A new case of neotropical monodominant forest: Spirotropis longifolia (Leguminosae-Papilionoideae) in French Guiana

The main interest in studying monodominant forests in the tropics (i.e. single-dominant forest sensu Richards 1996 and Connell & Lowman 1989) is that processes leading to monodominance may highlight mechanisms controlling species diversity (Hart et al. 1989). Among the various cases of monodominant forest (Hart 1990), the most intriguing are the rare ones that stand in contact with a considerably more diverse forest, without apparent environmental boundaries, and for many generations (i.e. type I sensu Connell & Lowman 1989). Rather than a single mechanism, it is likely that this type of monodominance results from a suite of interacting traits (Torti et al. 2001). This has been well illustrated for the neotropical tree Dicymbe corymbosa whose monodominance relies on: (1) ectomycorrhizal symbiosis (Henkel et al. 2002) linked to (2) mast fruiting (Henkel et al. 2005), (3) high seedling survival rate (Henkel et al. 2005, McGuire 2007a, 2007b) and, potentially, (4) slow litter decomposition (Mayor & Henkel 2006, McGuire et al. 2010), moreover, (5) the reiterative habit of D. corymbosa slows the gap dynamics, and reduces species richness (Woolley et al. 2008). Thus, a comprehensive understanding of monodominance may only emerge from the comparison of many case studies to point out shared mechanisms. Here, we report a new case of a monodominant species: Spirotropis longifolia (DC.) Baill.