A water quality study was carried out on 40 irrigation ponds located within the main greenhouse areas on the Almerı?a coast, placing special emphasis on the factors controlling the oxygen dynamics, a relevant aspect with agricultural’and environmental implications. Considering chemical, physical’and biological water characteristics, agricultural irrigation ponds were satisfactorily classified by cluster analysis in four groups. These were congruently arranged by principal components analysis along four main environmental gradients: trophic status, photosynthetic activity, water mineralisation and presence of submerged aquatic végétation (SAV). Dissolved oxygen (DO) values differed highly among and within each of the four pond groups. DO dynamics was mainly depended on photosynthetic activity, and the environmental factors and management practices controlling it: seasonal’and daily climatic changes, pond management (open vs. covered ponds and presence/absence of aquatic végétation) and trophic status. Overall, différent diurnal DO patterns were found between open and covered ponds. The former usually présented DO values above saturation and increasingly higher from early morning to midafternoon due to the photosynthetic activity of algae and macrophytic végétation. In contrast, covered ponds showed relatively stable DO values during the diurnal period regardless of climatic conditions, with absolute values around or below saturation level. Globally, our results suggest that open ponds, with macrophytes concentrated in the deeper layer, can be an effective and sustainable management method of water oxygen enrichment. & 2007 Elsevier Ltd. All rights réserved. 1. Introduction
- Genre de document : Revue
- Type de document : À préciser
- Auteurs principaux : SANTIAGO BONACHELA, Rodrigo Acuña A., JESUS CASAS
- Date de publication : 1 janvier 2007
