in the heavier isotopes 2H and 18O relative to rain. In contrast to our assumption, throughfall water was generally depleted in the heavier isotopes 2H and 18O relative to rainwater. Hence, the simple mixing model for most samples yielded an unrealistic percentage outside the reasonable range of 0–100%. For few samples, however, the estimated contribution of fog to throughfall ranged between 3 and 8% based on δ2H and 4 and 7% based on δ 18O, which is lower than that estimated for the same mountain regions by other authors using different methods and significantly lower than that reported for mountain ranges in neighbouring countries. Although using stable isotopes is a promising tool for determining the contribution of fog to the hydrological budget when assessing atmospheric deposition, the critical limitations are in the collection, manipulation and storing of the samples.

Soils represent important pools of soil organic carbon (SOC) that can be greatly influenced by labile C inputs, which are expected to increase in future due to CO2 enrichment of atmosphere and a concomitant rise in plant primary productivity. Studying effects of variable labile C inputs on SOC pool helps to understand how soils respond to global change. However, this knowledge is missing for coniferous forest soils despite being widespread throughout the northern temperate zone. We conducted a 7-month field manipulation experiment to study the effects of variable labile C inputs (simulated by additions of C4 sucrose) on the C content in soil fractions and on microbial abundance in the organic (O), surface mineral (A), and subsoil mineral (B) horizons of a temperate coniferous forest soil. SOC in less-protected soil fractions and total organic C were substantially decreased by labile C additions that simulated future increases in C inputs. The SOC losses were comparable between the A and B horizon (40% vs. 30%). However, because sucrose availability estimated from its incorporation into soil fractions and microbial biomass sharply decreased with soil depth, the loss of C was higher in the B than in the A horizon when related to the amount of sucrose added. Utilization of sucrose was highest by fungi in the O horizon and by bacteria in the mineral soil horizons. The results indicate that future increases in labile C inputs to coniferous forest soils will cause rapid and substantial losses of SOC in both the surface and subsoil mineral horizons.

Elucidating dynamics of soil microbial communities after disturbance is crucial for understanding ecosystem restoration and sustainability. However, despite the widespread practice of swidden agriculture in tropical forests, knowledge about microbial community succession in this system is limited. Here, amplicon sequencing was used to investigate effects of soil ages (spanning at least 60 years) after disturbance, geographic distance (from 0.1 to 10 km) and edaphic property gradients (soil pH, conductivity, C, N, P, Ca, Mg, and K), on soil bacterial and fungal communities along a chronosequence of sites representing the spontaneous succession following swidden agriculture in lowland forests in Papua New Guinea. During succession, bacterial communities (OTU level) as well as its abundant (OTU with relative abundance > 0.5%) and rare (n = 12) or rare (n = 653) for bacteria than fungi (abundant = 6, rare = 5), indicating bacteria were more tolerant than fungi to environmental gradients. Rare taxa showed higher successional dynamics than abundant taxa, and rare bacteria (mainly from Actinobacteria, Proteobacteria, Acidobacteria, and Verrucomicrobia) largely accounted for bacterial community development and niche differentiation during succession.

Factors shaping community structure of soil microbiota have been intensively studied; however, the pattern in community composition and structure of soil microbiota at large geographical scales and factors regulating its metabolic activity remains poorly understood. Here, we used a field transplantation experiments to investigate the effects of substrate and climatic conditions on basal soil respiration, microbial biomass C and diversity of soil microbiota by comparing local and transplanted soils along a latitudinal gradient. Soil samples collected in April 2008 at donor site (Sokolov, Czech Republic) in Central Europe were gamma-ray sterilized and transplanted to receptor sites in Europe and the USA in May and early June 2008. Soil samples were taken in June 2009 after one year of exposure and immediately prepared for laboratory analysis. Basal soil respiration in local soils increased from 22 to 42 mg CO2-C kg−1 h−1 with latitude while basal soil respiration in transplanted soils decreased with latitude from 32 to 19 mg CO2-C kg−1 h−1. The microbial biomass C in both transplanted and local soils decreased with latitude. Content of fungal and bacterial phospholipid fatty acids increased nearly twice with latitude in local soils. Shannon diversity index of fungal community decreased from 2.5 to 1.2 along the latitudinal gradient in transplanted soils while local soils increased from 0.9 to 2.4 with latitude. Based on our results, microbial activity is driven mainly by changes of the soil substrate along latitudinal and climatic gradients while microbial biomass is driven more by global climatic factors itself. The diversity of soil microbial communities is mostly affected by latitudinal and climatic factors while community structure is mostly shaped by substrate quality.

Microbial interconnections in soil are pivotal to ecosystem services and restoration. However, little is known about how soil microbial interconnections respond to slash-and-burn agriculture and to the subsequent ecosystem restoration after the practice. Here, we used amplicon sequencing and co-occurrence network analyses to explore the interconnections within soil bacterial and fungal communities in response to slash-and-burn practice and a spontaneous restoration (spanning ca. 60 years) of tropical forests after the practice, in Papua New Guinea. We found significantly higher complexity and greater variations in fungal networks than in those of bacteria, despite no significant changes observed in bacterial or fungal networks across successional stages. Within most successional stages, bacterial core co-occurrences (co-occurrences consistently present across all sub-networks in a stage) were more frequent than those of fungi, indicating higher stability of interconnections between bacteria along succession. The stable interconnections occurred frequently between bacterial taxa (i.e. Sporosarcina, Acidimicrobiale and Bacillaceae) and between ectomycorrhizal fungi (Boletaceae and Russula ochroleuca), implying important ecological roles of these taxa in the ecosystem restoration. Collectively, our results provide new insight into microbial interconnections in response to slash-and-burn agriculture and the subsequent ecosystem restoration, thus promoting a better understanding of microbial roles in ecosystem services and restoration.

The majority of studies that investigate plant functional trait effects on ecosystem properties use traits obtained from databases. However, we know little regarding their explanatory power proportionate to that of the semi-quantitative vegetation properties, and much less still is known when considering their temporal changes in a chronosequence. We determined whether soil chemical and biological properties were associated with plant functional traits, observed vegetation properties (“patch type” = bare soil, grassy, woody), and site age (10, 18, 28, and 55 years), at four spontaneously overgrown post-mining locations in the Czech Republic. Abiotic soil properties were expected to be closely related to the site age, while above and below ground macrofauna (epigeic and endogeic, respectively), mesofauna, and microbial biomass were expected to be related to the plant functional traits and patch types. Site age and plant functional traits were more important explanatory factors for most of the chemical, microbial, and macrofaunal soil properties than the patch types. Patch type was the only plant-related factor capable of explaining the mesofauna community variations. Epigeic macrofauna were found to correlate more strongly with the plant functional traits than endogeic macrofauna. The abundance of most fauna correlated positively with an increase in plant cover and litter input and was significantly higher in vegetated patches and old sites.

Soil microorganisms are recognized as key players in all biogeochemical cycles. However, little effort has been paid to incorporate them in predictive models for future climate change. Here, we investigated the variation of prokaryotic community composition in alpine meadow soil from the Qinghai-Tibet Plateau under dry-rewetting stress using MiSeq sequencing approach. We incubated soils treated by various frequencies of rewetting and durations of desiccation. Emission rates of methane, carbon dioxide and nitrous oxide were measured every week during five months of incubation, and soil samples were taken each month for community composition analysis. Our results revealed that soil prokaryotic community showed different response patterns to dry-wetting cycles. Diversity indices significantly increased in soils under short-term drought and soils rewetted after long-term drought. Higher niche partitioning was promoted by higher frequencies of disturbance and rapid physiological activation of inactive microbial communities during desiccation, allowing colonization by a diverse array of organisms. Null model percentage of NTI revealed a strong phylogenetic relatedness of soil prokaryotic communities across all treatments and incubation times, suggesting that desiccation and rewetting events were strong biological filters shaping community assemblies. Our results also indicated different responses of various genera belonging to same phylum. These results suggest that prokaryotes that are well adapted to extremely stressful conditions such as long-term desiccation may release more greenhouse gasses in a positive feedback loop and that this prospect should be considered when modeling climate change.

The arbuscular mycorrhizal (AM) grass Calamagrostis epigejos and predominantly ectomycorrhizal (EcM) tree Salix caprea co-occur at post-mining sites spontaneously colonized by vegetation. During succession, AM herbaceous vegetation is replaced by predominantly EcM woody species. To better understand the interaction of AM and EcM plants during vegetation transition, we studied the reciprocal effects of these species’ coexistence on their root-associated fungi (RAF). We collected root and soil samples from three different microenvironments: stand of C. epigejos, under S. caprea canopy, and contact zone where roots of the two species interacted. RAF communities and mycorrhizal colonization were determined in sampled roots, and the soil was tested for EcM and AM inoculation potentials. Although the microenvironment significantly affected composition of the RAF communities in both plant species, the effect was greater in the case of C. epigejos RAF communities than in that of S. caprea RAF communities. The presence of S. caprea also significantly decreased AM fungal abundance in soil as well as AM colonization and richness of AM fungi in C. epigejos roots. Changes observed in the abundance and community composition of AM fungi might constitute an important factor in transition from AM-dominated to EcM-dominated vegetation during succession.

In the Protected Landscape Area “Labské pískovce” (Czech Republic), there are many sandstone caves accessible by permission only and where climbing equipment is commonly required. The tradition of visiting the caves dates back to turn of the 19th and 20th centuries, and visitors traditionally record their visits in log-books. We have gathered attendance data from 12 caves from log-books and via survey (2-year form collection period). The attendance varied from less than 10 to ~650 visitors annually. Signs of inadequate behavior of visitors were observed, especially waste disposal and smoking in the caves. Sediment step-compression increased significantly the ratios of fungi/bacteria and gram-positive to gram-negative (G+/G−) phospholipid fatty acids (PLFA) as well as PLFA of actinobacteria and activities of sediment phosphatases, glucosidases, and peroxidases. The number of visitors was correlated positively with the G+/G− ratio and sediment nutrients but negatively with sediment moisture and the activity of peroxidases. The results indicate a significant effect of attendance on sediment microbial communities, most likely caused by the import of nutrients into caves. Hence, reconsideration of the cave attendance policy is recommended.