Co-occurrence of linguistic and biological diversity in biodiversity hotspots and high biodiversity wilderness areas

Abstract

As the world grows less biologically diverse, it is becoming less linguistically and culturally diverse as well. Biologists estimate annual loss of species at 1,000 times or more greater than historic rates, and linguists predict that 50-90% of the world's languages will disappear by the end of this century. Prior studies indicate similarities in the geographic arrangement of biological and linguistic diversity, although conclusions have often been constrained by use of data with limited spatial precision. Here we use greatly improved datasets to explore the co-occurrence of linguistic and biological diversity in regions containing many of the Earth's remaining species: biodiversity hotspots and high biodiversity wilderness areas. Results indicate that these regions often contain considerable linguistic diversity, accounting for 70% of all languages on Earth. Moreover, the languages involved are frequently unique (endemic) to particular regions, with many facing extinction. Likely reasons for co-occurrence of linguistic and biological diversity are complex and appear to vary among localities, although strong geographic concordance between biological and linguistic diversity in many areas argues for some form of functional connection. Languages in high biodiversity regions also often co-occur with one or more specific conservation priorities, here defined as endangered species and protected areas, marking particular localities important for maintaining both forms of diversity. The results reported in this article provide a starting point for focused research exploring the relationship between biological and linguistic-cultural diversity, and for developing integrated strategies designed to conserve species and languages in regions rich in both.

Fig. 1.

(A) Biodiversity hotspots (regions 1–35) and high biodiversity wilderness areas (regions 36–40). 1: Atlantic Forest; 2: California Floristic Province; 3: Cape Floristic Region; 4: Caribbean Islands; 5: Caucasus; 6: Cerrado; 7: Chilean Winter Rainfall-Valdivian Forests; 8: Coastal Forests of Eastern Africa; 9: East Melanesian Islands; 10: Eastern Afromontane; 11: Forests of East Australia; 12: Guinean Forests of West Africa; 13: Himalaya; 14: Horn of Africa; 15: Indo-Burma; 16: Irano-Anatolian; 17: Japan; 18: Madagascar and the Indian Ocean Islands; 19: Madrean Pine-Oak Woodlands; 20: Maputaland-Pondoland-Albany; 21: Mediterranean Basin; 22: Mesoamerica; 23: Mountains of Central Asia; 24: Mountains of Southwest China; 25: New Caledonia; 26: New Zealand; 27: Philippines; 28: Polynesia-Micronesia; 29: Southwest Australia; 30: Succulent Karoo; 31: Sundaland; 32: Tropical Andes; 33: Tumbes-Chocó-Magdalena; 34: Wallacea; 35: Western Ghats and Sri Lanka; 36: Amazonia; 37: Congo Forests; 38: Miombo-Mopane Woodlands and Savannas; 39: New Guinea; 40: North American Deserts. (B) Geographic distribution of indigenous and nonmigrant languages in 2009.

Fig. 2.

Bar charts showing the occurrence of the following by biodiversity hotspot and high biodiversity wilderness area. (A) All languages and languages endemic to individual regions. (B) Languages spoken by 10,000 or fewer and 1,000 or fewer people.

Fig. 3.

Bar charts showing the occurrence of the following by biodiversity hotspot and high biodiversity wilderness area. (A) All languages and endangered and critically endangered amphibians. (B) All languages and protected areas.