Status, trends and future dynamics of biodiversity and ecosystems underpinning nature’s contributions to people

Abstract

Biodiversity is linked to ecosystem functions and is highly relevant to NCP across the ecologically diverse and species-rich Americas. All units of analysis of the Americas considered contribute to human well-being. However, Tropical and subtropical moist forests, Temperate and boreal forests and woodlands, Tropical and subtropical dry forests, Mediterranean forests, woodlands and scrub, and Tundra and high elevation habitats stand out as particularly critical for NCP delivery. For quatic systems, freshwater is considered somewhat more important for NCP than marine. Except in a limited number of cases, this chapter shows that the biodiversity in the Americas´ terrestrial biomes and freshwater and marine habitats continues to undergo serious erosion. The introduction and spread of alien species can be expected to continue causing direct and indirect impacts on human well-being and biodiversity. The subregions currently undergoing most dramatic land use change, considering their spatial extent, are South America and Mesoamerica, where conversion of vegetation to support pastures, agriculture and exotic plantation forestry is widespread. These changes are leading to major losses of habitat with concomitant population and species declines. In the marine and freshwater realms, the number of threatened species is high, and many fish species are over-exploited. Climate change has begun to affect the distribution of biodiversity, but to a greater degree in North America than South America for the moment. Increased fire frequency in several biomes constitutes a growing threat. Despite significant progress in developing protective measures for the land and in the sea, they are often insufficient. The greatest challenges to policymakers and decision makers will be to: arrest or slow habitat loss; encourage more ecologically-friendly management practices to ensure long-term food- and water-security; and promote alternative biodiversity-based economic activities that are less destructive than current activities. These are not new challenges. Progress necessarily implies a conscious, collective societal effort. Many lessons can be learned from indigenous peoples who have succeeded in living in harmony on the land.