Avian communities’ preferences in recently created agricultural wetlands in irrigated landscapes of semi-arid areas

Abstract

Numerous wetlands have been created spontaneously in the Ebro river basin as a consequence of new irrigation developments over the last 50 years. Water used for irrigating farmland drains into the lower parts of small valleys to form wetlands that are mostly dominated by common reed (Phragmites australis). Bird communities established in these wetlands are still simple, partly due to the lack of management to enable their ecological functions to improve. A knowledge of which environmental features favor these bird communities is essential in order to improve the design of newly created or restored wetlands associated to future irrigation developments. For this purpose, the habitat and vegetation features of 15 wetlands have been sampled. The structure of bird communities (richness, abundance and diversity) was monitored over 3 years during the breeding season and in winter at foraging and nocturnal roosting. The presence of bushes, height of stems and distance from large wetlands ([1 ha) proved to be the most influential variables on bird community structure and on most abundant species during the breeding season. Wetland area and compactness influenced species richness and the most abundant species during winter foraging and roosting. There was a maximum stem height at which only reed-dwelling birds remained. Uncontrolled winter burning had a severe negative effect upon these recently established populations. The ecological functions of newly created or restored wetlands, including those for run-off treatment in agricultural catchments, could be substantially improved taking into account simple guidelines from these results which relate bird community characteristics to wetland features.

Importancia de las infraestructuras de riego tradicionales en la conservación de la avifauna en el entorno de humedales protegidos: el caso de Carrizales de Elche

“…Por ello, las propuestas no son tajantes o concluyentes, sino insinuadoras, tratando de acercar las dos posturas, haciendo además ver que la cuestión ecológica podría tenerse no como un impedimento, sino como una perspectiva de futuro, una marca o un 760 valor añadido al producto agrícola, cosechado en condiciones de elevada calidad ambiental. La eliminación indiscriminada del carrizo puede suponer una merma grave para las poblaciones que anidan dentro de los canales, como se refleja en los resultados que hemos obtenido, influyendo principalmente sobre el conjunto de especies totales y sobre especies concretas como el Carricero, de igual modo indicado por otros estudios (Graveland, 1999;Moreno-Mateos et al, 2009;. Así, una estrategia novedosa podría ser diseñada en colaboración con los agricultores.…”

“…Así como, cuáles son las características de los mismos que mayor influencia tienen sobre su establecimiento. La relación con otros medios construidos por el hombre como balsas de riego o humedales artificiales sí que han sido en parte analizados (Erwin et al, 1994;Herremans, 1999;Moreno-Mateos et al, 2009;Sánchez-Zapata et al, 2005), sin embargo, los canales han sido desestimados. Un único trabajo, en el desierto de Thar en la India, demostró que la construcción de una red de canales a través del mismo dio pie a la colonización de especies de aves acuáticas, palustres y zancudas, aumentando la biodiversidad (Rahmani and Soni, 1997).…”

Integrating Open Access Geospatial Data to Map the Habitat Suitability of the Declining Corn Bunting (Miliaria calandra)

“…The area consists of the comarques of Noguera, Segria, Urgell and Pla d'Urgell, covers approximately 3,920 square kilometers and is composed mainly of non-irrigated cropland and dry forests with extensive agriculture and dry pastures. Intensive agricultural practices are slowly being implemented in the region to replace the economically unviable low-intensity extensive farming methods that dominate the landscape of Lerida [23,24]. …”

A protocol to prioritize wetland restoration and creation for water quality improvement in agricultural watersheds

“…We followed the latter approach, using a rate constant 441 for nitrate removal that was higher than those for ammonium and 442 organic nitrogen (Kadlec and Wallace, 2008). In addition, plant 443 cover in the constructed wetlands in the study area is expected 444 to develop quickly due to the use of Phragmites australis (Moreno-445 Mateos et al, 2008bMateos et al, , 2009), a commonly used and efficient plant 446 cover. The establishment of plant cover will make it possible to 447 apply the plug-flow-based first-order model used for dimensioning 448 surface-flow wetlands (Kadlec et al, 2000).…”