Ecology

Ecology

Populations and Behaviour Ecology
1. Conditions
  1. Biotic or abiotic factors
  2. physicological features which are altered not consumed
  3. Neiche
    1. Huchinson 1957
      1. Individuals tollerances, requirements & interactions to define conditions and resorces needed for life
    2. A neiche is not a place but an idear of the tollerences and requirements of an organisim.
    3. Many dimentional organisims only use a small portion of their neiche (Realised neiche) there full neiche is the fundimental which is being used by other organims too
  4. Tempature
    1. tempature limits the groyth and repoduction for an organisim once it drops below their otpimum condtions
      1. Bubblebees shiver to warm up like humans do
      2. With climate change (warming the planet and chaning the conditions. This has potentiall to change all the life ballances on eartth.
    2. Temp is one dimention of a multidimentional system
    3. Metaboloic effectivness increases with temp increases untill a speific temp then the enzymes die.
    4. differenet tempatures suit diffreent orgaisims eg Lizzrads/ polar bear
2. intraspecific competition
  1. two species occupy the same neice
  2. Direct interaction (Interferance Competittion) no direct interaction (Exploitation)
    1. Male 'Little Penguins' (Eudyptula minor) fight for females for breading and then share the rearing of there chicks, they can have 1-3 hatches of chicks and are monogomous to each other for that breading season. Found in colonies morst know are the coloney off the coast of west Austrailia called penguin Island
    2. Competition for the same rescorse by plants, the brich trees and the bluebell fauna
    3. Can b one sided
  3. intraspecific comp is density dependent
  4. Mortality can be density dependent, more organisms in environments more death due to competition for basic resorces.
    1. All environments have a capacity that they can ballance the birth and death rates
      1. theoretical as due to mulitdementional factors means can never be level and stable number, fully dynamic
      2. carring capicity only seen where density depency is not strongly compencaing
    2. more birth than death= pop increase
    3. Net recuritment curves= numbers rather than rates
      1. sigmoid= simplie , too simple for most uses
  5. Asymmetic competition
    1. skewed data
      1. only in high densities and it goes left
    2. preemping resorces
      1. early plants gain space and establish self therefore less affected by competetion
4. Rescources
  1. most of the time when they hsve been used hey dont used they dont come back. Exeption being sunlight
    1. Examples are nesting sites, mates, food
  2. Plants
    1. Compeat for access to sunlight for phosynthises
      1. Use light engey to convert to sugar/food/growth and repair energy therfore sunlight is of greatest importance
    2. Primary producers, Greatest biomass of all the Organisims within food web.
    3. resources are Co2, solar ratdation, H2O, mineral nuitrents.
      1. they also require nitrogen to compleate photosynthies
      2. Photosynthesis and water
        Small guard cells in leavaes which open to allow CO2: Stomatoa.
        Can shut down during times of drought
        delicate ballance between
        Teucrium polium has different types of leaves in the dry and wet season to have optium chance of surviving!
        Native to the med and middle east
        used in cooking and in some medicines
        leaves change to prevent excess waterloss in dry season and change to absorb water and optimum photosynthesis in wet seson
    4. plants can be incompetition for light due to shadiing each other with the leaves , reduce competition.
  3. Carbon Pathways
    1. Plants change and evolove to sutit environement over time
    2. arid environments
      1. 3 pathways
        C4
        seperates the carbon fixation piror to photosynthesis in a seperate cell
        produces a 4 carbon acid in the mesophyll cells combining with phosphoenol pyruvate, wich has a high affinity with C02
        conserve water
        co2 has a higher afftinity within cells (due to PEP) so have to diffuse less co2 but still have same output meaning they can have fuewer stomata cells open therfore reduce the levels of h20 lost.
        Can conserve the co2 in bundle sheths in a 3 carbon compound, mening they prefore better in high temp, light intensity, and lmted water.
        8,000-10,000 species 18 plant families and about 1/2 of all grasses.
        CAM
        suculant plants in arid environments and epiphytes growing in forest canopies who photosynthise at night.
        carbon fixation happens at night wih lower temp reducing water loss, combine co2 with PEP then daylight and photosynthesis
        Comparison to normal photosynthesis
        Normal lose: 380-900g of water in dry mass C4 loose 250-300g CAm lose 50g
  4. Defence against being a resorce
    1. Plants
      1. Stings, Spines, toxins
    2. Animals
      1. poisin
      2. mimicary
        Batesin
        copy a toxic species, only works when toxic is common an mimic is rare!
        mullerian
        toxic mimics another toxic.
      3. convelution
        Adapt self to make self something else
        Monarch butterflies eat milkweed larve which gives them distatefull due to the toxin in milkweed larve
5. births and deaths
  1. density is better than size
    1. no individuals /pop area
    2. estimating pop size
      1. ariel photos
        population desities
      2. caputure mark relese recapture
        not accurate as dont re-capure enough, some are trap happy
  2. pop size between one point and another
    1. N(Now)=N(then) births- deaths+ Leavers- Movers
  3. Dispersion
    1. random
      1. no patttern, not common
        solatary bird nesting sites
    2. clumped
      1. patches of high density then patches with no individuals
        primates, schools of fish
    3. uniform
      1. individuals evenly spread
        seabirds, planted trees
  4. counting
    1. Births
      1. Birds, loads of data avalible
      2. protective mothers and lack of site lines
    2. Deaths
      1. countded by bones, decoposition makes difficult
  5. natural selection, shows life history of species
8. evolution of life history
  1. cohort life tables
    1. flows one species from birth to death
  2. Life tables
    1. Used to show the expected population rates and chart declines and increases
    2. survivor ship curves
      1. life curves displayed using cohort data
        Type I – mortality increases with age e.g. large mammals - few offspring that receive good care. Type II - mortality is constant over lifespan e.g. some rodents like the grey squirrel. Type III - highest mortality in juvinials
    3. Use statistics like mulitvariour analist for iteroparous species
  3. Life history evolution
    1. mainly schudule when born repoduce and die
    2. Masive differences between and in species
      1. Natural selection favours the individual with the best traits
    3. How many repoductive episods
      1. One
        Semplarity
        Annual plants
      2. More
        Iteroparity
        perinial plants
Interactions between species
Communities, Ecosystems and Global Biodiversity

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	Created by meghansarah over 10 years ago