INTERACTIONS WITHIN COMMUNITIES - PowerPoint PPT Presentation

Loading...

PPT – INTERACTIONS WITHIN COMMUNITIES PowerPoint presentation | free to download - id: 7ac49c-ZmZjM



Loading


The Adobe Flash plugin is needed to view this content

Get the plugin now

View by Category
About This Presentation
Title:

INTERACTIONS WITHIN COMMUNITIES

Description:

WITHIN COMMUNITIES Community: Populations of different species living in the same area. INTERACTIONS WITHIN COMMUNITIES Ecological niche: The role an organism fills ... – PowerPoint PPT presentation

Number of Views:90
Avg rating:3.0/5.0
Slides: 24
Provided by: onca
Learn more at: http://schools.alcdsb.on.ca
Category:

less

Write a Comment
User Comments (0)
Transcript and Presenter's Notes

Title: INTERACTIONS WITHIN COMMUNITIES


1
INTERACTIONS WITHIN COMMUNITIES
  • Community Populations of different species
    living in the same area.

2
INTERACTIONS WITHIN COMMUNITIES
  • Ecological niche The role an organism fills
    within a community (what it does, eats, its
    pattern of living)

3
INTERACTIONS WITHIN COMMUNITIES
  • Interspecific competition competition for
    resources among members of two or more different
    species.

Hyenas battle with a lioness and win the day.
Photo by Brittany Gunther, 2008
4
Types of Niches
  • Fundamental niche the role the organism would
    fill under ideal enviromental conditions (if
    there was no interspecific competition).

5
  • Realized niche the portion of the fundamental
    niche the organism actually fills (due to
    competition).

6
A. Symbiosis
  • Interactions in which members of two (or more)
    species maintain a close association.
  • There are 3 main types

7
1. Parasitism
  • The interaction is beneficial to one species and
    harmful (but not fatal) to the other species.
  • Parasites can be both micro- and macroscopic as
    well as ecto- and endoparasites.

8
  • Social parasites mimic the behaviour of another
    species in order to complete their lifecycle
    (i.e. cowbirds).

9
2. Mutualism
  • The interaction is beneficial to both species.
    Ex. Bees and flowers
  • Obligatory mutualism is when neither species can
    survive without the other (gut bacteria in
    herbivores, oxpecker birds).

10
3. Commensalism
  • The interaction is beneficial to one species
    while the other is unaffected.
  • Remoras and sharks are a possible example.

11
B. Types of Interspecific Competition
  1. Interference Competition two species are
    actually fighting over the resources (birds over
    birdhouses, lion vs. hyena).

12
B. Types of Interspecific Competition
  • Exploitative Competition two species are using
    a common resource and one species is more
    efficient at obtaining it
  • ex. arctic foxes and snowy owls eating arctic
    hares, canopy trees in rainforest.

13
Gause's Principle/ Principle of Competitive
Exclusion
  • if the resources are limited, no two species can
    remain in competition for exactly the same niche
    indefinitely.
  • One species will always out compete the other.

14
Resource Partitioning
  • The avoidance of, or reduction in, competition
    for similar resources by individuals of different
    species that do not occupy the same niche

15
Resource Partitioning
  • i.e. Plant root systems, lizards/insects/birds in
    different parts of the tree.

16
C. Predation
  • Predator-prey relationships are an important
    interaction in a community.

17
C. Predation
  • When the prey population increases, the predator
    population will increase shortly thereafter.
    Predator-prey populations follow a cyclical
    pattern.

18
C. Predation
  • Predator-prey interactions have caused prey to
    evolve diverse defence mechanisms in order not to
    be eaten.
  • Predators are evolving to bypass these defences
    (Evolutionary Arms Race).

19
D. Defense Mechanisms
  • Plants use morphological defenses such as thorns,
    hooks, needles, spines and chemical defenses such
    as toxins, hormones, and other chemicals to deter
    herbivores from eating them.

20
D. Defense Mechanisms
  • Animals use passive defences such as hiding /
    being poisonous or active defences such as
    fleeing/ fighting/ producing venom.

21
D. Defense Mechanisms
  • Some animals use mimicry, which is one species
    appearing very similar to another species.

22
D. Defense Mechanisms
  • Batesian mimicry a harmless species mimics a
    harmful one (ie. An edible butterfly mimics a
    toxic species so it won't get eaten)

23
D. Defense Mechanisms
  • Mullerian mimicry dangerous species all appear
    similar which causes predators to learn quickly
    to avoid them.
About PowerShow.com