نتایج جستجو برای: bog

تعداد نتایج: 1419  

2014
E. S. Euskirchen C. W. Edgar M. R. Turetsky M. P. Waldrop J. W. Harden

Changes in vegetation and soil properties following permafrost degradation and thermokarst development in peatlands may cause changes in net carbon storage. To better understand these dynamics, we established three sites in Alaska that vary in permafrost regime, including a black spruce peat plateau forest with stable permafrost, an internal collapse scar bog formed as a result of thermokarst, ...

Journal: :Journal of environmental monitoring : JEM 2004
Sebastien Rauch Harold F Hemond Bernhard Peucker-Ehrenbrink

Platinum, palladium, rhodium, iridium and osmium were found to be enriched relative to their expected natural concentrations in peat samples from Thoreau's Bog, an ombrotrophic peat bog in Concord, Massachusetts. The source of osmium into the bog was determined from its isotopic composition (187Os/188Os). Osmium is composed of 4% lithogenic osmium from atmospheric soil dust, 41% of anthropogeni...

Journal: :Environmental pollution 2016
Leon J L van den Berg Laurence Jones Lucy J Sheppard Simon M Smart Roland Bobbink Nancy B Dise Mike R Ashmore

Nitrogen (N) deposition impacts natural and semi-natural ecosystems globally. The responses of vegetation to N deposition may, however, differ strongly between habitats and may be mediated by the form of N. Although much attention has been focused on the impact of total N deposition, the effects of reduced and oxidised N, independent of the total N deposition, have received less attention. In t...

Journal: :International journal of clinical and experimental medicine 2015
Fady Ms Moiety Hesham A Salem Radwa A Mehanna Bedor S Abdel-Ghany

OBJECTIVE To compare induced surgical menopause in rat models following hysterectomy with ovarian preservation, unilateral or bilateral oophorectomy, versus control. Secondary objective was evaluation of certain physiological changes in the animal following the induced menopause. DESIGN A prospective case control study. SETTING University Research Centre. METHODOLOGY 80 female rats were d...

Journal: :The Analyst 2004
Robert Berstan Stephanie N Dudd Mark S Copley E David Morgan Anita Quye Richard P Evershed

The chemical analyses of "bog butters" recovered from peat bogs of Scotland were performed with the aim of determining their origins. Detailed compositional information was obtained from "bog butter" lipids using high temperature gas chromatography (HTGC) and GC-mass spectrometry (GC-MS). The results indicate the degree to which "bog butters" have undergone diagenetic alterations during burial ...

Journal: :Journal of environmental quality 2009
Danuta Kaczorek Gerhard W Brümmer Michael Sommer

Bog iron ores are widespread in Polish wetland soils used as meadows or pastures. They are suspected to contain high concentrations of heavy metals, which are precipitated together with Fe along a redox gradient. Therefore, soils with bog iron ore might be important sources for a heavy metal transfer from meadow plants into the food chain. However, this transfer depends on the different binding...

Journal: :FEMS microbiology ecology 2015
Heli Juottonen Mirkka Kotiaho Devin Robinson Päivi Merilä Hannu Fritze Eeva-Stiina Tuittila

Vegetation and water table are important regulators of methane emission in peatlands. Microform variation encompasses these factors in small-scale topographic gradients of dry hummocks, intermediate lawns and wet hollows. We examined methane production and oxidization among microforms in four boreal bogs that showed more variation of vegetation within a bog with microform than between the bogs....

2016
Marina Vilenica Andreja Brigić Mladen Kerovec Sanja Gottstein Ivančica Ternjej

Peat bogs are unique wetland ecosystems of high conservation value all over the world, yet data on the macroinvertebrates (including mayfly assemblages) in these habitats are still scarce. Over the course of one growing season, mayfly assemblages were sampled each month, along with other macroinvertebrates, in the largest and oldest Croatian peat bog and an adjacent stream. In total, ten mayfly...

Journal: :FEMS microbiology ecology 2014
Zuzana Urbanová Jiří Bárta

It is not well understood how the ecological status and microbial community composition of spruce swamp forests (SSF) relate to those found in bogs and fens. To clarify this, we investigated biogeochemical parameters and microbial community composition in a bog, a fen and two SSF using high throughput barcoded sequencing of the small ribosomal subunit (SSU) variable region V4. The results demon...

2003
Robert K. Booth Stephen T. Jackson

35 Abstract: We reconstructed the late-Holocene surface-moisture history and vegetation dynamics of a raised bog in Michigan using testate amoebae, peat humification, pollen, stomata and plant macrofossils. Our primary objective was to compare bog palaeohydrology with the water-level history of Lake Michigan, and to regional and local vegetation changes. Hydrologic histories inferred from testa...

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