Organic matter characteristics in a Mediterranean stream through amino acid composition: Changes driven by intermittency

Full Text
Organic-matter-characteristics.pdf embargoed access
Request a copy
When filling the form you are requesting a copy of the article, that is deposited in the institutional repository (DUGiDocs), at the autor or main autor of the article. It will be the same author who decides to give a copy of the document to the person who requests it, if it considers it appropriate. In any case, the UdG Library doesn’t take part in this process because it is not authorized to provide restricted articles.
Amino acid composition (quality) and abundance (quantity) of organic matter (OM) in an intermittent Mediterranean stream were followed during transitions from wet to dry and dry to wet conditions. Amino acids were analyzed in benthic material (epilithic biofilms, sand sediments, leaf material) as well as in the flowing water (dissolved organic matter, DOM). A principal component analysis and the estimation of the amino acid degradation index (DI) elucidated differences in amino acid composition and quality among the wet-drought-wet cycle. Amino acid content and composition were dependent on the source of OM as well as on its diagenetic state. The highest-quality OM (high DI and high N content) occurred on epilithic biofilms and the most degraded and lowest-quality OM occurred in sandy sediments. Differences between the pre- and post-drought periods were evident in DOM quality; autochthonous-derived material was predominant during the pre-drought (wet period preceding drying), while allochthonous inputs dominated during the post-drought period (wet period following drying). In contrast, benthic OM compartments were more stable, but benthic OM quality decreased continuously throughout the drought period. This study revealed that wet-drought-wet cycles resulted in subtle changes in benthic OM quality, and degradation of DOM was related to flow intermittency ​
​Tots els drets reservats