Articolo in rivista, 2018, ENG, 10.1016/j.jglr.2018.06.005
Levine, Suzanne N.; Lini, Andrea; Ostrofsky, Milton L.; Burgess-Grant, Heather; Lami, Andrea; Collyer-Gilles, Elizabeth; Reuter, Daun; Schwarting-Miller, Lindsay; Kamman, Neil
Univ Vermont; Univ Vermont; Allegheny Coll; CNR; Paul Smiths Coll; Vermont Agcy Nat Resources
Thirteen sediment cores from Lake Champlain (Vermont-New York-Quebec) were analyzed for sediment accumulation rate and eleven indicators of trophic status to reconstruct eutrophication history and relate it to phosphorus inputs from soil erosion, urban point sources, and agricultural runoff including P extracted from phosphate ore and brought to the catchment in fertilizer and livestock feed. Although the catchment was severely deforested and grazed by sheep and cattle in the 19th century, ten of thirteen sites accumulated excess sediment only in the 20th century, a consequence of slow sediment transport through the catchment. Of the three sites that received extra sediment, one remained oligotrophic, while two exhibited mild eutrophication. All sites underwent eutrophication in the 20th century. Three reached their current trophic status before agriculture's intensification, while point-source P input was maximal (1950-1980), four stayed in the reference state until agriculture intensified in the 1970s, and six responded incrementally first to point and then to agricultural P input. Pigment accumulation rates diminished at the surface of seven cores, evidence that the 1990s expansion of P removal from point sources reduced phytoplankton biomass. Additional water quality improvement depends on P management at the catchment border to balance inputs and outputs, and thus avoid P accumulation in soil that saturates phosphate sorption capacity, increasing the proportion of runoff P that is highly-bioavailable orthophosphate. Erosion control is of lower priority because the P native to the catchment's soil is of relatively low bioavailability, and retention structures do not retain dissolved P. (C) 2018 International Association for Great Lakes Research. Published by Elsevier B.V. All rights reserved.
Journal of Great Lakes research 44 (5), pp. 1043–1056
Lake Champlain, Eutrophication, Paleolimnology, Agriculture, Sediment, Restoration
ID: 407832
Year: 2018
Type: Articolo in rivista
Creation: 2019-10-15 12:12:06.000
Last update: 2019-10-20 12:30:05.000
CNR authors
CNR institutes
External IDs
CNR OAI-PMH: oai:it.cnr:prodotti:407832
DOI: 10.1016/j.jglr.2018.06.005
ISI Web of Science (WOS): 000447818500023