2024-03-29T02:28:32Zhttp://digital.csic.es/dspace-oai/requestoai:digital.csic.es:10261/1839152019-10-01T11:06:31Zcom_10261_57com_10261_8col_10261_436
Effects of erosion in the fate of soil organic carbon and soil aggregation in a Mediterranean hill-slope
Campo, Julián
Kammeraat, Erik
Gimeno-García, Eugenia
Andreu Pérez, V.
Generalitat Valenciana
Andreu Pérez, V. [0000-0003-2170-1394]
Trabajo presentado en la European Geosciences Union General Assembly, celebrada en Viena (Austria), del 17 al 22 de abril de 2016
The International Panel on Climate Change indicated a higher degree of confidence that meteorological conditions associated to climate change will be propitious to increasing extreme events manifested, among others, in bigger and more frequent wildfires (IPCC, 2014). Wildfires contribute to shaping the landscape, and geomorphological and hydrological processes that operate on soil are affected (Bento-Gonçalves et al., 2012).
Whereas it is well documented that wildfires produce significant changes on erosion processes, the associated fate of soil organic carbon (SOC) has received less attention. This research assesses this gap by studying the loss, redistribution, and stabilization of SOC in a Mediterranean forest hill-slope burned the 28-08-2014, with high severity fire, at the Natural Park of Sierra de Espadán, Spain (39°50'45.11"N, 0°22'20.52"W). To this end, soil was sampled (19-9-2014) in the foot¿s slope (depositional), middle part (transport) and top (eroding) at two depths (<2 cm, 2-5 cm), and in two environments (under canopy soil: UC; bare soil: BS). Sediments were collected from four sediment fences constructed at the foot¿s slope, and together with soil samples, analysed with regard to SOC content and aggregate stability (AS). The main objective is to increase the understanding on the fate of SOC, in Mediterranean burned areas experiencing soil erosion and deposition, with special attention to the role of aggregation and disaggregation in redistribution processes.
Immediately after the fire, SOC content was high (above 50 g kg-1) as well as the AS. Significant differences (ANOVA, p<0.05) in SOC contents were observed between environments (UC > BS) and soil depths (topsoil > subsoil). However, no significant differences were observed among eroding (58.8+ 20.8 g kg-1), transport (67.3+ 34.4 g kg-1), and depositional zones (62.0+ 31.3 g kg-1), which is not in agreement with other SOC redistribution studies (Wang et al., 2014). Significant differences (Kruskal-Wallis, p<0.05) were also found in AS between environments (UC > BS) but not between soil depths or hill-slope positions.
In the first post-fire erosive rains occurred in the area (29-11-14), closest pluviometer (Sot de Ferrer: 4.5km) registered a total daily rain up to 64.2 L m-2. In this event a total of 12.7 kg of sediment were collected (contributing area about 0.25ha). With a content of 252.6 g kg-1 the total SOC lost or stored in the depositional zone can reach up to 3.2 kg. In the second erosive event (23-3-15: 103.2 l m-2), total sediment in the fences was 143.6 kg, with content of 112.2 g C kg-1, made a total SOC eroded of up to 16.1 kg.
It is hypothesized that fire caused the homogenization of SOC content and AS in the different hill-slope positions, and only when erosion expose unburned organic matter to mineralization processes, SOC losses will increase in eroding sites, likely decreasing in transport and depositional ones. Ongoing work is related to the analyses of organic C in different soil fractions (determined by sieving and density) in order to understand C stabilization in post-fire soil, and its role in disaggregation and SOC redistribution by sediment in different hill-slope positions.
This work has been supported by the Generalitat Valenciana through the VALi+d postdoctoral contract (APOSTD/2014/010).
Peer reviewed
2019-06-13T06:29:07Z
2019-06-13T06:29:07Z
2016-04-17
comunicación de congreso
http://purl.org/coar/resource_type/c_5794
EGU General Assembly (2016)
http://hdl.handle.net/10261/183915
http://dx.doi.org/10.13039/501100003359
en
Sí
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