Population and BiodiversitySlide 2Slide 3Slide 4Slide 5Slide 6Slide 7Slide 8Slide 9Slide 10EEP153, spring 2005Population and BiodiversityWhat is biodiversity?Population & biodiversity “hotspots” (from Nature’s Place, Cincotta & Engelman, Pop Action Int’l)Main causes of loss in biodiversityPeople, parks and biodiversity:Protecting biodiversity through protected spaces and informed managementEEP153, spring 2005Population and BiodiversityBiological diversity = “the variability among living organisms from all sources including, inter alia, terrestrial, marine and other aquatic ecosystems and the ecological complexes of which they are part; this includes diversity within species, between species, and of ecosystems.” (Convention on Biological Diversity, Rio, 1992)Biodiversity benefits for humankind:Consumption goods – seafood, timber, pharmaceuticals…Life-support processes – water purification and storage, removal of carbon dioxide/air filtration, pollination, pest, flood & landslide control…Life-fulfilling conditions (existence values) - beauty, appreciation, recreation…Conservation of options (option values) - genetic diversity for food and health of future generations…Estimated total economic value of the biosphere’s natural ecosystems: 33 trillion dollars annually = 1.8 times the entire world’s GNP. “An interesting benchmark.”Constanza, R. Nature , May 1997.EEP153, spring 2005Population and BiodiversityToday’s problem – unprecedented loss of species due to human activity that degrades habitat and creates pollution.Estimated total number of species today – 10 million.Background rate of extinction – 1 to 10 extinctions each decade; estimated rate of extinction over the last century – 100 to 10,000 species per year;1/4 of all mammals, 1/10 of all birds, 1/3 of all fish – at risk of extinction;If only 10% of each type of natural habitat eventually remains (considered optimistic), around 50% of all species are projected to survive.EEP153, spring 2005Population and Biodiversity25 Global Biodiversity Hotspots:√“25 regions of the world where terrestrial biological diversity is most concentrated and the threat of loss most severe.” √12% of Earths’s land surface, of which only 2% are intact, naturally vegetated ecosystems, containing 44% of total plant diversity;√75% of all terrestrial animal species listed as threatened by the IUCN are found within the 25 hotspots.EEP153, spring 2005Population and BiodiversityHabitat disturbance, loss and fragmentation – the leading direct cause of extinction.Human population growth brings – Agricultural expansion,Water diversion,Rural settlement expansion,Urban sprawl.Consequence: habitat and breeding of terrestrial and aquatic species highly disturbed.EEP153, spring 2005Population and BiodiversityLocal people and biodiversity historically compatible, e.g. traditional ag, gardening, fishing & hunting systems protect or enhance habitats;Symbiotic relationship between biological diversity and sustainable agricultural, pastoral and forestry production (Eco-agriculture);Protecting biodiversity largely through restrictive reserves doesn’t work….Ecologists/conservation biologists understand how to manage habitats and protect species within human-managed ecosystems; IUCN Six Categories of Protected Areas: “Establishing well-managed protected areas may provide new approaches to resource management based on sustainable use, thereby restoring at least part of the balance that has enabled human populations to survive”. McNeeley/NessEEP153, spring 2005Population and Biodiversity1994 IUCN System for Categorizing Protected Areas1. Strict nature reserve/wilderness area (736 sites)2. National park: protected areas managed mainly for ecosystem conservation and recreation (1,508 sites)3. Natural monument: protected areas managed mainly for conservation of specific features (322 sites)4. Habitat/species management area: protected areas managed mainly for conservation through management intervention (3,955 sites)5. Protected lands/seascape: protected areas managed mainly for landscape/seascape conservation and recreation (2,120 sites)6. Managed resource protected area: protected areas managed mainly for the sustainable use of natural ecosystemsEEP153, spring 2005Population and Biodiversity_______ can claim more threatened species than any other U.S. state except Hawaii.Seen any grizzly bears lately? The state mammal disappeared from California’s forests in _______.EEP153, spring 2005Population and BiodiversityNot for students.People & Biodiversity Chart – Low fertility rate – China, Colombia, Mexico, Indonesia vs. high fertility in Congo, Madagascar, Papa New Guinea and even Philippines.EEP153, spring 2005Population and BiodiversityMediating factors for understanding impact of population on biodiversity conservation:Pressure from rural-to-rural migration - directed & spontaneous colonization; Agricultural intensification – “saves land for nature” but also pollutes;Urbanization and sprawl – patterns of settlement, see Nature article on increasing number of households even where population growth is slowing (e.g. Italy, Brazil);Creation of protected areas – conservation vs. recreation, pressure from bordering populations, enforcement capacity;Global inequality – the forces of poverty and affluence. “Simply put, species loss can create economic risks that are chiefly long-term, while many of the world’s poor face uncertainty about tomorrow’s meals. Poverty forces people to take sustenance from the most unprotected of resources.”Institutions – laws, markets, property rights. Do they or do they not promote biological