This study examined the effects of burrow digging and habitation by the European badger (Meles meles) and the red fox (Vulpes vulpes) on soil properties and the plant community. The vegetation of ...control plots located in a similar but undisturbed habitat was compared with that of 18 burrow plots established at badger setts (N = 9) and fox dens (N = 9) in a lowland forest area in Poland. Soil physicochemical properties at different disturbance levels (mounds, intermounds and reference areas) were also investigated. The animals altered nutrient availability in the burrow plots considerably by excavating material from deep soil horizons that were less acidic and higher in K, Ca, Mg and available P but poorer in C and N. The effect was stronger for the badger, probably because it displaced larger amounts of material and disturbed wider areas. The activity of the two carnivores induced similar changes in plant communities. They increased herbaceous species richness and caused a shift in the herbaceous species composition: versus the control plots, the burrow plots contained more fugitive species (short-living plants typical for disturbed environments), among which ruderal forbs, including nutrient-demanding species, dominated. The carnivores also increased the species richness of fleshy-fruited shrubs and trees. The primary reason for this was probably not burrowing but endozoochorous seed dispersal. Overall, the results indicate that the badger setts and fox dens differ significantly from the forest matrix in terms of soil and vegetation parameters, and that they contribute to habitat heterogeneity and biological diversity.
Question: Have past windstorm events influenced the structure and composition of mountain forests in the Tatra Mountains? Can severe and infrequent wind disturbances lead to dynamic coexistence of ...two tree species with different ecological requirements? Location: Subalpine mixed spruce-larch forest at 1200-1300 m a.s.l. in the Slovakian Tatra Mountains. A forested site affected by catastrophic large-scale windthrow on 19 November 2004. Methods: Sixty-seven spruce and 30 larch cross-sections from the oldest cohorts were collected in a regular pattern in a 100-ha plot. Tree-ring series were analysed to reconstruct growth releases associated with past windthrows. A boundary-line release criterion was applied to detect disturbance year. Spatial patterns of release signals were statistically detected with Mantel's test. We compared reconstructed years of disturbance events with historical records. Results: Releases in both species showed three main pulses. More than 85% showed major or moderate releases in 1865-1879, 48% in 1915-1924, and 25% in 1940-1949. All of these disturbance events affected the whole 100-ha area. Releases were spatially patterned in the first disturbances, but distributed randomly in the last. Releases co-occurred in time with enhanced production of compression wood, suggesting disturbances were of wind origin. Reconstructed dates of windthrows were confirmed using historical data on storms. Conclusions: At least three windthrows of major and moderate severity took place in the last 150 years on southern slopes of the Tatra Mountains. This disturbance regime may contribute to coexistence of spruce and larch through differences in vulnerability and response to heavy windstorms.
The presented paper is concerned with detection of presentation attacks against unsupervised remote biometric speaker verification, using a well-known challenge–response scheme. We propose a novel ...approach to convolutional phoneme classifier training, which ensures high phoneme recognition accuracy even for significantly simplified network architectures, thus enabling efficient utterance verification on resource-limited hardware, such as mobile phones or embedded devices. We consider Deep Convolutional Neural Networks operating on windows of speech Mel-Spectrograms as a means for phoneme recognition, and we show that one can boost the performance of highly simplified neural architectures by modifying the principle underlying training set construction. Instead of generating training examples by slicing spectrograms using a sliding window, as it is commonly done, we propose to maximize the consistency of phoneme-related spectrogram structures that are to be learned, by choosing only spectrogram chunks from the central regions of phoneme articulation intervals. This approach enables better utilization of the limited capacity of the considered simplified networks, as it significantly reduces a within-class data scatter. We show that neural architectures comprising as few as dozens of thousands parameters can successfully—with accuracy of up to 76%, solve the 39-phoneme recognition task (we use the English language TIMIT database for experimental verification of the method). We also show that ensembling of simple classifiers, using a basic bagging method, boosts the recognition accuracy by another 2–3%, offering Phoneme Error Rates at the level of 23%, which approaches the accuracy of the state-of-the-art deep neural architectures that are one to two orders of magnitude more complex than the proposed solution. This, in turn, enables executing reliable presentation attack detection, based on just few-syllable long challenges on highly resource-limited computing hardware.
We studied enchytraeid communities in several habitats polluted by heavy metals from Zn–Pb mining and smelting activities. We sampled 41 sites that differed in the type of substratum (carbonate rock, ...metal-rich carbonate mining waste, siliceous sand) and land management (planting Scots pine, topsoiling, leaving to natural succession), and the distance from the smelter. Our main aims were to determine which pollution variables and natural factors most influenced enchytraeid species composition, richness and density, and examine what was the effect of planting Scots pine (reclamation) on enchytraeid communities. The soils harboured on average 1 to 5 enchytraeid species and 700 to 18,300 individuals per square metre, depending on the habitat. These figures were generally lower than those reported from unpolluted regions. Redundancy and multiple regression analyses confirmed the negative impact of heavy metal pollution on both enchytraeid community structure and abundance. Among pollution variables, the distance from the smelter best explained the variation in enchytraeid communities. The concentrations of heavy metals in the soil had less (e.g. total Pb and exchangeable Zn) or negligible (water-soluble forms) explanatory power. Natural soil properties were nearly irrelevant for enchytraeids, except for soil pH, which determined the species composition. Plant species richness was an important explanatory variable, as it positively affected most parameters of enchytraeid community. The results of two-by-two factorial comparisons (planting Scots pine vs. natural succession; carbonate mining waste vs. siliceous sand) suggest that reclamation can improve soil quality for biota, since it increased the diversity and abundance of enchytraeids; this effect was not dependent on the type of substratum. In conclusion, enchytraeids responded negatively to heavy metal pollution and their response was consistent and clear. These animals can be used as indicators of metal toxicity even in the presence of high natural variability, but it is recommended to study their species composition.
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•Enchytraeid communities in a Zn–Pb mining and smelting area were studied.•Negative effects of HMs on enchytraeids were found in different habitats.•Distance from the smelter was a better explanatory variable than soil contents of HMs.•Enchytraeids benefited from the high species richness of plants.•Afforestation of mining wasteland positively affected enchytraeid communities.
•Soil changes caused by Quercus rubra and Q. robur were compared in a pot experiment.•Effects of adding litter, planting a sapling, and a combination of both were studied.•Both species increased the ...content of available nutrients and phenolic compounds.•Q. robur had a stronger effect on nutrients, and Q. rubra on phenolic compounds.•Soil changes were mainly associated with sapling growth (rhizodeposition, nutrient uptake)
Quercus rubra is an invasive species which can modify soil properties and change the structure and functions of the forest ecosystem. Its effect on soil physicochemical properties, including the content of nutrients (total and available) and phenolic compounds, was compared with that of native Quercus robur in a two-year pot experiment. Three treatments were applied to pots with soil: adding leaf litter (L), planting a sapling (S), and their combination (S + L). The litter was analyzed for its chemical composition before being added to the pots to determine whether it varied between species and whether this variation was reflected in the properties of L and S + L soils. The treatments were compared with the control, which consisted of soil-only pots, i.e., without litter and sapling. Both species increased the content of available nutrients (except N-NO3) and the content of phenolic compounds in the soil, with the former (namely N-NH4, P-PO4, and exchangeable K, Ca, and Mg) more affected by Q. robur and the latter (especially t-ferulic acid, myricetin, and quercetin) more affected by Q. rubra. Interestingly, this effect was pronounced for pots with saplings (S and S + L), while it was almost insignificant for pots with litter (L) only. When compared to the control, the treatments generally did not affect the total nutrient content in the soil. However, when comparing species, there was less total K and Mg under Q. rubra than under Q. robur saplings. The litter used in the experiment was significantly different between the two species. The Q. rubra leaves contained less N, P, K, Ca, total phenolics, and condensed tannins, and more organic C, (+)-catechin, ellagic acid, (–)-epicatechin, t-ferulic acid, kaempferol, and syringic acid than the leaves of Q. robur. However, since the effect of adding litter was negligible, these differences did not translate into differences in soil properties. Based on the obtained results, it is expected that the growth of invasive Q. rubra will result in worse soil conditions (less total and available nutrients and more phenolics) in the short term than the growth of native Q. robur in the same habitat. This means that planting Q. rubra outside its native range is associated with a risk of soil deterioration and, therefore, should be avoided, and the spontaneous dispersal of this species should be prevented.
This study assessed recent (2015) and past (2001) levels of air pollution in four regions of Poland by moss monitoring. The surveyed regions encompassed, among others, copper and zinc-lead industrial ...districts, large urban agglomerations and an area away from pollution sources. Moss (Pleurozium schreberi) was sampled from 117 sites. In 2001, the concentrations of Cd, Cr, Cu, Fe, Ni, Pb, and Zn were determined. In 2015, 10 extra elements were analyzed in addition to these metals. The results showed that the regions substantially differed in the chemical profile of air pollution, which corresponded well with the type of industry and the degree of industrialization and urbanization. There was also a significant change in air pollution between the 2001 and 2015 surveys, but it was inconsistent: its magnitude and direction were both metal-dependent and region-dependent. Namely, while the levels of some metals (e.g., Cd and Pb) decreased, other metals (e.g., Cr and Ni) showed the opposite trend. Importantly, these decreases (or increases) were usually limited to regions of low concentrations of a given metal. The results suggest that air quality has not significantly improved recently, but the type of emissions has changed. It seems that the importance of non-industrial pollution sources has increased.
Although air quality in Europe is continually improving, there are regions, especially in central and eastern European countries, where this trend has been unnoticeable and even reversed in recent ...years. To understand the possible reasons for the persistence of these pollution “hotspots”, we investigated the case of the Kraków region (S Poland) known for its heavy pollution caused by a large steelworks. In 1975, at the apogee of industrial emissions, atmospheric deposition of trace metals was evaluated in this area using moss Pleurozium schreberi as a biomonitor. The survey was repeated in 1992, 1998 and 2014. The collected data showed that air quality improved significantly over 40 years: the amount of Cd, Pb, Fe, Cu and Zn accumulated by mosses decreased by a factor of 10, 9, 3.5, 2 and 2, respectively. The downward trend continued for most metals throughout the study period, although the biggest changes occurred at the very beginning (1975–1992). This improvement was mostly due to drops in industrial production and the introduction of environmentally friendly technologies. At the end of the study (1998–2014), clear increases in the concentrations of some trace metals in moss were observed (overall or at some locations). Spatiotemporal variability of moss elemental composition suggests that this is the result of the recent emergence of new (non-industrial) sources of metal pollution, associated with the urban sprawl and intensification of agriculture. Since this process is unlikely to stop in the near future, air quality will deteriorate rather than improve.
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•Trace metals in mosses near a large steelworks (S Poland) were surveyed over 40 years.•Air pollution has decreased significantly but is still above the European median.•Air quality improvement was mainly due to drops in industrial emissions.•Urban sprawl and agriculture are responsible for recent increases in metal deposition.•New sources of pollution undermine the benefits of reducing industrial emissions.
The presented paper introduces a novel method for enabling appearance modifications for complex image objects. Qualitative visual object properties, quantified using appropriately derived visual ...attribute descriptors, are subject to alterations. We adopt a basic convolutional autoencoder as a framework for the proposed attribute modification algorithm, which is composed of the following three steps. The algorithm begins with the extraction of attribute-related information from autoencoder’s latent representation of an input image, by means of supervised principal component analysis. Next, appearance alteration is performed in the derived feature space (referred to as ‘attribute-space’), based on appropriately identified mappings between quantitative descriptors of image attributes and attribute-space features. Finally, modified attribute vectors are transformed back to latent representation, and output image is reconstructed in the decoding part of an autoencoder. The method has been evaluated using two datasets: images of simple objects—digits from MNIST handwritten-digit dataset and images of complex objects—faces from CelebA dataset. In the former case, two qualitative visual attributes of digit images have been selected for modifications: slant and aspect ratio, whereas in the latter case, aspect ratio of face oval was subject to alterations. Evaluation results prove, both in qualitative and quantitative terms, that the proposed framework offers a promising tool for visual object editing.
•Effects of herbaceous plant species on beech and riparian forest soils were studied.•Plant growth had a positive effect on microbiological performance in both soil types.•Species combinations had a ...stronger effect than single-species treatments.•Plant treatments had different effects on the soil physicochemical properties.•Species identity significantly affected soil parameters.
Although herbaceous plant species have the potential to affect soil abiotic and biotic properties, and thus ecosystem processes, they still remain an underappreciated component of forest ecosystems. We performed an outdoor pot experiment to assess the influence of four herbaceous plant species and their combinations on beech and riparian forest soils. The following plant cover treatments were used in the experiment: (1) bare (unplanted) soil, (2) Aegopodium podagraria, (3) Allium ursinum, (4) Anemone nemorosa, (5) Ficaria verna, (6) two-species combination (A. podagraria + A. ursinum), and (7) four-species combination. After 15 months of the experiment, the soils were collected from the pots and analyzed for microbiological properties, i.e., basal respiration, substrate-induced respiration (SIR), phospholipid fatty acid (PLFA) concentrations, enzymatic activity, and physicochemical properties, including moisture, pH, total and available nutrient contents. Herbaceous plants strongly influenced beech and riparian forest soils. Plant growth, either in monocultures or in combinations, resulted in high microbial performance. On the contrary, bare soils were characterized by the lowest values of many microbial indices. Overall, species combinations and A. podagraria had the strongest positive effects on microbes and processes, though the latter mainly in riparian soil; they increased PLFA-biomass (total, bacteria, G+ and G- bacteria, saprotrophic fungi), SIR-biomass, soil respiration, acid phosphatase, alkaline phosphatase, arylsulfatase, and/or urease activity. Plant species combinations and A. podagraria (in riparian soil) also stood out from other treatments in their effects on soil physicochemical properties, decreasing soil water content and the availability of some nutrients (N-NO3, P-PO4). Moreover, A. podagraria increased organic C and total N in riparian soil. Concluding, our experiment showed that the presence of herbaceous plant species positively influences microbes in beech and riparian forest soils, and this effect becomes stronger as plant species diversity increases. Herbaceous plant species are an important component of temperate forests because they play a significant role in supporting soil microorganisms and processes, maintaining soil health in these ecosystems. As such, they should be included in forest management practices.
Electrical capacitance tomography (ECT) is one of non-invasive visualization techniques which can be used for industrial process monitoring. However, acquiring images trough 3D ECT often requires ...performing time consuming complex computations on large size matrices. Therefore, a new parallel approach for 3D ECT image reconstruction is proposed, which is based on application of multi-GPU, multi-node algorithms in heterogeneous distributed system. This solution allows to speed up the required data processing. Distributed measurement system with a new framework for parallel computing and a special plugin dedicated to ECT are presented in the paper. Computing system architecture and its main features are described. Both data distribution as well as transmission between the computing nodes are discussed. System performance was measured using LBP and the Landweber's reconstruction algorithms which were implemented as a part of the ECT plugin. Application of the framework with a new network communication layer reduced data transfer times significantly and improved the overall system efficiency.
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