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BIODIVERSITY EXTINCTION: 40.000 pr. YEAR!? IS BIODIVERSITY IMPORTANT?! WHAT IS BIODIVERSITY Effect of climate on biodiversity Disturbance and biodiversity The VALUE of BIODIVERSITY Bio-organizational hierarchy Biosphere Bioms, e.g. rainforest Landscapes “Ecosystems” Communities landscapes Communities SPECIES Populations; breeding individuals Individual Populations Individual Fig. 4.2, p. 72 What is biodviresity • SPECIES RICHNESS = NUMBER OF SPECIES IN A GIVEN AREA (measurable & comparable) • TURNOVER OF SPECIES IN LANDSCAPES = LANDSCAPE DIVERSITY • NUMBER OF RARE OR ENDEMIC SPECIES • NUMBER OF SPECIES WITH FEW REALTIVES = ISOLATED LINAGES • DIFFRENCES BETWEEN INDIVIDUALS WITHIN POPULATIONS (GENE DIVERSITY) BIODIVERSITY IS NOT BIOLOGICAL RESOURCES • 2 ISLANDS WITH DIFFERENT DIVERSITY 30 SPECIES NON ARE EDIBLE 5 SPECIES 4 ARE EDIBLE WHERE DO YOU WANT TO LIVE? POTENTIAL RESOURCE SPECIES NOT USEFUL TODAY CAN BE USEFUL FOR HUMANS IN THE FUTURE Biomes: Latitude and Altitude Elevation high Alpine Tundra Elevation Montane Coniferous Forest Deciduous Forest low Tropical Forest Tropical Forest High Temperate Deciduous Forest Northern Coniferous Forest Temperature && Moisture Availability Temperature Moisture availability Arctic Tundra Low Fig. 6.18, p. 133 Latitude Species diversity Biodiversity: equator to the poles 200 1,000 100 100 0 10 90˚N 60 30 0 Latitude 30˚S 60 80˚N 60 40 Latitude Fig. 8.3, p. 175 20 0 Biodiversity: elevation gradient Species richness agriculture Low land ---- high land Common: latitude & elevation gradient Altitud e Temperature Production Growing season Latitude Increasing Biodiversity Many physically diverse habitats Landscape diversity Short unfavorable seasons, tropical Middle stages of ecological succession Moderate environmental disturbance AREA Ecological Succession: Communities in Transition Primary succession Secondary succession Pioneer species Successional species Primary Succession & species richness Species richness biomass Exposed Lichens rocks and mosses Small herbs and shrubs Heath mat Jack pine, black spruce, and aspen time Balsam fir, paper birch, and white spruce climax community Fig. 8.15, p. 188 Secondary Succession & species richness Species richness biomass Mature oak-hickory forest Young pine forest Annual weeds Perennial weeds and grasses Shrubs time Biodiversity: succession Number of species= species richness Successional time Biodiversity and biomass species richness Increasing biomass Biodiversity and disturbance disturbance = reduced biomass species richness Increasing disturbance Biodiversity, succession and disturbance species richness increasing biomass increasing disturbance Tropical forest are rich in species because of large area + many strata More strata= more surface= more species Indirect: i.e., small plants growing in shade of larger plants Community Structure: Appearance and Species Diversity Stratification 100 30 20 Species richness 50 10 ft m Tropical rain forest Coniferous forest Deciduous forest Thorn forest Thorn scrub Tall-grass prairie Short-grass prairie Desert scrub Specie area curve Log (species number) Log(area) EXTINCTION estimate: how did the 40.000 species pr year appear? Myers 1979 >100 species pr. year including known and unknown species guess 1 million species extinct in 25 years = 40,ooo pr year 50 % reduction in rainforest leads 20 % reduction in species (Lovjoy 1980) vegetation Origins of Life Chemical evolution Biological evolution Chemical Evolution (1 billion years) Formation of the earth’s early crust and atmosphere Small organic molecules form in the seas Large organic molecules (biopolymers) form in the seas Biological Evolution (3.7 billion years) First protocells form in the seas Single-cell prokaryotes form in the seas Single-cell eukaryotes form in the seas Variety of multicellular organisms form, first in the seas and later on land Key Concepts Origins of life Evolutionary processes Species formation Species extinction Species Extinction Local extinction Regional extinction Biological or total extinction Ex-situ conservation e.g. wild relatives of crop plants Extinction Background extinction Mass extinction Extinction Rates Background (natural) rate of extinction Geological Periods Number of families of marine animals Mass extinction Carboniferous Cretaceous Devonian Jurassic Silurian Triassic Tertiary Ordovician Permian Quaternary Cambrian 800 Mass extinctions 600 ? 400 200 0 570 505 438 360 408 286 208 144 245 Millions of years ago 65 0 2 Realistic figures • • • • • 95 % of earlier species are extinct 1.6 million known species 10 to 80 million unknown species Natural extinction 2 pr. 10 year Known extinction 25 pr. 10 year since 1600 AD Extinction rate ca. 0.7 % , but since total number of species is unknown the percentage is not a good expression Why Should We Care About Biodiversity? Speciation Speciation Geographic isolation Reproductive isolation Northern population Early fox population Spreads northward and southward and separates Arctic Fox Different environmental conditions lead to different selective pressures and evolution into two different species. Southern population Gray Fox Adapted to cold through heavier fur, short ears, short legs, short nose. White fur matches snow for camouflage. Adapted to heat through lightweight fur and long ears, legs, and nose, which give off more heat. Fig. 5.8, p. 113 A thin layer of life in a big void: app. 20 km Biosphere Atmosphere Biosphere Vegetation and animals Soil Crust Rock Diversity in the biospere is good and core Lithosphere ’a must’ for evolution to continue Mantle Crust Crust (soil and rock) Biosphere (Living and dead organisms) Hydrosphere (water) Lithosphere (crust, top of upper mantle) Atmosphere (air) Why Should We Care About Biodiversity? Value of Nature Instrumental value Intrinsic value Instrumental Intrinsic (human centered) (species or ecosystem centered) Utilitarian Nonutilitarian Goods Existence Ecological services Aesthetic Information Bequest Option Recreation Nice mammals & ugly creeps: Have all species equal value? Many small species and few big species • Why is it dangerous to be big? • Why is it safe to be small? number size Reproductive Patterns and Survival Asexual reproduction r-selected species Sexual reproduction K-selected species K-Selected Species elephant r-Selected Species saguaro Fewer, larger offspring High parental care and protection of offspring Later reproductive age Most offspring survive to reproductive age Larger adults Adapted to stable climate and environmental conditions Lower population growth rate (r) Population size fairly stable and usually close to carrying capacity (K) Specialist niche High ability to compete Late successional species cockroach dandelion Many small offspring Little or no parental care and protection of offspring Early reproductive age Most offspring die before reaching reproductive age Small adults Adapted to unstable climate and environmental conditions High population growth rate (r) Population size fluctuates wildly above and below carrying capacity (K) Generalist niche Low ability to compete Early successional species Broad and Narrow Niches Generalist species Specialist species Endangered and Threatened Species Endangered species Threatened (vulnerable) species Rare species FLAGSHIP SPECIES, BIG MAMMALS & BIRDS Florida manatee Northern spotted Gray wolf owl (threatened) Florida panther Bannerman's turaco (Africa) Fig. 22.7a, p. 556 PLANTE GEOGRAFI PLANTE GEOGRAFI • LOKALT SJELDEN • I UTKANTEN AV UTBREDELSE OMRÅDET • GLOBALT SJELDEN • SJELDEN NATURTYPE I NORGE= SAND DYNER STRENDER Sjelden i Norge: Silkenellik I UTKANTEN AV UTBREDELSES OMRÅDET Sodaurt PLANTE GEOGRAFI • SJELDEN NATURTYPE I NORGE • F. EKS SAND DYNER med fugle og plante liv Causes of Premature Extinction of Wild Species Habitat degradation Introduction of non-native species Habitat loss Habitat degradation Overfishing Climate change • • • • Basic Causes Population growth Rising resource use No environmental accounting Poverty Introducing nonnative species Commercial hunting and poaching Pollution Predator and pest control Sale of exotic pets and decorative plants Fig. 22.13, p. 564 Why Mountains are important Mimic latitude “Islands” = isolation= speciation = endemics Greenhouse Effect Greenhouse gases (a) Rays of sunlight penetrate the lower atmosphere and warm the earth's surface. (b) The earth's surface absorbs much of (c) As concentrations of greenhouse the incoming solar radiation and gases rise, their molecules absorb degrades it to longer-wavelength and emit more infrared radiation, infrared radiation (heat), which rises which adds more heat to the into the lower atmosphere. Some of lower atmosphere. this heat escapes into space and some is absorbed by molecules of greenhouse gases and emitted as infrared radiation, which warms the Fig. 6.13, p. 128 lower atmosphere. Elevation gradient and climate change: 1750 AD No. of individuals Temperature niche Alpine plant 1000 m elevation = decrease 5 0C 20 10 0 0C Elevation gradient and climate change: 2100 AD + 10 degrees No. of individuals Temperature niche disappear Alpine species goes locally extinct 30 20 10 critical thinking • Realised versus fundamnetal niche Fundamental niche = only climate Realised niche Biotic control 1750 20 10 0 2100 30 20 10 Land Use in the World Cropland 11% Urban 2% Tundra and wetlands 9% Desert 20% Rangeland and pasture 26% Forest 32% Fig. 23.2, p. 586 Emergent Forest Structure Birds, invertebrates, bats Canopy Birds, reptiles, amphibians, lichens, mosses Understory Shade-tolerant plants, birds, squirrels, lizards, chipmunks Snag Floor Rotting debris, worms, insects, bacteria Subsoil Bole Nematodes, microrganisms Symbiotic Species Interactions: Commensalism Indirect: i.e., small plants growing in shade of larger plants Direct: i.e., epiphytes, remoras Endangered and Threatened Species Endangered species Threatened (vulnerable) species Rare species Florida manatee Northern spotted Gray wolf owl (threatened) Florida panther Bannerman's turaco (Africa) Nuclear threat!!!! Mass extinction VALUE of species Extinction Background extinction Mass extinction