Enrichment planting of native tree species in the eastern Amazon of Brazil: Silvicultural, financial, and household assessments.

摘要

Enrichment planting (EP) is a silvicultural tool capable of adding long-term value to forests. Here EP case studies and experimental trials are assessed at two scales: large industrial and family farm planting. Tree growth responses to treatments are reported. Financial cost-benefit analysis (CBA) and Ethnographic Linear Programming (ELP) are used to determine sensitivity to short- and long-term costs and benefits. The goal is to define factors that promote or hinder EP in order to help inform landholders and policy makers of effective use of EP.;A case study in the Brazilian Amazon revealed that EP produces multiple timber harvests but may be expensive without short-term financial benefits. Sensitivity analysis of costs and benefits showed that revenue from activities additional to EP, such as carbon sequestration payments, can make EP profitable. A social appraisal of EP may reveal social benefits that would justify governmental, financial, and policy support. Fertilization and site preparation experiments showed that they produce little benefit in growth and survival and therefore may incur unnecessary expenses in these settings. Considering the finding of the CBA results and the treatment experiments, it is suggested that early costs be kept low and therefore planting treatments kept to a minimum. The particular minimum treatment depends on species and site conditions.;Relative abundance of EP by smallholders is intriguing given difficulties some large companies experience when implementing EP. ELP was used to assess planting conducted by Amazon smallholders. Diverse short-term benefits, multitasking, low opportunity costs, low start-up costs, reliable tree survivorship and ability to care for planted trees promoted EP among smallholders. As for industrial foresters, monetary payments for EP are also an effective incentive.;Both industrial planters and smallholders need short-term benefits and minimal costs but there are differences between the scales. Industrial planters perceive financial benefits; biodiversity conservation or local economy stability are external. To make them internal, and thereby make EP more feasible, external benefits need to be translated into shorter-term financial gains for the companies. Smallholders respond well to payments and other non-financial benefits. Differences between scales should be considered when developing policies or programs to encourage EP.