Enrichment planting in overexploited subtropical forests of the Paranaense region of Misiones, Argentina.
Line enrichment experiments using native species of commercial value were established in 1988-1991 in overexploited forests at 2 locations in Misiones, Argentina, on public and private lands. Ten timber species were tested, as well as Euterpe edulis (palmito) which can be harvested after 10-12 years for its heart of palm. Mixed (2 species) and single species line plantings were used. At 4 to 7 years old, the timber species with the greatest mean height and diameter at breast height (d.b.h.) were Bastardiopsis densiflora, Enterolobium contortisiliquum, Nectandra lanceolata, Ocotea puberula and Peltophorum dubium. Cordia trichotoma and Balfourodendron riedelianum, both highly appreciated timber species, could also be recommended for enrichment despite their relatively slower growth. The palm E. edulis had a low survival rate but the remaining individuals showed good height and d.b.h. The other timber species included in the test but not performing so well were Parapiptadenia rigida, Didymopanax morototoni and Jacaranda micrantha. Labour costs associated with establishment and care of enrichment plantings were similar to those from other reports for the region. The incorporation of species with a short harvest age and a high economic value such as the palm E. edulis can accelerate and increase investment returns of enrichment plantings. Although long-term results are required to document the potential for growth and quality of production for each species, results from these experiments can provide insights into the use of these species in the enrichment of overexploited and secondary forests in the region.