@article {2822,
	title = {Sediment accumulation and sedimentation rates in playas on the High Plains of western Kansas, USA},
	journal = {Geomorphology},
	volume = {342},
	year = {2019},
	month = {Jan-10-2019},
	pages = {117 - 126},
	abstract = {Grassland ecosystems are some of the most modified ecosystems in the world, largely due to conversion to cropland, and the High Plains of the central United States is no exception. Playa wetlands are ubiquitous features of the High Plains and have experienced increased sediment accumulation, which is the primary cause of reduced playa ecosystem function. Seven playas on the High Plains of western Kansas, five with cropland-dominated watersheds and two with grassland-dominated watersheds, were examined to quantify the amount of recent (past ~100{\textendash}175 yr) sediment accumulated within playas and to establish chronologies of playa filling. Thicknesses of recent sediment were determined in the field, and soil cores were extracted from study playas. Four playa cores were analyzed for 210Pb to establish the chronology of recent sediment accumulation and sedimentation rates. Chronologies of pre-agricultural sediments and sedimentation rates were calculated by 14C dating of buried soils preserved within playa cores. Radiocarbon ages indicate playa stratigraphic records span the Holocene and that these playas have persisted on the landscape since at least the Late Pleistocene. Long-term, natural sedimentation rates were highest during the Pleistocene-Holocene transition and early Holocene, at ~2{\textendash}4 cm/century. During the middle and late Holocene, sedimentation rates averaged ~1 cm/century. Cropland playas accumulated ~10{\textendash}15 cm of recent sediment at average rates of ~6.5{\textendash}10 cm/century, while grassland playas accumulated only ~2 cm of recent sediment. Conversion of watersheds to cropland has greatly accelerated sediment accumulation within playas, which is generally resulting in a decline in critical playa ecosystem functions.},
	keywords = {210Pb, Agricultural, chronology, Holocene, Radiocarbon dating, sedimentation},
	issn = {0169555X},
	doi = {10.1016/j.geomorph.2019.06.014},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S0169555X19302612},
	author = {Bowen, Mark W. and Johnson, William C.}
}
@article {2573,
	title = {Historical records of organic matter supply and degradation status in the East Siberian Sea},
	journal = {Organic Geochemistry},
	volume = {91},
	year = {2016},
	month = {Jan-01-2016},
	pages = {16 - 30},
	abstract = {Destabilization and degradation of permafrost carbon in the Arctic regions could constitute a positive feedback to climate change. A better understanding of its fate upon discharge to the Arctic shelf is therefore needed. In this study, bulk carbon isotopes as well as terrigenous and marine biomarkers were used to construct two centennial records in the East Siberian Sea. Differences in topsoil and Pleistocene Ice Complex Deposit permafrost concentrations, modeled using δ13C and Δ14C, were larger between inner and outer shelf than the changes over time. Similarly, lignin-derived phenol and cutin acid concentrations differed by a factor of ten between the two stations, but did not change significantly over time, consistent with the dual-carbon isotope model. High molecular weight (HMW) n-alkane and n-alkanoic acid concentrations displayed a smaller difference between the two stations (factor of 3{\textendash}6). By contrast, the fraction for marine OC drastically decreased during burial with a half-life of 19{\textendash}27 years. Vegetation and degradation proxies suggested supply of highly degraded gymnosperm wood tissues. Lipid Carbon Preference Index (CPI) values indicated more extensively degraded HMW n-alkanes on the outer shelf with no change over time, whereas n-alkanoic acids appeared to be less degraded toward the core top with no large differences between the stations. Taken together, our results show larger across-shelf changes than down-core trends. Further investigation is required to establish whether the observed spatial differences are due to different sources for the two depositional settings or, alternatively, a consequence of hydrodynamic sorting combined with selective degradation during cross-shelf transport.},
	keywords = {210Pb, Arctic, East Siberian Arctic Shelf, HMW wax lipids, Lignin, Monte Carlo, δ13C, Δ14C},
	issn = {01466380},
	doi = {10.1016/j.orggeochem.2015.10.008},
	url = {https://doi.org/10.1016/j.orggeochem.2015.10.008},
	author = {Broder, Lisa and Tesi, Tommaso and Andersson, August and Eglinton, Timothy I. and Semiletov, Igor P. and Dudarev, Oleg V. and Roos, Per and Gustafsson, ?rjan}
}
