Abstract The article gives a geobotanical description and a floristic analysis of communities with the participation of the rare and relict species Alnus glutinosa in condition of Aktobe region. The ...aim of the study is to provide a geobotanical assessment of the current status of a rare, relict species of the Alnus glutinosa population, which was included in the Red Data Book of Kazakhstan. At present, the flora of the Aktobe region is not sufficiently studied. Conservation of the biodiversity of the Aktobe region flora is one of the most topical issues. In Aktobe region, due to the lack of grazing, felling of trees, using as fuel and the emergence of uncontrolled tourism and at the same time due to the lack of natural renewal of the area, these consequences lead to a quantitative reduction in the species. In this regard, it is necessary to study the species and organize protection and conservation measures. The results of the study showed that the plant Alnus glutinosa is rarely found in the flora of Kazakhstan and also the distribution areas are reduced. Of the three investigated points, plants from 24 families were identified. Plant communities of Alnus glutinosa are being studied for the first time in the Aktobe region. For the first time in the conditions of the Aktobe region, the habitat of black alder was discovered. The floral composition of plant communities of Alnus glutinosa grown in various ecological environments was revealed, the ratio of life forms and phytocenotic features were studied for the first time. In addition, alder felt mite and ground bug, damaging black alder, were identified from 3 studied populations. It has been established that the main reason for the spread of this pest is a very strong moistening of the ground on which sticky Alder grows. Results sequencing showed that the DNA sample under study belongs to the fungus Alternaria alternata.
Resumo O artigo apresenta uma descrição geobotânica e uma análise florística de comunidades com a participação da espécie rara Alnus glutinosa, na região de Aktobe. O objetivo do estudo é fornecer uma avaliação geobotânica do estado atual de uma espécie rara da população de Alnus glutinosa, que foi incluída no Livro Vermelho de Dados do Cazaquistão. Atualmente, a flora da região de Aktobe não é suficientemente estudada. A conservação da biodiversidade da flora da região de Aktobe é uma das questões mais atuais. Nessa região, em razão da falta de pastoreio, do abate de árvores para utilização como combustível, do surgimento do turismo descontrolado e, ao mesmo tempo, por causa da falta de renovação natural da área, vem ocorrendo uma redução quantitativa das espécies. Neste sentido, é necessário estudar as espécies e organizar medidas de proteção e conservação delas. Os resultados do estudo mostraram que a planta Alnus glutinosa é raramente encontrada na flora do Cazaquistão e também que as áreas de distribuição são reduzidas. Dos três pontos investigados, foram identificadas plantas de 24 famílias. Pela primeira vez, estão sendo estudadas as comunidades vegetais de Alnus glutinosa na região de Aktobe, bem como foi descoberto o habitat do amieiro-negro. Foi revelada a composição floral das comunidades vegetais de Alnus glutinosa cultivadas em vários ambientes ecológicos, assim como foram estudadas pela primeira vez a proporção de formas de vida e as características fitocenóticas. Além disso, o ácaro do feltro do amieiro e o percevejo-do-solo, que danificam o amieiro-preto, foram identificados em três populações estudadas. Foi estabelecido que a principal razão para a propagação desta praga é o forte umedecimento do solo onde cresce o amieiro. O sequenciamento dos resultados mostrou que a amostra de DNA em estudo pertence ao fungo Alternaria alternata.
During early afforestation stages, biotic and abiotic soil characteristics change at different paces. However, the extent that each of these characteristics contribute to plant performance and ...subsequent herbivory remains unclear. This study aimed to study the effects of biotic and abiotic characteristics of forest soil on Alnus glutinosa performance and their subsequent impact on foliar herbivory during early afforestation. Soils were collected from a series of replicated forests of 10, 15 or 25 years old, planted in agricultural soils. Two experiments were conducted, focusing on the effect of soil microbiome (live vs. sterilized forest soil, and bulk sterilized soil vs. bulk inoculated with forest soil) and forest age on tree performance, root-associated microbial communities, and plant-herbivore interactions. In 10-year-old forest soil, A. glutinosa stems were thinner when grown in sterilized soil than when grown in live soil. In 15- and 25-year-old soil, trees exhibited lower fine root percentages and thicker stems in sterilized than in live soils, suggesting age-dependent responses possibly arising from plant and microbe nutrient competition. Overall root-associated microbial communities showed no significant differences in their composition based on forest ages. Streptomyces sp. and Rokubacteriales were differentially more abundant in the roots of trees growing in 15-year-old soils and their relative abundance was correlated positively with aboveground biomass, suggesting that effects of forest age on tree performance are contingent on the unique microbiome of each forest. The herbivory assay using Mamestra brassicae larvae revealed a positive correlation between leaf nitrogen content and leaf area consumption in the live vs. sterilized soil experiment, but not in the inoculated soil experiment. Trees in 10-year-old forest soils exhibited the highest herbivore performance, suggesting heightened herbivore susceptibility in early afforestation. Our findings underscore that intricate relationships between soil conditions, microbial communities, and plant-herbivore interactions affect tree performance and herbivory during early afforestation.
•Alder growth depends on the soil microbiome but there is no effect of soil age.•Root nodule density in alder decreased with increasing age of the forest soil.•The effect of soil sterilization on tree growth depended on the age of the soil.•Streptomyces and Rokubacteriales enhanced tree performance in 15-year-old soils.
Sustained increased productivity of trees growing in elevated CO sub(2) depends in part on their stoichiometric flexibility, i.e., increasing their nutrient use efficiency, or on increased nutrient ...uptake from the soil. Phosphorus (P) may be a nutrient as limiting as nitrogen (N) in terrestrial ecosystems and may play a key-process in global terrestrial C storage. For this study archived litter and soil samples of two free air CO sub(2) enrichment (FACE) experiments were analyzed for C, N and P. Populus euramericana, nigra and alba and Betula pendula, Alnus glutinosa and Fagus sylvatica were grown in ambient and elevated CO sub(2) at respectively the Euro- and BangorFACE experiments. At EuroFACE, aboveground litter accumulated in L, F and H layers, while at BangorFACE almost all aboveground litter was incorporated into the mineral soil due to bioturbation. At EuroFACE, more P was lost from the F and H litter layers due to trees growing in elevated CO sub(2), while at BangorFACE more P was lost from the mineral soil. Results of this study imply that trees growing in elevated CO sub(2) were P limited at both experiments. Therefore, with increasing atmospheric CO sub(2), P may play a more pronounced role than previous thought in regulating secondary forest growth. Moreover, increased atmospheric CO sub(2) and ample N may allow a larger pool of P to become available for uptake due to, for instance, increased phosphatase activity resulting in increased organic matter turnover and biogenic weathering. Therefore, it may be postulated that under non-N-limited conditions, e.g., during regrowth, under high N deposition or in systems with high N sub(2)-fixation, increased P availability and uptake may allow P-limited forests to sustain increased growth under increasing atmospheric CO sub(2).
Anthropogenic impacts on freshwater ecosystems cause critical losses of biodiversity that can in turn impair key processes such as decomposition and nutrient cycling. Forest streams are mainly ...subsidized by terrestrial organic detritus, so their functioning and conservation status can be altered by changes in forest biodiversity and composition, particularly if these changes involve the replacement of functional groups or the loss of key species. We examined this issue using a microcosm experiment where we manipulated plant functional diversity (FD) (monocultures and low-FD and high-FD mixtures, resulting from different combinations of deciduous and evergreen Quercus species) and the presence of a key species (Alnus glutinosa), all in presence and absence of detritivores, and assessed effects on litter decomposition, nutrient cycling, and fungal and detritivore biomass. We found (i) positive diversity effects on detritivore-mediated decomposition, litter nutrient losses and detritivore biomass exclusively when A. glutinosa was present; and (ii) negative effects on the same processes when microbially mediated and on fungal biomass. Most positive trends could be explained by the higher litter palatability and litter trait variability obtained with the inclusion of alder leaves in the mixture. Our results support the hypothesis of a consistent slowing down of the decomposition process as a result of plant biodiversity loss, and hence effects on stream ecosystem functioning, especially when a key (N-fixing) species is lost; and underscore the importance of detritivores as drivers of plant diversity effects in the studied ecosystem processes.
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•Effects of functional diversity loss on instream litter decomposition were assessed.•Diversity effects were mostly controlled by the N-fixing Alnus glutinosa.•Overall positive diversity effects were detected for detritivore-mediated processes.•Overall negative diversity effects were detected for microbially-mediated processes.•Key plant species and detritivores, more than functional diversity, were the essential drivers of diversity effects.
Several human activities often result in increased nitrogen (N) and phosphorus (P) inputs to running waters through runoff. Although headwater streams are less frequently affected by these inputs ...than downstream reaches, the joint effects of moderate eutrophication and global warming can affect the functioning of these ecosystems, which represent two thirds of total river length and thus are of major global relevance. In a microcosm study representing streams from a temperate area (northern Spain), we assessed the combined effects of increased water temperature (10.0, 12.5, and 15.0 °C) and nutrient enrichment (control, high N, high P, and high N + P concentrations) on the key process of leaf litter decomposition (mediated by microorganisms and detritivores) and associated changes in different biological compartments (leaf litter, aquatic hyphomycetes and detritivores). While warming consistently enhanced decomposition rates and associated variables (leaf litter microbial conditioning, aquatic hyphomycete sporulation rate and taxon richness, and detritivore growth and nutrient contents), effects of eutrophication were weaker and more variable: P addition inhibited decomposition, addition of N + P promoted leaf litter conditioning, and detritivore stoichiometry was affected by the addition of both nutrients separately or together. In only a few cases (variables related to detritivore performance, but not microbial performance or leaf litter decomposition) we found interactions between warming and eutrophication, which contrasts with other experiments reporting synergistic effects. Our results suggest that both stressors can importantly alter the functioning of stream ecosystems even when occurring in isolation, although non-additive effects should not be neglected and might require exploring an array of ecosystem processes (not just leaf litter decomposition) in order to be detected.
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•We examined the joint effects of warming and eutrophication on key stream processes.•Warming consistently enhanced leaf litter decomposition rates and related variables.•Eutrophication had weaker and more variable effects on different processes.•The interaction of both stressors mostly affected detritivore performance.•Considering multiple processes is recommended to detect multi-stressor impacts.
Integrated buffer zones (IBZs) represent a novel form of edge-of-field technology in Northwest Europe. Contrary to the common riparian buffer strips, IBZs collect tile drainage water from ...agricultural fields by combining a ditch-like pond (POND), where soil particles can settle, and a flow-through filter bed (FILTERBED) planted with Alnus glutinosa (L.), a European alder (black alder). The first experimental IBZ facility was constructed and thoroughly tested in Denmark for its capability to retain various nitrogen (N) and phosphorus (P) species within the first three years after construction. We calculated the water and nutrient budget for the total IBZ and for the two compartments, POND and FILTERBED, separately. Furthermore, a tracer experiment using sodium bromide was conducted in order to trace the water flow and estimate the hydraulic residence time in the FILTERBEDs. The monthly average removal efficiency amounted to 10–67% for total N and 31–69% for total P, with performance being highest during the warm season. Accordingly, we suggest that IBZs may be a valuable modification of dry buffer strips in order to mitigate the adverse impacts of high nutrient loading from agricultural fields on the aquatic environment.
The aim of this study was to perform a phytoscreening of per- and polyfluoroalkyl substances (PFAS) at a contaminated site in Germany, to investigate the applicability of this technique for PFAS ...contaminations. Foliage of three species, namely, white willow (Salix alba L.), black poplar (Populus nigra L.), and black alder (Alnus glutinosa L.), were sampled to evaluate seasonal and annual variations in PFAS concentrations. The results of the phytoscreening clearly indicated species and specific differences, with the highest PFAS sum concentrations ∑23 observed in October for white willow (0–1800 μg kg–1), followed by black poplar (6.7–32 μg kg–1) and black alder (0–13 μg kg–1). The bulk substances in leaves were highly mobile short-chain perfluoroalkyl carboxylic acids (PFCAs). In contrast, the PFAS composition in soil was dominated by long-chain PFCAs, perfluorooctanoic acid (PFOA) and perfluorodecanoic acid (PFDA), as a result of the lower mobility with ∑23PFAS ranging between 0.18 and 26 μg L–1 (eluate) and between 66 and 420 μg kg–1 (solid). However, the PFAS composition in groundwater was comparable to the spectrum observed in leaves. Spatial interpolations of PFAS in groundwater and foliage correspond well and demonstrate the successful application of phytoscreening to detect and delineate the impact of the studied PFAS on groundwater.
•We studied VOC emissions in Alnus glutinosa induced by abiotic and biotic interacting stresses.•Herbivores were more strongly attracted to well-watered plants than the plants under drought.•The ...study demonstrates an important priming effect of drought in VOC emissions.
Plant volatile organic compounds (VOCs) elicited in response to herbivory can serve as cues for parasitic and predatory insects, but the modification of VOC elicitation responses under interacting abiotic stresses is poorly known. We studied foliage VOC emissions in the deciduous tree Alnus glutinosa induced by feeding by the larvae of green alder sawfly (Monsoma pulveratum) under well-watered and drought-stressed conditions. Drought strongly curbed photosynthesis rate and stomatal conductance, but there were no effects of insect feeding on photosynthetic characteristics. Feeding induced emissions of volatile products of lipoxygenase pathway and monoterpenes, and emissions of stress marker compounds (E)-β-ocimene and homoterpene DMNT. The emissions were more strongly elicited and reached a maximum value earlier in drought-stressed plants. In addition, methyl salicylate emissions were elicited in herbivory-fed drought-stressed plants. Herbivores were more strongly attracted to well-watered plants and consumed more than a four-fold greater fraction of leaf area than they consumed from drought-treated plants. Overall, this study demonstrates an important priming effect of drought, suggesting that plants under combined drought/herbivory stress are more resistant to herbivores.
•We compared observed genetic structure in Alnus swamp with spatial simulations.•We found positive autocorrelations at < 30 m in the natural old-growth forest.•The gap dynamic model was the most ...probable scenario fitting observed data.•Other tested scenarios led to more coarse-grained structures than that observed.
Advanced knowledge of forest disturbance regimes (the temporal and spatial patterns of periodic disturbances) has key relevance to implementation of effective managements for forest communities. For many forest ecosystems such knowledge is inadequate or is lacking. Spatially explicit simulations, testing effects of alternative disturbance regimes on fine-scale spatial genetic structure (FSGS) may provide information on key components of forest disturbance regimes. Here, we compare FSGSs assessed using 18 microsatellite markers with spatially explicit simulations, to characterise a natural disturbance regime in a European temperate swamp forest dominated by Alnus glutinosa. Individual-based population genetic simulations were carried out for three previously introduced models of disturbance regime, to determine which best fits the FSGS assessed by the kinship coefficient in a natural old-growth forest. We hypothesised a low proportion of trees removed (the gap dynamic model) accentuates high-relatedness among individuals over short distances (i.e. it accentuates FSGS), while a high proportion of trees eliminated by a disturbance (the cyclic succession model and the stand-replacing dynamic model) leads either to random FSGS (i.e. a point pattern of genotypes that cannot be differentiated from a complete spatial randomness) or a high spatial clustering of genotypes. Spatial genetic analyses found significant positive autocorrelations of genotypes at < 30 m in the natural old-growth forest, which indicates A. glutinosa individuals were more highly clustered than for a null model with complete spatial randomness. However, the strength of FSGS was low as indicated by a kinship coefficient < 0.02. Comparing the FSGSs of simulated disturbance regimes with the FSGS recorded in the old-growth forest, the gap dynamic model was the most probable scenario, with small canopy gaps occurring continually through time. The cyclic succession model and the stand-replacing dynamic model also led to non-random FSGSs but in both these models, the FSGS was stronger and more coarse-grained than that observed. The approach of comparing the FSGS recorded in a natural forest with simulations of disturbance regimes allows support to be found for (or against) previously hypothesised disturbance patterns. This approach should be considered alongside the well-established dendrochronological and palaeoecological methods.
Research on the modern distribution of 137Cs in soils of different forest site types in black alder (Alnus glutinosa (L.) Gaerth.) stands was conducted. In forest litter, there is not a high ...percentage of its total activity in soil: in moist fairly fertile site type (C3) – 13.4 %, damp fairly fertile site type (C4) – 16.3 %, and wet fairly fertile site type (C5) – 3.8 %. The mineral part of the soil in moist and damp fairly fertile site type is characterized by decreased density of radioactive contamination of soil layers with depth. In wet fairly fertile site type, this indicator increases to a depth of 6 - 8 cm and decreases with further deepening. A 10-cm layer of moist fairly fertile site type (C3) contains 61.8 % of the total radionuclide activity in soil, damp fairly fertile site type (C4) – 68.1%, and wet fairly fertile site type (C5) – 70.1 %, correspondingly; a 20-cm layer has 75.4, 78.3, 91.9 % and a 30-cm layer – 80.9, 82.2, 96.0 % of the total radionuclide activity.