1. Value and Maintenance of Biodiversity Biology/Env S 204 Spring 2009

2. Value and Maintenance Benefits to humans, direct or indirect Intrinsic value What kind of a world do we want to live in? Redundancy in ecosystems (how much is enough?)

3. Benefits to humans Direct use value = marketable commodities –Food –Medicine –Raw materials –Recreational harvesting –Ecotourism

4. Benefits to humans: food About 3,000 species (ca. 1% of 300,000 total) of flowering plants have been used for food About 200 species have been domesticated Wild relatives source of genes for crop improvement in both plants and animals

5. Benefits to humans: medicine Organisms as chemists About 25% of all medical prescriptions in the U.S. are based on plant or microbial products or on derivatives or on synthetic versions Some medicinal products from animals (e.g., anticoagulant from leeches)

6. Benefits to humans: raw materials Industrial materials: –Timber –Fibers –Resins, gums –Perfumes –Adhesives –Dyes –Oils, waxes, rubber –Agricultural chemicals

7. Benefits to humans: recreational harvesting Recreational harvesting: –Hunting –Fishing –Pets –Ornamental plants

8. Benefits to humans: ecotourism By definition based on biodiversity Growing portion of the tourism industry

9. Indirect Use Value Indirect use value = services provided by biodiversity that are not normally given a market value (often regarded as free) Include primarily ecosystem services: atmospheric, climatic and hydrological regulation; photosynthesis; nutrient cycling; pollination; pest control; soil formation and maintenance, etc.

10. Indirect Use Value Biosphere 2 was an attempt to artificially create an ecosystem that would sustain human life Ca. US$200 million invested in design and construction plus millions more in operating costs Could not sustain 8 humans for two years

11. Intrinsic value Simply because it exists Moral imperative to be good stewards, the preservation of other life for its own sake Supported in many different religious or cultural traditions Recognized in the Convention on Biodiversity

12. Intrinsic Value Biophilia = the connection that human beings subconsciously seek with the rest of life (nature) or the innate connection of humans to biodiversity

13. Intrinsic Value Biophilia = the connection that human beings subconsciously seek with the rest of life (nature) or the innate connection of humans to biodiversity Should we put a monetary value on everything?

14. Intrinsic Value Biophilia = the connection that human beings subconsciously seek with the rest of life (nature) or the innate connection of humans to biodiversity Should we put a monetary value on everything? If something can be valued, it can be devalued.

15. What kind of a world do we want to live in? Human co-opt about 40% of the net primary productivity on an annual basis Human population at over 6 billion and growing at about 80 million per year Loss of some biodiversity is inevitable

16. What kind of a world do we want to live in? Current extinction rate much higher than background; also commitment to extinction Extinction is forever; species may have unforeseen uses or values (e.g., keystone species, medicinal value, etc.) Biodiversity has recovered after previous mass extinctions, but are we also eliminating that possibility by severely restricting conditions conducive to evolution?

17. What kind of a world do we want to live in? If 6 billion people consume 40% of the annual net primary productivity, what is the theoretical limit (= carrying capacity) for humans under current conditions? 2.5 x 6 billion = 15 billion

18. What kind of a world do we want to live in? But this number does not factor in the costs of dealing with wastes or non- renewable resources. Nor does it leave room for other biodiversity, upon which we depend for ecosystem services (such as waste removal/recycling). Human population is expected to reach ca. 12 billion by 2050.

19. What kind of a world do we want to live in? This is why many now argue that we have to find a way to put biodiversity into the economic equation Previously no monetary values were associated with natural resources except the actual ones generated by extraction (the world is there for us to use)

20. What kind of a world do we want to live in? Extraction costs (e.g., labor, energy) usually computed But cost of replacement not included, nor costs of the loss of the services provided by that resource or its ecosystem (e.g., cutting forest for timber) Because costs are undervalued, benefits of extraction are overvalued

21. What kind of a world do we want to live in? Green accounting proposed as part of the solution But requires that environmental assets have proper prices (p. 171, Chichilnisky essay in text) Tie in to property rights for natural resources

22. Redundancy in Ecosystems Or, how much biodiversity is enough? How much redundancy is built into ecological processes/communities? To what extent do patterns of diversity determine the behavior of ecological systems?

23. Redundancy in Ecosystems Two opposing views: rivet hypothesis vs. redundancy hypothesis rivet redundancy

24. Redundancy in Ecosystems Rivet hypothesis: most if not all species contribute to the integrity of the biosphere in some way Analogy to rivets in an aircraft—there is a limit to how many can be removed before the structure collapses Progressive loss of species steadily damages ecosystem function

25. Redundancy in Ecosystems Redundancy hypothesis: species richness is irrelevant; only the biomass of primary producers, consumers and decomposers is important Life support systems of the planet and ecological processes will generally work fine with relatively few species

26. Redundancy in Ecosystems In the past (from fossils), most ecological systems have been conspicuously less species rich But no evidence that they operated any differently

27. Redundancy in Ecosystems Major patterns of energy flow and distribution of biomass in existing ecological systems may be broadly insensitive to species numbers But systems with higher diversity and more kinds of interactions may be more buffered from fluctuations Lack of data regarding the link between species-richness and ecosystem function

28. Redundancy in Ecosystems Middle ground: ecosystem processes often but not always have considerable redundancy built into them –Not all species are equal (e.g., functional groups, keystone species) –The loss of some species is more important than the loss of others –Species loss may be tolerated up to some critical threshold