Earlier winter/spring runoff and snowmelt during warmer winters lead to lower summer chlorophyll-a in north temperate lakes

Bibliographische Detailangaben
Veröffentlicht in:	Global change biology. - 1999. - 27(2021), 19 vom: 20. Okt., Seite 4615-4629
1. Verfasser:	Hrycik, Allison R (VerfasserIn)
Weitere Verfasser:	Isles, Peter D F, Adrian, Rita, Albright, Matthew, Bacon, Linda C, Berger, Stella A, Bhattacharya, Ruchi, Grossart, Hans-Peter, Hejzlar, Josef, Hetherington, Amy Lee, Knoll, Lesley B, Laas, Alo, McDonald, Cory P, Merrell, Kellie, Nejstgaard, Jens C, Nelson, Kirsten, Nõges, Peeter, Paterson, Andrew M, Pilla, Rachel M, Robertson, Dale M, Rudstam, Lars G, Rusak, James A, Sadro, Steven, Silow, Eugene A, Stockwell, Jason D, Yao, Huaxia, Yokota, Kiyoko, Pierson, Donald C
Format:	Online-Aufsatz
Sprache:	English
Veröffentlicht:	2021
Zugriff auf das übergeordnete Werk:	Global change biology
Schlagworte:	Journal Article chlorophyll-a climate change long-term data phytoplankton biomass snowmelt stream discharge Chlorophyll 1406-65-1 Chlorophyll A YF5Q9EJC8Y

Beschreibung
Zusammenfassung:	© 2021 John Wiley & Sons Ltd. Winter conditions, such as ice cover and snow accumulation, are changing rapidly at northern latitudes and can have important implications for lake processes. For example, snowmelt in the watershed-a defining feature of lake hydrology because it delivers a large portion of annual nutrient inputs-is becoming earlier. Consequently, earlier and a shorter duration of snowmelt are expected to affect annual phytoplankton biomass. To test this hypothesis, we developed an index of runoff timing based on the date when 50% of cumulative runoff between January 1 and May 31 had occurred. The runoff index was computed using stream discharge for inflows, outflows, or for flows from nearby streams for 41 lakes in Europe and North America. The runoff index was then compared with summer chlorophyll-a (Chl-a) concentration (a proxy for phytoplankton biomass) across 5-53 years for each lake. Earlier runoff generally corresponded to lower summer Chl-a. Furthermore, years with earlier runoff also had lower winter/spring runoff magnitude, more protracted runoff, and earlier ice-out. We examined several lake characteristics that may regulate the strength of the relationship between runoff timing and summer Chl-a concentrations; however, our tested covariates had little effect on the relationship. Date of ice-out was not clearly related to summer Chl-a concentrations. Our results indicate that ongoing changes in winter conditions may have important consequences for summer phytoplankton biomass and production
Beschreibung:	Date Completed 20.09.2021 Date Revised 20.09.2021 published: Print-Electronic Citation Status MEDLINE
ISSN:	1365-2486
DOI:	10.1111/gcb.15797