Neotropic (Neotropical) Ecozone

Boundaries and major regions

Boundaries of the Neotropic are defined by patterns of shared taxa rather than strict political lines. Major subregions commonly recognized within the ecozone include lowland Amazonia, the Andean corridor, the Brazilian shield and cerrado, the Llanos of Venezuela and Colombia, Central American forests and the insular Caribbean. The Mexican lowlands are often treated as the northernmost Neotropical foothold reaching into North American landmasses. These subdivisions reflect shifts in elevation, rainfall and biotic communities across the region.

Climate and habitats

The Neotropic contains a wide range of climates from humid equatorial zones to seasonal tropics and temperate areas in southern South America. It supports the largest extent of tropical rainforest on Earth, as well as cloud forests, montane grasslands (páramo), dry forests, savannas and coastal mangroves. Environmental gradients created by the Andes, Amazon Basin and coastal plains produce many distinct habitat types and microclimates, allowing high ecological diversity at local and regional scales.

Biodiversity, endemism and ecosystems

The Neotropic is globally important for its species richness, high levels of endemism and complex ecological interactions. The Amazon Basin is the most expansive contiguous rainforest complex and a central reservoir of tropical diversity, while mountainous regions such as the Andes generate rapid speciation through elevation gradients. Characteristic ecosystems include:

• Amazonian lowland rainforests and seasonally flooded várzea and igapó forests
• Andean cloud forests, montane forests and páramo ecosystems
• Neotropical savannas such as the Brazilian cerrado and the Llanos
• Tropical dry forests and coastal mangrove systems

These ecosystems function as major stores of carbon, influence regional hydrology and act as crucial repositories of global biodiversity, with consequences for the wider Earth system.

Geological history and faunal interchange

The evolutionary character of the Neotropic reflects long periods of isolation followed by episodes of connection with other regions. Many lineages diversified in relative isolation when South America was separated from other continents. The rise of the Isthmus of Panama, about 2 to 3 million years ago, enabled extensive interchange of species with North America and reshaped the distribution of mammals, birds and plants in an event often referred to as the Great American Biotic Interchange.

Human presence, use and cultural diversity

Human societies have long inhabited Neotropical landscapes, developing diverse cultures, land-use systems and knowledge of local biodiversity. Indigenous peoples maintain important stewardship of large tracts of forest and have shaped ecological mosaics through practices such as swidden agriculture, agroforestry and selective harvesting. Contemporary economies in the region mix subsistence livelihoods, industrial agriculture, forestry, mining and urban development, with varying impacts on ecosystems and species.

Threats and conservation

Human activities have profoundly transformed many Neotropical habitats. Large-scale conversion of forest for agriculture, cattle ranching, road building, mining and urban expansion—commonly described as deforestation—accelerated during the late 20th century and continues in parts of the region. Habitat fragmentation, overexploitation of wildlife and climate change add pressures to endemic species and ecological functions. Conservation responses include establishment of protected areas, recognition of indigenous land rights, restoration projects and transnational initiatives aimed at conserving biodiversity while addressing social and economic needs.

Research, monitoring and classification

Scientific study of the Neotropic spans taxonomy, ecology, climatology and social sciences. Ongoing efforts document species, monitor habitat change, map ecoregions and develop conservation priorities. Classifications of Neotropical ecoregions and biomes are used by researchers and conservation organizations to guide planning and to compare patterns of diversity across the Americas.

Importance and outlook

Understanding the Neotropic is essential for global biodiversity science, conservation planning and sustainable development. The region's ecological complexity, cultural diversity and role in global biogeochemical cycles make it a priority for research and policy. Long-term outcomes will depend on balancing development and livelihoods with measures that safeguard ecological integrity and the services these ecosystems provide to humanity.

For regional overviews and further context, consult resources describing Mexican lowlands, island biotas of the Caribbean, and comparative frameworks linking this ecozone to neighboring realms such as the Nearctic.