Decrease in Biodiversity

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Managing C sinks brings a conflict between the Climate Convention and the Biodiversity Convention, as the Kyoto Protocol explicitly avoids the protection of existing C storage in primary forests and aims at the establishment of plantations with low biomass, but high productivity (NPP), on cleared areas.

In Chapter 4 a detailed case is made that biodiversity means more than diversity of species. Despite this, diversity of species is the only parameter available for an assessment of the situation at global scale. Considering the world map of plant distribution (see also Chap. 4.1), there are 25 so-called hot spots (Fig. 5.5.1) - regions with very high diversity and genetic centres of crop plants, and they only partially overlap. Originally, these hot spots covered about 12% of the earth's surface. Including the genetic centres, both cover about 20% of the earth's surface. Currently, about 1.1 billion people live on the original area of the hot spots (Cincotta et al. 2000); together with forestry industries and changes in land use they have decreased these areas to about 1.4% of the earth's surface. If it were possible to protect these residual spaces at present, it would be possible to protect 44% of all plant species, as well as 35% of birds, mammals, reptiles and amphibians. Whether this will succeed depends essentially on ecologists and their ability to bring together diversity and ecosystem research (Schulze and Mooney 1993), i.e. to create a bond between the Kyoto Protocol and the Biodiversity Convention.

The decline in species has several causes (Fig. 5.5.2 A; Schulze and Gerstberger 1993). For Germany, the changes in management of agriculture and forestry are responsible for 50% of the decline in species. The remaining 50% is due to changes in land use (tourism, mining, industry, infrastructure). Some species are also endangered because of scientific research, and from collectors.

In the German flora, orchids are particularly protected, but despite this the distribution of all

Hotspots of diversity

Genetic centres of cultivated plants

"ig. 5.5.1. Global distribution of the so-called diversity hot spots (Meyers et al. 2000) and the genetic origins of economically important plants (Reid and Miller 1989), with an indication of the most important crop plants

Thuringia, Germany

Thuringia, Germany

Number of 2 x 2 km squares containing a certain species (1850 to 1990)

orchid species has significantly decreased (Fig, 5.5.2B). Species covering less than 100 grid cells (2x2 km) at the beginning of the last century are now almost extinct (2000 a.d.), showing the limitations of methods of protection, and also how relatively rare species assume a particular and important indicator function, to illustrate the effects of global change.

The effect of intensified and extended agriculture on the diversity of species can be seen worldwide. It is a direct consequence of increasing populations as well as of changes in food habits, including increased meat consumption which requires more animal feed (only 5% of N eaten by animals is converted into meat). Despite all attempts to increase agricultural production, cereal production per head of the world population (Fig, 5.5.3 A; WBGU 1999) is decreasing at present. With increasing scarcity of food, the scope for reduction of agricultural expansion is very limited, as is the scope for the stabilisation and protection of climate, and also for the

"ig. 5.5.2. A Anthropogenic factors that led to extinction of species in Germany (from Schulze and Gerstberger 1993). B Distribution of species of orchids in Thuringia, Germany, before 1990 (observed since 1900) compared to the period after 1990. All species showed a decline in distribution in about 150 grid cells (2x2 km). Each dot represents a species of orchid

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Science

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Forestry and hunting

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