Climate seasonality limits leaf carbon assimilation and wood productivity in tropical forests.

The seasonal climate drivers of the carbon cy- cle in tropical forests remain poorly known, although these forests account for more carbon assimilation and storage than any other terrestrial ecosystem. Based on a unique combina- tion of seasonal pan-tropical data sets from 89 experimental sites (68 include aboveground wood productivity measure- ments and 35 litter productivity measurements), their asso- ciated canopy photosynthetic capacity (enhanced vegetation index, EVI) and climate, we ask how carbon assimilation and aboveground allocation are related to climate seasonal- ity in tropical forests and how they interact in the seasonal carbon cycle. We found that canopy photosynthetic capacity seasonality responds positively to precipitation when rain- fall is < 2000 mm yr-1 (water-limited forests) and to radia- tion otherwise (light-limited forests). On the other hand, in- dependent of climate limitations, wood productivity and lit- terfall are driven by seasonal variation in precipitation and evapotranspiration, respectively. Consequently, light-limited forests present an asynchronism between canopy photosyn- thetic capacity and wood productivity. First-order control by precipitation likely indicates a decrease in tropical forest pro- ductivity in a drier climate in water-limited forest, and in cur- rent light-limited forest with future rainfall < 2000 mm yr-1.

PERCEPCIÓN Y PREVENCIÓN DEL RIESGO POR LAHAR EN LOS DIQUES DE CARTAGO

En los Diques de Taras de Cartago reside una población con alto grado de vulnerabilidad a la ocurrencia de lahares  provenientes del  Río Reventado.  En este artículo se analiza la situación del Barrio La Unión ante un eventual lahar, tanto desde el punto de vista de la amenaza, a la que están expuestos, como de la percepción del riesgo que tienen sus habitantes.Palabras clave: Lahar, desastres naturales, percepción del riesgo, diquesAbstract:In Taras Diques, Cartago, the inhabitants are highly vulnerable to mud slides from the Reventado River. This article analyzes the situation of the La Unión Community in an event of a mud slide, from the danger`s point of view they are exposed to as well as how the inhabitants perceive the risk.Keywords: Lahar, natural disasters, perception of the risk, dikes