Définition : Open shrubland and savanna in the north of Brazil and in Colombia and Venezuela, with low, sparse vegetation growing on sandy soils mostly within terra firme land in the Amazon. It can be of the ‘forested’ type, similar to a gallery forest, ‘wooded’ where the trees are shorter, and finally ‘grassy-woody’, where it occurs in wet plains near rivers and lakes. Amongst the more frequent plant families are the Arecaceae, Bromeliaceae, Clusiaceae, Humiriaceae, Marantaceae, Meliaceae and Rapateaceae.
Définition : Arenosols are sandy soils, including both soils developed in residual sands after in situ weathering of usually quartz-rich sediments or rock, and soils developed in recently deposited sands such as dunes in deserts and beach lands.
Définition : A group of species that exploit the same food resources, and/or use the same feeding or foraging methods. http://en.wikipedia.org/wiki/Guild_(ecology)