Near-natural Conditions Research Articles

SIP-Metaproteomics: Linking Microbial Taxonomy, Function, and Activity.

Stable isotope probing combined with metaproteomics enables the detection and characterization of active key species in microbial populations under near-natural conditions, which greatly helps to understand the metabolic functions of complex microbial communities. This is achieved by providing growth substrates labeled with heavy isotopes such as 13C, which will be assimilated into microbial biomass. After subsequent extraction of proteins and proteolytic cleavage into peptides, the heavy isotope enrichment can be detected by high-resolution mass spectrometric analysis, and linked to the functional and taxonomic characterization of these biomarkers. Here we provide protocols for obtaining isotopically labeled proteins and for downstream SIP-metaproteomics analysis.

Combined effects of pumped-storage operation and climate change on thermal structure and water quality

The assessment of ecological impacts of pumped-storage (PS) hydropower plants on the two connected water bodies is usually based on present climatic conditions. However, significant changes in climate must be expected during their long concession periods. We, therefore, investigate the combined effects of climate change and PS operations on water temperature and quality, as well as extent and duration of stratification and ice cover, using a site in Switzerland. For this purpose, a coupled two-dimensional hydrodynamic and water quality model for the two connected water bodies is run with 150 years long synthetic stochastic meteorological forcing for both current and future climate conditions under two PS and two reference scenarios. The results show relevant synergistic and antagonistic effects of PS operations and climate change. For example, hypolimnion temperatures in September are projected to increase by < 0.6 °C in a near-natural reference scenario and by ~ 2.5 °C in an extended PS scenario. Ice cover, which occurs every year under near-natural conditions in the current climate, would almost completely vanish with extended PS operation in the future climate. Conversely, the expected negative impacts of climate change on hypolimnetic dissolved oxygen concentrations are partially counteracted by extended PS operations. We, therefore, recommend considering future climate conditions for the environmental impact assessment in the planning of new or the recommissioning of existing PS hydropower plants.

Discovery of Actinomycetes from Extreme Environments with Potential to Produce Novel Antibiotics.

IntroductionAntimicrobial-resistant pathogens pose serious challenges to healthcare institutions and health of the public. Thus, there is an urgent need for the discovery of new and effective antimicrobial agents. Microorganisms that exist in extreme environments such as those with high salinity or alkalinity, are known as extremophiles, and include various species of actinomycetes. The goal of this study is to discover novel antibiotics from extremophiles found in Kazakhstan that are effective against drug resistant pathogens.MethodsSoil from extreme environments of Kazakhstan was collected, and pure cultures of actinomycetes were isolated and cultured in modified Bennett’s broth with either high concentrations of salt or high pH to mimic extreme environments. Extracts obtained from selected actinomycetes strains were used to test for antimicrobial activity against Staphylococcus aureus, Escherichia coli and Aspergillus niger.ResultsA total of 5936 strains of extremophile actinomycetes were isolated; from these, 2019 strains were further isolated into pure cultures. Of these, 415 actinomycetes strains that demonstrated antagonistic antibacterial activities were selected. These actinomycetes were further classified into groups and subgroups based on their responses to different culture conditions. Antimicrobial antagonism activity for some of the actinomycetes strains was dependent on culture conditions and development of aerial mycelia under extreme conditions.ConclusionWe identified several interesting candidate extracts with putative antimicrobial activities against several strains of drug resistant pathogens. Our research of the actinomycetes’ ability to produce antibiotics in the near-natural conditions provides a great opportunity to assess their biodiversity and distribution in the Central Asian region and to develop new methodological approaches to the screening of new antimicrobial agents.

Determination of Input Parameters of the Neural Network Model, Intended for Phoneme Recognition of a Voice Signal in the Systems of Distance Learning

The article is devoted to the problem of voice signals recognition means introduction in the system of distance learning. The results of the conducted research determine the prospects of neural network means of phoneme recognition. It is also shown that the main diculties of creation of the neural network model, intended for recognition of phonemes in the system of distance learning, are connected with the uncertain duration of a phoneme-like element. Due to this reason for recognition of phonemes, it is impossible to use the most eective type of neural network model on the basis of a multilayered perceptron, at which the number of input parameters is a xed value. To mitigate this shortcoming, the procedure, allowing to transform the non-stationary digitized voice signal to the xed quantity of mel-cepstral coecients, which are the basis for calculation of input parameters of the neural network model, is developed. In contrast to the known ones, the possibility of linear scaling of phoneme- like elements is available in the procedure. The number of computer experiments conrmed expediency of the fact that the use of the oered coding procedure of input parameters provides the acceptable accuracy of neural network recognition of phonemes under near-natural conditions of the distance learning system. Moreover, the prospects of further research in the eld of development of neural network means of phoneme recognition of a voice signal in the system of distance learning is connected with an increase in admissible noise level. Besides, the adaptation of the oered procedure to various natural languages, as well as to other applied tasks, for instance, a problem of biometric authentication in the banking sector, is also of great interest.

Effects of predispersal insect seed predation on the early life history stages of a rare cold sand-desert legume

Seed predation by insects is common in seeds of Fabaceae (legume) species with physical dormancy (PY). However, the consequences of insect seed predation on the life history of legumes with PY have been little studied. In the largest genus of seed plants, Astragalus (Fabaceae), only one study has tested the effects of insect predation on germination, and none has tested it directly on seedling survival. Thus, we tested the effects of insect predation on seed germination and seedling growth and survival of Astragalus lehmannianus, a central Asian sand-desert endemic. Under laboratory conditions, seeds lightly predated in the natural habitat of this perennial legume germinated to a much higher percentage than intact seeds, and seedlings from predated and nonpredated seeds survived and grew about equally well. Further, in contrast to our prediction seedlings from predated seeds that germinated “out-of-season” under near-natural conditions in NW China survived over winter. The implication of our results is that individual plants from predated seeds that germinate early (in our case autumn) potentially have a fitness advantage over those from nonpredated seeds, which delay germination until spring of a subsequent year.

Human influences on streamflow drought characteristics in England and Wales

Abstract. Human influences can affect streamflow drought characteristics and propagation. The question is where, when and why? To answer these questions, the impact of different human influences on streamflow droughts were assessed in England and Wales, across a broad range of climate and catchments conditions. We used a dataset consisting of catchments with near-natural flow as well as catchments for which different human influences have been indicated in the metadata (“Factors Affecting Runoff”) of the UK National River Flow Archive (NRFA). A screening approach was applied on the streamflow records to identify human-influenced records with drought characteristics that deviated from those found for catchments with near-natural flow. Three different deviations were considered, specifically deviations in (1) the relationship between streamflow drought duration and the base flow index, BFI (specifically, BFIHOST, the BFI predicted from the hydrological properties of soils), (2) the correlation between streamflow and precipitation and (3) the temporal occurrence of streamflow droughts compared to precipitation droughts, i.e. an increase or decrease in streamflow drought months relative to precipitation drought months over the period of record. The identified deviations were then related to the indicated human influences. Results showed that the majority of catchments for which human influences were indicated did not show streamflow drought characteristics that deviated from those expected under near-natural conditions. For the catchments that did show deviating streamflow drought characteristics, prolonged streamflow drought durations were found in some of the catchments affected by groundwater abstractions. Weaker correlations between streamflow and precipitation were found for some of the catchments with reservoirs, water transfers or groundwater augmentation schemes. An increase in streamflow drought occurrence towards the end of their records was found for some of the catchments affected by groundwater abstractions and a decrease in streamflow drought occurrence for some of the catchments with either reservoirs or groundwater abstractions. In conclusion, the proposed screening approaches were sometimes successful in identifying streamflow records with deviating drought characteristics that are likely related to different human influences. However, a quantitative attribution of the impact of human influences on streamflow drought characteristics requires more detailed case-by-case information about the type and degree of all different human influences. Given that, in many countries, such information is often not readily accessible, the approaches adopted here could provide useful in targeting future efforts. In England and Wales specifically, the catchments with deviating streamflow drought characteristics identified in this study could serve as the starting point of detailed case study research.

Aerobic environment ensures viability and anti-oxidant capacity when seeds are wet with negative effect when moist: implications for persistence in the soil

AbstractInterchangeable effects of temperature, moisture content and oxygen on seed longevity have been mostly examined to estimate seed viability during long-term dry storage, whereas few experiments have studied seed viability under near-natural conditions to evaluate seed persistence in the soil. To this end, we artificially aged seeds ofRanunculus baudotii, a hydrophyte widely distributed in temporary ponds constituting an abundant soil seed bank. Seeds were exposed to controlled ageing at three different relative humidities (RH) under both aerobic and anoxic conditions. Their viability, water content, membrane damage, oxidative stress and anti-oxidant enzymatic defence activity were evaluated. Seed survival was longer at higher relative humidity (97% RH), and lowest at a relative humidity (90% RH) simulating moist but not waterlogged soils. Anoxic conditions showed a protective role on viability at lower moisture contents (70% RH). Seed viability was negatively associated with hydrogen peroxide content and correlated with anti-oxidant enzyme activities, but not with membrane damage. Altogether, these results suggest negative roles for moist soils and anoxia in determining seed persistence in the field, but at higher moisture contents the negative effects of anaerobia diminished. The anti-oxidant system activation, even under unfavourable conditions, might recover seeds once all protective processes can operate, pointing out the plasticity of mechanisms involved in seed loss viability.

Immature stages of Molipteryx fuliginosa (Uhler) (Heteroptera, Coreidae) in the South of the Russian Far East

The morphology of the egg and the I-V-instar nymphs of Molipteryx fuliginosa (Uhler) was studied based on the observations made under near-natural conditions in Primorskii Territory since the emergence of over-wintered adults till the appearance of adults of the new generation, including egg production, maturation and molt at each nymphal instar. The egg and the nymphal instars are described and the distinguishing characters of Molipteryx fuliginosa and Coreus marginatus (Linnaeus) are given.

Hydrodynamic sensory threshold in harbour seals (Phoca vitulina) for artificial flatfish breathing currents.

Harbour seals have the ability to detect benthic fish such as flatfish using the water currents these fish emit through their gills (breathing currents). We investigated the sensory threshold in harbour seals for this specific hydrodynamic stimulus under conditions which are realistic for seals hunting in the wild. We used an experimental platform where an artificial breathing current was emitted through one of eight different nozzles. Two seals were trained to search for the active nozzle. Each experimental session consisted of eight test trials of a particular stimulus intensity and 16 supra-threshold trials of high stimulus intensity. Test trials were conducted with the animals blindfolded. To determine the threshold, a series of breathing currents differing in intensity was used. For each intensity, three sessions were run. The threshold in terms of maximum water velocity within the breathing current was 4.2 cm s-1 for one seal and 3.7 cm s-1 for the other. We measured background flow velocities from 1.8 to 3.4 cm s-1 Typical swimming speeds for both animals were around 0.5 m s-1 Swimming speed differed between successful and unsuccessful trials. It appears that swimming speed is restricted for the successful detection of a breathing current close to the threshold. Our study is the first to assess a sensory threshold of the vibrissal system for a moving harbour seal under near-natural conditions. Furthermore, this threshold was defined for a natural type of stimulus differing from classical dipole stimuli which have been widely used in threshold determination so far.

Hydrodynamic detection and localization of artificial flatfish breathing currents by harbour seals (Phoca vitulina).

Harbour seals are known to be opportunistic feeders, whose diet consists mainly of pelagic and benthic fish, such as flatfish. As flatfish are often cryptic and do not produce noise, we hypothesized that harbour seals are able to detect and localize flatfish using their hydrodynamic sensory system (vibrissae), as fish emit water currents through their gill openings (breathing currents). To test this hypothesis, we created an experimental platform where an artificial breathing current was emitted through one of eight different openings. Three seals were trained to search for the active opening and station there for 5 s. Half of the trials were conducted with the seal blindfolded with an eye mask. In blindfolded and non-blindfolded trials, all seals performed significantly better than chance. The seals crossed the artificial breathing current (being emitted into the water column at an angle of 45deg to the ground) from different directions. There was no difference in performance when the seals approached from in front, from behind or from the side. All seals responded to the artificial breathing currents by directly moving their snout towards the opening from which the hydrodynamic stimulus was emitted. Thus, they were also able to extract directional information from the hydrodynamic stimulus. Hydrodynamic background noise and the swimming speed of the seals were also considered in this study as these are aggravating factors that seals in the wild have to face during foraging. By creating near-natural conditions, we show that harbour seals have the ability to detect a so-far overlooked type of stimulus.

Amazon boundary layer aerosol concentration sustained by vertical transport during rainfall.

The nucleation of atmospheric vapours is an important source of new aerosol particles that can subsequently grow to form cloud condensation nuclei in the atmosphere. Most field studies of atmospheric aerosols over continents are influenced by atmospheric vapours of anthropogenic origin (for example, ref. 2) and, in consequence, aerosol processes in pristine, terrestrial environments remain poorly understood. The Amazon rainforest is one of the few continental regions where aerosol particles and their precursors can be studied under near-natural conditions, but the origin of small aerosol particles that grow into cloud condensation nuclei in the Amazon boundary layer remains unclear. Here we present aircraft- and ground-based measurements under clean conditions during the wet season in the central Amazon basin. We find that high concentrations of small aerosol particles (with diameters of less than 50 nanometres) in the lower free troposphere are transported from the free troposphere into the boundary layer during precipitation events by strong convective downdrafts and weaker downward motions in the trailing stratiform region. This rapid vertical transport can help to maintain the population of particles in the pristine Amazon boundary layer, and may therefore influence cloud properties and climate under natural conditions.

Biodegradation mechanism of microcystin-LR by a novel isolate of Rhizobium sp. TH and the evolutionary origin of the mlrA gene

The frequent presence of microcystin (MC) in eutrophic water bodies worldwide poses a serious threat to ecosystems. Biodegradation has been extensively investigated as a main pathway for MC attenuation, and an mlr-dependent mechanism of MC degradation have been elucidated in detail. However, the evolutionary origin and the distribution of mlr genes in MC-degrading bacteria is poorly understood. In this study, a novel Rhizobium sp. TH, which is the first α-proteobacterial MC-degrading bacterium other than Sphingomonadales, was isolated. Strain TH degraded MC via the mlr-dependent mechanism with a first-order rate constant of 0.18–0.29 h−1 under near-natural conditions. The partial length mlr gene cluster was sequenced, and the function of its key gene, mlrA, was verified by heterologous expression in Escherichia coli. Phylogenetic analyses show that the mlrA gene initially arose in α-proteobacteria by vertical evolution, and the two strains from β- and γ-proteobacteria acquired it by horizontal gene transfer. Therefore, the mlrA gene mainly exists in α-proteobacteria but is seldom present in other bacteria. A pair of primers matching well with mlrA sequences reported so far were designed and could be used to determine the MC-degrading mechanism for novel isolates or to screen for MC-degrading ability among environmental samples.

Palaeovegetation of Honghe wetland in Sanjiang Plain as a basis for conservation management and restoration

This paper documents the history of vegetation assemblage in Honghe Wetland (NE China) during the last 6200 years. Vegetation changes were reconstructed based on high-resolution plant macrofossil analysis of sedimentary sequence obtained from Honghe National Nature Reserve located in Sanjiang Plain, in conjunction with Accelerator Mass Spectrometry (AMS) 14C radiocarbon data. Results indicate that plant macrofossil composition of Honghe wetland ecosystem are dynamic and have undergone several significant changes. Around 2500cal yr BP, plant composition transited from Equisetum fluviatile community to Carex lasiocarpa- Drepanocladus aduncus community, and then following by Drepanocladus aduncus community at 460cal yr BP. Another major vegetation changes occurred at 220cal yr BP, transitioning to Carex sp. community. By comparison between the plant macrofossil assemblages and the climate changes during the last 6200cal yr BP, we suggest that ASM (Asian summer monsoon) is the main driving force for the vegetation succession before the impacts of human activities. Since some restoration programs have been undertaken at Honghe wetland, thus our results can provide valuable baseline data for assessment of the practicability and suitability of the former restoration plan and the further designing of conservation management and restoration targets. Since the vegetation composition of Honghe wetland is pronouncedly sensitive to water level, it can be inferred that wetland ecosystem can be restored to near-natural condition through the effective management and restoration by controlling the water source of the wetland.

Post-copulatory opportunities for sperm competition and cryptic female choice provide no offspring fitness benefits in externally fertilizing salmon.

There is increasing evidence that females can somehow improve their offspring fitness by mating with multiple males, but we understand little about the exact stage(s) at which such benefits are gained. Here, we measure whether offspring fitness is influenced by mechanisms operating solely between sperm and egg. Using externally fertilizing and polyandrous Atlantic salmon (Salmo salar), we employed split-clutch and split-ejaculate in vitro fertilization experiments to generate offspring using designs that either denied or applied opportunities for sperm competition and cryptic female choice. Following fertilizations, we measured 140 days of offspring fitness after hatch, through growth and survival in hatchery and near-natural conditions. Despite an average composite mortality of 61%, offspring fitness at every life stage was near-identical between groups fertilized under the absence versus presence of opportunities for sperm competition and cryptic female choice. Of the 21 551 and 21 771 eggs from 24 females fertilized under monandrous versus polyandrous conditions, 68% versus 67.8% survived to the 100-day juvenile stage; sub-samples showed similar hatching success (73.1% versus 74.3%), had similar survival over 40 days in near-natural streams (57.3% versus 56.2%) and grew at similar rates throughout. We therefore found no evidence that gamete-specific interactions allow offspring fitness benefits when polyandrous fertilization conditions provide opportunities for sperm competition and cryptic female choice.

Genetic inviability is a major driver of type III survivorship in experimental families of a highly fecund marine bivalve.

The offspring of most highly fecund marine fish and shellfish suffer substantial mortality early in the life cycle, complicating prediction of recruitment and fisheries management. Early mortality has long been attributed to environmental factors and almost never to genetic sources. Previous work on a variety of marine bivalve species uncovered substantial genetic inviability among the offspring of inbred crosses, suggesting a large load of early-acting deleterious recessive mutations. However, genetic inviability of randomly bred offspring has not been addressed. Here, genome-wide surveys reveal widespread, genotype-dependent mortality in randomly bred, full-sib progenies of wild-caught Pacific oysters (Crassostrea gigas). Using gene-mapping methods, we infer that 11-19 detrimental alleles per family render 97.9-99.8% of progeny inviable. The variable genomic positions of viability loci among families imply a surprisingly large load of partially dominant or additive detrimental mutations in wild adult oysters. Although caution is required in interpreting the relevance of experimental results for natural field environments, we argue that the observed genetic inviability corresponds with type III survivorship, which is characteristic of both hatchery and field environments and that our results, therefore, suggest the need for additional experiments under the near-natural conditions of mesocosms. We explore the population genetic implications of our results, calculating a detrimental mutation rate that is comparable to that estimated for conifers and other highly fecund perennial plants. Genetic inviability ought to be considered as a potential major source of low and variable recruitment in highly fecund marine animals.

Spawning Behavior of Lingcod in the Seattle Aquarium

Lingcod (Ophiodon elongates) are members of the family Hexagrammidae and are found in the northeast coastal waters of the Pacific Ocean. Hexagrammids are demersal spawners with the male fish guarding eggs until hatching occurs. The spawning behavior of Lingcod has only been observed and described once in the literature (Wilby 1937). Although other investigators have described various aspects of Lingcod life history and reproductive activity (for example, Jewell 1968; Low and Beamish 1978; LaRiviere and others 1981; Giorgi 1981; Cass and others 1990; Jagielo 1994), none directly observed spawning. Withler and others (2004) genetically evaluated progeny and documented polygamous mating by Lingcod. This note describes a Lingcod spawning event in the Seattle Aquarium and compare this spawning to that described previously by Wilby (1937). The Underwater Dome exhibit of the Seattle Aquarium is in the form of an igloo-like public observation volume immersed in a large cylindrical vessel. The vessel is approximately 20 m in diameter and 6 m deep, containing more than 1800 m of filtered seawater pumped from adjacent Elliot Bay, in an open system with the water discharged back to the bay. The surface of the vessel is not enclosed, and is protected by an awning covering a portion of the water surface. Environmental conditions inside the exhibit, such as temperature and lighting, match ambient conditions. A low-light level is maintained in the exhibit at night. The exhibit topography mimics rocky and nearshore habitat conditions found in the Salish Sea. The highrelief rocky reef structure is made of concrete, and the bottom is covered with a shallow layer of coarse beach sand. The exhibit is home to a variety of fish and invertebrate species found in local waters. The animals are fed a variety of fish and shellfish similar to their natural diet. The Lingcod feed primarily on forage fish and squid, and occasionally prey on smaller exhibit fish, usually salmonids. Lingcod in the exhibit typically spawn each season between mid-December and mid-March, usually near year-end, using one or more of 3 specific locations. Characteristics of the 3 sites are consistent with sites selected by fish in the wild (KWJ, pers. obs.), distinguished by rocky reef ledges with deep cracks or crevices suitable for deposition of egg masses, supporting the premise that physical characteristics of the exhibit are conducive for display specimens to behave and reproduce in near-natural conditions. The site of the observed spawning is an approximately parallel-sided cavity 20 cm wide between a flat-sided boulder and a vertical reef surface. The site is about 2 m from viewing windows. The dome exhibit was home to 5 adult Lingcod ranging from 75to 110-cm total length at the time of the observed spawning. Two of the fish were known to be female and 2 were known to be male. The sex of the 5th fish was unknown. The ages of the fish were also not known. Observations were visual and notes were made after the event. Measurements were made using a 1-m-long plastic tube graduated in 10-cm increments. On 1 January 2015, a pair of Lingcod spawned in the Underwater Dome exhibit of the Seattle Aquarium. The spawners were the largest female and largest male in the exhibit. The female was gravid and swollen to the point of concern by aquarium staff that she was egg-bound. The site selected by the spawners was the site most frequently used for egg laying in previous years. The male fish had established long-standing dominance of this site during the spawning season by remaining at the location, performing courtship display when females were present, and chasing other fish from the area. At approximately 08:30 Pacific Standard Time, in crepuscular conditions, the female Lingcod was observed by a maintenance diver at the spawning location. She was aligned with the cavity with her ventral side up. The fish was alternately squirming and quivering. The male was nearby (Fig. 1A). After an GENERAL NOTES

Effects of Two-Year Variation in Soil Moisture Condition on the Development of Larch Root System in Eastern Siberia

Recent climate changes, including an increase in precipitation, have affected tree physiology in eastern Siberia. We investigated the response of larch to wet and dry soil water conditions in pot experiments using larch seedlings grown under near-natural conditions in eastern Siberia over two growing seasons. Three patterns of wet- and dry-treatment combinations were applied over 2 years: wet treatments in 2006 and 2007 (WW treatment), dry in 2006 and wet in 2007 (DW treatment), and dry in 2006 and 2007 (DD treatment). After 1 year of treatment, no significant difference between the dry and wet treatment was found in root distribution and needle water content, except for the content of abscisic acid in roots. After 2 years of treatment, the DW treatment induced different tendencies in the gas exchange activity and in the needle biomass and root distribution of seedlings in comparison with WW treatments, despite the same water condition in 2007. We suggest a possibility that seedlings that experience drought stress might store some memory of drought that influences their physiology in the next growing season.

UNVEILING ALGAL BIODIVERSITY OF EL-FARAFRA OASIS (WESTERN DESERT, EGYPT) AND POTENTIAL RELEVANCE OF ITS USE IN WATER BIO-ASSESSMENT: SPECIAL INTEREST ON SPRINGS AND DRILLED WELLS

For the first time, comprehensive phycological screening on El-Farafra Oasis (Western Desert, Egypt) had been implemented for unveiling and characterization of its cryptic algal diversification, with special interest on springs and drilled wells. Overall during summer 2011 and winter 2012, 82 different algal taxa have been found in all studied habitats as naturally-grown and culture-induced propagations. Of these, different 14 algal strains have been recorded only using water-culturing techniques on different four algal media (Kolkwitz's solution, Chu #10, BBM and modified BG-11 media). Culturing techniques not only permitted to discover the cryptic algal taxa present in the viable spores state, but also allowed to follow and confirm the complete life cycle of the rare stigonematalean true T-branched cyanoprokaryote Westiellopsis prolifica. This inventory enriched the freshwater Egyptian algal flora with 6 new algal taxa for the first time namely Symploca dubia, Westiellopsis prolifica, Euastrum insulare, Penium margaritaceum, Zygnemopsis sp. and Nitellopsis obtusa. In this study, some recorded taxa are considered to be crenophilous, e.g. Geitlerinema jasorvense and Phormidium carboniciphilum, to be crenoxenic e.g. Jaaginema subtilissimum, Phormidium corium, Westiellopsis prolifica and Zygnemopsis sp. Only, Oscillatoria tenuis had the highest-grade constancy of occurrence throughout the whole investigation period. This species shows a strong α-mesosaprobic indication for water eutrophication in this oasis. In general, El-Farafra Oasis wells and springs are considered isolated and azonal habitats still bearing partially near-natural conditions with some agricultural, pastures and humans impacts, and have freshwater type with slight seasonal variations in their mineralization contents as a kind of ecotones-characteristic features. Finally, these hyper-arid-desert-dwelling water systems are just about excellent potable water resources in the context of water quality guidelines of Egyptian Higher Committee for Water (EHCW) and World Health Organization (WHO), but they substantially still need special governmental efforts in the future to mainly eliminate the relatively high contents of Fe, Mn and Zn.

Vegetation recovery after removal of invasive Trachycarpus fortunei in a fragmented urban shrine forest

To evaluate the effectiveness of active management on ecological restoration of urban forest fragments, we investigated recovery of the native vegetation in an urban shrine forest in central Japan after complete removal of the invasive warm-temperate palm, Trachycarpus fortunei Wendl. Nine years after removal, stand density and basal area of the remaining tree species had recovered to pre-removal values. Number and basal area of native evergreen trees, such as Cinnamomum japonicum Sieb. and Ficus erectus Thunb., had increased, especially in the lowest canopy layer where T. fortunei had dominated. As a result, species composition of the shrub layer shifted from dominance by single invasive species (T. fortunei) to multiple native species. However, exotic species and escaped ornamentals, such as Lingustrum lucidum Ait. and Euronymus japonicus Thunb., had also increased, especially in the forest edge. Our results indicate that removal of invasive species contributes to recovery of native vegetation. However, to maintain near-natural conditions considered ideal for shrine forests, continuous monitoring and management will be needed to prevent invasion by exotic and ornamental species.

EFFECTIVENESS OF APPLICATION OF MODAL ANALYSIS FOR THE MONITORING OF STRESSED OR OPERATED STRUCTURES

This paper presents a brief summary of the research results of the application of experimental and operational modal analysis (EMA and OMA) effectiveness for the assessment of the change in the condition of operating structures by modifying their dynamic characteristics. Special focus is given to the topicality of the operational modal analysis for the definition of the dynamic features of the structures (frequencies, modes and deformation) under near-natural conditions. The research was conducted using two operating laboratory models, when the first one imitated a part of a fuel/gas pipeline and the second – a helicopter blade. The results of finite-element model simulation, identification of natural mode and the influence of the two types of virtual defects on the changes in the dynamic properties are provided. The work describes the results of experimental research of the dynamic behaviour of the pipe model, using the methods of OMA and comparing them with the modelling results. The research results demonstrate how the modification of the condition of the large-scaled models impacts pipe and blade models when the defects of local and global nature are introduced.