Sediment delivery and lake dynamics in a Mediterranean mountain watershed: Human-climate interactions during the last millennium (El Tobar Lake record, Iberian Range, Spain)

Fernando Barreiro-Lostres, Erik Brown, Ana Moreno, Mario Morellón, Mark Abbott, Aubrey Hillman, Santiago Giralt, Blas Valero-Garcés

Research output: Contribution to journalArticlepeer-review

10 Scopus citations

Abstract

Land degradation and soil erosion are key environmental problems in Mediterranean mountains characterized by a long history of human occupation and a strong variability of hydrological regimes. To assess recent trends and evaluate climatic and anthropogenic impacts in these highly human modified watersheds we apply an historical approach combining lake sediment core multi-proxy analyses and reconstructions of past land uses to El Tobar Lake watershed, located in the Iberian Range (Central Spain). Four main periods of increased sediment delivery have been identified in the 8. m long sediment sequence by their depositional and geochemical signatures. They took place around 16th, late 18th, mid 19th and early 20th centuries as a result of large land uses changes such as forest clearing, farming and grazing during periods of increasing population. In this highly human-modified watershed, positive synergies between human impact and humid periods led to increased sediment delivery periods. During the last millennium, the lake depositional and geochemical cycles recovered quickly after each sediment delivery event, showing strong resilience of the lacustrine system to watershed disturbance. Recent changes are characterized by large hydrological affections since 1967 with the construction of a canal from a nearby reservoir and a decreased in anthropic pressure in the watershed as rural areas were abandoned. The increased fresh water influx to the lake has caused large biological changes, leading to stronger meromictic conditions and higher organic matter accumulation while terrigenous inputs have decreased. Degradation processes in Iberian Range watersheds are strongly controlled by anthropic activities (land use changes, soil erosion) but modulated by climate-related hydrological changes (water availability, flood and runoff frequency).

Original languageEnglish (US)
Pages (from-to)506-519
Number of pages14
JournalScience of the Total Environment
Volume533
DOIs
StatePublished - Nov 5 2015

Bibliographical note

Funding Information:
This research has been supported by the GLOBALKARST ( CGL2009-08415 ) and GRACCIE — Consolider CSD2007-00067 projects funded by the Spanish Ministry of Economy and Competitiveness and by the I-LINK programme (I-LINK0510 ) funded by the CSIC. F. Barreiro and M. Morellón hold ‘JAE-PreDoc’ and ‘JAE-Doc’ pre and postdoctoral contracts respectively, both co-funded by C.S.I.C. and the European Social Fund.

Keywords

  • Iberian Peninsula
  • Karstic lake
  • Late Quaternary

Fingerprint

Dive into the research topics of 'Sediment delivery and lake dynamics in a Mediterranean mountain watershed: Human-climate interactions during the last millennium (El Tobar Lake record, Iberian Range, Spain)'. Together they form a unique fingerprint.

Cite this