From Seedling to Forest

Natural regeneration: cheapest, slowest, most biodiverse. Simply fence off degraded land from grazing, stop fires, and wait. Seed banks in soil sprout, birds/animals disperse seeds, native species return. Cost: ~$50/ha for fencing. Works best in tropical regions with nearby seed sources. Takes 5-10 years for tree canopy, 30-50 for mature forest. Examples: Costa Rica's pasture-to-forest transitions, Atlantic Forest regrowth in Brazil.

Assisted natural regeneration (ANR): guided recovery. Remove invasive species (vines, grasses competing with seedlings), plant starter species to provide shade, protect natural seedlings from herbivores. Cost: $200-500/ha. Accelerates recovery to 3-7 years. Used in Philippines (after logging), Ethiopia (church forests expansion), Australia (post-mining restoration). Balance: human intervention speeds process while maintaining ecological diversity.

Active tree planting: fastest carbon, but risks monocultures. Grow seedlings in nurseries, plant in rows at 1,000-2,000 trees/ha. Cost: $500-2,000/ha depending on species, terrain, labor. Carbon accumulation starts year 2-3. Challenges: survival rates 50-80% (drought, browsing, poor site prep), low diversity if single-species plantations. Good for degraded sites lacking seed sources, but avoid native grasslands—planting trees where they shouldn't be harms ecosystems.

Agroforestry: trees + crops/livestock for immediate income. Plant timber or fruit trees alongside agriculture—alley cropping, silvopasture, scattered paddock trees. Farmers earn income while carbon accumulates. Cost: $1,000-3,000/ha (higher because of agricultural inputs). Carbon less than pure forest but socially sustainable. Proven in: cocoa agroforestry (Ghana), coffee shade systems (Colombia), silvopasture (Australia). Policy support critical—farmers need secure land tenure and technical training.