Various studies have tried to classify silvicultural systems, usually along one of two main axes: an economic axis, where systems are categorized according to production factor utilization and economic return (Speidel et al. 1969, Dummel 1970, Arano and Munn 2006), or an ecological axis, where the categories depend on the degree of modification of natural conditions (Pro Silva 1999, Seymour and Hunter 1999, Gamborg and Larsen 2003, MCPFE 2003c).