Biodiversity matters to Humans: Biodiversity –> Ecosystem services –> Human well-being.
Scientific evidence has shown that based on fossil records the current rate of biodiversity loss is happening at a faster pace than in the past.1 But the impact of the loss of biodiversity on human well-being was not made clear until recently. In the June 2012 issue of Nature, a group of 17 prominent ecologists led by Bradley Cardinale of the University of Michigan School of Natural Resources and Environment claim that biodiversity loss impacts humans far more seriously and intricately than originally thought.2
Twenty years ago, at the 1992 Earth Summit in Rio de Janeiro Brazil, the Convention on Biological Diversity was created with the goal of conserving biodiversity and sustainably using natural resources. There are currently 193 signatory nations to the Convention. After the Earth Summit, a large number of studies were conducted all over the world to determine the importance of biodiversity loss, its impact on the Earth’s ecosystems, and how humans are ultimately affected by ecosystem changes due to the loss of biodiversity. The Nature paper by Cardinale et al. summarizes 1,000 of these published studies over the past 20 years.
According to the paper, the loss in biodiversity results in a less productive and less sustainable ecosystem. What this means for humans is that if there is a loss in biodiversity in an ecosystem, there is a corresponding decrease in the ability of such an ecosystem to provide society with goods (e.g. water, food, wood, fodder, fertile soils, etc.) and services (e.g. protection from pests and diseases and air and water purification).
The Millennium Ecosystem Assessment (MA), a United Nations-backed panel of 1360 experts from about 95 countries, published a 2005 report entitled Ecosystems and Human Well-being:
Current State and Trends that assessed the changing conditions of Earth’s ecosystems and the services they provide.3 Of the many ecosystem services identified by the group, they selected eleven services that they considered “of vital importance almost everywhere in the world and represent, in the opinion of the Working Group, the main services that are most important for human well-being and are most affected by changes in ecosystem conditions.” The following are the services they identified:
- Fresh water
- Timber, fuel, and fiber
- New biodiversity products and industries
- Biological regulation
- Nutrient cycling
- Climate and air quality
- Ecosystem regulation of infectious diseases
- Waste processing and detoxification
- Regulation of floods and fires
- Cultural and amenity services
According to the MA, “Over the past 50 years, humans have changed ecosystems more rapidly and extensively than in any comparable period of time in human history, largely to meet rapidly growing demands for food, fresh water, timber, fiber and fuel. This has resulted in a substantial and largely irreversible loss in the diversity of life on Earth.”4 The group also found that about 15 out 24 (roughly 60%) of the ecosystem services it examined were being “degraded or used unsustainably.” These unfortunate ecosystem services include the purification of air and water; the regulation of regional and local climates, natural hazards, and pests; fresh water; and capture fisheries. 3
|Box 1: From the Millennium Ecosystem Assessment Conceptual Framework of Interactions between Biodiversity, Ecosystem Services, Human Well-being, and Drivers of Change. Remarks refer to the image immediately below them. Changes in drivers that indirectly affect biodiversity, such as population, technology, and lifestyle (upper right corner), can lead to changes in drivers directly affecting biodiversity, such as the catch of fish or the application of fertilizers to increase food production (lower right corner). These result in changes to biodiversity and to ecosystem services (lower left corner), thereby affecting human well- being.|
 These interactions can take place at more than one scale and can cross scales. For example, international demand for timber may lead to a regional loss of forest cover, which increases flood magnitude along a local stretch of a river.
[4+] Similarly, the interactions can take place across different time scales. Actions can be taken either to respond to negative changes or to enhance positive changes at almost all points in this framework. Local scales refer to communities or ecosystems and regional scales refer to nations or biomes, all of which are nested within global scale processes.
To illustrate the relationship between biodiversity, ecosystems, and society, consider that of the estimated 9 million species of plants, animals, fungi and protists that make Earth their home, only 12 species of plants make up 80% of the world’s total food needs and only 15 species of mammals and birds are used in 90% of domestic livestock production worldwide.5,6,7 The numbers may indicate that loss of biodiversity is not vital to human survival, but when we consider the ecosystem in which these plants and animals live, we find that these few species depend on thousands of other species for their survival. Plants rely on many types of insects and birds for pollination. In fact, in the European Union, of the 264 crops grown in its member countries, 80% depend on insects as pollinators. Insects such as ladybugs, dragonflies, and wasps and small animals such as moles, bats, and frogs all serve as natural pest control agents for many crops.8 Many animals raised as livestock depend on non-food plants such as hay and other species of grass for fodder. All these plants and animals host a variety of bacteria and fungi that maintain symbiotic relationships with their hosts. Furthermore, various non-food plant species make up the forest ecosystem that is responsible for trapping and cycling water, providing fertile soils, purifying the air, sequestering carbon, and regulating natural hazards such as fires and floods. The animals that thrive in it have unique predator-prey relationships that prevent the dominance and outbreak of any one species. There is also a vast marine and freshwater ecosystem that covers much more of the Earth. So not only does biodiversity serve its own ecosystem, this ecosystem is also a resource upon which every system and every life on Earth draws upon.
Diaz et al (2005) presented two important effects of biodiversity on the global climate and human life.9 First, the diversity of species in marine ecosystems is largely responsible for biogeochemical cycling (i.e. carbon, nitrogen, and sulfur cycling by benthic organisms) and carbon sequestration (marine photosynthesis by phytoplankton). It is important to note that benthic organisms and phytoplankton also have an important role in the food web that maintains marine biodiversity. Second, a diverse number of marine microorganisms functions in detoxification processes such as filtering water, reducing the effects of eutrophication, and degrading toxic hydrocarbons. By creating a clean marine environment, the plants and animals are able to thrive and humans are able to harvest them for food and other uses.
The major reason for the loss of biodiversity is habitat destruction. Rockstrom et al (2009) identified two causes for habitat loss: land use change due to man-made and natural causes and climate change.1 Man-made changes in land use have the most significant effect and primarily involve the conversion of natural ecosystems for agriculture and urban uses. Other causes of change include disturbances from wildfires and the introduction of new and invasive species into land and water ecosystems.8 The speed at which the global climate changes is expected to become an increasingly important driver of biodiversity loss as, for instance, polar habitats diminish and the increase in sea temperatures threaten the existence of marine ecosystems. In fact, stresses put on other areas (e.g. agriculture and energy use) may eventually become stressors to biodiversity and ecosystem services, thus further worsening the problem.8
Biodiversity clearly plays a much more important role to humans than just the number of species. Changes or losses in biodiversity have direct and indirect societal consequences that if not addressed will impact the future survival of humanity. Cardinale et al are calling for efforts to conserve biodiversity on an international scale through policies that would prevent further loss of species and perhaps restore the degraded ecosystems that host them.2 By doing so, we would not only be helping biodiversity, we would also be ensuring that ecosystem services that derive from biodiversity can continue to provide vital resources that are necessary for human survival.
- Rockström, J., Steffen, W., Noone, K., Persson, Å., Chapin, F. S. III, Lambin, E. F.,…Foley, J.A. (2009). A safe operating space for humanity. Nature, 461, 472–475. doi:10.1038/461472a
- Cardinale, B.J., Duffy, E., Emmett, J., Gonzalez, A., Hooper, D.U., Perrings, C.,…Naeem, S. (2012). Biodiversity loss and its impact on humanity. Nature, 486(7401): 59–67. doi:10.1038/nature11148
- Hassan, H., Scholes, R., & Ash, N. (Eds.). (2005). Ecosystems and Human Well-Being: Current State and Trends, Volume 1. Retrieved from http://www.millenniumassessment.org/documents/document.766.aspx.pdf
- Millenium Ecosystem Assessment (n.d.). Guide to millenium assessment reports. Retrieved April 12, 2013 from http://www.unep.org/maweb/en/Index.aspx
- Food and Agriculture Organization of the United Nations. (n.d.). The international treaty on plant genetic resources for food and agriculture. Retrieved April 12, 2013 from ftp://ftp.fao.org/docrep/fao/010/i0112e/i0112e10.pdf
- Food and Agriculture Organization of the United Nations. (2010). FAOSTAT Top 25 Commodities (world). Retrieved April 15, 2013 from http://faostat3.fao.org/home/index.html#VISUALIZE_TOP_20
- Small, Ernest. (2009). Top 100 Food Plants. Ottawa, Canada: NRC Press. 636 p.
- Biodiversity and human health. (n.d.). Harvard School of Public Health Center for Health and the Global Environment. Retrieved April 10, 2013 from http://chge.med.harvard.edu/category/biodiversity-and-human-health
- Díaz, S., Tilman, D., Fargione, J. (2005). Biodiversity regulation of ecosystem services. In H. Hassan, R. Scholes, & N. Ash (Eds.), Ecosystems and Human Well-Being: Current State and Trends (pp. 297–329). Retrieved from http://www.unep.org/maweb/documents/document.280.aspx.pdf
- Staudinger, M.D., Grimm, N.B., Staudt, A., Carter, S.L., Chapin, F.S. III, Kareiva, P.,… Stein, B.A. (2012). Impacts of Climate Change on Biodiversity, Ecosystems, and Ecosystem Services: Technical Input to the 2013 National Climate Assessment. Cooperative Report to the 2013 National Climate Assessment. 296 p. Retrieved from http://downloads.usgcrp.gov/NCA/Activities/Biodiversity-Ecosystems-and-Ecosystem-Services-Technical-Input.pdf
- Ecologists call for preservation of planet’s remaining biological diversity. (2012, June). ScienceDaily. Retrieved from http://www.sciencedaily.com/releases/2012/06/120606164938.htm