Webbläsaren som du använder stöds inte av denna webbplats. Alla versioner av Internet Explorer stöds inte längre, av oss eller Microsoft (läs mer här: * https://www.microsoft.com/en-us/microsoft-365/windows/end-of-ie-support).

Var god och använd en modern webbläsare för att ta del av denna webbplats, som t.ex. nyaste versioner av Edge, Chrome, Firefox eller Safari osv.

Hakim Abdi. Foto.

Hakim Abdi

Forskare

Hakim Abdi. Foto.

Drought Offsets the Controls on Colored Dissolved Organic Matter in Lakes

Författare

  • Enass Said Al-Kharusi
  • Geert Hensgens
  • Abdulhakim M. Abdi
  • Tiit Kutser
  • Jan Karlsson
  • David E. Tenenbaum
  • Martin Berggren

Summary, in English

The concentration of colored dissolved organic matter (CDOM) in lakes is strongly influenced by climate, land cover, and topographic settings, but it is not known how drought may affect the relative importance of these controls. Here, we evaluate the controls of CDOM during two summers with strongly contrasting values of the Palmer drought index (PDI), indicating wet vs. dry conditions. We hypothesized that lake CDOM during a wet summer season is regulated mainly by the surrounding land cover to which the lakes are hydrologically connected, while, during drought, the lakes are disconnected from the catchment and CDOM is regulated by climatic and morphometric factors that govern the internal turnover of CDOM in the lakes. A suite of climate, land cover, and morphometric variables was assembled and used to explain remotely sensed CDOM values for 255 boreal lakes distributed across broad environmental and geographic gradients in Sweden and Norway. We found that PDI explained the variability in CDOM among lakes in a dry year, but not in a wet year, and that severe drought strongly decreased CDOM during the dry year. Large lakes, especially, with a presumed high degree of catchment uncoupling, showed low CDOM during the dry year. However, in disagreement with our hypothesis, climate, land cover, and morphometry all showed a stronger impact on lake CDOM in wet vs. dry years. Thus, drought systematically weakened the predictability of CDOM variations at the same time as CDOM was offset toward lower values. Our results show that drought not only has a direct effect on CDOM, but also acts indirectly by changing the spatial regulation of CDOM in boreal lakes.

Avdelning/ar

  • Institutionen för naturgeografi och ekosystemvetenskap
  • Centrum för miljö- och klimatvetenskap (CEC)
  • BECC: Biodiversity and Ecosystem services in a Changing Climate
  • Biodiversitet och bevarandevetenskap
  • MECW: The Middle East in the Contemporary World
  • Centrum för Mellanösternstudier (CMES)
  • LU profilområde: Naturbaserade framtidslösningar

Publiceringsår

2024

Språk

Engelska

Publikation/Tidskrift/Serie

Remote Sensing

Volym

16

Issue

8

Dokumenttyp

Artikel i tidskrift

Förlag

MDPI AG

Ämne

  • Environmental Sciences

Nyckelord

  • boreal lakes
  • coloured dissolved organic matter (CDOM)
  • drought
  • Palmer drought index (PDI)
  • remote sensing data
  • spatial variables

Status

Published

Forskningsgrupp

  • Biodiversity and Conservation Science

ISBN/ISSN/Övrigt

  • ISSN: 2072-4292