. Ecosystems and Human Well-Being: Biodiversity Synthesis. (C8, C26). Within the tropics, rates of land conversion to agricul- tural use range from very high in the Indo-Malayan realm to moderate in the Neotropics and the Afrotropics, where large increases in cropland area have taken place since the 1950s. Aus- tralasia has relatively low levels of cultivation and urbanization, but these have also increased in the last 40 years at a similar rate to those of the Neotropics. The majority of biomes have been greatly modified. Between 20% and 50% of 9 out of 14 global biomes have been trans- forme
. Ecosystems and Human Well-Being: Biodiversity Synthesis. (C8, C26). Within the tropics, rates of land conversion to agricul- tural use range from very high in the Indo-Malayan realm to moderate in the Neotropics and the Afrotropics, where large increases in cropland area have taken place since the 1950s. Aus- tralasia has relatively low levels of cultivation and urbanization, but these have also increased in the last 40 years at a similar rate to those of the Neotropics. The majority of biomes have been greatly modified. Between 20% and 50% of 9 out of 14 global biomes have been trans- formed to croplands. Tropical dry forests were the most affected by cultivation between 1950 and 1990, although temperate grasslands, temperate broadleaf forests, and Mediterranean for- ests each experienced 55% or more conversion prior to 1950. Biomes least affected by cultivation include boreal forests and tundra. (See Figure ) While cultivated lands provide many provisioning services (such as grains, fruits, and meat), habitat conversion to agriculture typically leads to reductions in local native biodiversity (). Rates of human conversion among biomes have remained similar over at least the last century. For example, boreal forests had lost very little native habitat cover up to 1950 and have lost only a small additional percentage since then. In contrast, the temperate grasslands biome had lost nearly 70% of its native cover by 1950 and lost an additional since then. Two biomes appear to be exceptions to this pattern: Mediterranean forests and temperate broadleaf forests. Both had lost the major- ity of their native habitats by 1950 but since then have lost less than additional habitat. These biomes contain many of the world's most established cities and most extensive surrounding agricultural development (Europe, the United States, the Medi- terranean basin, and China). It is possible that in these biomes the most suitable land for agriculture had already
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