scholarly journals Changing Microarthropod Communities in Front of a Receding Glacier in the High Arctic

Insects ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 226 ◽  
Author(s):  
Dariusz J. Gwiazdowicz ◽  
Bogna Zawieja ◽  
Izabella Olejniczak ◽  
Piotr Skubała ◽  
Anna K. Gdula ◽  
...  
Keyword(s):  
Dominant Species ◽  
Diversity Index ◽  
Rapid Change ◽  
High Arctic ◽  
Soil Characteristics ◽  
Landscape Scale ◽  
Soil Samples ◽  
Pioneer Species ◽  
The Mean ◽  
Study Sites

This study was carried out at Ny-Ålesund on Spitsbergen in Svalbard (High Arctic). Eight study sites were established along a transect from the fjord to the snout of the glacier. The sites differed from each other by the type of vegetation cover and soil characteristics. Soil samples were collected and placed in Tullgren funnels. Extracted arthropods were represented by two groups of mites (Mesostigmata and Oribatida) and springtails (Collembola). The pioneer species that occurred first after retreat of the glacier were representatives of the Collembola (Agrenia bidenticulata and Hypogastrura concolor). Later, other springtails appeared including Folsomia alpha, Folsomia quadrioculata, Hypogastrura concolor, Isotoma anglicana, Sminthurinus concolor and the first species of oribatid mites; Camisia foveolata and Tectocepheus velatus velatus. Arthropod communities recorded along the transect were characterized by large variations in both species composition and abundance of individuals. The greater the distance from the glacier snout, the greater the species richness (2 to 22 species). The mean number of species per sample was the lowest at site 8 (1 ± 0.71) (the closest to the glacier) and greatest at site 1 (14 ± 1.41) (furthest from the glacier). The Simpson’s diversity index (D) was distinctly greater at sites 1 (4.61 ± 0.06) and 3 (3.94 ± 0.11) than at other sites, especially site 8 (1.07 ± 0.06). Densities were least in the samples closest to the glacier (30 to 101 individuals; density 3000–10,100 individuals/m2). At the other locations, abundance was highly variable (905 to 7432 individuals; density 90,500–743,200 individuals/m2). The mean abundances were greatest at sites 2 and 3. The great variations in total abundances observed were often due to the presence or absence of one or more dominant species exhibiting extreme abundance variability between sites. The microarthropod community of the High Arctic is composed of heterogeneous circumpolar species, yet on a landscape scale is extremely dependent on local environmental conditions which may be subject to rapid change.

scholarly journals Spatiotemporal dynamics of soil rotifers in a South-Bohemian beech forest

2009 ◽  
Vol 44 (8) ◽  
pp. 1027-1032 ◽  
Author(s):  
Miloslav Devetter
Keyword(s):  
Vertical Profile ◽  
Dominant Species ◽  
Diversity Index ◽  
Great Part ◽  
Abundant Species ◽  
Beech Forest ◽  
Soil Samples ◽  
Species Level ◽  
Fresh Litter ◽  
South Bohemia

The objective of this work was to determine seasonal variation and vertical distribution of the soil rotifer assemblage in a climax beech forest in South Bohemia. During 2005, soil rotifer was investigated to the species level. Soil samples of 10 cm² and 10 cm in depth were divided into five layers, which were processed separately. Thirty one rotifer species were identified during the investigation. Dominant species significantly changed throughout the seasons. The most abundant species were Encentrum arvicola and Wierzejskiella vagneri among the monogononts, and Adineta steineri, Ceratotrocha cornigera, Habrotrocha filum, Habrotrocha ligula, Macrotrachela plicata, Mniobia tentans, Mniobia incrassata and Mniobia granulosa among the bdelloids. Mean Shannon diversity index varied from 1.99 to 2.63. Total rotifer abundance varied from 212±63 to 513±127 10³ individuals m-2 along the year, with the highest numbers found in May, and the lowest in July. The great part of the community was concentrated in the upper (fresh litter) and second (partially decomposed litter) layers and significantly decreased in the soil vertical profile on all sampling dates. The highest rotifer density of 43 individuals g-1 was found in the upper layer in May.

scholarly journals Correlation of Red-Shouldered Hawk Abundance and Macrohabitat Characteristics in Southern Ohio

The Condor ◽  
2001 ◽  
Vol 103 (3) ◽  
pp. 652-656
Author(s):  
Cheryl R. Dykstra ◽  
F. Bernard Daniel ◽  
Jeffrey L. Hays ◽  
Melinda M. Simon
Keyword(s):  
Response Rate ◽  
Landscape Scale ◽  
Data Grid ◽  
Habitat Characteristics ◽  
Abundance Index ◽  
Buteo Jamaicensis ◽  
The Mean ◽  
Study Sites ◽  
Permanent Stream

Abstract We measured an index of Red-shouldered Hawk (Buteo lineatus) abundance along streams in southern Ohio and related differences in abundance index to landscape-scale habitat characteristics within the surveyed areas. Fifteen study sites, each a 5.8-km reach of a permanent stream, were surveyed four times using broadcasts of Red-shouldered Hawk calls and Red-tailed Hawk (Buteo jamaicensis) calls. We determined the landcover types in a corridor surrounding each surveyed area using a GIS landcover data grid, and counted the number of small ponds within each corridor. We calculated hawk response rate for each species as the mean number of visual or aural detections per survey. Red-shouldered Hawk response rate was inversely correlated to Red-tailed Hawk response rate (r = −0.52, P < 0.04), and was positively correlated to the number of small ponds within each stream corridor (r = 0.77, P < 0.01), suggesting that the number of small ponds was an important factor associated with Red-shouldered Hawk abundance. Correlación entre la Abundancia de Buteo lineatus y Características de Macrohábitat en el Sur de Ohio Resumen. Calculamos un índice de abundancia de Buteo lineatus a lo largo de varios arroyos en el sur de Ohio y relacionamos las diferencias en este índice con características del hábitat a escala del paisaje de las áreas censadas. Trabajamos en 15 sitios (cada uno comprendiendo 5.8 km alrededor de un arroyo permanente), que fueron censados cuatro veces reproduciendo vocalizaciones de B. lineatus y B. jamaicensis. Determinamos el tipo de uso de la tierra en un corredor alrededor de cada área censada utilizando un sistema de información geográfica y contamos el número de pequeños estanques al interior de cada corredor. Calculamos la tasa de respuesta de las dos especies de gavilanes como el número promedio de detecciones visuales o auditivas por censo. La tasa de respuesta de B. lineatus se correlacionó negativamente con la tasa de respuesta de B. jamaicensis (r = −0.52, P < 0.04) y positivamente con el número de estanques dentro de cada corredor (r = 0.77, P < 0.01). Los resultados sugieren que el número de estanques es un factor importante asociado a la abundancia de B. lineatus.

Analisis Keragaman Tanaman Sebagai Jasa Lingkungan Pada Lanskap Agroforestri di Daerah Aliran Sungai Krueng Aceh

2019 ◽  
Vol 4 (2) ◽  
Author(s):  
Zulkifli Aiyub Kadir ◽  
Bahagia Bahagia
Keyword(s):  
Water Conservation ◽  
Vegetation Structure ◽  
Swot Analysis ◽  
Diversity Index ◽  
Middle Stream ◽  
Land Management System ◽  
Study Sites ◽  
Aleurites Moluccana ◽  
Lansium Domesticum ◽  
Agroforestry Practices

<p>Humans have utilized landscape for  produces a diverse character of the wider area of the watershed. Agroforestry is a land management system in addressing the problems that arise due to changes in land use of soil and water conservation. The aim of the study was to analyze plant diversity in agroforestry practices that have services in the Krueng watershed landscape in Aceh watershed. Develop strategies in the Krueng Aceh DAS agroforestry service. This research was conducted in the upper, middle and downstream of the Krueng Aceh watershed, with a rapid method of Agro-Biodiversity Appraisal and SWOT. The results showed that the composition of the vegetation structure found in the study sites tended to vary with the diversity index of agroforestry that was currently in the upstream and middle of the Krueng Aceh watershed. Based on SWOT analysis, internal scores are 2.45 and external scores are 3.21. Agroforestry practices in the upper stream of Krueng Aceh watershed were dominated by <em>Aleurites moluccana</em>, <em>Areca cathecu</em>, and  <em>Averrhoa bilimbi</em> L  species with the highest INP in the upper stream of Krueng Aceh watershed. Vegetation at the middle stream of Krueng Aceh watershed dominated by <em>Areca cathecu,</em> <em>Lansium domesticum</em> and Musa<em> paradisiaca</em>.  </p>

Study on Composition of Zoobenthos in Coastal Areas, Thai Binh Province

2017 ◽  
Vol 33 (4) ◽  
Author(s):  
Ngo Xuan Nam
Keyword(s):  
Diversity Index ◽  
Coastal Areas ◽  
Study Sites

The zoobenthos samples were collected in 30 collecting sections from 02nd to 13th June and from 02nd to 13th October 2014. Investigation of species compositon of zoobenthos in coastal areas, Thai Binh province was identified 72 species belonging to 56 genera of 33 families, 14 orders, 4 classes (Gastropoda, Bivalvia, Crustacea, Polychaeta), 3 phyla (Mollusca, Arthropoda, Annelida). In particular, Mollusca was by far the most popular with 46 species, accounting for roughly 63.8%, compared to the figure of Arthropoda was 23 species, occupying approximately 31.9%, Annelida was 3 species, occupying approximately 4.3%. The density of zoobenthos at the sampling sites averaged from 17 to 420 individuals/m2. The Shannon-Weiner (H') diversity index at the study sites averaged from 2.13 to 3.63.

scholarly journals Five-Year Enhanced Natural Attenuation of Historically Coal-Tar-Contaminated Soil: Analysis of Polycyclic Aromatic Hydrocarbon and Phenol Contents

2021 ◽  
Vol 18 (5) ◽  
pp. 2265
Author(s):  
Arkadiusz Telesiński ◽  
Anna Kiepas-Kokot
Keyword(s):  
Aromatic Hydrocarbons ◽  
Natural Attenuation ◽  
Soil Analysis ◽  
Coal Tar ◽  
Soil Samples ◽  
Lower Intensity ◽  
Sampling Points ◽  
Polycyclic Aromatic ◽  
Monoaromatic Hydrocarbons ◽  
The Mean

The objective of this study was to assess the soil pollution on an industrial wasteland, where coal-tar was processed in the period between 1880 and 1997, and subsequent to assess the decline in the content of phenols and polycyclic aromatic hydrocarbons (PAHs) during enhanced natural attenuation. The soil of the investigated area was formed from a layer of uncompacted fill. Twelve sampling points were established in the investigated area for collecting soil samples. A study conducted in 2015 did not reveal any increase in the content of heavy metals, monoaromatic hydrocarbons (BTEX), and cyanides. However, the content of PAHs and phenols was higher than the content permitted by Polish norms in force until 2016. In the case of PAHs, it was observed for individual compounds and their total contents. Among the various methods, enhanced natural attenuation was chosen for the remediation of investigated area. Repeated analyses of the contents of phenols and PAHs were conducted in 2020. The results of the analyses showed that enhanced natural attenuation has led to efficient degradation of the simplest substances—phenol and naphthalene. The content of these compounds in 2020 was not elevated compared to the standards for industrial wastelands. The three- and four-ring hydrocarbons were degraded at a lower intensity. Based on the mean decrease in content after 5-year enhanced natural attenuation, the compounds can be arranged in the following order: phenols > naphthalene > phenanthrene > fluoranthene > benzo(a)anthracene > chrysene > anthracene.

scholarly journals Potential Fertilization Capacity of Two Grapevine Varieties: Effects on Agricultural Production in Designation of Origin Areas in the Northwestern Iberian Peninsula

Agronomy ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 961
Author(s):  
J. Antonio Cortiñas Rodríguez ◽  
María Fernández-González ◽  
Estefanía González-Fernández ◽  
Rosa A. Vázquez-Ruiz ◽  
F. Javier Rodríguez-Rajo ◽  
...  
Keyword(s):  
Airborne Pollen ◽  
Germination Rate ◽  
Pollen Viability ◽  
Weather Conditions ◽  
Triphenyl Tetrazolium Chloride ◽  
Tetrazolium Chloride ◽  
The Mean ◽  
Study Sites ◽  
Fertilization Capacity

In the present study, we analyzed the main parameters related with the potential fertilization ability of two grapevine varieties, Godello and Mencía, during the years 2017 and 2018. The research was carried out in two vineyards of the Galician winegrowing Designation of Origin areas of Ribeiro and Ribeira Sacra. Ten vines of each variety were selected for bunch and flower counting, pollen calculations, pollen viability studies by means of aceto-carmine (AC) stain and 2, 3, 5-triphenyl tetrazolium chloride (TTC) methods, and the determination of their germination rate. In all vineyards the 50% fruitset was reached, except for Godello in Cenlle during 2017. The mean coulure value was higher for Godello (40.5%) than for Mencía (31%). Analyzing the pollen production per plant and airborne pollen levels, we observed important discordances between them, which can be due to the influence of weather conditions and be related with self-pollination processes. We found important differences on pollen viability depending on the applied method and variety, with higher values for the AC method than the TTC for both varieties in all study plots, and higher values for Mencía variety than Godello. Regarding germination rates, we observed a marked reduction in 2017 with respect to 2018, in all study sites and for both varieties. The analyzed parameters were useful to explain the different productive abilities of Godello and Mencía varieties in the two studied bioclimatic regions of Ribeiro and Ribeira Sacra.

scholarly journals Factors Influencing Smallholder Crop Diversification: A Case Study of Manicaland and Masvingo Provinces in Zimbabwe

2016 ◽  
Vol 3 (2) ◽  
pp. 1 ◽  
Author(s):  
Lighton Dube
Keyword(s):  
Smallholder Farmers ◽  
Diversity Index ◽  
Tobit Model ◽  
Crop Diversification ◽  
Factors Associated ◽  
Head Of Household ◽  
The Mean ◽  
Female Headed Households ◽  
Extension Support

<p>This study analyzes the degree of crop diversification and factors associated with crop diversification among 479 smallholder farmers in Manicaland and Masvingo provinces of Zimbabwe. The Herfindahl index used to estimate diversification, while the Tobit model evaluated factors associated with crop diversification.  The mean crop diversity index is 0.54. On average households in Nyanga and Bikita are the most diversified with indices of 0.48 and 0.49 respectively. The most specialized households are in Mutasa and Chiredzi with indices of 0.62. An analysis by gender shows that male headed households are slightly more diversified than female headed households. The Tobit model indicates that gender of head of household, education, number of livestock units, access to irrigation, membership to a farmers group, access to markets, farming experience, farms on flat terrain, farmer to farm extension, routine extension, agro-ecological zone and household income are significant contributors to increasing crop diversification. In turn, crop specialization is significantly associated with off-farm employment, soil fertility, farmers who are happy with extension contacts per year, farmers trained using the farmer field school approach and farmers who receive NGO extension support.</p>

Le système radiculaire dans les érablières du Québec. I. Nouvelle méthode d'estimation du volume et de la masse des radicelles

1992 ◽  
Vol 22 (10) ◽  
pp. 1562-1567 ◽  
Author(s):  
Fernand Pagé ◽  
Bady Badibanga ◽  
Annie Sauvesty ◽  
Colette Ansseau
Keyword(s):  
Standard Deviation ◽  
Sugar Maple ◽  
Soil Samples ◽  
Diameter Class ◽  
Thin Sections ◽  
Truncated Cone ◽  
The Mean ◽  
Diameter Classes

A method for rapidly estimating the rootlet volume and mass in sugar maple groves was developed in relation with the rootlet size. Soil samples were obtained with corers and cut in 2-cm thick slices. The number of rootlets of diameter classes <0.3, 0.3–0.5, 0.5–0.8, and 0.8–1.0 mm were determined under microscope (× 150) on the upper surface of slices. Rootlet surface for each class was measured on thin sections of soil, with an optic microscope connected to a digitalizing board. Mean rootlet surface [Formula: see text] showed a small standard deviation within each diameter class. The rootlet surface (S) on a surface of soil St can be estimated as [Formula: see text], where N is the number of rootlets observed in nc fields of observation, each field having a surface So. If two soil slices are located at depths h1 and h2, respectively, and if the rootlet surfaces of those slices are S1 and S2, the rootlet volume V of the first slice corresponds approximately to the volume of a truncated cone, and can be calculated as V = [S1 + S2 + (S1S2)0,5] (h2–h1)/3. The rootlet density (g•cm−3 of root) was also determined for each diameter class. The standard deviation from [Formula: see text], the mean density for each diameter class was small. Thus, the rootlet mass M was determined as [Formula: see text]. Estimated and real rootlet volume and mass values were compared. A difference of about 10% was found between estimated and real values.

scholarly journals Resource Utilization and Costs of Care prior to ART Initiation for Pediatric Patients in Zambia

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Hari S. Iyer ◽  
Callie A. Scott ◽  
Deophine Lembela Bwalya ◽  
Gesine Meyer-Rath ◽  
Crispin Moyo ◽  
...  
Keyword(s):  
Pediatric Patients ◽  
Blood Chemistry ◽  
Full Blood Count ◽  
National Guidelines ◽  
Art Initiation ◽  
Time To Initiation ◽  
The Mean ◽  
Study Sites ◽  
Cd4 Percentage ◽  
Mean Cost

Objective. We estimated time to initiation, outpatient resource use, and costs of outpatient care during the 6 months prior to ART initiation for HIV-infected pediatric patients in Zambia.Methods. We enrolled 1,102 children who initiated ART at <15 years of age between 2006 and 2011 at 5 study sites. Of these, 832 initiated ART ≤6 months after first presenting to care at the study sites. Data on time in care and resources utilized during the 6 months prior to ART initiation were extracted from patient medical records. Costs were estimated from the provider’s perspective and are reported in 2011 USD.Results. For the patients who initiated ART ≤6 months after presenting to care, median age at presentation to care was 3.9 years; median CD4 percentage was 13%. Median time to ART initiation was 26 days. Patients made, on average, 2.38 clinic visits prior to ART initiation and received 0.81 CD4 tests, 0.74 full blood count tests, and 0.49 blood chemistry tests. The mean cost of pre-ART care was $20 per patient.Conclusions. Zambian pediatric patients initiating ART ≤6 months after presenting to care do so quickly, utilize fewer resources than mandated by national guidelines, and accrue low costs.

scholarly journals Characterization of Canadian High Arctic glacier surface albedo from MODIS C6 data, 2001–2016

2017 ◽  
Author(s):  
Colleen A. Mortimer ◽  
Martin Sharp
Keyword(s):  
Large Scale ◽  
Surface Albedo ◽  
Temporal Trends ◽  
Principal Component ◽  
High Arctic ◽  
Shortwave Radiation ◽  
Glacier Surface ◽  
Annual Variations ◽  
The Mean ◽  
Moderate Resolution Imaging Spectroradiometer

Abstract. Inter-annual variations and longer-term trends in the annual mass balance of glaciers in Canada's Queen Elizabeth Islands (QEI) are largely attributable to changes in summer melt. The largest source of melt energy in the QEI in summer is net shortwave radiation, which is modulated by changes in glacier surface albedo. We used measurements from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensors to investigate large scale spatial patterns and temporal trends and variability in the summer surface albedo of QEI glaciers and their relationship to observed changes in glacier surface temperature from 2001 to 2016. Mean summer black-sky shortwave broadband albedo (BSA) decreased at a rate of 0.029 ± 0.025 decade-1 over that period. Larger reductions in BSA occurred in July (−0.050 ± 0.031 decade-1). No change in BSA was observed in either June or August. Most of the decrease in BSA, which was greatest at lower elevations around the margins of the ice masses, occurred between 2007 and 2012 when mean summer BSA was anomalously low. The First Principal Component of the 16-year record of mean summer BSA was well correlated with the mean summer North Atlantic Oscillation Index, except in 2006, 2010, and 2016. During this 16-year period, the mean summer LST increased by 0.046 ± 0.036 °C yr-1 and the BSA record was negatively correlated (−0.64, p 

Sign in / Sign up

Export Citation Format

Share Document