Estimating yield and control costs of Pinus spp. invasions – a case study in a municipal protected area in Atlantic Forest, Florianópolis, Brazil

Abstract

Pines invading a municipal protected area in southern Brazil were eliminated over 17 days at a cost of US $ 10,000. The number of pines eliminated per day varied with: (1) slope; (2) vegetation; and (3) pine density. Yield was assessed based on the combination of these three factors. Seven yield classes were defined to estimate the number of pines a team of four workers can eliminate per day. Yield varied between approximately 100 and more than 700 pines per day. A formula was developed to provide yield estimates to support management of control activities. The formula can be adjusted to other limiting factors. A breakdown of costs is presented for reference. Cost varied from US$ 5.45 to US$ 0.88 per tree. Despite the higher individual cost, isolated trees must be controlled first to avoid higher future costs from abundant seed spread.