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Global Biodiversity. Global Biodiversity Patterns and Processes. Global Biodiversity Patterns and Processes. What is Biodiversity? Biological diversity is the sum of all living things It can be considered at many levels (e.g. genetic, regional, evolutionary lineage, number of ecosystems)

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global biodiversity patterns and processes1
Global BiodiversityPatterns and Processes
  • What is Biodiversity?
  • Biological diversity is the sum of all living things
  • It can be considered at many levels (e.g. genetic, regional, evolutionary lineage, number of ecosystems)
  • Hierarchical perspective: genes, pop(s), species, communities, ecosystems, landscapes
global biodiversity patterns and processes2
Global BiodiversityPatterns and Processes
  • Genetic Diversity
  • Genetic diversity is the ultimate source of biodiversity at all levels
  • Recent advancements now allow us to measure (and quantify) genetic diversity
  • Important in establishing breeding programs
  • May allow species to broaden tolerances
global biodiversity patterns and processes3
Global BiodiversityPatterns and Processes
  • Genetic Diversity
  • Consider the use of genes in crops and livestock…can be either incorporating genes or just preserving existing breadth
  • Consider Bt cotton: Bacillus thuringiensis (Bt) is a spore forming bacterium that produces crystals proteins, which are toxic to many species of insects.
global biodiversity patterns and processes6
Global BiodiversityPatterns and Processes
  • Population-level Diversity
  • The variation within members of a species or population is extremely important (represents evolutionary history and is the source of potential future adaptations)
  • Also provides a great deal of information about the amount and rate of gene flow between and among populations (more later)
global biodiversity patterns and processes7
Global BiodiversityPatterns and Processes
  • It is the local populations where environmental challenges occur and genetic diversity is maintained
  • Consider a species/population of corn that evolved in soil with high mineral (e.g. metals or salt) levels
  • That population maybe become an invaluable crop species in some locations
global biodiversity patterns and processes8
Global BiodiversityPatterns and Processes
  • Guppies in Trinidad streams have evolved without fish predators
  • Consequently, they have very different life-history characteristics than species/populations exposed to predators
  • If a reintroduction or population supplementation is needed, knowledge of genetics and plasticity important
global biodiversity patterns and processes9
Global BiodiversityPatterns and Processes
  • Populations may also serve a functional role, which may be independent of other populations
  • E.g. pollinators
global biodiversity patterns and processes10
Global BiodiversityPatterns and Processes
  • Human Cultural Diversity
  • Consider human cultural diversity and the reservoir of knowledge, skills, and traditions throughout the world
  • E.g. 6,526 distinct languages
global biodiversity patterns and processes12
Global BiodiversityPatterns and Processes
  • Non-random distribution of habitats
global biodiversity patterns and processes13
Global BiodiversityPatterns and Processes
  • Diversity of Species
  • Despite many references to ‘biodiversity’ and others at the species level (e.g. ESA, CITES) it is the populations that are as or more important (but not as easily comprehended by the public or politicians)
global biodiversity patterns and processes14
Global BiodiversityPatterns and Processes
  • What is the difference between a species and population?
  • Can be somewhat difficult to determine if they are one species or two…
  • Why?
  • Problems: fossils, asexual organisms, lack of knowledge

It is really a gradient

global biodiversity patterns and processes15
Global BiodiversityPatterns and Processes
  • For many ‘bioinventories” or rapid assements, may use concept of ‘morphospecies’
  • As species (and populations) evolve, they continue to accumulate genetic differences
  • To determine relatedness among these species (or pop(s)), biologists attempt to reconstruct phylogenies (more later)
global biodiversity patterns and processes16
Global BiodiversityPatterns and Processes
  • Biological classification system based upon the idea of hierarchical organization and relatedness
  • King Phillip Came Over For Golf Saturday
  • Should always be a bifurcating tree
global biodiversity patterns and processes18
Global BiodiversityPatterns and Processes
  • How many species are there?
  • Approximately 1.75M named with another 300K fossil sp
  • On average, 300 sp named each day
  • Two new phyla have been named in past 25 yrs
  • Range is 10M-50M
global biodiversity patterns and processes20
Global BiodiversityPatterns and Processes
  • For starters, the immense richness of viruses, bacteria, archaea (singled-cell organisms in extreme environs), protists and other unicellular organisms
  • Only 80,000 fungi described
  • In Britain, 6x fungi vs. vascular plants
  • Extrapolate worldwide, 1.6M fungi
  • Nematodes >200 sp in a few cm3
global biodiversity patterns and processes21
Global BiodiversityPatterns and Processes
  • Mites: 30,000 sp described (but probably >1M)
  • Insects: almost 1M described, but consider canopy fogging
  • 4 sites <70km proximity, 1% common


global biodiversity patterns and processes22
Global BiodiversityPatterns and Processes
  • Diversity of higher taxa
  • Until recently, 5 kingdoms recognized




Monera (bacteria)


global biodiversity patterns and processes23
Global BiodiversityPatterns and Processes
  • Today, there is a recognized division among the prokaryotes and we have the Archaea and Bacteria
  • Genetic diversity is as great as that across Eukaryotes
  • Many new kingdoms ascribed to Archaea, Bacteria, and Protists
  • Why care?
global biodiversity patterns and processes24
Global BiodiversityPatterns and Processes
  • They evolutionary lineage of each species is important for several reasons
  • 1) evolutionary potential relies on the diversity of life (many differences, albeit small)
  • 2) lineages are storehouses of info on the history of life
  • 3)functioning ecosystems depend upon the variety of life
  • 4) aesthetic benefits correlated with diversity
global biodiversity patterns and processes25
Global BiodiversityPatterns and Processes
  • Diversity of biological communities
  • The composition of communities changes over time and space
  • Membership within a community is probabilistic
  • 3 common metrics
    • Sp richness, evenness, abundance
  • Frequently compare metrics across habitats or sites (or genes)
  • Could also use weighted measures…
global biodiversity patterns and processes26
Global BiodiversityPatterns and Processes
  • Are there limitations to using a metric like diversity?
    • Species identity…lose valuable information on functional role, exotic vs. native, life-history characteristics
  • Biological communities are of conservation interest because the relative abundances, combinations, +/- can all provide valuable information
global biodiversity patterns and processes27
Global BiodiversityPatterns and Processes
  • Ecosystem and Biome Diversity
  • Typically terrestrial systems typically classified by shape and life-forms of the plants that dominate them
  • Holdridge’s widely used life zone system is entirely based upon climatic variables
  • Although communities grade into one another, major divisions are useful for analyses and descriptions
global biodiversity patterns and processes31
Global BiodiversityPatterns and Processes
  • Things also change at relatively large scales based upon: latitude, altitude, and precipitation gradients
  • At a finer scale, things change with soil type, slope, and species composition
  • Recently the WWF reclassified the Earth’s biomes into 867 terrestrial biomes (thought to represent distinct assemblages)
global biodiversity patterns and processes32
Global BiodiversityPatterns and Processes
  • Ecosystem approach
  • Managing at the ecosystem allows for common goals across multiple owners and allows for ‘large scale’ planning that is likely appropriate for even relatively large organisms
global biodiversity patterns and processes33
Global BiodiversityPatterns and Processes
  • Species Richness over Geologic Time
  • The number of species at any given moment represents the balance between extinction and speciation rates
  • That number will vary according to the frequency and intensity of extinction and/or speciation events
global biodiversity patterns and processes34
Global BiodiversityPatterns and Processes
  • The fossil record shows a rough estimate of trends in species richness during the history of life on Earth
  • Cellular life began about 3.8 bya (bacteria) and eukaryotics probably about 2 bya
  • Things were relatively quiet until the ‘Cambrian explosion’
global biodiversity patterns and processes35
Global BiodiversityPatterns and Processes
  • Fig 2.5 Diversity of marine families from Cambrian to present
global biodiversity patterns and processes36
Global BiodiversityPatterns and Processes
  • Terrestrial plant appeared early in the Silurian and their richness increased rapidly during the Devonian
  • Then during the Cretaceous, another important event occurred, the appearance of ‘angiosperms’
  • Had ‘cascading effects’
global biodiversity patterns and processes37
Global BiodiversityPatterns and Processes
  • Fig 2.6
  • Each group, ferns, gymnosperms and angiosperms, have all dominated at one time
global biodiversity patterns and processes40
Global BiodiversityPatterns and Processes
  • Rates of species formation
  • Speciation rates are not consistent
  • When do you think it accelerates?
global biodiversity patterns and processes41
Global BiodiversityPatterns and Processes
  • Rates of species formation
  • The first was the Cambrian (500mya)
  • Second Paleozoic (440mya)
  • The third set diversity way back in Permian (250mya), followed by Triassic explosion
global biodiversity patterns and processes42
Global BiodiversityPatterns and Processes
  • Cambrian: all major groups of living organisms appeared during this time (and some that did not make it)
  • Paleozoic and Triassic greatly increased families, genera and species, but no new phyla emerged
global biodiversity patterns and processes43
Global BiodiversityPatterns and Processes
  • Factors impacting rates of speciation
  • Any guesses?
    • Mass extinctions
    • Increasing separation of landmasses
    • New species and species interactions
global biodiversity patterns and processes44
Global BiodiversityPatterns and Processes
  • Diversity explosions throughout the ages
global biodiversity patterns and processes46
Global BiodiversityPatterns and Processes
  • Rates of Extinction
  • Similarly, rates vary throughout time
  • 6 major events

60% 75% 95% 65% 75% **

global biodiversity patterns and processes47
Global BiodiversityPatterns and Processes
  • Although species generally recovered, there is a lag of about 10my
  • The major impact of mass extinctions events has been to eliminate some lineages while opening ecological niches for others
global biodiversity patterns and processes48
Global BiodiversityPatterns and Processes
  • Current patterns of species richness
  • Diversity is not spread evenly
global biodiversity patterns and processes50
Global BiodiversityPatterns and Processes
  • To properly preserve species, it is important to know where species occur
  • One such tool is a GIS
  • Another useful approach is to divide species richness into major components
    • Alpha-richness (small homogeneous area)
    • Beta (rate of change across communities)
    • Gamma (changes across larger landscapes)
global biodiversity patterns and processes51
Global BiodiversityPatterns and Processes
  • High α generally means many rare sp
  • High β means the cumulative number of species recorded rapidly increases as additional areas are censused along some environmental gradient
  • High γ may result from having many different types of habitats within a larger landscape and each of those habitats having some unique members
global biodiversity patterns and processes52
Global BiodiversityPatterns and Processes
  • Species turnover for birds in Mediterranean
global biodiversity patterns and processes53
Global BiodiversityPatterns and Processes
  • Differentials of turnover curves
global biodiversity patterns and processes54
Global BiodiversityPatterns and Processes
  • Patterns of Endemism
  • Everything is endemic at some scale
  • There are areas of high endemism, usually resulting from isolation (e.g. islands, large dispersal barriers)
  • Areas of endemism are usually not associated with areas of high diversity
  • Why?
global biodiversity patterns and processes56
Global BiodiversityPatterns and Processes
  • Patterns of Endemism
  • Not surprisingly, patterns of endemism differ greatly across taxa
  • For example, SAf and sw Aust have very high levels of plant endemism, but not animals
  • However, there are correlates for endemism among vertebrates
global biodiversity patterns and processes57
Global BiodiversityPatterns and Processes
  • Marine diversity (damselfish)
  • Indo- Pacific a hotspot
global biodiversity patterns and processes58
Global BiodiversityPatterns and Processes
  • Latitudinal Gradient in Species Richness
  • In both terrestrial and marine environments, tropical regions have more species than temperate ones for many (or most) all taxonomic groups
  • Exceptions: marine birds and mammals, seaweeds, salamanders
global biodiversity patterns and processes61
Global BiodiversityPatterns and Processes
  • Although the pattern is widespread, the mechanism (process) generating it remains in question
  • Additionally, it is likely that different groups have different combinations of factors determining their distribution
global biodiversity patterns and processes62
Global BiodiversityPatterns and Processes
  • Species-area Curve
  • One of the first ecological relationships established empirically was the relationship between area and number of species
  • S is species number, A is area, z represents how quickly species are accumulated and c is a constant


global biodiversity patterns and processes63
Global BiodiversityPatterns and Processes
  • z varies across taxonomic groups and habitats
    • E.g. relatively low values ≈0.15 on oceanic islands to 0.25 to 045 for continents
global biodiversity patterns and processes65
Global BiodiversityPatterns and Processes
  • Landbirds and freshwater birds in SE Asia
global biodiversity patterns and processes66
Global BiodiversityPatterns and Processes
  • One confounding factor is the relatively large area of the tropics
  • Consequently, is the higher diversity in the tropics a result of simply larger areas?
  • What other factors may contribute to higher diversity in the tropics?
global biodiversity patterns and processes67
Global BiodiversityPatterns and Processes
  • Species Richness-energy Relationships
  • Simply the more energy that is available the more biomass enables more individuals (hence species) to coexist
  • In tropics, even less energy used to maintain oneself
  • Higher productivity can also allow for dietary specialization
global biodiversity patterns and processes68
Global BiodiversityPatterns and Processes
  • Evidence for these patterns are not consistent
    • E.g. strong correlation between annual evapotranspiration and tree sp richness in NAm
    • E.g. some of the most productive ecosystems (estuaries, hotsprings, seagrass beds) are species-poor
  • Look at relationship between soil fertility, plant richness & seed dispersers
global biodiversity patterns and processes69
Global BiodiversityPatterns and Processes
  • Marine systems: richness and depth
  • ‘the paradox of enrichment’
  • Sp do well in either fresh or saltwater
global biodiversity patterns and processes70
Global BiodiversityPatterns and Processes
  • Energy may also influence richness indirectly through increases habitat complexity (structure)
  • Habitat complexity and richness is generally positive for a wide-ranging group of organisms (think birds in grasslands vs. forests)
  • Conversely, think about lizard richness in the desert…
global biodiversity patterns and processes71
Global BiodiversityPatterns and Processes
  • Disturbance and Species Richness
  • Easy to understand how large climatic variation could reduce sp richness
  • More poleward populations are impacted by remaining individuals having characteristics that favor lower speciation rates (less specialization, larger ranges and greater vagility)
global biodiversity patterns and processes72
Global BiodiversityPatterns and Processes
  • Disturbance and Species Richness
global biodiversity patterns and processes73
Global BiodiversityPatterns and Processes
  • Disturbance and Richness
  • Physical disturbances can influence local richness by destroying habitat, selectively (or not) killing individuals, and sterilizing soils
  • Consider a constant environment, what should this lead to? Why?
global biodiversity patterns and processes74
Global BiodiversityPatterns and Processes
  • Intermediate Disturbance Hypothesis
global biodiversity patterns and processes75
Global BiodiversityPatterns and Processes
  • Consider the rocky intertidal communities of the Pacific Coast
  • Pisaster ochranceus feeds on the competitively dominant mussel Mytilus californianus
  • When it is removed, allows ‘less’ competitive individuals to become established on the rocks
global biodiversity patterns and processes76
Global BiodiversityPatterns and Processes
  • Intermediate Disturbance Hypothesis
global biodiversity patterns and processes77
Global BiodiversityPatterns and Processes
  • Interactions between local and regional species richness…
  • Local species richness can strongly be influenced by local interactions and process operating at larger spatial and temporal scales (e.g. dispersal, speciation, historical biogeography)
  • Ultimately, are there limits to community numbers?
global biodiversity patterns and processes78
Global BiodiversityPatterns and Processes
  • Is it limited by niche overlap?
  • Does the chemical warfare between plants and herbivores set limits to sp richness or does it promote speciation?
  • Are there limits to the size of mimicry systems and do mimicry systems allow for more or less species to coexist?
  • Has the richness generated by plant-pollinators been reached? Seed dispersers?
global biodiversity patterns and processes79
Global BiodiversityPatterns and Processes
  • Importance of Biodiversity
  • Merit vs. money?
  • Many examples of ecosystem services
global biodiversity patterns and processes81
Global BiodiversityPatterns and Processes
  • Importance of Biodiversity
  • Merit vs. money?
  • Many examples of ecosystem services
  • However, it is not clear what the relationship between ecosystem function and species richness
  • Importance of rare species, which are most common, is poorly understood
global biodiversity patterns and processes83
Global BiodiversityPatterns and Processes
  • Increasingly there are opportunities for researchers to test some ecosystem theory at very large spatial scales
global biodiversity patterns and processes84
Global BiodiversityPatterns and Processes
  • Biological dynamics of forest fragment project (Manaus, Brazil)
global biodiversity patterns and processes85
Global BiodiversityPatterns and Processes
  • Calling Lake fragmentation exp (Canada)
global biodiversity patterns and processes86
Global BiodiversityPatterns and Processes
  • Savannah River Corridor Project
global biodiversity patterns and processes87
Global BiodiversityPatterns and Processes
  • Future of Biodiversity Studies
  • Need to generate many more taxonomists; especially in tropical countries and in groups poorly studied
global biodiversity patterns and processes88
Global BiodiversityPatterns and Processes
  • E.O. Wilson: 50yr inventory
  • Rapid Assessment Program: focus on areas of high endemism and diversity
    • Groups of experts on the better known groups (e.g. butterflies, birds, flowers)
  • Establish research stations in same area
  • Combine RAP and intensive studies from research stations
global biodiversity patterns and processes89
Global BiodiversityPatterns and Processes
  • Continue phylogenetic studies
  • Further examinations on anthropogenic stresses on the environment
  • Millennium Ecosystem Assessment: a multi-agency, governmental coalition of international development and conservation organizations, and scientists to assess the status the Earth’s ecosystems
  • Hope is to help focus research on the connections between the status of biodiversity and ecosystem services