Terrain and Land Use
Costa Rica's phytogeographic units (Unidades Fitogeográficas) classify the country's landscape according to landform, elevation, and topography — grouping terrain into named regions whose physical structure shapes the vegetation and ecological character found within them. The elevation banding across these four regions tracks real shifts in land use: the flat Upper Guatuso Plains support settlement and agriculture, while the Slopes band above it — broken terrain on both the East and West sides of the cordillera — favors forest, pasture, and agroforestry over cultivation, with rainfall differences between the Caribbean- and Pacific-facing slopes often driving more variation than elevation or topography alone.
Ecoregions
WWF's classification groups landscapes by distinct species assemblages and ecological dynamics,. Three ecoregions meet across this stretch of northern Costa Rica: the Isthmian–Atlantic moist forests occupy the hot, wet Caribbean-facing lowlands below 500m, characterized by tall evergreen canopy, dense epiphyte growth, and species like the scarlet macaw and jaguar; the Talamancan montane forests rise above this band from roughly 500–2,000m, cooler and more intact, with 62% under protection and endemics like the Talamancan oryzomys; and the Costa Rican seasonal moist forests lie to the southwest on the Pacific side, defined by a pronounced dry season and deciduous tree cover — the same elevational and geographic gradient as the terrain zones, read here through the lens of what actually lives there.
Primary vs. Secondary Forest
Primary forest is original, uncut old-growth forest, while secondary forest is regrowth on land previously cleared for agriculture or pasture — recovering structure and biodiversity over time, but remaining ecologically distinct from primary growth even decades later. Rincón de la Vieja's eastern foothills — in the tropical moist forest zone — still hold primary rain forest, though most of the surrounding area is now a mosaic of old growth, selectively logged patches, and secondary regrowth on former farmland. This region has seen one of the area's most significant restoration efforts, beginning in the 1980s and reconnecting large tracts of previously fragmented forest.