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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. Biosphere. landscapes. Communities.
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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 Biosphere landscapes Communities Populations Individual • Bioms, e.g. rainforest • Landscapes “Ecosystems” • Communities • SPECIES • Populations; breeding individuals • 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 5 SPECIES 4 ARE EDIBLE 30 SPECIES NON ARE EDIBLE WHERE DO YOU WANT TO LIVE?
POTENTIAL RESOURCESPECIES NOT USEFUL TODAY CAN BE USEFUL FOR HUMANS IN THE FUTURE
Biomes: Latitude and Altitude Elevation high Alpine Tundra Elevation Tropical Forest low Tropical Forest Temperate Deciduous Forest Northern Coniferous Forest Arctic Tundra High Temperature & Moisture Availability Low Montane Coniferous Forest Deciduous Forest Temperature & Moisture availability Fig. 6.18, p. 133
Biodiversity: equator to the poles 200 1,000 Species diversity 100 100 0 10 60 40 20 0 60 30 0 60 80˚N 90˚N 30˚S Latitude Latitude • Latitude Fig. 8.3, p. 175
Biodiversity: elevation gradient Species richness agriculture Low land ---- high land
Common: latitude & elevation gradient • Altitude 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 Exposed rocks Lichens and mosses Balsam fir, paper birch, and white spruce climax community Jack pine, black spruce, and aspen Heath mat Small herbs and shrubs Species richness biomass time Fig. 8.15, p. 188
Secondary Succession & species richness Mature oak-hickory forest Young pine forest Shrubs Perennial weeds and grasses Annual weeds Species richness biomass time
Biodiversity: succession Number of species= species richness Successional time
Biodiversity and biomass species richness Increasing biomass
Biodiversity and disturbancedisturbance = 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 100 30 20 50 10 ft m Tropical rain forest Coniferous forest Deciduous forest Thorn forest Thorn scrub Tall-grass prairie Short-grass prairie Desert scrub • Stratification • Species richness
Specie area curve Log(area) • Log (species number)
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)
Origins of Life Chemical Evolution (1 billion years) Biological Evolution (3.7 billion years) Variety of multicellular organisms form, first in the seas and later on land Formation of the earth’s early crust and atmosphere Large organic molecules (biopolymers) form in the seas Small organic molecules form in the seas First protocells form in the seas Single-cell prokaryotes form in the seas Single-cell eukaryotes form in the seas • Chemical evolution • Biological evolution
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 Geological Periods Carboniferous Cretaceous Devonian Jurassic Silurian Triassic Tertiary Ordovician Permian Quaternary Cambrian Mass extinctions 800 600 ? 400 200 0 570 505 438 360 286 208 144 65 0 408 245 2 Millions of years ago • Background (natural) rate of extinction • Massextinction Number of families of marine animals
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
Speciation Adapted to cold through heavier fur, short ears, short legs, short nose. White fur matches snow for camouflage. Northern population Arctic Fox Spreads northward and southward and separates Different environmental conditions lead to different selective pressures and evolution into two different species. Early fox population Adapted to heat through lightweight fur and long ears, legs, and nose, which give off more heat. Southern population Gray Fox • Speciation • Geographic isolation • Reproductive isolation Fig. 5.8, p. 113
A thin layer of life in a big void:app. 20 km Atmosphere Biosphere Vegetation and animals Soil Crust Rock core Lithosphere Mantle Crust (soil and rock) Crust Biosphere (Living and dead organisms) Atmosphere (air) Hydrosphere (water) Lithosphere (crust, top of upper mantle) • Biosphere Diversity in the biospere is good and ’a must’ for evolution to continue
Why Should We Care About Biodiversity? Value of Nature Instrumental Intrinsic (human centered) (species or ecosystem centered) Nonutilitarian Utilitarian Goods Existence Ecological services Aesthetic Information Bequest Option Recreation • Instrumental value • Intrinsic 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 r-Selected Species K-Selected Species cockroach dandelion elephant saguaro 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 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 • r-selected species • Asexual reproduction • K-selected species • Sexual reproduction
Broad and Narrow Niches • Generalist species • Specialist species
Endangered and Threatened Species Florida manatee Northern spotted owl (threatened) Gray wolf Florida panther Bannerman's turaco (Africa) • Endangered species • Threatened (vulnerable) species • Rare species • FLAGSHIP SPECIES, BIG MAMMALS & BIRDS Fig. 22.7a, p. 556
PLANTE GEOGRAFI LOKALT SJELDEN I UTKANTEN AV UTBREDELSE OMRÅDET GLOBALT SJELDEN SJELDEN NATURTYPE I NORGE= SAND DYNER STRENDER
PLANTE GEOGRAFI SJELDEN NATURTYPE I NORGE F. EKS SAND DYNER med fugle og plante liv
Causes of Premature Extinction of Wild Species Habitat loss Habitat degradation Overfishing Basic Causes Introducing nonnative species Climate change • Population growth • Rising resource use • No environmental accounting • Poverty Commercial hunting and poaching Pollution Sale of exotic pets and decorative plants Predator and pest control • Habitat degradation • Introduction of non-native species Fig. 22.13, p. 564
Why Mountains are important • Mimic latitude • “Islands” = isolation= speciation = endemics
Greenhouse Effect (a) (b) (c) Rays of sunlight penetrate the lower atmosphere and warm the earth's surface. The earth's surface absorbs much of the incoming solar radiation and degrades it to longer-wavelength infrared radiation (heat), which rises into the lower atmosphere. Some of this heat escapes into space and some is absorbed by molecules of greenhouse gases and emitted as infrared radiation, which warms the lower atmosphere. As concentrations of greenhouse gases rise, their molecules absorb and emit more infrared radiation, which adds more heat to the lower atmosphere. • Greenhouse gases Fig. 6.13, p. 128
Elevation gradient and climate change: 1750 AD No. of individuals Temperatureniche Alpine plant • 1000 m elevation = decrease 5 0C 20 10 0 0C
Elevation gradient and climate change: 2100 AD + 10 degrees No. of individuals Temperatureniche disappear Alpine species goes locally extinct 30 20 10