A Free Air CO2 Enrichment (FACE) Facility in a Wetland to Study the Effects of Elevated Atmospheric Carbon Dioxide: System Description and Performance

Abstract

The Free Air CO 2 Enrichment (FACE) system has proved suitable for exposing plants to elevated [CO 2 ] with minimal disturbance of their natural environment. Here we describe a FACE facility in a floodplain wetland in detail and, additionally, its performance after the first year of operation (2012). The FACE system consisted of six 3-m diameter emission rings in which Phragmitesaustralis was grown. The target [CO 2 ] was 550 µmol mol-1 and fertilization was carried out continuously. Daily temporal [CO 2 ] performance was adequate with 61% and 83% of air samples at the ring's centre having a [CO 2 ] within 10% and 20% of the target, respectively, with values closest to their target during summer months and daytime. Spatial [CO 2 ] distribution showed no significant gradients across the ring. Increased wind speed improved the system's spatial performance, as [CO 2 ] was within ±10% of the target in the whole ring. Across the entire fertilization season, CO 2 requirements for maintaining a mean [CO 2 ] of 582 µmol mol-1 in wetland plots averaged 17.4 kg CO 2 ring-1 day-1. Our requirements (2.5 kg CO 2 m-2 day-1) were very low compared to other FACE systems, demonstrating its high potential to study the effects of elevated CO 2 in wetlands at low cost.

Caracterización y cambios de la vegetación en un humedal salino continental. Laguna de El Hito (Cuenca, España)

“…ex L., era a mediados del siglo pasado de 570 ha, y en la actualidad se ha reducido a 477 ha, lo que supone una disminución del 16,3 % (93 ha). La mayor alteración y eliminación de dicha vegetación se ha detectado para el periodo 1960-1980, cuando se inició una ampliación de los terrenos cultivables en los márgenes de muchas de las lagunas castellano-manchegas (Sánchez Carrillo et al, 2016). Ya en el año 1997 la superficie modificada para cultivos llegó al 25% (142 ha), pero se recuperó parcialmente debido a la escasa calidad y salinidad del terreno.…”