Actor-networking the ‘failed state’ — an enquiry into the life of concepts

Concepts such as the ‘failed state’ are jointly produced by academics and political actors and hence connect academia and global politics. Little attention has been spent to study such concepts and the practices that create them and sustain their relevance. We develop an innovative framework for studying concepts. Relying on actor-network theory, we suggest studying concepts as effects of relations between different actors building an actor-network. We introduce actor-network theory and demonstrate its value for international relations (IR) research. Our empirical case study of the concept of failed states combines bibliometric analysis and qualitative text analysis. We show how various actors have brought the concept of failed states to life; analyse how actors transformed because of their participation; and investigate the persistent struggles to define and homogenise the concept. In summary, this is an article about the life of the failed state, the discipline of IR and its relations to other actors, and an introduction of the actor-network theory toolbox to the sociology of IR

A synthesis of radial growth patterns preceding tree mortality

Altres ajuts: this study generated from the COST Action STReESS (FP1106) financially supported by the EU Framework Programme for Research and Innovation HORIZON 2020. And the EU Project FEDER 0087 TRANSHABITAT and LIFE12 ENV/FI/000409Tree mortality is a key factor influencing forest functions and dynamics, but our understanding of the mechanisms leading to mortality and the associated changes in tree growth rates are still limited. We compiled a new pan-continental tree-ring width database from sites where both dead and living trees were sampled (2970 dead and 4224 living trees from 190 sites, including 36 species), and compared early and recent growth rates between trees that died and those that survived a given mortality event. We observed a decrease in radial growth before death in ca. 84% of the mortality events. The extent and duration of these reductions were highly variable (1-100 years in 96% of events) due to the complex interactions among study species and the source(s) of mortality. Strong and long-lasting declines were found for gymnosperms, shade- and drought-tolerant species, and trees that died from competition. Angiosperms and trees that died due to biotic attacks (especially bark-beetles) typically showed relatively small and short-term growth reductions. Our analysis did not highlight any universal trade-off between early growth and tree longevity within a species, although this result may also reflect high variability in sampling design among sites. The intersite and interspecific variability in growth patterns before mortality provides valuable information on the nature of the mortality process, which is consistent with our understanding of the physiological mechanisms leading to mortality. Abrupt changes in growth immediately before death can be associated with generalized hydraulic failure and/or bark-beetle attack, while long-term decrease in growth may be associated with a gradual decline in hydraulic performance coupled with depletion in carbon reserves. Our results imply that growth-based mortality algorithms may be a powerful tool for predicting gymnosperm mortality induced by chronic stress, but not necessarily so for angiosperms and in case of intense drought or bark-beetle outbreaks