BEMO T03 ECOLOGICAL BIOGEOGRAPHY MARINE EVOLUTION AND BIOGEOGRAPHY RITA CASTILHO Ecological Biogeography

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  • ECOLOGICAL BIOGEOGRAPHY MARINE EVOLUTION AND BIOGEOGRAPHY RITA CASTILHO

    Ecological BiogeographyEcological Biogeography

    Accounts for the present distributions in terms of interactions between organisms and their physical and biotic environments

    Ecological Biogeography Ecological Biogeography

    Distributional patterns

  • Ecological Biogeography

    Why is a species confined to its present range in space?


    Ecological Biogeography What enables it to live where it does?

    What prevents it from expanding into another areas?


    Ecological Biogeography

    What roles do water, climate, latitude, topography and interactions with other organisms play in limiting its distribution?


    Ecological Biogeography

    How do we account for the replacement of species as one moves from one environment to another?


  • Ecological Biogeography

    Why are there more species in the tropics than in cooler environments?


    Ecological Biogeography

    What controls the diversity of organisms that is found in any particular region? 


    Ecological Biogeography

    Short-term periods of time, with local, within-habitat, intracontinental questions, with species and subspecies living organisms.

    PATTERNS

  • Ecological Biogeography No two species are identical in their patterns of distribution

    Ecological Biogeography Causes of pattern vary according to the taxonomic level

    Family

    Genus

    Ecological Biogeography Causes of patterns also vary with the spatial scale

    Ecological Biogeography Factors in patterns of distribution

    Geological history

    Climate

    Availability of food Chemistry of Environment

    Competition

  • Ecological Biogeography

    Expected changes in the abundance of the cod stocks with a temperature increase above current levels.

    1 °C 2 °C

    3 °C 4 °C

    Ecological Biogeography Spatial and temporal isolation leads to speciation

    Ravinet et al. PloS One in press

    Ecological Biogeography Migratory movements

    Ecological Biogeography

  • Ecological Biogeography Tintensor et al. 2010

    Ecological Biogeography Tintensor et al. 2010

    Ecological Biogeography Tintensor et al. 2010

    Ecological Biogeography Tintensor et al. 2010

  • Ecological Biogeography Tintensor et al. 2010

    Ecological Biogeography Tintensor et al. 2010

    Ecological Biogeography Tintensor et al. 2010

    Ecological Biogeography Tintensor et al. 2010

  • Ecological Biogeography

    Primarily coastal taxa have peaks of diversity in the western Pacific and show clear latitudinal gradients along the coasts of continents (Fig. a–g).

    Tintensor et al. 2010 Ecological Biogeography

    Primarily coastal taxa have peaks of diversity in the western Pacific and show clear latitudinal gradients along the coasts of continents (Fig. a–g). X

    Tintensor et al. 2010

    Ecological Biogeography

    Primarily oceanic taxa tended to show pantropical or circumglobal distributions with diversity peaking at latitudes between 20° and 40° in all oceans (Fig. h–m).

    Tintensor et al. 2010 Ecological Biogeography

  • SCALE

    Ecological Biogeography ● SCALE

    Ecological Biogeography ● SCALE Ecological Biogeography ● SCALE

    • Spatial and temporal dimension of sampling and observation – Extent: size of the study area or the duration of

    time under consideration – Grain: level of spatial resolution

  • Ecological Biogeography ● SCALE

    Size of the study area

    Ecological Biogeography ● SCALE

    Level of spatial resolution

    Ecological Biogeography ● SCALE

    Duration1 week

    1 month

    1 year

    Ecological Biogeography ● SCALE

  • Ecological Biogeography

    Schematic drawing showing the dominant space- and time-scales in the marine environment for physical processes and biological population

    WHAT IS BIODIVERSITY

    Ecological Biogeography ● BIODIVERSITY

    WHAT COMES TO OUR MIND?

    Ecological Biogeography ● BIODIVERSITY

    “A definition of biodiversity that is altogether simple, comprehensive, and fully operation (i.e., responsive to real- life management and regulatory questions) is unlikely to be found”

    Noss (1990)

  • Ecological Biogeography ● BIODIVERSITY

    “The total variability of life on earth”

    (Heywood et al. 1995)

    Ecological Biogeography ● BIODIVERSITY

    “More useful than a definition, perhaps, would be a characterization of biodiversity that identifies the major components at several levels of organization”

    Noss (1990)

    Ecological Biogeography ● BIODIVERSITY

    “The variety and variability among living organisms and the ecological complexes in which they occur”

    OTA (1987)

    Ecological Biogeography ● BIODIVERSITY

    “The variability of life from all sources, including within species, between species, and of ecosystems”

    Whitaker and Fernandez-Palacios (2007).

  • Ecological Biogeography ● BIODIVERSITY

    “... the variety of life and its processes; ... the variety of living organisms, the genetic differences among them, and the communities and ecosystems in which they occur.”

    Keystone Center (1991)

    Ecological Biogeography ● BIODIVERSITY

    “Biodiversity, simply stated, is the total expression of life on Earth”

    Conservation International

    Ecological Biogeography ● BIODIVERSITY Ecological Biogeography ● BIODIVERSITY

    Genetic Diversity

    Ecosystem Diversity Species Diversity

    Biodiversity means the full range of life on earth

  • Ecological Biogeography ● DIVERSITY Ecological Biogeography ● SPECIES

    Knowledge on global diversity must be established to appreciate the increasing extinction rate of

    species

    • Since there is no absolute idea on how many species existed in the first place, extinction rates are vaguely estimated

    • Little is known about extinction rates of microorganisms • We can rarely be sure that a species is actually lost, that no

    isolated members remain

    DIVERSITY MEASUREMENTS

    Ecological Biogeography ● DIVERSITY

    WHAT do you measure?

    WHEN and WHERE do 
 you measure it?

    HOW do you compare
 different types of 
 measurement?

  • Ecological Biogeography ● DIVERSITY

    The number of species per unit.

    The more species present in a sample, the 'richer' the sample.

    Alp ha

    dive rsit

    y

    Ecological Biogeography ● DIVERSITY

    ✘ 2 2 2 2 2 2 2

    1 1 8 1 1 1 1

    Evenness is a measure of the relative abundance of the different species making up the richness of an area.

    Alp ha

    dive rsit

    y

    Ecological Biogeography ● DIVERSITY

    Shannon-Wiener index (H)

    Species richness (S)

    Proportion of each species within a zone (E)

    +

    Alp ha

    dive rsit

    y Ecological Biogeography ● DIVERSITY Shannon-Wiener index (H)

    1.5 > H < 3.5

    H = -sum(Pilog[Pi])

    Relation between Evenness, Heterogeneity and Species richness: E = H/log(S) H = E/log(S)

    Pi : abundance of a given species in a zone divided by the total number of species observed in that zone.

    http://www.pisces-conservation.com/sdrhelp/index.html?shannonw.htm

    Alp ha

    dive rsit

    y

  • Ecological Biogeography ● DIVERSITY

    Sample S E H 1 2 0.08 0.056 2 2 1 0.693 3 3 1 1.098

    Sample Species 1 Species 2 Species 1 1 99 1 0 2 50 50 0 3 33 33 33

    Alp ha

    dive rsit

    y Ecological Biogeography ● DIVERSITY

    Distribution of the numbers of individuals among the species counted

    Beta diversity To what extent do species turnover between different sites or along a

    gradient?

    Alp ha

    dive rsit

    y

    Ecological Biogeography ● DIVERSITY

    Changing levels of alpha diversity along an environmental gradient that creates a series of different habitats (H1, H2, H3) reflect beta diversity (average number of species in different habitats).

    Environmental gradient

    H1 H2 H3

    N um

    be r o

    f s pe

    ci es

    Bet a d

    iver sity Ecological Biogeography ● DIVERSITY

    high alpha (3 species per box)

    high beta (3 different boxes)

    low alpha (1 species per box)

    high beta (3 different boxes)

    low alpha (1 species per box)

    low beta (1 type of box)

    high alpha (3 species per box)

    low beta (1 type of box)

    ?

  • Ecological Biog