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Biodiversity Patterns and Processes Conservation Biology focuses on the study and preservation of biodiversity! Some definitions… The applied science of maintaining the earth’s biological diversity (Hunter 1996). An emerging synthetic discipline that deals with the basic issue of eroding biological diversity (Temple et al. 1988). Treats the content of biodiversity, the natural processes that produce it, and the techniques used to sustain it in the face of human-caused environmental disturbance (Wilson 1992). The effort to retain the actors in the evolutionary play and the ecological stage on which it is performed (paraphrased after Hutchinson 1965)* The application of biology to the care and protection of plants and animals to prevent their loss or waste (Salwasser 1994) *The Ecological Theater and the Evolutionary Play Biodiversity More Select Definitions • • • • sum total of all living things richness and variation of the living world variety of life and its processes variability among living organisms from all sources (marine, aquatic, terrestrial) and the ecological complexes of which they are a part (Convention on Biological Diversity Rio Summit) • variety of species and ecosystems on Earth and the ecological processes of which they are a part (Canadian Biodiversity Strategy) < 1% of all species have been described by science ~estimated 10-12 million species Does species diversity = biodiversity? Not necessarily! Biodiversity is more than a species numbers game! Quality often more important than quantity! The important task is to not so much to define biodiversity, but in any given defined area to: • Determine biodiversity components (organisms), distribution (where it occurs), interrelationships, threats, monitoring and measurement criteria, and conservation strategies and measures • • • • Landscape Community/Ecosystem Species/Population Genetic Decreasing Complexity Biodiversity (Spatial Scales of Measurement) REALM BIOME ECOREGION LANDSCAPE ECOSYSTEM COMMUNITY POPULATION/SPECIES GENETIC Earth’s Biogeographic Realms: Large regions within which ecosystems share a broadly similar biota. Mostly terrestrial and freshwater oriented – marine realms are poorly defined. Oceanic Antarctic Australasian Nearctic Neotropic Palearctic Afrotropic Indo-malay (note Wallace’s Line) REALM BIOME ECOREGION LANDSCAPE ECOSYSTEM COMMUNITY POPULATION/SPECIES GENETIC Earth’s Biomes: Broad habitat and vegetation types that span biogeographic realms. 2.4 Biomes and climate Biomes % Biomes Conserved/Protected % protected Tropical & sub-tropical moist broadleaf forests 5.5 Tropical & sub-tropical dry broadleaf forests 4.9 Tropical & sub-tropical coniferous forests 2.5 Temperate broadleaf and mixed forests 3.8 Temperate coniferous forests 8.9 Boreal forests/taiga 6.3 Tropical & subtropical grasslands, savannas, & shrublands 5.5 Temperate grasslands, savannas, and shrublands 1.9 Flooded grasslands and savannas 8.7 Montane grasslands and shrublands 3.8 Tundra 13.7 Mediteranean forests, woodlands, and scrub 2.8 Deserts and xeric shrublands 3.7 Mangroves 8.6 Which are the least and most protected and why? From: Millenium Ecosystem Assessment 2005 (Island Press) REALM BIOME relatively large area, dominant assemblage of species, communities, and conditions ECOREGION LANDSCAPE ECOSYSTEM COMMUNITY POPULATION/SPECIES GENETIC 867 Terrestrial Ecoregions (WWF) (US Environmenatal Protection Agency class types I-IV Ecoregions) – I = 15 – II = 52 – III = 104 – IV = hundreds (under revision) • Kentucky is in 1 Biome: Temperate Broadleaf and Mixed Forest • KY is in 3 Broad Ecoregions (according to WWF) - Appalachian Mixed-Mesophytic Forests - Central U.S. Hardwood Forests - Mississippi Lowland Forests Kentucky’s Traditional (i.e. what you find in most literature) Major Ecoregions (non-EPA) REALM BIOME ECOREGION LANDSCAPE ECOSYSTEM COMMUNITY POPULATION/SPECIES GENETIC Repeated pattern of interacting ecosystems (e.g. Inner Bluegrass) Landscape Example: Bluegrass Region of Kentucky? Savanna-Woodland-Meadow Landscape of Bluegrass Region of KY “The flats on either side of the river were crowded with immense herds of buffalo…and a number of elk were seen on the bare ridges which surround a spring.” - Simon Kenton 1771 Savanna-Woodland-Meadow Landscape of Bluegrass Region of KY Generally “well-timbered”? The land is light with timber, little oak- mostly sugar tree, walnut, ash, buckeye… - 1775 The land is so good I cannot give it due praise. It’s timber is honey locust, black walnut, sugar tree, hickory, ironwood, mulberry, ash, elm, and some oak.” - 1781 “The Elkhorn lands…soil is deep and black, and the natural growth, large walnuts, honey and black locust, poplar, elm, oak, hickory, and sugar trees.” - 1789 Savanna-Woodland-Meadow Landscape of Bluegrass Region of KY “There are many canebrakes so thick and tall that it is difficult to pass through them, and a man on horseback could easily get lost.” “The canebrake where my father settled on Cane Ridge in Bourbon County extended for 20 miles.” -John Filson 1781 “A canebrake extended for almost 6 miles from Lexington to Walnut Hill Church” • Winchester, Georgetown, and Versailles settled in the midst of canebrakes. • Historically (~1790), the diverse timber cover, cane, and meadow descriptions suggest a landscape mosaic/complex in the Bluegrass Region of central Kentucky REALM BIOME ECOREGION POPULATION/SPECIES GENETIC LANDSCAPE ECOSYSTEM COMMUNITY Biotic community and abiotic environment.; Often have complex food (trophic) webs and “self-contained” nutrient cycles such as nitrogen cycle Mixed-Mesophytic Forest Ecosystem (eastern U.S.) 2.3 Large marine ecosystems of the world and their associated major watersheds Chihuahuan Desert Ecosystem (southwestern U.S.) Typical (simplified) Ecosystem Trophic Model (as portrayed from the bottom up) What is a primary producer, primary consumer, secondary consumer, tertiary consumer, and detritivore? Omnivore – eats both plants and animals Herbivore – eats plants only Carnivore – generally solely a meat eater, or of the Order Carnivora Scavengers – eat dead animals Parasites – obtain nutrition from by living inside or on another organism REALM BIOME ECOREGION POPULATION/SPECIES GENETIC LANDSCAPE ECOSYSTEM COMMUNITY Interacting assemblage of species in a defined area For Example: Biotic Communities at Lexington Cemetery Examples major taxa: Animal Community: House Sparrow, Northern Cardinal, Cooper’s Hawk, Canada Goose, Carolina Chickadee, House Finch, Blue Jay, raccoon, Virginia opossum, eastern box turtle, spring peeper, bullfrog, garter snake, Misc. insects and invertebrates Plant Community: American Basswood, KY Fescue 31, Bush honeysuckle, Winter creeper, Northern red oak, Gingko, Black walnut, Broom sedge, multiflora rose, Colorado blue spruce, Virginia pine, bur oak, blue ash, spring beauty, blue phlox Fungi: Molly’s eyewinker, golden trumpets, artist’s conk, angel-of-death, elegant stinkhorn Or Could add all these together for the total biological community…or whatever category you wanted to include as a community (e.g. the vertebrate community, or herpetological community) there are many ways to categorize “community”. Guild/Functional group – use resources in similar ways but partition the resources by space and time. In this example: large herbivores LANDSCAPE ECOSYSTEM COMMUNITY POPULATION/SPECIES GENETIC Population- is local occurrence individuals of the same species; typically the unit of management used to maintain viability in natural patterns, abundances, and distributions (e.g. the cheetah population of the Serengeti ecosystem, or the elk population in Kentucky). LANDSCAPE ECOSYSTEM • Best known level of biodiversity • 1.8 million known species, 10-100 million are estimated, and 300/day are being discovered • Species Richness = # species/unit area COMMUNITY POPULATION/SPECIES GENETIC The hierarchy of biological classification Biodiversity and the Definition of Species Morphological Species = (Morphospecies) groups distinctive based on observable morphological characteristics; commonly used by botanists Biological Species = (Biospecies) = groups with interbreeding individuals but reproductively isolated from other groups (Mayr 1969) Genetic Species = are separated according to genetic differences; thus far, highly subjective and changing Cladistic Species = Species separated according to cladograms. Each branch is a new species usually with traceable ancestral linkages. Biodiversity and the Definition of Species Morphological Species = (Morphospecies) groups distinctive based on observable morphological characteristics; commonly used by botanists Biological Species = (Biospecies) = groups with interbreeding individuals but usually reproductively isolated from other groups (Mayr 1969); interbreeding can occur between some species but behavioral barriers or physical size differences or incompatibilities usually prevent this. Genetic Species = are separated according to genetic differences; thus far, highly subjective and changing Cladistic Species = Species separated according to cladograms. Each branch is a new species usually with traceable ancestral linkages. Biodiversity and the Species Concept Morphological Species = (Morphospecies) groups distinctive based on observable morphological characteristics; commonly used by botanists Biological Species = (Biospecies) = groups with interbreeding individuals but reproductively isolated from other groups (Mayr 1969) Genetic Species = are separated according to genetic differences; thus far, highly subjective and changing Cladistic Species = Species separated according to cladograms. Each branch is a new species usually with traceable ancestral linkages. Biodiversity and the Definition of Species Morphological Species = (Morphospecies) groups distinctive based on observable morphological characteristics; commonly used by botanists Biological Species = (Biospecies) = groups with interbreeding individuals but reproductively isolated from other groups (Mayr 1969) Genetic Species = are separated according to genetic differences; thus far, highly subjective and changing Cladistic Species = Species separated according to cladograms. Each branch is a new species usually with traceable ancestral linkages. 2.2 (A) Domains of biodiversity: Bacteria, Archaea, and Eukarya ? Phylogeny – hypothesis that describes the history of evolutionary descent of a group of organisms from its common ancestor Cladogram is the structure typically used to illustrate phylogenetic relationships 2.2 (C) Major groups of animals Morphological, developmental, physiological, behavioral, molecular traits are used to construct phylogenies. LANDSCAPE ECOSYSTEM Genes – functional unit of heredity, fundamental unit of biodiversity COMMUNITY POPULATION/SPECIES GENETIC • Species differ in gene frequencies and genotypes • genetic material is the raw material of evolution Biodiversity and the Definition of a Species • 2 most commonly used definitions are: Morphological Species Biological Species • Why? • • • Testable and operational Compatible with legal concepts inherent in conservation laws Focus on a level of biodiversity that is a familiar, traditional expressions of conservation and management Biodiversity Characteristics/Indicators. What are 3 important ways to visualize/describe biodiversity? Biodiversity (Characteristics/Indicators; 3 important ways to describe) 1. Compositional (the living parts) 2. Structural (how the parts are arranged in the “house”; note often the living parts comprise part of the house) 3. Functional (what work/job does it perform?) Geologic Time and Biodiversity – How old is Earth? Is biodiversity increasing over time? How are new species produced? Geologic Time, Extinction, and Biodiversity How old is Earth? Is biodiversity increasing over time? How are new species produced? Extant – still exists Extinct – no longer exists (spatially defined) • Global extinction – absent from Earth • Local extinction – absent from defined place • Ecological extinction – usually refers to an extant species, but is at such low numbers to be functionally extinct 2.5 Diversity of marine families from the Cambrian to the present 2.6 Terrestrial plant species richness High rates of speciation (formation of new species) favored by: • Mass extinctions • Major land separations • Evolution of new life forms • Types of Competition (increased complexity usually = increased speciation/richness) A good rule of thumb is biodiversity begets more biodiversity. Extinction Events 1) Ordovician-Silurian: 450 myb; 100 marine families were lost (brachiopods, trilobites, etc.) 2) Devonian: 364 myb; all agnathan (jawless) fish lost 3) Permian: 250 myb; Earth’s most severe extinction event (96% of marine species, 70% of terrestrial vertebrates): corals, reptiles, land plants – continental drift? 4) Triassic-Jurassic: 200 myb; many amphibians and marine families lost, half of all species on Earth. Caused by volcanic gases? 5) Cretaceous-Tertiary (K-T Boundary): 65 myb; dinosaurs, 17% of sessile marine invertebrates, freshwater mollusks; led to the rise of mammals. Asteroid impact. 2.7 Extinctions of families through geologic time Major extinction events can create a 10 million year or more lag in biodiversity “norms” LATE PLEISTOCENE EXTINCTION ~ 15,000 years ago (ya); (A “mini-extinction” event; in the scheme of geologic time) Painting by Mauricio Anton, in The Big Cats and their Fossil Relatives, Columbia University Press. 1997. Extinct living large large (>45kg) (>45kg) mammals mammals of of the the late late Quaternary Quaternary (N.A.) (N.A.)** & living Extinct & Glyptodont American mastodon Mountain deer Big-tongued ground sloth Columbian mammoth Woodland caribou Jefferson's ground sloth Dwarf mammoth Moose Shasta ground sloth Jefferson's mammoth Wapiti Dire wolf Woolly mammoth Pronghorn Gray wolf Mexican horse Pleistocene mountain goat Black Bear Western horse Mountain goat Brown Bear Pleistocene tapir Bighorn Giant short-faced bear Western camel Shrub ox Saber-toothed cat Long-legged llama Bonnet-headed musk ox American lion Long-nosed peccary Musk ox Jaguar Flat-headed peccary Pleistocene bison American cheetah Mule deer American bison Mountain lion White-tailed deer * from Martin & Burney 1999 WildEarth Current rates of species extinctions are very high, above background extinction rates, and approximate a 6th major extinction event. The era of human population growth and modification of the planet on a global scale, including causing the loss of biodiversity, has been unofficially dubbed the “Anthropocene” era. http://en.wikipedia.org/wiki/Anthropocene Five Minute Drill: 1) What scalar units (scale) can biodiversity be measured in? What is the most common unit used, and why? 2) Biodiversity patterns over time…describe the general trends and major influences. 3) What is our general state of knowledge about biodiversity? 4) If all species go extinct, then why are we worried about the loss of biodiversity? Biodiversity patterns • Not uniformly distributed • Need to know where to preserve and manage it! • GIS and models are now commonly used tool to study biodiversity Describing Biodiversity patterns What is endemic? Species Richness? What is a biodiversity hotspot? Madagascar • • Long-isolated from other continents Extremely high endemism; ~80% of all animals and plants are endemic, 90% of all plants! – Often referred to as the “8th continent” its so biodiverse. Box 2.1 (A) Hot spots or rarity and species richness in the lower 48 United States Rarity-weighted richness index (RWRI) Global Biodiversity Hotspots Species richness is greatest in tropical ecosystems Tropical Rain Forests • • • 7% Land area but > 50% world’s species 5-30 million insect species 40% of all plants Coral Reefs • • • “tropical rain forest” of the ocean High productivity (2500 g/m2/yr vs. 125 g/m2/yr in open ocean) Example Great Barrier Reef is 0.1% of ocean are but supports 8% of all fish species Global Biodiversity Hotspots 2.10 The Indo-West Pacific is a marine diversity hotspot Why are tropical ecosystems so biodiverse? Some theories include: 1. High solar energy and rain = high primary productivity 2. Relatively long-term stable environment vs. temperate ones 3. Warm temps and high humidity support more available niches (e.g. tree canopies) and speciation; little to no energy goes into special behaviors or adaptations to withstand drought, freezing temps, or having to migrate. More Biodiversity Patterns • • • • Latitudinal Gradients Disturbance Gradients Area/Size Relationships Other predictors 2.11 Latitudinal species richness in bivalve mollusks 2.12 Latitudinal gradients of species richness of birds and mammals in North and Central America Box 2.1 Table A More Biodiversity Patterns • • • • Latitudinal Gradients Disturbance Gradients Area/Size Relationships Other predictors 2.18 Model of the intermediate disturbance hypothesis intermediate disturbance hypothesis: largely based on woody species models Old Growth Forests and Biodiversity • Some models suggest that biodiversity reaches its maximum at the end of the life expectancy of old growth forests. Why? • Large trees at maximum height provide more structural and microclimatic diversity than young ones. More snags, biomass total, deadfall, biomass, with establishment of multiple species of wildlife, fungi, invertebrates, non-woody plant species, and microorganisms than younger forests More Biodiversity Patterns • • • • Latitudinal Gradients Disturbance Gradients Area/Size Relationships Other predictors More Biodiversity Patterns • • • • Latitudinal Gradients Disturbance Gradients Area/Size Relationships Other predictors Island Formation: Land-Bridge versus Volcanic/Oceanic Islands Land Bridge Island Forest Uncut Cut Volcanic/Oceanic Island Ocean Volcanic Activity New Island Lexington’s forest “islands” in a sea of urbanization; examples of Land Bridge Islands Some Examples of Island Types National Parks and other Protected Areas: often become a managed island due to high contrast with surrounding lands; these lands can thus Land-bridge islands, in behave as islands by this case created by a influencing movement of dam at Barro Colorado species Island Nature Preserve Mangrove Island near Florida is an oceanic island, so is all of Hawaii created by volcanic activity Theory of Island Biogeography Distance to island or nearest habitat patch A B Mainland (or nearest habitat patch) C D size The size of the island and the distance to the mainland or nearest habitat patch determine how many species can be maintained on any given island or habitat patch; i.e. there are only x number of available niches that can be occupied by organisms Island Formation: Land-Bridge versus Volcanic/Oceanic Islands Land Bridge Island Relaxation – gradual loss of species over time following isolation of an island or habitat patch; eventually reach dynamic equilibrium; what happens when chunks of land are cut off from a “mainland”; applications to parks and other protected area management Volcanic/Oceanic Island During formation of new islands you see increase in # species over time until colonization and extinction processes reach dynamic equilibrium Species-Area Relationship Theory of Island Biogeography (MacArthur and Wilson (1967) S = CAz (S = # species on island, A = area of the island, C and Z are constants determined by (Z) movement ability (restricted versus highly mobile) and (C) typical species numbers values for taxa (abundant vs. less abundant) Each of these points represent a dynamic equilibrium between colonization and extinction! Understanding island biogeographic theory is important for understanding forestry and management of other habitats, as well as the functionality of national parks and other protected areas; here we can unfortunately see that the loss of rainforest on the biodiverse island of Sumatra from deforestation has created a series of increasingly smaller islands that can sustain an much smaller amount of biodiversity than only 100 years ago. Many species in these islands are classified as the living dead…those organisms stranded on these forest islands with relatively low numbers to maintain themselves Calculating the number of species for a given group of organisms (e.g. birds) on different island sizes. S = CAz If C =1 and Z = 0.25 what is the predicted # of bird species for islands that are 10, 100, 1000, and 10,000 km2 in size? The answers are 2, 3, 6, 10 Topography (“3-D effect” creates unique microclimatic effects and vertical structuring that can lead to isolation, new niches, and speciation) Topography (“3-D effect” creates unique microclimatic effects and vertical structuring that can lead to isolation, new niches, and speciation) Identifying Species Impacts on Ecosystems: Some Terminology on Relative Ecological Importance Habitat Generalists – can exploit a variety of habitats within an area/range; can easily switch from available and/or preferred to less preferred habitats Examples: White-tailed deer, elk, raccoon, bluegill, white oak Habitat Specialists – can exploit (usually very well) 1 or only a few habitats within an area/range; most habitats unsuitable and cannot be used Examples: Kirtland’s warbler, running buffalo clover, desert pupfish, red-cockaded woodpecker Ecosystem Services – What are they? • Why do we need to qualify and quantify them? What components of biodiversity are necessary for ecosystem function? How does removing 1% of species make a difference? 2.19 Ecosystem function could increase quickly with species richness Rivet/Redundant Top-Down Regulation by Carnivores Ecological Release Strong Ecosystem Influence Dominant Species Keystone Species Ecosystem Engineers (Special Keystones that modify habitats on large scales) Weak Ecosystem Influence Common Species Rare Species 2.20 Ecosystem function can be influenced by the functional diversity among species 2.1 Linguistic diversity and numbers of indigenous cultures across the world (Part 1) 2.1 Linguistic diversity and numbers of indigenous cultures across the world (Part 2) Basic Measurements of Biodiversity Alpha, Beta, and Gamma Diversity Calculating Species Alpha Diversity (Species Richness) Site 1 Site 2 Site 3 House sparrow Elegant Trogon Canyon Wren European Starling Bicknell’s Thrasher Northern Cardinal House Wren Lucy’s Warbler American Crow Northern Cardinal Anna’s Hummingbird Common Raven Chimney Swift Painted Redstart Red-tailed Hawk Mountain Chickadee Richness = # species/unit area Which site has the highest species richness? Evenness (measure of relative/abundance) Site 1 House sparrow Site 2 60 150 European Starling 50 10 House Wren 45 15 Northern Cardinal 60 5 Chimney Swift 25 50 Which site has the highest species richness? Measuring Alpha Diversity Walnut Woods McConnell Springs Blue Jay Blue Jay Cardinal Cardinal Carolina Chickadee Carolina Chickadee Blue Jay Site A Site B Which site has the highest species richness? Measuring Alpha Diversity Palisades Bluegrass Upland Bluegrass Canebrake Blue Jay Blue Jay Black Vulture Cardinal Cardinal Cardinal Carolina Chickadee Carolina Chickadee Whipporwill Blue Jay Blue Jay Site A Site B Site C Which site has the highest species richness? Describing Biodiversity patterns Gamma Diversity – # species across larger landscape gradients/collection of sites • Usually refers to denote diversity of communities within a landscape • Can also be thought of as a species turnover rate with distance between similar habitat or with expanding geographic area • Can be calculated as follows: γ = S1 + S2 − c where, S1= the total number of species recorded in the first community, S2= the total number of species recorded in the second community, and c= the number of species common to both communities (see handout for more description) . Describing Biodiversity patterns Beta Diversity – rate of change in spp. across/among habitats or communities; 1st approximation of regional diversity • S/alpha or alternatively S/alpha-1 where S = # species in entire set of habitats where alpha = mean # species per site Stick w/ the first formula S/alpha in this course • = gamma diversity/mean alpha diversity • Rate of change determined by 1) species range size, 2) habitat specialization • High with distinct habitats with distinct species, low when the same spp. found throughout the region. • Inversely proportional to average geographic range size of a collection of species in a given area • See handout for additional explanation and ways to calculate 2.9 Species turnovers along habitat gradients (Part 1) Here you can see that as the habitat gradient (the difference or contrast between neighboring habitats) goes up, then that sharp difference provides more ecological niches for many species in a relatively short amount of geographic space thus leading to a rapid increase in beta diversity. Thinking about the 3 standard scales for measuring biodiversity (alpha, beta, gamma)