FIGURE 2.7 The history of regional vegetation and fire frequency in Yellowstone National Park over the past 17,000 years based on fossil pollen and charcoal. Since 11,000 years ago the vegetation has remained relatively stable despite significant long-term changes in fire frequency driven by climate change related to changes in July insolation related to changes in Earths orbital geometry. SOURCE: Millspaugh et al. (2000).

FIGURE 2.7 The history of regional vegetation and fire frequency in Yellowstone National Park over the past 17,000 years based on fossil pollen and charcoal. Since 11,000 years ago the vegetation has remained relatively stable despite significant long-term changes in fire frequency driven by climate change related to changes in July insolation related to changes in Earth’s orbital geometry. SOURCE: Millspaugh et al. (2000).

agriculture,2 may support local human populations and also serve to mimic natural disturbance regimes and thus help preserve biodiversity (Robbins et al., 2006; see also Chapter 5).

The geographical sciences have contributed to current debates about the premises behind widely used conservation strategies such as the best approach for ex situ biodiversity conservation.3 Although the concept of the modern park, or “Yellowstone model,” dates to the late 19th century, the related notion of a hunting preserve took form across the tropics during the colonial era (Cronon, 1996). These preserves endured over time, eventually becoming national parks that gained considerable international support following the rise of an environmental movement in high-income countries during the 1970s and 1980s. By the late 1980s, however, it was becoming clear that the park model was failing in many tropical countries. In most cases there was

2

Swidden agriculture is the practice of clearing relatively small patches of forest through cutting and burning and then cultivating crops for a short period—typically 3 to 5 years—until soil nutrients decrease. The plot is then withdrawn from cultivation and secondary forest succession is allowed to occur. After several fallow years during which soil nutrients are restored, the forest on the patch is again cleared and the land cultivated. The practice produces a landscape with a diverse spatial pattern of cultivated fields and patches of forest of various ages, structure, and species composition.

3

Ex situ biodiversity conservation is the maintenance of endangered species at areas outside their natural ranges or habitats. Examples include the preservation of an animal species population in a zoo or wild animal conservation areas or the preservation of a plant species population in a botanical garden.



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