Fuel 77:95–107ĭolislager LJ, VanCuren R, Pederson JR, Lashgari A, McCauley E (2009) A summary of the Lake Tahoe atmospheric deposition study (LTADS). Springer, Netherlands, pp 189–226ĭemir I, Ruch RR, Damberger HH, Harvey RD, Steele JD, Ho KK (1998) Environmentally critical elements in channel and cleaned samples of Illinois coals. In: Croudace IW, Rothwell RG (eds) Micro-XRF studies of sediment cores. Geol Soc Spec Publ 267:51–63ĭavies SJ, Lamb HF, Roberts SJ (2015) Micro-XRF core scanning in palaeolimnology: recent developments. Limnol Oceanogr 22:361–369Ĭroudace IW, Rindby A, Rothwell RG (2006) ITRAX description and evaluation of a new multi-function X-ray core scanner. 01-334, US For Serv Pac Southwest Res StnĬarlson RE (1977) A trophic state index for lakes. Final report to California Air Resources Board, Contract N. Geophys Res Lett 34:1–5īytnerowicz A, Arbaugh M, Padgett P (2004) Evaluation of ozone and HNO 3 vapor distribution and ozone effects on conifer forests in the Lake Tahoe Basin and eastern Sierra Nevada. Quat Sci Rev 30:1067–1085īrown ET, Johnson TC, Scholz CA, Cohen AS, King JW (2007) Abrupt change in tropical African climate linked to the biopolar seesaw over the past 55,000 years. Springer, Netherlands, pp 19–92īowerman ND, Clark DH (2011) Holocene glaciations of the central Sierra Nevada, California. Wiley, New York, pp 527–570īirks HJB (2012) Overview of numerical methods in paleolimnology: tracking environmental change using lake sediments. Handbook of holocene palaeoecology and palaeohydrology. Bioscience 61:602–613īattarbee RW (1986) In: Berglund BE (ed) Diatom analysis. CATENA 5:1–8īaron JS, Driscoll CT, Stoddard JL, Richer EE (2011) Empirical critical loads of atmospheric nitrogen deposition for nutrient enrichment and acidification of sensitive US lakes. The data collected show that the FLL record is sensitive to climatic cooling during the Little Ice Age and to anthropogenic activities commencing in the 1800s that increased throughout the latter half of the twentieth century however the effects of anthropogenic N deposition in these lakes could not be substantiated.Īppleby PG, Oldfield F (1978) The calculation of lead-210 dates assuming a constant rate of supply of unsupported 210 Pb to the sediment. Asterionella formosa is present in the water column at Gilmore Lake and absent from the sediment, indicating a very recent appearance. Asterionella formosa is a dominant component in the FLL water column today, but has been present in similar abundances for at least the last 1200 years. Lack of support for N deposition includes the asynchrony in the appearance of the N-sensitive diatom Asterionella formosa in FLL and a lower impact site at Gilmore Lake, and an uninformative δ 15N record. Down core proxies for atmospheric N deposition in the FLL watershed are, at best, weakly expressed and appear to be overshadowed by stronger signals. Beginning around 1910 and accelerating in the 1940s, increased building, land-use, and recreation around FLL caused an increase in terrestrial sedimentary input. The Transitional Zone increases in elemental Co, Zn, and Sn that may be attributed to an increase in coal burning and smelting activities in California and Nevada. Four diatom zones are recognized from a core taken at Fallen Leaf Lake (FLL), a site moderately impacted by human activities: (1) Pre-Little Ice Age Zone (840–1385), (2) Little Ice Age Zone (1385–1810) characterized by Stephanodiscus alpinus and Aulacoseira subarctica, (3) Transitional Zone (1810–1950) of warming and anthropogenic influence with increased Lindavia rossii- ocellata group and Discostella stelligera and decreased Pseudostaurosira brevistriata, and (4) Anthropogenic Zone (1950–2010) characterized by a rapid increase of mesotrophic diatoms of the Fragilaria tenera- nanana group, Tabellaria flocculosa strain IIIP, and Nitzschia gracilis. This study addresses the effects of climate, land-use, and atmospheric nitrogen (N) deposition on the Fallen Leaf Lake watershed, Lake Tahoe Basin, through diatom and geochemical analyses of sediment cores.
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