Abstract
Knowing which restoration approach provides the best returns on
investment for accumulating carbon is essential to foster restoration
planning, financing, and implementation. We assessed the recovery of
carbon stocks, implementation and land opportunity costs of forests
established by natural regeneration and high-diversity native tree
plantations. Our study was based on chronosequences (10-60 yr) of 12
naturally regenerating forests, 13 restoration plantations, and 5
reference forests located in Brazil’s Atlantic Forest. Restoration
plantations accumulated approximately 50% more above-ground carbon than
regenerating forests throughout the chronosequence. When controlling for
soil clay content, soil carbon stocks were higher in reference than in
restored forests, but they were comparable between plantations and
regenerating forests. After 60 years of stand development, recovery of
total carbon stocks in both restoration management types reached only
half of the average stocks of reference forests. Total
cost-effectiveness for carbon accumulation, including both
implementation and land opportunity costs, was on average 60% higher
for regenerating forests than for plantations (15.1 kgC.US$-1 and 9.4
kgC.US$-1, respectively). Both restoration management types had
cost-effectiveness for carbon accumulation markedly lower than the price
of carbon credits considered, so some voluntary forest carbon markets
are not adequately priced to support restoration derived offsets.
Although tree plantations initially had higher rates of carbon storage
than regenerating forests, their higher implementation and land
opportunity costs make them less cost-effective for carbon farming. Our
results further suggest that carbon markets alone have a limited
potential to up-scale restoration efforts in Brazil’s Atlantic Forest.