Sammanfattning

Using a sediment core covering the last 3,500 years, we analysed photosynthetic pigments' concentrations in lake sediments and carbon stable isotopic composition of chironomid (Diptera, Chironomidae) remains (delta C-13(HC)). We aimed to reconstruct temporal changes in aquatic primary productivity and carbon resources sustaining chironomid larvae in a high mountain lake (Lake Pyramid Inferior; 5,067 m a.s.l.) located in the Nepalese Himalayas. Both pigments and delta C-13(HC) trends followed a similar fluctuating pattern over time, and we found significant positive relationships between these proxies, suggesting the strong reliance of benthic consumers on the aquatic primary production. Temporal trends matched well with main known climatic phases in the Eastern part of the Himalayan Mountains. Past glacier dynamics and associated in-lake solute concentrations appeared to be the main driver of autochthonous primary productivity, suggesting then the indirect impact of climate change on carbon processing in the benthic food web. During warm periods, the glacier retreat induced a rise in in-lake solute concentrations leading to an increasing primary productivity. Complementary investigations are still needed to strengthen our understanding about the response of past aquatic carbon cycling in CO2-limiting environments.

Nyckelord

Food webs; Carbon stable isotope; Subfossil chironomid; Sedimentary pigments; Paleolimnology

Publicerad i

Hydrobiologia
2018, Volym: 809, nummer: 1, sidor: 285-295
Utgivare: SPRINGER

SLU författare

• Belle, Simon

  • Institutionen för vatten och miljö, Sveriges lantbruksuniversitet
    

Globala målen

SDG13 Vidta omedelbara åtgärder för att bekämpa klimatförändringarna och dess konsekvenser


UKÄ forskningsämne

Oceanografi, hydrologi, vattenresurser


Publikationens identifierare

DOI: https://doi.org/10.1007/s10750-017-3477-8

Permanent länk till denna sida (URI)

https://res.slu.se/id/publ/93867