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One definition What is Biodiversity? Another definition Some common elements "Biological diversity -- or biodiversity - is the sum total of life's physical expression and genetic potential, embedded in the array of organisms now alive. "The diversity of life in all its forms (plants, animals, fungi, bacteria, and other microorganisms) and at all levels of organization (genes, species, and ecosystems)." M. L. Hunter In a practical sense, biodiversity is the living savings bank for Earth's successful genes, a bank that holds some 3.5 billion years of life's solutions to the problems Taxonomic diversity Hierarchically Structure organized and function of surviving and competing on this planet." R. P. Cincotta and R. Engelman Dimensions of biodiversity Genetic component Spatial component Functional component Temporal component e.g. reproductive behavior, predation, parasitism seasonal within individuals communities within populations ecosystems between populations landscapes annual ecoregions geological or evolutionary between species daily Components of Biodiversity: Genetic Diversity biogeographic regions 1 Components of Biodiversity: Genetic Diversity Variation within and between individuals and populations of organisms. Resides in variation in the sequence of the four base-pairs which, as components of nucleic acids, constitute the genetic code. Gene diversity Each species is the repository of an immense amount of genetic information. The number of genes range from about 1,000 in bacteria 10,000 in some fungi 700,000 or more in many flowering plants and a few animals The typical “higher organism” (anything from an amoeba on up to a human being) contains from 1 to 10 billion nucleotide pairs or genetic letters. 2 Interactions Variation arises in individuals by gene and chromosome mutations Genes generally function in complexes Myriads of unique combinations are what produces the variation we see Prescribe unique traits in anatomy and behavior and biochemistry In turn exquisitely adapt the species to the ecosystem in which it lives Caribbean land snails Why be concerned with intraspecific genetic diversity? Genetic diversity in wild species is key to preserving their ecological “adaptedness” and evolutionary potential Evolution = Selection | Variation | Heredity Economic reasons An example of intra-specific genetic variation: Brassica oleracea Genes from wild relatives constitute an important source for improvement of domesticated species of economic importance to human society 3 Genetic Variability Among Natural Populations: A local example… Red-backed salamander and climate warming Striped morphs experience higher mortality in warmer than colder sites Distribution in variation among populations Fraction among = 0 Fraction among = 1 Consider in context of global climate change 1, 2, 3 1, 1, 1 2, 1, 3 2, 2, 2 3, 2, 1 •e.g., in many Plethodon 50-80% of genetic variation is unique to local populations •For many vertebrates 12% is typical •This hastens genetic divergence and perhaps speciation rates as well Pronounced genetic differentiation over a few kilometers in Desmognathus imitator 3, 3, 3 Proportion of total genetic variation within species due to genetic differences between geographic populations (from Avise 1994) Group Population Differences Mammals 0.242 Birds 0.076 Reptiles 0.258 Amphibians 0.315 Fishes 0.135 Insects 0.097 Crustaceans 0.169 Mollusks 0.263 4 Range collapse California condor A specific example of what’s at stake… Consider the problem of restoring an endangered species from a few, remnant individuals and repopulating its range, The northern elephant seal reduced to ~20 individuals in the late 1800's from a historic range extending from Mexico to Alaska. Now rebounded to many thousands Conclusions about genetic diversity Loss of isolated populations along with their unique component of genetic variation. Perhaps the greatest, but most disguised tragedies of the biodiversity crisis 5 Components of Biodiversity: Species diversity Components of Biodiversity: Species diversity “Species” is generally regarded as the most natural scale at which to consider wholeorganism diversity. The origination and extinction of species are the principal agents in governing biological diversity Perhaps the most readily measured currency of biodiversity Species diversity vs. richness •Species richness: the number of species present in a given area RICHNESS vs. EVENNESS 250 Ecosystem A SR = 4 H' = 1.3086 SE = 0.94 Ecosystem B Ecosystem C SR = 3 H' = 1.0807 SE = 0.98 SR = 3 H' = 1.0323 SE = 0.94 200 • Species diversity: species number weighted by measure of importance, such as abundance, productivity or size For example: Shannon’s diversity index (H) = -∑ρi ln ρi ρi is the proportion of the total number of specimens of species i expressed as a proportion of the total number of specimens for all species in the 150 Species 1 Species 2 Species 3 Species 4 100 ecosystem. Many people use the term “species diversity” when they mean species richness 50 0 Ecosystem Adapted from: Hunter, M. Jr. 2002. Fundamentals of Conservation Biology. Second Edition. Blackwell Science, Massachusetts, U.S.A. Species diversity is a slippery concept Species concepts Morphological Biological Phylogenetic – Each definition of species produces a different count of species. – Therefore, each definition has a different effect on how we plan conservation. 6 An Extraordinary Number Cryptic Species Rana livida complex taxonomically cryptic species look very similar to other species may be misidentified (and hence overlooked as being a different species). So far, about 1.5-1.75 million species have been identified. Scientists estimate that there may be between 3 and 117 million species. Most estimates range between 13-20 million Spector ©AMNH-CBC Cone head katydid Source: Bain ©AMNH-CBC How many species? Spatial scales and diversity Estimated Number of Described Species Bacteria 9,021 (0.5%) Archaea 259 (0.01%) Nematoda Actinopterygii 20,000 (1.1%) 23,712 (1.4%) Other Vertebrata 27,199 (1.6%) Other Eucarya 36,702 (2.1%) Crustacea 38,839 (2.2%) Other Plantae 49,530 (2.8%) Arachnida 74,445 (4.3%) Insecta 827,875 (47.3%) Alpha-diversity Beta-diversity Other invertebrate Metazoa 82,047 (4.7%) Fungi 100,800 (5.8%) Measured locally, at a single site Measures the uniqueness; the difference between two sites Gamma-diversity Stramenopiles 105,922 (6.1%) Measured over a large scale, same concept as alpha-diversity Adapted from: Meffe et al. 2002. Ecosystem management: adaptive, community-based conservation. Island Press, Washington, D.C., U.S.A. Mollusca 117,495 (6.7%) from Lecointre and Guyader (2001). Angiospermae 233,885 (13.4%) Types of Species Diversity: Alpha Diversity The number of species that live in a homogenous habitat. To some extent a function of the area of the habitat But focus is on the number of species that are adapted for a particular habitat. Types of Species Diversity: Beta Diversity Species turnover from one habitat to another in a heterogeneous region. Will beta diversity be higher in a region comprised of: (1) savannah and prairie? (2) wetlands and forest? 7 Which is: Low alpha, high beta? High alpha, low beta? Types of Species Diversity: Gamma Diversity The number of species that live in a heterogeneous region - broad area that has similar climatic and topographical features but may have different habitats. The actual species may be different in the habitats, so species turnover is important. Antarctica Consider the flowering plants of Antarctica! a single grass species, Deschampsia antarctica, and a small cushion-forming plant or pearlwort, Colobanthus quintensis. Usually co-occur at the same site Can gamma = alpha such that beta = 0? An example? Arcane academic topics? Who cares? Spatial scale is a critical consideration Let’s “maximize” species diversity – who can argue with it? Land managers have for years tried to do so by creating edge habitats in public forests 8 “Edge maximizes diversity” Outcome of fragmentation Clear Lake, Northern California Since 1800 fish diversity has increased from 12 to 25 species! Net increase in alpha diversity: Many edge-loving species, such as deer, turkeys, sparrows, American robins, etc. These are somewhere common and secure Net decrease in gamma diversity: All the “area-sensitive” species, e.g., Red-cockaded Woodpecker These may not occur elsewhere Reality 12 original native species, 3 of which were endemic Dam and introductions knocked out 3 species, including two of the endemics: Clear Lake splittail Thicktail chub Added 16 new species (carp, cattfish, many sunfishes and basses, etc.) 12 + 16 – 3 = 25 (alpha) versus – 2 (gamma/global) Evolutionary distinctiveness Other aspects of species diversity: Evolutionary distinctiveness A straightforward count of the number of species only provides a partial indication of biological diversity Evolutionary distinctiveness is also important The more different a species is from any other species then the greater its contribution to any overall measure of global biological diversity. 9 Symbiodinium is an extremely diverse genus of dinoflagellates. Consider the Tuatara Just two species of tuatara. •Most common species is Sphenodon punctatus, the tuatara which is found on the Northern Islands. •Second species is the Brothers tuatara Sphenodon guntheri which is unique to Brothers Island and has an olive skin with yellow spots. North Brother Island Hey…what’s the big deal? ~3,000 species of lizards on earth ~6,850 lizards, snakes, and amphisbaneans Developing this idea further Marine habitats frequently have more different phyla but fewer species than terrestrial habitats This is to say higher taxonomic diversity but lower species diversity. Thus important to incorporate quantification of the evolutionary uniqueness of species. 10 Phylum Ctenophora (comb jellies) Phyletic and functional diversity All except one of the presently described 33 phyla occur in the ocean while only about half that occur on land Consequently, marine organisms display a much larger “phyletic” diversity than those on land Furthermore, 15 phyla are exclusively marine! The marine environment has not only a high phyletic diversity but also a great functional diversity See: Norse, E.A. 1993. Global marine biological diversity: A strategy for building conservation into decision making. Island Press, Washington D.C.383 pp. Phylum Echiuroidea (Inn keeper worms) Phylum Nemertea (Ribbon worms) Phylum Echinodermata, Class: Holothuroid Implications for conservation Components of Biodiversity: Ecosystem Diversity 11 Components of Biodiversity: Ecosystem Diversity Ecosystems are characteristic assemblages of species and their interactions with the environment Diffuse to very tight linkages. “Ecosystem diversity” difficult concept -- not discrete entities but grade into one another along a continuum. Also explicitly include abiotic components, being partly determined by soil parent material and climate. Example of ecosystem types: Brackish interdunal swales Coastal oak-beech forest Coastal oak-heath forest Coastal oak-hickory forest Coastal oak-holly forest Coastal oak-laurel forest Maritime beech forest Maritime holly forest Red maple-sweetgum swamp Sea level fen Endangered Ecosystems of the United States: A Preliminary Assessment of Loss and Degradation Reed F. Noss University of Idaho Department of Fish and Wildlife Moscow, Idaho 83844 Edward T. LaRoe III2 National Biological Service Washington, D.C. 20240 J. Michael Scott National Biological Service Idaho Cooperative Fish and Wildlife Research Unit University of Idaho Moscow, Idaho 83844 http://biology.usgs.gov/pubs/ecosys.htm Critically Endangered (>98% decline) Ecosystems Old-growth and other virgin stands in the eastern deciduous forest biome. Spruce-fir (Picea rubens-Abies fraseri) forest in the southern Appalachians. Red pine (Pinus resinosa) and white pine (Pinus strobus) forests (mature and old-growth) in Michigan. Longleaf pine (Pinus palustris) forests and savannas in the southeastern coastal plain. Slash pine (Pinus elliottii) rockland habitat in South Florida. Loblolly pine-shortleaf pine (Pinus taeda-Pinus echinata) hardwood forests in the West Gulf Coastal Plain. Arundinaria gigantea canebrakes in the Southeast. Tallgrass prairie east of the Missouri River and on mesic sites across range. Bluegrass savanna-woodland and prairies in Kentucky. Black Belt prairies in Alabama and Mississippi and in the Jackson Prairie in Mississippi. Ungrazed dry prairie in Florida. Oak (Quercus spp.) savanna in the Midwest. Wet and mesic coastal prairies in Louisiana. Lakeplain wet prairie in Michigan. Sedge (Carex spp. and others) meadows in Wisconsin. Hempstead Plains grasslands on Long Island, New York. Lake sand beaches in Vermont. Serpentine barrens, maritime heathland, and pitch pine (Pinus rigida)-heath barrens in New York. Prairies (all types) and oak savannas in the Willamette Valley and in the foothills of the Coast Range, Oregon. Palouse prairie (Idaho, Oregon, and Washington and in similar communities in Montana). Native grasslands (all types) in California. Alkali sink scrub in southern California. Coastal strand in southern California. Ungrazed sagebrush steppe in the Intermountain West. Basin big sagebrush (Artenisia tridentata) in the Snake River Plain of Idaho. Atlantic white-cedar (Chamaecyparis thyoides) stands in the Great Dismal Swamp of Virginia and in North Carolina and possibly across the entire range. Streams in the Mississippi Alluvial Plain. 12 “Ecosystem mapping” Mount Marcy, New York (< 100 acres of alpine habitat in New York) Despite conceptual difficulties, ecosystem mapping and classification is now a major area of activity in conservation biology Partly due to efficiency (ecosystem mapping and management as surrogate for tracking individual species) and new technologies. Provides the “coarse filter” for conservation An ecosystem map of Tasmania Latest and greatest on ecosystem classification http://www.natureserve.org/explorer/classeco.htm Components of Biodiversity: Interspecies interactions 13 Components of Biodiversity: Inter-species interactions The number of potential interactions among species is mind-boggling predation, competition, parasitism, mutualism. Some of these linkages are very tight and are considered an important component of biodiversity Details The Weird Sex Life of Figs Unusual flowering system: flowers are on the inside of a structure called a syconium Female fig wasp enters with pollen the syconium through an opening called the ostiole. Female lays eggs in particular flowers with short styles. Chemicals released by the female wasp cause gall formation thus providing the larvae with an ample food source. The long-styled flowers do not have wasp eggs laid in them, and get pollinated by the fig pollen carried by the female wasp Last details… More details… Larva develop into adult wasps barely visible to the naked eye. Males hatch early, are wingless rove around inside dark chamber, chomp a hole in the wall of the now mature fig, fertilize female larvae, promptly die! The fertilized female leaves the fig through this hole, taking pollen with her. Other examples: Flowering plants and pollinators The mature fig remains for you or some other animal to eat. The seeds pass through your digestive system, with their seed coats weakened by the acid in your stomach, and fall on the ground, germinating into another fig tree. 14 Ants and aphids Termites and endosymbiotic protozoa Hummingbird flower mites can go extinct if either the hummingbirds they use for transport or flowers on which the mites depend for nectar and pollen go extinct. In the illustration, the mite Tropicoseius uniformis, monophagous on its host plant Psychotria poepegiana, is phoretic on the hummingbird Amazilia tobaci in Trinidad, West Indies. Anemone and clownfish Cultural Diversity Mostly a issue for vertebrate animals: Cultural Diversity knowledge of migration routes, water holes, food patches, nesting sites, refugia etc. based on information passed from older to younger animals. Despite our notion of animals as being evolutionarily hard-wired, much "teaching" goes on. 15 Examples Consider what happens to many elephant herds when the matriarch, who knows the location of water holes during times of drought, is killed. Many species reintroduction programs fail because of lack of regard for cultural transmission, e.g., thickbilled parrot, golden lion tamarin. Does this information constitute "biodiversity"? Cultural and Biological Diversity: Human culture Some 200 million indigenous peoples (4 percent of the world's population) live in territories that harbor exceptionally high levels of biodiversity. Long occupation of a particular place means development of cultural, spiritual, and economic ties to an area that permitted them to live in a sustainable fashion there End: “What is biodiversity?” 16