Resistance of seagrass habitats to ocean acidification via altered interactions in a tri-trophic chain
Despite the wide knowledge about prevalent effects of ocean acidification on single species, the consequences on species interactions that may promote or prevent habitat shifts are still poorly understood. Using natural CO2 vents, we investigated changes in a key tri-trophic chain embedded within all its natural complexity in seagrass systems. We found that seagrass habitats remain stable at vents despite the changes in their tri-trophic components. Under high pCO2, the feeding of a key herbivore (sea urchin) on a less palatable seagrass and its associated epiphytes decreased, whereas the feeding on higher-palatable green algae increased. We also observed a doubled density of a predatory wr…
Long-term effects of elevated CO2 on the population dynamics of the seagrass Cymodocea nodosa: Evidence from volcanic seeps
Population reconstruction techniques was used to assess for the first time the population dynamics of a seagrass, Cymodocea nodosa, exposed to long-term elevated CO2 near three volcanic seeps and compared them with reference sites away from the seeps. Under high CO2, the density of shoots and of individuals (apical shoots), and the vertical and horizontal elongation and production rates, were higher than at the reference sites. Nitrogen limitation effects on rhizome elongation and production rates and on biomass were more evident than CO2 as these were highest at the location where the limitation of nitrogen was highest. At the seep where the availability of CO2 was highest and nitrogen low…
Altered epiphyte community and sea urchin diet in Posidonia oceanica meadows in the vicinity of volcanic CO2 vents
Ocean acidification (OA) predicted for 2100 is expected to shift seagrass epiphyte communities towards the dominance of more tolerant non-calcifying taxa. However, little is known about the indirect effects of such changes on food provision to key seagrass consumers. We found that epiphyte communities of the seagrass Posidonia oceanica in two naturally acidified sites (i.e. north and south sides of a volcanic CO2 vent) and in a control site away from the vent at the Ischia Island (NW Mediterranean Sea) significantly differed in composition and abundance. Such differences involved a higher abundance of non-calcareous crustose brown algae and a decline of calcifying polychaetes in both acidif…
Book reviews - Crítica de libros - Crítica de livros (Historia Agraria, 79)
Book reviews / Crítica de libros / Crítica de livros: Rosa Congost and Pablo F. Luna (Eds.): Agrarian Change and Imperfect Property: Emphyteusis in Europe (16th to 19th Centuries) Rui Santos Herbert S. Klein and Francisco Vidal Luna: Feeding the World: Brazil’s Transformation into a Modern Agricultural Economy Andrea Montero Mora Joshua Specht: Red Meat Republic: A Hoof-to-Table History of How Beef Changed America Iker Saitua Eva Fraňková, Willi Haas, Simron J. Singh (Eds.): Socio-Metabolic Perspectives on the Sustainability of Local Food Systems. Insights for Science, Policy and Practice Elena Galán del Castillo Jane Whittle (Ed.): Servants in Rural Europe, 1400-1900 Gabriel Jover Fabien C…