5. Human Population Size Resources use Land Transformation Land Clearing Forestry Grazing Intensification Biotic Additions and Loss Invasion Hunting Fishing Carbon Nitrogen Water Climate Change Enhanced Greenhouse Aerosols Land cover Loss of Biological Diversity Extinction of species and populations Loss of ecosystems Vitousek et. al (1997) Science, 277, p.494-499 Human Enterprises Agriculture Industry Recreation International Commerce Global Biogeochemistry
6. Humans Change of the Earth Expressed as % Change Vitousek et. al (1997) Science, 277, p.494-499
28. Invasive species Zebra Mussel US and UK Asian Clam San Francisco Coqui frog Hawaii Brow Tree Snake Guam Rabbits Australia Africanized Honeybee South America
39. Identifying a protected area's goods and services, determining who values those goods and services, and measuring these values is not always a straightforward process. The goods and services include recreation and tourism, plant and wildlife habitat, genetic resources, water supply, protection against natural disasters, and so on. Many of these goods and services are not traded on commercial markets and therefore have no evident market value. The values of non-market goods and services need to be measured and expressed in monetary terms, where possible, so that they can be weighed on the same scale as commercially traded components.
40. The concept of total economic value (TEV) is now a well-established and useful framework for identifying the various values associated with protected areas. The total economic value of a protected area consists of its use values and non-use values.
