Living fences in Costa Rican agriculture

The use of living trees and shrubs as posts for fences has become a widely diffused technique in various ecological zones of Costa Rica. Many agricultural crops are protected by living fences, though the majority of them may be seen along the edges of coffee plantations, pastures and sugar cane fields. The number of species used for live fence posts is impressive: during a six month of field survey 57 species were identified as being regularly planted as components of fences. Of these the 26 most important are described individually in systematic order. An analyisis of the evolution of the fencing patterns shows clearly that the species diversity has been reduced during the last four years, mainly through road-widening projects and because posts treated with preservatives are being used as a substitute to this traditional technique. (author)