Restoration costs
Restoration implementation costs were obtained from Molin et al. (2018),
which indicated that restoration plantations established on croplands
and pasturelands in the region cost US$2,500.ha-1 and
US$3,750.ha-1, respectively (more expensive in
pasturelands due to fencing costs); these estimates include all costs
associated with tree planting and maintenance for up to three years
(Molin et al., 2018). Unassisted
natural regeneration in croplands had no implementation cost and in
pasturelands it was US$1,250.ha-1 due to fencing
costs (Molin et al., 2018). Annual land opportunity cost was estimated
based on land rental prices for sugarcane and cattle ranching in the
Piracicaba region (where the Corumbataí watershed is located), based on
official survey of the Institute of Agriculture Economics of São Paulo
(SãoPaulo, 2017), and was estimated as
US$106.66.ha-1.year-1 for cattle
ranching and US$389.23.ha-1.year-1for sugarcane (Molin et al., 2018). We calculated the accumulated land
opportunity cost by multiplying these aforementioned annual costs by the
age of the restored forests. Total restoration cost was calculated by
summing implementation and accumulated land opportunity costs (e.g.,
total cost for 10-year old restoration plantation on cropland =
US$2,500.ha-1 +
US$389.23.ha-1.year-1 x 10 years =
US$6392.3). No discount rate was applied because we aimed to compare
tree planting and natural regeneration on the present value.