Specific Local Environmental Conditions Research Articles

Nitrogen fixation in the North Atlantic supported by Gulf Stream eddy-borne diazotrophs

Mesoscale oceanic eddies contribute to the redistribution of resources needed for plankton to thrive. However, due to their fluid-trapping capacity, they can also isolate plankton communities, subjecting them to rapidly changing environmental conditions. Diazotrophs, which fix dinitrogen (N2), are key members of the plankton community, providing reactive nitrogen, particularly in large nutrient-depleted regions such as subtropical gyres. However, there is still limited knowledge about how mesoscale structures characterized by specific local environmental conditions can affect the distribution and metabolic response of diazotrophs when compared with the large-scale dynamics of an oceanic region. Here we investigated genetic diazotroph diversity and N2 fixation rates in a transect across the Gulf Stream and two associated eddies, a region with intense mesoscale activity known for its important role in nutrient transport into the North Atlantic Gyre. We show that eddy edges are hotspots for diazotroph activity with potential community connectivity between eddies. Using a long-term mesoscale eddy database, we quantified N2 fixation rates as up to 17 times higher within eddies than in ambient waters, overall providing ~21 µmol N m−2 yr−1 to the region. Our results indicate that mesoscale eddies are hotspots of reactive nitrogen production within the broader marine nitrogen cycle.

Yarrow (Achillea millefolium) for low-input lawns in the Mediterranean environment

In recent years, environmental concerns have created a desire for the sustainable care of grass swards, with a specific goal of reducing resources needed for turfgrass maintenance by utilising low-input species best adapted to specific local environmental conditions. A two-year field experiment was conducted to compare the aesthetic or ornamental quality, and function potential, of different swards. The treatments consisted of four monostands of white clover (Trifolium repens L.), yarrow (Achillea millefolium L.), strong creeping red fescue (Festuca rubra L. ssp. rubra Gaudin), and tall fescue (Festuca arundinacea Schreb. = Schedonorus arundinaceus Schreb. Dumort.), three two-species mixtures of white clover + yarrow, white clover + strong creeping red fescue, and yarrow + strong creeping red fescue, and one three-species mixture of white clover + yarrow + strong creeping red fescue. Within each plot, a botanical survey was performed each spring to estimate species relative abundance by determining the proportions of different species present. All plots were evaluated every two weeks during the growing period for visual quality and normalised difference vegetative index. Vegetation canopy height in each plot was measured before each biweekly mowing event, and clippings were collected to measure vegetative dry matter. Relative abundance of yarrow, strong creeping red fescue, and tall fescue was stable throughout the entire study period. The mixtures including yarrow displayed sufficient or higher quality ratings (≥6) in all seasons with the exception of winter, however, yarrow + strong creeping red fescue compensated each other's defects by maintaining their relative abundance (≥ 80%) over time as well suppressing or prevent significant weed invasion (relative abundance <15%). Moreover, yarrow or strong creeping red fescue monostands, or yarrow + strong creeping red fescue could be maintained with lower number of mowing events, due to their lower vertical growth. In conclusion, alternative plant species to turf-type grasses produced a visual quality equal to or better than tall fescue maintained under low fertilisation and mowing frequency. All swards that included yarrow produced better visual quality, exhibited better weed control, had lower vertical growth rate, and provided an aesthetically pleasant, persistent, and sustainable vegetative ground cover than other swards, and can be utilised as a low-input species.

Resources and specificity of reclamation at the coal mining spoils

The article analyses Khakassia environmental conditions with the aim to estimate their resources and role in the efficient reclamation of coal mining spoils. The availability of potentially fertile soil substrate as a resource for large-scale reclamation was evaluated by the thickness of the quaternary clay and loamy bedrock layers, taking into account the amount of the substrate needed for reclamation. The availability of resources of the potentially fertile soil substrate was carried out by taking into account the thickness and soil bulk density of the humus horizon of the most fertile soils of the region, and considering the obtained estimayes within the framework of the methodical rules and normative regulations for optimal reclamation. The availability of hydrothermal resources was estimated by active temperature sums and hydrothermal coefficient. Overall the distribution of reclamation resources was found to be very uneven throughout the region. In the south of Khakassia with its large areas occupied by technogenic landscapes the reclamation resources were concluded to be in deficit, insufficient for carrying out the reclamation according with the optimal protocols. Such lack of resources is indirectly confirmed by prevailing areas occupied by self-revegetating coal mining spoils. The article also describes some successful reclamation examples where specific local environmental conditions were used in such a way as to decrease the effect of deficient resources, thus increasing the efficacy of the self-restoration of technogenic landscapes.

Sea ice dynamics in the Bransfield Strait, Antarctic Peninsula, during the past 240 years: a multi-proxy intercomparison study

Abstract. In the last decades, changing climate conditions have had a severe impact on sea ice at the western Antarctic Peninsula (WAP), an area rapidly transforming under global warming. To study the development of spring sea ice and environmental conditions in the pre-satellite era we investigated three short marine sediment cores for their biomarker inventory with a particular focus on the sea ice proxy IPSO25 and micropaleontological proxies. The core sites are located in the Bransfield Strait in shelf to deep basin areas characterized by a complex oceanographic frontal system, coastal influence and sensitivity to large-scale atmospheric circulation patterns. We analyzed geochemical bulk parameters, biomarkers (highly branched isoprenoids, glycerol dialkyl glycerol tetraethers, sterols), and diatom abundances and diversity over the past 240 years and compared them to observational data, sedimentary and ice core climate archives, and results from numerical models. Based on biomarker results we identified four different environmental units characterized by (A) low sea ice cover and high ocean temperatures, (B) moderate sea ice cover with decreasing ocean temperatures, (C) high but variable sea ice cover during intervals of lower ocean temperatures, and (D) extended sea ice cover coincident with a rapid ocean warming. While IPSO25 concentrations correspond quite well to satellite sea ice observations for the past 40 years, we note discrepancies between the biomarker-based sea ice estimates, the long-term model output for the past 240 years, ice core records, and reconstructed atmospheric circulation patterns such as the El Niño–Southern Oscillation (ENSO) and Southern Annular Mode (SAM). We propose that the sea ice biomarker proxies IPSO25 and PIPSO25 are not linearly related to sea ice cover, and, additionally, each core site reflects specific local environmental conditions. High IPSO25 and PIPSO25 values may not be directly interpreted as referring to high spring sea ice cover because variable sea ice conditions and enhanced nutrient supply may affect the production of both the sea-ice-associated and phytoplankton-derived (open marine, pelagic) biomarker lipids. For future interpretations we recommend carefully considering individual biomarker records to distinguish between cold sea-ice-favoring and warm sea-ice-diminishing environmental conditions.

Aerobiological studies – current state and future challenges

Aerobiology is the interdisciplinary science focused on the study of airborne organisms and biological materials, like pollen grains, fungal spores, bacteria, viruses, mycotoxins. The results of the aerobiological monitoring are practically employed in medicine, agriculture, beekeeping, meteorology, monument protection. The information of the current and predicted exposure is transmitted to patients and physicians through the electronic tools, applications, media, to compile the optimal therapy of respiratory diseases, especially pollen allergy. It is worth taking into account some confirmed phenomena to interpret the aerobiological data correctly: (i) many airborne particles occur seasonally and their amount and seasonal dynamics are more or less variable; (ii) threshold values for the airborne particles causing the threat for humans (e.g. for allergic individuals) are important, but the personal sensitivity must be also included; (iii) overlapping occurrence of different airborne particles, like pollen, spores, pollution makes clinical symptoms worsening; (iv) modern pollen and spores fall is affected in direct and indirect way by the climate changes, anthropogenic pollution, long range transport and the specific local environmental conditions. Currently the implementation of the automatic measurement systems and the analyses of allergen particles in the air are the main challenges for aerobiologists. Joined activity of this group of enthusiastic specialists of different interests is performed in frame of the multi centre networks and supported by the International Association for Aerobiology together with the regional.

A novel integrative performance evaluation of constructed wetland on removal of viable bacterial cells and related pathogenic, virulent and multi-drug resistant genes from wastewater systems

Integrative performance evaluation of constructed wetland in removal different aspects of bacteria under specific local environmental conditions needs to be explored in detail to ensure selection of appropriate and highly efficient macrophytes candidates. To achieve this, integrative purification performance evaluation approach that holistically considers all the aspects of pathogenic bacterial biology (colony numbers, functional gene, species, virulent, pathogenicity and resistant genes) needs to be adopted rather than the commonly known unidimensional approaches that take into account a single bacterial aspect. This study experimentally evaluated the individual performance of three native and one exotic winter tolerant submerged macrophytes combined with a single emergent macrophyte in eradicating faecal related bacterial species and pathotypes across horizontal surface flow constructed wetland. It involved the new multi-dimensional approach that integrated the faecal bacterial colony numbers, functional gene copies, species survival, virulent and pathogenicity as well as antimicrobial resistant in constructed wetland purification evaluation. The results showed Elodea nuttallii and Myriophyllum spicatum as the best candidate partners to Typha latifolia for the highest Purification Efficiency (P < 0.05), of above 97% for removal of faecal bacteria colonies and functional genes, and more than 75% for removal of faecal bacterial strains, pathotypes, virulent and well as resistant genes. However, M. spicatum being a Chinese native species should be much preferred to the invasive E. nuttallii. Therefore, the study recommends the application of local macrophytes such as M. spicatum as the best candidates and the decision should emanate from such a multidimensional/intergrative purification-based evaluation approach.

Local weather, food resources and breeding stage influence Thrush Nightingale movement

Insectivorous migrants breeding at northern latitudes often time the breeding period with the seasonal peak of food resources. Whether this general pattern transfers to movement behaviour during the breeding season requires detailed study from a local perspective. We investigated fine-scale environmental correlates of movements by six actively-breeding adult Thrush Nightingales (Luscinia luscinia) at a breeding site in Denmark, using radio tracking and multiple regression models. Overall, the chick-rearing period coincided with the peak of vegetation greenness at the site. Adults flew further from nesting areas during stable weather and as vegetation greenness decreased. Adults were more active at higher environmental temperatures and when fledglings were older but still dependent on adults. These changes in local movements likely reflect adjustments to chick developmental needs and to specific local environmental conditions, including resource availability.

Integrating MFT-qPCR techniques in constructed wetland faecal bacterial purification monitoring; a case of a typical tropical hybrid constructed wetland system.

The sanitation control of pathogens in the tropical effluents needs much more attention to ensure ecosystem health integrity and the safety of human health. The common use of chemicals in achieving this in wastewater treatment has remained unsustainable due to much health concern. Indeed, based on the numerous challenges associated with faecal pathogenic bacteria in wastewaters, the focus is now on achieving higher purification efficiencies in the elimination of the human pathogens from wastewater through eco-sustainable systems such as constructed wetlands (CWs). Hence, the need to explore the application of constructed wetlands in wastewater treatment under specific local environmental conditions for accurate understanding and improved treatment efficiency. This study therefore aimed at monitoring constructed wetlands faecal bacteria purification efficiency through integrated non-molecular membrane filtration technique and molecular quantitative polymerase chain reaction (MFT-qPCR) technique. The results showed some shortfall in the treatment system and also proved that integrating MFT-qPCR in faecal bacterial purification monitoring within a constructed wetland system provides a more accurate and reliable outcome. Additionally, the wetland purification efficiency was low (<80%) with the dissolved oxygen posing the strongest influence on faecal pathogenic bacterial purification trend across the wetland. Hence, the need to regularly carry out dredging and macrophyte harvesting as well as the use of holistic and more integrative approaches such as MFT-qPCR in managing and monitoring the performance of CWs in faecal pathogen eradication for improved CWs purification efficiency.

The continuous persistence of open oak forests in the Miechów Upland (Poland) in the second half of the Holocene

The archaeological site 3 in Miechów provided samples for anthracological, carpological, zooarchaeological and malacofaunal analysis in order to investigate the dynamics of local vegetation and to understand people-environment interactions. The main research tasks included the characterization of local forests, the determination of the landscape openness near the site and a verification of the presence of xerothermic vegetation in the Atlantic period. The majority of samples came from the Neolithic period, which in Miechów began in the second half of the VIth millennium BC with the appearance of the Linear Pottery Culture and continued with several occupation phases until the development of the Funnel Beaker and Baden cultures. Younger periods were represented by archaeological features dated to the Late Bronze Age, the Iron Age and the Middle Ages. Therefore, the recovered materials have been valuable sources of information about the local environment near human settlements developed during the second part of the Holocene. The anthracological study has revealed the dominance of open oak forests with Quercus, Pinus sylvestris and Betula during all occupational phases. The presence of feather grass Stipa sp., since the beginning of the settlement, has pointed toward the existence of patches of xerothermic steppe-like vegetation during the Holocene climatic optimum and in younger periods. Also, the molluscan assemblages have shown a dominance of taxa characteristic of open landscapes during the entire occupational sequence. The interdisciplinary results have indicated that due to specific local environmental conditions, the landscape in the vicinity of the settlement remained open in the second half of the Holocene.

The impact of Wnt signalling and hypoxia on osteogenic and cementogenic differentiation in human periodontal ligament cells.

Cementum is a periodontal support tissue that is directly connected to the periodontal ligament. It shares common traits with bone tissues, however, unlike bone, the cementum has a limited capacity for regeneration. As a result, following damage the cementum rarely, if ever, regenerates. Periodontal ligament cells (PDLCs) are able to differentiate into osteoblastic and cementogenic lineages according to specific local environmental conditions, including hypoxia, which is induced by inflammation or activation of the Wnt signalling pathway by local loading. The interactions between the Wnt signalling pathway and hypoxia during cementogenesis are of particular interest to improve the understanding of periodontal tissue regeneration. In the present study, osteogenic and cementogenic differentiation of PDLCs was investigated under hypoxic conditions in the presence and absence of Wnt pathway activation. Protein and gene expression of the osteogenic markers type 1 collagen (COL1) and runt-related transcription factor 2 (RUNX2), and cementum protein 1 (CEMP1) were used as markers for osteogenic and cementogenic differentiation, respectively. Wnt signalling activation inhibited cementogenesis, whereas hypoxia alone did not affect PDLC differentiation. However, hypoxia reversed the inhibition of cementogenesis that resulted from overexpression of Wnt signalling. Cross-talk between hypoxia and Wnt signalling pathways was, therefore, demonstrated to be involved in the differentiation of PDLCs to the osteogenic and cementogenic lineages. In summary, the present study suggests that the differentiation of PDLCs into osteogenic and cementogenic lineages is partially regulated by the Wnt signalling pathway and that hypoxia is also involved in this process.

Neolithization Processes in the Levant

The Near East is one of those unique places where the transition(s) from hunter-gatherers to farmers occurred locally, so it is possible to observe the whole sequence of these processes within the region as a whole. We discuss the archaeological evidence pertaining to those transformations within the Levant, presenting the particularistic local changes in settlement patterns and the character of the different communities juxtaposed with the landscapes and environmental background. The asynchronous developments clearly reflect the mosaic nature of the Levant in terms of specific local environmental conditions that influenced the scope and pace of Neolithization processes.

Glacier fluctuations between 1975 and 2008 in the Greater Himalaya Range of Zanskar, southern Ladakh

Glaciers in the Himalaya are often heavily covered with supraglacial debris, making them difficult to study with remotely-sensed imagery alone. Various methods such as band ratios can be used effectively to map clean-ice glaciers; however, a thicker layer of debris often makes it impossible to distinguish between supraglacial debris and the surrounding terrain. Previously, a morphometric mapping approach employing an ASTER-derived digital elevation model has been used to map glaciers in the Khumbu Himal and the Tien Shan. This study on glaciers in the Greater Himalaya Range in Zanskar, southern Ladakh, aims (i) to use the morphometric approach to map large debris-covered glaciers; and (ii) to use Landsat and ASTER data and GPS and field measurements to document glacier change over the past four decades. Field work was carried out in the summers of 2008. For clean ice, band ratios from the ASTER dataset were used to distinguish glacial features. For debris-covered glaciers, topographic features such as slope were combined with thermal imagery and supervised classifiers to map glacial margins. The method is promising for large glaciers, although problems occurred in the distal and lateral parts and in the fore field of the glaciers. A multitemporal analysis of glaciers in Zanskar showed that in general they have receded since at least the mid- to late-1970s. However, some few glaciers that advanced or oscillated — probably because of specific local environmental conditions — do exist.

Feeding the scavengers. Actualistic taphonomy in the Jordan Valley, Israel

This paper describes the results of a 3-year project carried out in the Jordan Valley, Israel, in which the influence of specific local environmental conditions, such as scavenging, weathering and scattering of carcasses, were related to the rate of their bone survival. During the 3 year period, the taphonomy of 16 whole animal carcasses, deposited in a nature reserve and agricultural cultivated area were compared. The exact age, date of death and weight of all animals was known. Results of animal scavenging activities on the carcasses, such as disappearance of bones and damage, such as tooth marks, breakage, gnawing to the leftover bones, were recorded at the end of the initial, intensive scavenging period (Phase I), and at later dates. Bone scattering maps were drawn at the end of Phase I and 2.5 and 3 years later. Weathering of surviving bones at the sites is described. Results show that in the Jordan Valley Nature Reserve, scavenging is the most important taphonomic agent causing total disappearance of all bones of young dairy calves, and reducing amount of bones remaining of more mature animals to a minimum. These small number of leftover bones, after only 2–3 years are the only candidates for eventual burial and fossilization. The loss of most of the bones through scavenging in the nature reserve might cause serious bias to conclusions about subsistence behaviour of prehistoric man. This is a taphonomic actualistic analogue to eventual conditions in prehistoric times. Copyright © 2000 John Wiley & Sons, Ltd.

The Mobilization of Human Resources by Non-Governmental Organizations in the Bolivian Andes

In the tropical Andes, a long tradition exists in the utilization and mobilization of rural resources. In certain periods, agriculture and settlement patterns were well adapted to the specific local environmental conditions; at other times, constraints of the natural environment, of historical burdens, and of current social, economic, and political problems contributed to widespread conditions of poverty and underdevelopment. This paper examines the development issues and the activities of non-governmental organizations (NGOs) and a number of affiliated agencies in two representative regions of highland Bolivia: the northern Altiplano and the eastern Cordillera region in the Departamento de Cochabamba. Based on documentation of the agencies and on numerous talks and formal interviews with representatives of the NGOs and the campesinos, an attempt was made to identify the major problems and constraints of specific micro-regions, as well as the perceived development priorities, and the strategies of the agencies and local communities to implement the development process. Although the NGOs may use different approaches and methods, it became obvious that the key to successful and sustained development lies in programs and projects that take into account the specific local environmental conditions, the cultural traditions of the indigenous communities, and the felt needs of the local people. Based on these premises, an effective partnership may be established between NGOs and the campesinos which can lead to a mobilization of local human and material resources and to appropriate sustainable forms of rural development.