Miriam C. Jones

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Thermokarst lakes formed across vast regions of Siberia and Alaska during the last deglaciation and are thought to be a net source of atmospheric methane and carbon dioxide during the Holocene epoch. However, the same thermokarst lakes can also sequester carbon, and it remains uncertain whether carbon uptake by thermokarst lakes can offset their greenhouse(More)
Northern peatlands represent one of the largest biospheric carbon (C) reservoirs; however, the role of peatlands in the global carbon cycle remains intensely debated, owing in part to the paucity of detailed regional datasets and the complexity of the role of climate, ecosystem processes, and environmental factors in controlling peatland C dynamics. Here we(More)
Drained thermokarst lake basins accumulate significant amounts of soil organic carbon in the form of peat, which is of interest to understanding carbon cycling and climate change feedbacks associated with thermokarst in the Arctic. Remote sensing is a tool useful for understanding temporal and spatial dynamics of drained basins. In this study, we tested the(More)
Recent high-latitude warming is increasing the vulnerability of permafrost to thaw, which is amplified by local disturbances such as fire. However, the long-term ecological effects and carbon dynamics are not well understood. Here we present a 2200-year record of pollen, plant macrofossils, testate amoebae, and apparent carbon (C) accumulation rates from(More)
We used stable oxygen isotopes derived from bulk peat (dOTOM), in conjunction with plant macrofossils and previously published carbon accumulation records, in a w14,500 cal yr BP peat core (HT Fen) from the Kenai lowlands in south-central Alaska to reconstruct the climate history of the area. We find that patterns are broadly consistent with those from(More)
A multicompartment model with time-dependent transfer rates is fitted to data on ovarian follicle dynamics in mice. The fitted model arises from an interplay between parametric and nonparametric approaches to fitting curves to these data. Nonparametric regression estimates, in the form of spline smoothers, are used in conjunction with the biologically(More)
The Arctic has experienced much greater warming than the global average in recent decades due to polar amplification. Warming has induced ecological changes that have impacted climate carbon-cycle feedbacks, making it important to understand the climate and vegetation controls on carbon (C) dynamics. Here we used the Holocene Thermal Maximum (HTM, 11e9 ka(More)
Experiments are reported in which two configurations for ablation-plasma-ion-implantation ~APII! are characterized by diagnostics and compared. The first configuration oriented the target parallel to the deposition substrate. This orientation yielded ion-beam-assisted deposition of thin films. A delay (.5 ms) between laser and high voltage was necessary for(More)
Tasmania is an island of area 63 300 square kilometres, with a central plateau containing peaks to about 1500 metres above sea level (Fig. 1). Oceans that are meteorologically data-sparse border it to the west and south, and these are the directions from which all cold fronts come. To the west the closest meteorological station is at Kerguelen Island, 5700(More)
Permafrost peatlands store one-third of the total carbon (C) in the atmosphere and are increasingly vulnerable to thaw as high-latitude temperatures warm. Large uncertainties remain about C dynamics following permafrost thaw in boreal peatlands. We used a chronosequence approach to measure C stocks in forested permafrost plateaus (forest) and thawed(More)
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