6 research outputs found
The International Boreal Forest Research Association: Understanding Boreal Forests and Forestry in a Changing World
biogeochemical cycles, boreal biome, carbon, circumpolar, climate change, disturbance, ecology, forest science, global change, IBFRA, sustainable forest management,
Seasonal variations of dissolved nitrogen and DOC:DON ratios in an intermittent Mediterranean stream
22 páginas, 6 figuras, 4 tablas.Seasonal variations of dissolved inorganic nitrogen (DIN) (NO3–N and NH4–N) and
dissolved organic nitrogen (DON) were determined in Fuirosos, an intermittent stream draining an
unpolluted Mediterranean forested catchment (10.5 km2) in Catalonia (Spain). The influence of
flow on streamwater concentrations and seasonal differences in quality and origin of dissolved
organic matter, inferred from dissolved organic carbon to nitrogen ratios (DOC:DON ratios), were
examined. During baseflow conditions, nitrate and ammonium had opposite behaviour, probably
controlled by biological processes such as vegetation uptake and mineralization activity. DON
concentrations did not have a seasonal trend. During storms, nitrate and DON increased by several
times but discharge was not a good predictor of nutrient concentrations. DOC:DON ratios in
streamwater were around 26, except during the months following drought when DOC:DON ratios
ranged between 42 and 20 during baseflow and stormflow conditions, respectively. Annual N
export during 2000–2001 was 70 kg km 1 year 1, of which 75% was delivered during stormflow.
The relative contribution of nitrogen forms to the total annual export was 57, 35 and 8% as
NO3–N, DON and NH4–N, respectively.This study was supported by a Formacio´n de
Personal Investigador (FPI) grant and funds provided by the Comisio´ n
Interministerial de Ciencia y Tecnologı´a (CICT, reference REN2001-3327).Peer reviewe