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Fig. 5.2. A Cecropia tree in a secondary forest on the Pacific coast of Costa Rica (note a sloth hanging from a branch near the center). Several species of Cecropia are characteristic of early stages of succession in secondary forests in Latin America. (Photo: F. Mon-tagnini)

Fig. 5.2. A Cecropia tree in a secondary forest on the Pacific coast of Costa Rica (note a sloth hanging from a branch near the center). Several species of Cecropia are characteristic of early stages of succession in secondary forests in Latin America. (Photo: F. Mon-tagnini)

Research on management of secondary forests by CATIE Despite the large body of ecological information on secondary forest succession in Central America, few forestry-based experiments have investigated how secondary forests react to management practices. CATIE researchers are characterizing secondary forest structures and floristics and developing guidelines for sustainable management in Costa Rica and Nicaragua (Current et al. 1998; Guariguata 1999). In Costa Rica, the area of secondary forests already exceeds the area of primary forest legally available for production, while in Puerto Rico nearly all forest cover is classified as secondary forest (Kammesheidt 2002; Fig. 5.2).

In Costa Rica, CATIE has investigated the effects of silvicultural practices such as liberation thinning, whole-canopy removal, and substrate preparation techniques on stand dynamics and regeneration of secondary forests in order to provide guidelines for sustainable management of timber. In the Atlantic lowlands of Costa Rica, short-term growth responses in individuals of four commercial species (Laetia procera, Simarouba amara, Tapirira guianensis, and Vochysia ferruginea) were evaluated following liberation thinning in a young secondary forest. Liberation thinning significantly increased the diameter growth of future crop trees with respect to unmanipulated counterparts (Table 5.2). The study concluded that young stands in the region may be attractive systems for simple silvi-cultural manipulations due to rapid growth responsiveness, facilitated by manageable tree size (Guariguata 1999).

The type of intervention needed for management will significantly vary according to the status of secondary forests. In tropical Asia, five major categories can be found: post-extraction secondary forests, post-fire secondary forests, swidden fallow secondary forests, secondary forest gardens, and rehabilitated secondary forests (Chokkalingam et al. 2001). An understanding of where each particular forest is situated in a continuum of disturbances and regeneration stages can help guide management of secondary forests.

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