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While the importance of permanent grasslands (PG) for the conservation of high nature value habitats is often acknowledged, their role in most of the main sustainable food system scenarios published in the last few years is less explicit. In the best case, the place of permanent grassland in scenarios and policy agendas is their conservation; in the worst one, they are simply replaced by afforested land or cropland, considered as a better option when the focus is on GHG emissions only. In this paper, we defend the idea that several misinterpretations of the positive and negative impacts of ruminants, the 'natural' users of PG, explain why ruminants are poorly addressed by most scenarios. Based on the findings of an agroecological scenario for Europe—TYFA, standing for Ten Years For Agroecology—in which extensive permanent grassland and ruminants together play a prominent role for biodiversity conservation, nitrogen cycling and climate change mitigation and adaptation, we call for a research agenda that would better inform the specific role of PG in the provision of ecosystem services—and in particular those that depend on nitrogen management. [ABSTRACT FROM AUTHOR]

Cecropia species, ranging from Mexico to northern Argentina and the West Indies, are pioneer trees that colonize cleared areas with high light. To determine their ages to help pinpoint the date of the area's disturbance, we need to understand their developmental and architectural changes over time. The simple architecture of Cecropia conforms to the model of Rauh; that is, it has orthotropic axes with lateral flowering and rhythmic branching. The axes are made of a succession of nodes and internodes whose length and associated lateral productions remain measurable for years. Thus, by describing the tree trunk node by node, we can depict the sequence of events involved in tree development. For 25 trees of C. sciadophylla, from two stations in French Guiana and Colombia, we recorded internode length and any presence of branches, and flowers for each node. Using autocorrelation coefficients, we found a high periodicity in flowering and branching, with inflorescences at every 25 nodes, stages of branches spaced by a multiple of 25 nodes, and alternation of long and short nodes every 25 nodes. Considering that flowering is annual for many Cecropia species, the main conclusion of this work is that C. sciadophylla has strong annual growth, branching, and flowering rhythms. In addition, the age of the tree can be estimated retrospectively by observing its adult morphology. [ABSTRACT FROM AUTHOR]