What do δ15N Signatures tell Us about Nitrogen Relations in Natural Ecosystems?

2001 ◽  
pp. 91-101 ◽  
Author(s):  
George R. Stewart
Keyword(s):  
Natural Ecosystems ◽  
Nitrogen Relations

The issue of radioactive contamination in context of ecosystem services development

2016 ◽  
Vol 3 (3) ◽  
pp. 48-53 ◽  
Author(s):  
G. Chobotko ◽  
L. Raychuk ◽  
I. McDonald
Keyword(s):  
Ecosystem Services ◽  
The State ◽  
Natural Ecosystems ◽  
Type Region ◽  
State Register ◽  
Agrarian Policy ◽  
Literary Sources ◽  
Radiation Contamination ◽  
Logical Research

The aim of the article was to defi ne the role of the radioactive environment contamination in the formation of ecosystem services strategy. Methods. Monographic, systemic and structural, factor analysis, abstract and logical research methods have been used. The data from the State Statistics Service of Ukraine, the Ministry of Agrarian Policy and Food of Ukraine, the Ministry of Ecology and Natural Resources of Ukraine, materials of scientifi c researches, international materials and reports and other literary sources on the issues investigated have been used as an information base. Results. Retrospective analysis of sources and state of radioactive eco- systems contamination was conducted and the priority steps in developing the concept of ecosystem services in conditions of radiation contamination were found. Conclusions. The current socio-ecological paradigm of the transition from environmental use to environmental management should be refl ected in the relevant envi- ronmental management mechanisms. Currently, when assessing the state of ecosystem services in Ukraine and worldwide one must take into account the changes in food demand of residents of radioactively contaminated areas, the exploitation of radioactively safe ecosystems growth, their overload and degradation. All of this re- quires an inventory of ecosystem services by type, region, consumers, etc. and the formation of a state register of ecosystem services with a clear assignment of area of responsibility for appropriate natural ecosystems. This will help to make the economic evaluation of different ecosystem services and mechanisms of charges for ecosystem services.

Landscape Change in the Steppe of Algeria South-West Using Remote Sensing

2018 ◽  
Vol 18 (1) ◽  
pp. 41-52
Author(s):  
Tayeb Sitayeb ◽  
Ishak Belabbes
Keyword(s):  
Remote Sensing ◽  
Social Systems ◽  
Bare Soil ◽  
Climatic Conditions ◽  
Landscape Dynamics ◽  
Landsat 8 ◽  
Natural Ecosystems ◽  
Stipa Tenacissima ◽  
Steppe Species ◽  
Sparse Vegetation

Abstract Landscape dynamics is the result of interactions between social systems and the environment, these systems evolving significantly over time. climatic conditions and biophysical phenomena are the main factors of landscape dynamics. Also, currently man is responsible for most changes affecting natural ecosystems. The objective of this work is to study the dynamics of a typical landscape of western Algeria in time and space, and to map the distribution of vegetation groups constitute the vegetation cover of this ecosystem. as well as using a method of monitoring the state of a fragile ecosystem by remote sensing to understand the processes of changes in this area. The steppe constitutes a large arid area, with little relief, covered with low and sparse vegetation. it lies between the annual isohyets of 100 to 400 mm, subjected to a very old human exploitation with an activity of extensive breeding of sheep, goats, and camels. Landsat satellite data were used to mapping vegetation groups in the Mecheria Steppe at a scale of 1: 300,000. Then, a comparison was made between the two maps obtained by a classification of Landsat-8 sensor Operational Land Imager (OLI) acquired on March 18, 2014, and Landsat-5 sensor Thematic Mapper (TM) acquired on April 25, 1987. The results obtained show the main changes affecting the natural distribution of steppe species, a strong change in land occupied by the Stipa tenacissima steppe with 65% of change, this steppe is replaced by Thymelaea microphylla, Salsola vermiculata, lygeum spartum and Peganum harmala steppe. an absence from the steppe Artemisia herba-alba that has also been replaced by the same previous steppes species. The groups with Quercus ilex and Juniperus phoenicea are characterized by a strong regression that was lost 60% of its global surface and transformed by steppe to stipa tenacissima and bare soil.

CONTRIBUIÇÃO AO CONHECIMENTO DA AVIFAUNA DO MUNICÍPIO DE TAQUARA, RIO GRANDE DO SUL

2019 ◽  
Vol 2 ◽  
pp. 28
Author(s):  
Marcelo Pereira de Barros ◽  
Ana Paula Lima da Silveira ◽  
Bruna Reis Ferreira
Keyword(s):  
Rural Areas ◽  
Rio Grande ◽  
Bird Community ◽  
Frequency Of Occurrence ◽  
Diverse Group ◽  
Rio Grande Do Sul ◽  
Natural Ecosystems ◽  
Environmental Disturbances ◽  
Environmental Pressures ◽  
Hydrographic Basin

As aves destacam-se dentro dos vertebrados por serem um grupo diverso e adaptado a diferentes ambientes, a composição da comunidade de aves de um determinado local é um importante bioindicador ambiental, pois ela reflete alterações recentes ou pretéritas de determinada área. Na Bacia Hidrográfica do Rio dos Sinos, as pressões sobre os remanescentes de ecossistemas naturais são intensas em decorrência da urbanização crescente, do estabelecimento de indústrias e da ampliação das fronteiras agrícolas, esses fatores associados geram a redução e fragmentação de habitats, com impactos irrecuperáveis para a flora e a fauna. Devido à escassez de dados sobre a avifauna do município de Taquara, o presente estudo teve como objetivo levantar informações sobre o grupo, listando as espécies de aves locais. Entre agosto de 2016 e junho de 2017 foram realizadas quatro amostragens mensais em duas áreas rurais do município, totalizando 44 campanhas de observação e 132 horas de esforço amostral. As espécies foram identificadas e classificadas conforme sua frequência de ocorrência mensal, em espécies comuns e raras. Foram registradas 133 espécies distribuídas em 47 famílias, o que representa mais de 20% das espécies ocorrentes para o estado. Ao longo do período amostrado, 90 espécies foram classificadas como comuns e 47 consideradas raras para as áreas pesquisadas.Palavras-chave: Aves. Bacia hidrográfica do Rio dos Sinos. Preservação.ABSTRACTBirds stand out within vertebrates because they are a diverse group adapted to different environments. The composition of the bird community of a certain place is an important environmental bioindicator since it reflects recent or previous environmental disturbances of a certain area. In the Sinos River Basin, environmental pressures on the remnants of natural ecosystems are intense as a result of increasing urbanization, the establishment of industries and expansion of agricultural frontiers which generate habitat reduction and fragmentation with irrecoverable damages on flora and fauna. Due to the scarcity of data on the avifauna of the municipality of Taquara, the present study aimed to gather information and list the species of local birds. Between August 2016 and June 2017, four monthly samplings were carried out in two rural areas of the municipality, totaling 44 observation campaigns and 132 hours of sample effort. The species were identified and classified as common and rare according to their frequency of occurrence. There were 133 species distributed in 47 families, representing more than 20% of the species that occurred in the state. During the sampled period, 90 species were classified as common and 47 were considered rare for the areas surveyed.Keywords: Birds. Hydrographic basin of Sinos River. Preservation.

Biological effects of low-intensity radiofrequency fields and risk assessment for biota

2020 ◽  
Vol 60 (9) ◽  
pp. 592-596
Author(s):  
Elena I. Sarapultseva ◽  
Darya V. Uskalova ◽  
Ksenya V. Ustenko
Keyword(s):  
Radio Frequency ◽  
Electromagnetic Radiation ◽  
Electromagnetic Fields ◽  
Negative Impact ◽  
Biological Effects ◽  
High Sensitivity ◽  
Communication Technologies ◽  
Natural Ecosystems ◽  
Low Intensity ◽  
Different Levels

Despite the fact that there are still conflicting opinions about the damage caused by modern wireless communication technologies, most scientists report on the negative biological effects of low-intensity radio frequency electromagnetic radiation at different levels of the organization of live nature. There is no doubt that there is a need not only for a sanitary and hygienic assessment of man-made electromagnetic effects on humans, but also for an environmental assessment for biota. The purpose of the study was to assess the potential environmental risk of electromagnetic impact in the centimeter range on natural ecosystems. The initial data were the authors' own results in the field of radiobiology of non-ionizing radiation, as well as published of other researchers. The article analyzes the biological effects of radio frequency electromagnetic fields detected in organisms of different systematic groups and levels of organization. The data on the non-thermal biological effects of electromagnetic fields indicate a high sensitivity of different species to this factor. The analyzed research results emphasize the need to take into account the features of non-thermal effects of electromagnetic radiation on biota, since these radiations can have a negative impact on different hierarchical levels in natural ecosystems.

Introduction

2017 ◽  
Author(s):  
Christer Brönmark ◽  
Lars-Anders Hansson
Keyword(s):  
Food Web ◽  
Natural Ecosystems ◽  
Environmental Threats ◽  
Food Web Interactions

The chapter introduces the reader to the book structure, including the overall topics the abiotic frame, the organisms, biotics, food web interactions and biodiversity and environmental threats. In addition to laying out the structure, this chapter brings up some overarching concepts such as the niche, generalists versus specialists and factors determining the distribution of organisms in natural ecosystems.

scholarly journals Agroforestry Systems of the Tehuacán-Cuicatlán Valley: Land Use for Biocultural Diversity Conservation

Land ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 24
Author(s):  
Mariana Vallejo ◽  
M. Isabel Ramírez ◽  
Alejandro Reyes-González ◽  
Jairo López-Sánchez ◽  
Alejandro Casas
Keyword(s):  
Land Use ◽  
Agricultural Land ◽  
Agroforestry Systems ◽  
World Heritage Site ◽  
Biocultural Diversity ◽  
Semiarid Region ◽  
Agricultural Land Use ◽  
Visual Interpretation ◽  
Natural Ecosystems ◽  
Human Settlements

The Tehuacán-Cuicatlán Valley, Mexico, is the semiarid region with the richest biodiversity of North America and was recently recognized as a UNESCO's World Heritage site. Original agricultural practices remain to this day in agroforestry systems (AFS), which are expressions of high biocultural diversity. However, local people and researchers perceive a progressive decline both in natural ecosystems and AFS. To assess changes in location and extent of agricultural land use, we carried out a visual interpretation of very-high resolution imagery and field work, through which we identified AFS and conventional agricultural systems (CAS) from 1995 to 2003 and 2012. We analyzed five communities, representative of three main ecological and agricultural zones of the region. We assessed agricultural land use changes in relation to conspicuous landscape features (relief, rivers, roads, and human settlements). We found that natural ecosystems cover more than 85% of the territory in each community, and AFS represent 51% of all agricultural land. Establishment and permanence of agricultural lands were strongly influenced by gentle slopes and the existence of roads. Contrary to what we expected, we recorded agricultural areas being abandoned, thus favoring the regeneration of natural ecosystems, as well as a 9% increase of AFS over CAS. Agriculture is concentrated near human settlements. Most of the studied territories are meant to preserve natural ecosystems, and traditional AFS practices are being recovered for biocultural conservation.

scholarly journals Effects of climate change and industrialization on Lake Bolshoe Toko, eastern Siberia

2021 ◽  
Vol 65 (3) ◽  
pp. 335-352
Author(s):  
Boris K. Biskaborn ◽  
Biljana Narancic ◽  
Kathleen R. Stoof-Leichsenring ◽  
Lyudmila A. Pestryakova ◽  
Peter G. Appleby ◽  
...  
Keyword(s):  
Climate Change ◽  
Nineteenth Century ◽  
Deep Water ◽  
Boreal Lakes ◽  
Lake Ecosystem ◽  
Intermediate Water ◽  
Eastern Siberia ◽  
Natural Ecosystems ◽  
Planktonic Diatoms ◽  
Recent Climate

AbstractIndustrialization in the Northern Hemisphere has led to warming and pollution of natural ecosystems. We used paleolimnological methods to explore whether recent climate change and/or pollution had affected a very remote lake ecosystem, i.e. one without nearby direct human influence. We compared sediment samples that date from before and after the onset of industrialization in the mid-nineteenth century, from four short cores taken at water depths between 12.1 and 68.3 m in Lake Bolshoe Toko, eastern Siberia. We analyzed diatom assemblage changes, including diversity estimates, in all four cores and geochemical changes (mercury, nitrogen, organic carbon) from one core taken at an intermediate water depth. Chronologies for two cores were established using 210Pb and 137Cs. Sedimentation rates were 0.018 and 0.033 cm year−1 at the shallow- and deep-water sites, respectively. We discovered an increase in light planktonic diatoms (Cyclotella) and a decrease in heavily silicified euplanktonic Aulacoseira through time at deep-water sites, related to more recent warmer air temperatures and shorter periods of lake-ice cover, which led to pronounced thermal stratification. Diatom beta diversity in shallow-water communities changed significantly because of the development of new habitats associated with macrophyte growth. Mercury concentrations increased by a factor of 1.6 since the mid-nineteenth century as a result of atmospheric fallout. Recent increases in the chrysophyte Mallomonas in all cores suggested an acidification trend. We conclude that even remote boreal lakes are susceptible to the effects of climate change and human-induced pollution.

scholarly journals CaptureSeq: Hybridization-Based Enrichment of cpn60 Gene Fragments Reveals the Community Structures of Synthetic and Natural Microbial Ecosystems

2021 ◽  
Vol 9 (4) ◽  
pp. 816
Author(s):  
Matthew G. Links ◽  
Tim J. Dumonceaux ◽  
E. Luke McCarthy ◽  
Sean M. Hemmingsen ◽  
Edward Topp ◽  
...  
Keyword(s):  
Microbial Community ◽  
Microbial Communities ◽  
Dna Sequences ◽  
Pcr Amplification ◽  
Shotgun Sequencing ◽  
Natural Ecosystems ◽  
Gene Markers ◽  
Microbial Profile ◽  
Microbial Ecosystems ◽  
Pcr Targeting

Background. The molecular profiling of complex microbial communities has become the basis for examining the relationship between the microbiome composition, structure and metabolic functions of those communities. Microbial community structure can be partially assessed with “universal” PCR targeting taxonomic or functional gene markers. Increasingly, shotgun metagenomic DNA sequencing is providing more quantitative insight into microbiomes. However, both amplicon-based and shotgun sequencing approaches have shortcomings that limit the ability to study microbiome dynamics. Methods. We present a novel, amplicon-free, hybridization-based method (CaptureSeq) for profiling complex microbial communities using probes based on the chaperonin-60 gene. Molecular profiles of a commercially available synthetic microbial community standard were compared using CaptureSeq, whole metagenome sequencing, and 16S universal target amplification. Profiles were also generated for natural ecosystems including antibiotic-amended soils, manure storage tanks, and an agricultural reservoir. Results. The CaptureSeq method generated a microbial profile that encompassed all of the bacteria and eukaryotes in the panel with greater reproducibility and more accurate representation of high G/C content microorganisms compared to 16S amplification. In the natural ecosystems, CaptureSeq provided a much greater depth of coverage and sensitivity of detection compared to shotgun sequencing without prior selection. The resulting community profiles provided quantitatively reliable information about all three domains of life (Bacteria, Archaea, and Eukarya) in the different ecosystems. The applications of CaptureSeq will facilitate accurate studies of host-microbiome interactions for environmental, crop, animal and human health. Conclusions: cpn60-based hybridization enriched for taxonomically informative DNA sequences from complex mixtures. In synthetic and natural microbial ecosystems, CaptureSeq provided sequences from prokaryotes and eukaryotes simultaneously, with quantitatively reliable read abundances. CaptureSeq provides an alternative to PCR amplification of taxonomic markers with deep community coverage while minimizing amplification biases.

scholarly journals Unraveling the Metabolic Potential of Asgardarchaeota in a Sediment from the Mediterranean Hydrocarbon-Contaminated Water Basin Mar Piccolo (Taranto, Italy)

2021 ◽  
Vol 9 (4) ◽  
pp. 859
Author(s):  
Andrea Firrincieli ◽  
Andrea Negroni ◽  
Giulio Zanaroli ◽  
Martina Cappelletti
Keyword(s):  
Archaeal Community ◽  
Hydrocarbon Biodegradation ◽  
Natural Ecosystems ◽  
Central Mediterranean ◽  
Metabolic Potential ◽  
Metabolic Role ◽  
Sequencing Studies ◽  
Terrestrial Environments ◽  
Metagenome Sequencing ◽  
Aliphatic And Aromatic Hydrocarbons

Increasing number of metagenome sequencing studies have proposed a central metabolic role of still understudied Archaeal members in natural and artificial ecosystems. However, their role in hydrocarbon cycling, particularly in the anaerobic biodegradation of aliphatic and aromatic hydrocarbons, is still mostly unknown in both marine and terrestrial environments. In this work, we focused our study on the metagenomic characterization of the archaeal community inhabiting the Mar Piccolo (Taranto, Italy, central Mediterranean) sediments heavily contaminated by petroleum hydrocarbons and polychlorinated biphenyls (PCB). Among metagenomic bins reconstructed from Mar Piccolo microbial community, we have identified members of the Asgardarchaeota superphylum that has been recently proposed to play a central role in hydrocarbon cycling in natural ecosystems under anoxic conditions. In particular, we found members affiliated with Thorarchaeota, Heimdallarchaeota, and Lokiarchaeota phyla and analyzed their genomic potential involved in central metabolism and hydrocarbon biodegradation. Metabolic prediction based on metagenomic analysis identified the malonyl-CoA and benzoyl-CoA routes as the pathways involved in aliphatic and aromatic biodegradation in these Asgardarchaeota members. This is the first study to give insight into the archaeal community functionality and connection to hydrocarbon degradation in marine sediment historically contaminated by hydrocarbons.

scholarly journals Assessing Annual Actual Evapotranspiration Based on Climate, Topography and Soil in Natural and Agricultural Ecosystems

Climate ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 20
Author(s):  
Kleoniki Demertzi ◽  
Vassilios Pisinaras ◽  
Emanuel Lekakis ◽  
Evangelos Tziritis ◽  
Konstantinos Babakos ◽  
...  
Keyword(s):  
Water Balance ◽  
Large Scale ◽  
Hydrological Model ◽  
Actual Evapotranspiration ◽  
Irrigated Agriculture ◽  
Climate Data ◽  
Natural Ecosystems ◽  
Loading Effects ◽  
Very High ◽  
Of Greece

Simple formulas for estimating annual actual evapotranspiration (AET) based on annual climate data are widely used in large scale applications. Such formulas do not have distinct compartments related to topography, soil and irrigation, and for this reason may be limited in basins with high slopes, where runoff is the dominant water balance component, and in basins where irrigated agriculture is dominant. Thus, a simplistic method for assessing AET in both natural ecosystems and agricultural systems considering the aforementioned elements is proposed in this study. The method solves AET through water balance based on a set of formulas that estimate runoff and percolation. These formulas are calibrated by the results of the deterministic hydrological model GLEAMS (Groundwater Loading Effects of Agricultural Management Systems) for a reference surface. The proposed methodology is applied to the country of Greece and compared with the widely used climate-based methods of Oldekop, Coutagne and Turk. The results show that the proposed methodology agrees very well with the method of Turk for the lowland regions but presents significant differences in places where runoff is expected to be very high (sloppy areas and areas of high rainfall, especially during December–February), suggesting that the proposed method performs better due to its runoff compartment. The method can also be applied in a single application considering irrigation only for the irrigated lands to more accurately estimate AET in basins with a high percentage of irrigated agriculture.

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