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100 _aHillman, Aubrey L
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245 _aTwo millennia of anthropogenic landscape modification and nutrient loading at Dian Lake, Yunnan Province, China
260 _bsage
_c2019
300 _aVol 29, Issue 3, 2019 : (505-517 p.).
520 _aLandscapes have been shaped by human activities for millennia and there is a pressing need to characterize pre-industrial impacts in order to mitigate present-day effects. We present the analysis of two sediment cores from Dian Lake in Yunnan, China, which span 4000 years. We compare cores from the northern and southern ends of the lake to investigate spatial variability in natural and anthropogenic environmental changes in this large (300 km2) lake. To document the initiation of human impacts on the landscape and characterize the attendant changes in the lake water and sediment quality, we rely on organic and inorganic geochemical measurements as well as sedimentology and stratigraphy. The character and magnitude of proxy changes are coherent between the two core sites with slight differences in the timing of events. At both core sites, we find definitive evidence for substantial anthropogenic change beginning AD 100 (1850 yr BP), coincident with the introduction of terraced agriculture. Sedimentological shifts are distinctive and characterized by an increase in magnetic susceptibility values and a visible change to red, fine-grained clay. The geochemistry of this sediment suggests that it was sourced from the eastern catchment of the lake and delivered into the basin following intensive agriculture and soil erosion. Anthropogenic impacts intensify after AD 900 through hydrologic modification and cultural eutrophication resulting from increased nutrient loading. This study presents evidence that human-affected landscapes have been present in this region of China for longer than previously believed and that ‘small-scale’ land use change can have measureable impacts on lakes.
650 _aanthropogenic change,
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650 _aarchaeology,
_950689
650 _a carbon isotopes,
_951642
650 _aChina,
_950071
650 _ageochemistry,
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650 _a landscape erosion,
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650 _anitrogen isotopes,
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650 _apaleolimnology
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700 _a Yao, Alice
_951646
700 _aAbbott, Mark B
_951545
773 0 _012756
_916504
_dLondon: Sage Publication Ltd, 2019.
_tHolocene/
_x09596836
856 _uhttps://doi.org/10.1177/0959683618816504
942 _2ddc
_cART
999 _c12796
_d12796