Agroforestry systems on Careiro Island

Agroforestry systems on the island of Careiro originate from rubber and cocoa plantations developed at the beginning of this century. Four main types of systems were defined according to their present-day composition, and show an evolution from the former plantations towards polyspecific orchards or pastures with scattered trees. Distribution of perennial crops depends upon topography and the associated risks of flooding. The total area cultivated is closely linked to the dynamics of levées in the várzea. These agroforestry systems require little maintenance and provide a living environment for the inhabitants as well as a panoply of subsistence and market products. Because of physical and socio-economic constraints in the várzea, these systems are becoming increasingly monospecific or being converted into pasture

On free loop spaces of toric spaces

Growth of the Hilbert-Poincar\"e series for the rational homology of the free loop space of a toric space is addressed. In case the toric space is a manifold, the structure of the fan dictates whether the Hilbert-Poincar\"e series has exponential growth. Applications are made to the existence of infinitely many geometrically distinct periodic geodesics