TY - JOUR
T1 - Sediment delivery and lake dynamics in a Mediterranean mountain watershed
T2 - Human-climate interactions during the last millennium (El Tobar Lake record, Iberian Range, Spain)
AU - Barreiro-Lostres, Fernando
AU - Brown, Erik
AU - Moreno, Ana
AU - Morellón, Mario
AU - Abbott, Mark
AU - Hillman, Aubrey
AU - Giralt, Santiago
AU - Valero-Garcés, Blas
N1 - Publisher Copyright:
© 2015 Elsevier B.V.
PY - 2015/11/5
Y1 - 2015/11/5
N2 - 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).
AB - 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).
KW - Iberian Peninsula
KW - Karstic lake
KW - Late Quaternary
UR - http://www.scopus.com/inward/record.url?scp=84937011077&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84937011077&partnerID=8YFLogxK
U2 - 10.1016/j.scitotenv.2015.06.123
DO - 10.1016/j.scitotenv.2015.06.123
M3 - Article
C2 - 26186465
AN - SCOPUS:84937011077
SN - 0048-9697
VL - 533
SP - 506
EP - 519
JO - Science of the Total Environment
JF - Science of the Total Environment
ER -