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Economic benefits of natural biota
Ecological Economics 25 (1998) 45 – 47
SPECIAL SECTION: FORUM ON VALUATION OF ECOSYSTEM SERVICES
Economic benefits of natural biota David Pimentel Cornell Uni6ersity, Ithaca, NY 14853 -0901, USA Accepted 13 November 1997
Recent investigations of the economic benefits of natural biota by Costanza et al. (1997), Daily (1996), and Pimentel et al. (1997) are valuable contributions. These authors approach the economic benefits question differently, but all make important contributions to our understanding of the valuable services provided by nature. There are several ways to assess the economic benefits of biodiversity to human society. One is to provide the best estimate of the service and another is to estimate humans’ willingness to pay to maintain biodiversity. Generally the willingness to pay provides a higher estimate of the value of the service than the service’s estimated real value. Pimentel et al. (1997) attempted to estimate the real value of the services provided by biodiversity. The following are some of the aspects that they investigated. An important biological service is the decomposition of the large quantity of organic wastes produced by humans, livestock and crops. These wastes weigh about 38 billion t worldwide and are recycled by various decomposer organisms. Assuming a conservative amount of 2 ¢/kg for all organic waste recycled by decomposers — which includes human, livestock and crop wastes — the contributions made by decomposer organisms is
more than $62 billion/year for the United States and more than $760 billion/year worldwide. This does not take into account the value of decreased environmental pollution, the recycling of nutrients, and the reduction of human diseases. Related to organic waste disposal is the bioremediation of the more than 1100 kg of chemicals utilized per person annually in the USA. Included are more than 70000 different chemicals including pesticides. A diverse group of organisms, mostly soil microbes, help degrade these chemical wastes. The annual benefits of bioremediation of chemical wastes in the United States is at least $23 billion and is approximately $135 billion worldwide. Fertile soil is an essential component of the world ecosystem because all plant and animal species either require it and/or the products grown in it for their survival. More than 99% of the total human food supply is produced on land, while only 0.6% comes from the oceans and other aquatic ecosystems. Diverse soil biota, the major components of soil, facilitate soil formation and improve it for crop production. On average, 1 ha of productive soil contains 1300 kg of earthworms, 1000 kg of arthropods, 3000 kg bacteria, and 4000 kg of fungi and other plants and animals. These soil
0921-8009/98/$19.00 © 1998 Elsevier Science B.V. All rights reserved. PII S0921-8009(98)00014-7
46
D. Pimentel / Ecological Economics 25 (1998) 45–47
biota enhance crop productivity because they recycle the basic nutrients required for all ecosystems, including nitrogen, phosphorus, potassium, and calcium. The movements of earthworms and other biota further improve the productivity of the soil by increasing water infiltration, thereby reducing the surface water runoff that leads to soil erosion. Earthworms and other invertebrates bring between 10 and 500 t/ha per year of subsurface soil to the surface, thereby aiding the formation of approximately 1 t/ha per year of topsoil. Based on this assumption and the value of about $12/t of topsoil under agricultural conditions, the total value of soil biota activity to soil formation on US agricultural land (: 400 million ha) is conservatively about $5 billion each year. For the 4.5 billion ha of world agricultural land, their yearly contribution is estimated to be approximately $25 billion. Nitrogen in the soil from natural and commercial sources is vital to plant and animal survival and frequently is the major limiting factor for production in both natural and agricultural ecosystems. Soil nitrogen is enhanced especially by nitrogen-fixing plants and obligate endophytic diazotroph bacteria. Each year biological nitrogen fixation in the United States yields approximately 14 million t of nitrogen which has a calculated value of $8 billion/year. This is equivalent to about half of the commercial nitrogen fertilizer applied to US farmlands every year. Worldwide, 140 – 170 million t of nitrogen, valued at approximately $90 billion, are fixed by microorganisms in agricultural and natural systems each year. Of the estimated 250000 plant species in the world, humans use as many as 20000 plant species for food. Since 1945 world crop yields have increased between 2- and 4-fold depending on the crop. An estimated 20–40% of this increase has resulted from improvements achieved through genetic breeding, including hybrid vigor and host-plant resistance. Because all plant breeding relies on wild genotypes to provide new genes for improving commercial crop varieties, conservation of diverse plant species is vital.
Genetic resources have also increased production yields in the livestock industry, especially in dairy cattle, hogs, and poultry. For example, milk production per dairy cow in 1935 was about 3600 kg/year, but now the yield is about 8600 kg. In 1930, average egg production per hen was only 93 eggs/year, and today the number has risen to 246 eggs. Both crop and livestock production is limited by pest attack. Approximately 70000 pest species attack agricultural crops and destroy more than 40% of all potential food production despite the yearly application of about 3 million t of pesticide worldwide. Approximately 99% of crop pests are controlled by natural enemies and the presence of genetic resistance in host-plants. Each insect pest, for example, has ten to 15 natural enemies helping to control it. The benefits of natural enemies are estimated to be at least $12 billion in the United States and about $100 billion worldwide. Additional benefits of pest control are associated with host-plant resistance. Pollinators like bees, butterflies, and bats play vital environmental and economic roles in agricultural and natural ecosystems. As much as onethird of the US and the world’s food production relies either directly or indirectly on insect pollination. Bees, the largest group of pollinators, provide about 80% of all insect pollination. In North America, approximately 5000 species of bees have some capability to pollinate. Worldwide, at least 20000 species of bees are associated with pollination. Approximately 20000 species of native flowering plants in the United States, and an estimated one-third of the world’s plant species, depend upon biological cross-pollination. In US agriculture, crops valued at $40 billion depend on bee pollination. Assuming that worldwide the economic value is conservatively at least five times that of the USA, the contribution of pollination to world agriculture is estimated to be $200 billion/year. In addition to food products, plants with medicinal properties are harvested from the wild. Nearly half of the medicinal prescriptions now in
D. Pimentel / Ecological Economics 25 (1998) 45–47
use have a natural plant origin, and between 35000 and 70000 species of higher plants are used directly as medicines. Plant-based US drugs and medicines have an annual market value of $36 billion and those on the Asian market $70 billion/year. Extrapolating, the estimated value in the world market is more than $200 billion. In addition, included in the analysis by Pimentel et al. (1997) were wild foods, fisheries, tourism, sequestering of carbon dioxide by forests, and several other services provided by natural biota (biodiversity). Although these appraised economic benefits are estimates at best, they enlarge our understanding of the many essential services that diverse species provide to humans. The estimated economic and environmental benefits of all biota and their genetics (biodiversity) in the United States and the world are about $300 billion and $3000 billion per year, respectively (Pimentel et al., 1997). However, these estimated benefits are incomplete and do not include the many other economically valuable services provided such as yeasts in bread making, microbes in cheese production, and the various microbes used in beer and wine making, to mention a few. In addition to the economic benefits provided by plant and animal species — including pollination, waste degradation, and biological pest control —most of their contributions cannot be
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47
provided by any known human technology. Biodiversity is critical for the functioning of a healthy ecosystem. Costanza et al. (1997) estimate the value of the worldwide services provided by nature at approximately $30000 billion, or about ten times greater than the estimate developed by Pimentel et al. (1997). This quantitative difference is the result of different natural services being assessed by Costanza et al. (1997) and by Pimentel et al. (1997), plus in some cases different techniques were employed by each research group in making their analyses. Both studies, however, mutually reinforce each other and clearly highlight the enormous value of natural biota and biodiversity to human society. Also, both studies confirm that the intrinsic value of natural systems is more than just the services that they provide to humans.
References Costanza, R., d’Arge, R., de Groot, R., Farber, S., Grasso, M., Hannon, B., Naeem, S., Limburg, K., Paruelo, J., O’Neill, R.V., Raskin, R., Sutton, P., van den Belt, M., 1997. The value of the world’s ecosystem services and natural capital. Nature 387, 253 – 260. Daily, G., 1996. Nature’s Services: Societal Dependence on Natural Ecosystems. Island Press, Washington, DC. Pimentel, D., Wilson, C., McCullum, C., Huang, R., Dwen, P., Flack, J., Tran, Q., Saltman, T., Cliff, B., 1997. Economic and environmental benefits of biodiversity. BioScience 47 (11), 747 – 757.
.
SPECIAL SECTION: FORUM ON VALUATION OF ECOSYSTEM SERVICES
Economic benefits of natural biota David Pimentel Cornell Uni6ersity, Ithaca, NY 14853 -0901, USA Accepted 13 November 1997
Recent investigations of the economic benefits of natural biota by Costanza et al. (1997), Daily (1996), and Pimentel et al. (1997) are valuable contributions. These authors approach the economic benefits question differently, but all make important contributions to our understanding of the valuable services provided by nature. There are several ways to assess the economic benefits of biodiversity to human society. One is to provide the best estimate of the service and another is to estimate humans’ willingness to pay to maintain biodiversity. Generally the willingness to pay provides a higher estimate of the value of the service than the service’s estimated real value. Pimentel et al. (1997) attempted to estimate the real value of the services provided by biodiversity. The following are some of the aspects that they investigated. An important biological service is the decomposition of the large quantity of organic wastes produced by humans, livestock and crops. These wastes weigh about 38 billion t worldwide and are recycled by various decomposer organisms. Assuming a conservative amount of 2 ¢/kg for all organic waste recycled by decomposers — which includes human, livestock and crop wastes — the contributions made by decomposer organisms is
more than $62 billion/year for the United States and more than $760 billion/year worldwide. This does not take into account the value of decreased environmental pollution, the recycling of nutrients, and the reduction of human diseases. Related to organic waste disposal is the bioremediation of the more than 1100 kg of chemicals utilized per person annually in the USA. Included are more than 70000 different chemicals including pesticides. A diverse group of organisms, mostly soil microbes, help degrade these chemical wastes. The annual benefits of bioremediation of chemical wastes in the United States is at least $23 billion and is approximately $135 billion worldwide. Fertile soil is an essential component of the world ecosystem because all plant and animal species either require it and/or the products grown in it for their survival. More than 99% of the total human food supply is produced on land, while only 0.6% comes from the oceans and other aquatic ecosystems. Diverse soil biota, the major components of soil, facilitate soil formation and improve it for crop production. On average, 1 ha of productive soil contains 1300 kg of earthworms, 1000 kg of arthropods, 3000 kg bacteria, and 4000 kg of fungi and other plants and animals. These soil
0921-8009/98/$19.00 © 1998 Elsevier Science B.V. All rights reserved. PII S0921-8009(98)00014-7
46
D. Pimentel / Ecological Economics 25 (1998) 45–47
biota enhance crop productivity because they recycle the basic nutrients required for all ecosystems, including nitrogen, phosphorus, potassium, and calcium. The movements of earthworms and other biota further improve the productivity of the soil by increasing water infiltration, thereby reducing the surface water runoff that leads to soil erosion. Earthworms and other invertebrates bring between 10 and 500 t/ha per year of subsurface soil to the surface, thereby aiding the formation of approximately 1 t/ha per year of topsoil. Based on this assumption and the value of about $12/t of topsoil under agricultural conditions, the total value of soil biota activity to soil formation on US agricultural land (: 400 million ha) is conservatively about $5 billion each year. For the 4.5 billion ha of world agricultural land, their yearly contribution is estimated to be approximately $25 billion. Nitrogen in the soil from natural and commercial sources is vital to plant and animal survival and frequently is the major limiting factor for production in both natural and agricultural ecosystems. Soil nitrogen is enhanced especially by nitrogen-fixing plants and obligate endophytic diazotroph bacteria. Each year biological nitrogen fixation in the United States yields approximately 14 million t of nitrogen which has a calculated value of $8 billion/year. This is equivalent to about half of the commercial nitrogen fertilizer applied to US farmlands every year. Worldwide, 140 – 170 million t of nitrogen, valued at approximately $90 billion, are fixed by microorganisms in agricultural and natural systems each year. Of the estimated 250000 plant species in the world, humans use as many as 20000 plant species for food. Since 1945 world crop yields have increased between 2- and 4-fold depending on the crop. An estimated 20–40% of this increase has resulted from improvements achieved through genetic breeding, including hybrid vigor and host-plant resistance. Because all plant breeding relies on wild genotypes to provide new genes for improving commercial crop varieties, conservation of diverse plant species is vital.
Genetic resources have also increased production yields in the livestock industry, especially in dairy cattle, hogs, and poultry. For example, milk production per dairy cow in 1935 was about 3600 kg/year, but now the yield is about 8600 kg. In 1930, average egg production per hen was only 93 eggs/year, and today the number has risen to 246 eggs. Both crop and livestock production is limited by pest attack. Approximately 70000 pest species attack agricultural crops and destroy more than 40% of all potential food production despite the yearly application of about 3 million t of pesticide worldwide. Approximately 99% of crop pests are controlled by natural enemies and the presence of genetic resistance in host-plants. Each insect pest, for example, has ten to 15 natural enemies helping to control it. The benefits of natural enemies are estimated to be at least $12 billion in the United States and about $100 billion worldwide. Additional benefits of pest control are associated with host-plant resistance. Pollinators like bees, butterflies, and bats play vital environmental and economic roles in agricultural and natural ecosystems. As much as onethird of the US and the world’s food production relies either directly or indirectly on insect pollination. Bees, the largest group of pollinators, provide about 80% of all insect pollination. In North America, approximately 5000 species of bees have some capability to pollinate. Worldwide, at least 20000 species of bees are associated with pollination. Approximately 20000 species of native flowering plants in the United States, and an estimated one-third of the world’s plant species, depend upon biological cross-pollination. In US agriculture, crops valued at $40 billion depend on bee pollination. Assuming that worldwide the economic value is conservatively at least five times that of the USA, the contribution of pollination to world agriculture is estimated to be $200 billion/year. In addition to food products, plants with medicinal properties are harvested from the wild. Nearly half of the medicinal prescriptions now in
D. Pimentel / Ecological Economics 25 (1998) 45–47
use have a natural plant origin, and between 35000 and 70000 species of higher plants are used directly as medicines. Plant-based US drugs and medicines have an annual market value of $36 billion and those on the Asian market $70 billion/year. Extrapolating, the estimated value in the world market is more than $200 billion. In addition, included in the analysis by Pimentel et al. (1997) were wild foods, fisheries, tourism, sequestering of carbon dioxide by forests, and several other services provided by natural biota (biodiversity). Although these appraised economic benefits are estimates at best, they enlarge our understanding of the many essential services that diverse species provide to humans. The estimated economic and environmental benefits of all biota and their genetics (biodiversity) in the United States and the world are about $300 billion and $3000 billion per year, respectively (Pimentel et al., 1997). However, these estimated benefits are incomplete and do not include the many other economically valuable services provided such as yeasts in bread making, microbes in cheese production, and the various microbes used in beer and wine making, to mention a few. In addition to the economic benefits provided by plant and animal species — including pollination, waste degradation, and biological pest control —most of their contributions cannot be
.
47
provided by any known human technology. Biodiversity is critical for the functioning of a healthy ecosystem. Costanza et al. (1997) estimate the value of the worldwide services provided by nature at approximately $30000 billion, or about ten times greater than the estimate developed by Pimentel et al. (1997). This quantitative difference is the result of different natural services being assessed by Costanza et al. (1997) and by Pimentel et al. (1997), plus in some cases different techniques were employed by each research group in making their analyses. Both studies, however, mutually reinforce each other and clearly highlight the enormous value of natural biota and biodiversity to human society. Also, both studies confirm that the intrinsic value of natural systems is more than just the services that they provide to humans.
References Costanza, R., d’Arge, R., de Groot, R., Farber, S., Grasso, M., Hannon, B., Naeem, S., Limburg, K., Paruelo, J., O’Neill, R.V., Raskin, R., Sutton, P., van den Belt, M., 1997. The value of the world’s ecosystem services and natural capital. Nature 387, 253 – 260. Daily, G., 1996. Nature’s Services: Societal Dependence on Natural Ecosystems. Island Press, Washington, DC. Pimentel, D., Wilson, C., McCullum, C., Huang, R., Dwen, P., Flack, J., Tran, Q., Saltman, T., Cliff, B., 1997. Economic and environmental benefits of biodiversity. BioScience 47 (11), 747 – 757.
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