Community Ecology

Community Ecology

ECOSYSTEM DYNAMICS I PP. 405-410 Stability and Change Ecosystems are characterized by both stability and change

Change can be a healthy component of the ecosystem as long as an ecosystem is resilient (ability to recover) The resilience of an ecosystem depends on three factors: biodiversity, health, and disturbances

Biodiversity Biodiversity is a measure of the variety of organisms in a given area The greater the biodiversity, the more the roles in a food web to create stability Ecosystem Health

A healthy ecosystem usually recovers quickly because they have more options for dealing with different types of disturbance or even disease Disturbance Frequency A disturbance is an event that changes a community,

removes organisms from it, and alters resource availability Moderate levels of disturbance can foster greater diversity than high or low levels of disturbance Disturbance may promote slow-growing species and inhibit dominant species from excluding less competitive species

Figure 54.20 Number of taxa 35 30

25 20 15 Index of disturbance intensity (log scale) 10 0.9 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2.0

Succession The natural, sequential, and gradual growth and change of a community There are two types of succession, primary and secondary succession

Primary succession occurs when land is first formed due to glacial retreat or as new land forms (ex. Volcanic activity) Microbes, lichens and mosses must create soil before other plants can grow. Pioneer species: first species to dominate early in succession (small and fast growing)

Secondary succession occurs when succession must start over after the destruction of a climax community A climax community is marked by the domination of long-lived species and great diversity. Takes place on sites that have already supported life Fire is a significant disturbance in most terrestrial

ecosystems. In some ecosystems, fire is needed for seedlings to germinate

Recently Viewed Presentations


    C-1 1787 Dakota sign first written treaty with the British Crown at Fort Michilimackinac, renewing the bonds of the Dakota-Crown alliance. C-2 1812 War of 1812 begins. C-3 1813: King George III Indian Peace medals issued to First Nations participants...
  • The Amazon Rainforest -

    The Amazon Rainforest -

    The Amazon Rainforest by: Karen Marshall Where is the Amazon Rainforest located? Continent of South America Covers many different countries The majority is located in Brazil The largest tropical rainforest on Earth Click the picture for extra info!!
  • Open Geography as a Concept: -

    Open Geography as a Concept: -

    Open Geography is a combination of user needs, data, products, and dissemination. The portals are the primary means of disseminating geography data. The design of them is informed by user feedback and requirements.
  • 'The Magic Finger' By Roald Dahl - Our Happy School

    'The Magic Finger' By Roald Dahl - Our Happy School

    'The Magic Finger' By Roald Dahl. Created By: Marea Refalo. Introduction. I am going to talk about a book called the ' The Magic Finger' by Roald Dahl. Chapter 1. The family next to Matilda's house was the family of...
  • 15-744: Computer Networking

    15-744: Computer Networking

    15-744: Computer Networking L-7 QoS * How to Choose Service - Implicit Network could examine packets and implicitly determine service class No changes to end hosts/applications Fixed set of applications supported at any time Can't support applications in different uses/modes...
  • What Is Plagiarism?

    What Is Plagiarism?

    a. Use synonyms (words with same meaning) b. Interchange active and passive voice. 3. Give credit to original author. a. Use . In-text Citation ( author-date style) 4. Compare what you wrote with the original text. a. Are main ideas...
  • Enzyme Mechanisms -

    Enzyme Mechanisms -

    General Metabolism I Andy Howard Introductory Biochemistry 19 November 2013 11/19/2013 Biochemistry: Metabolism I * * * * * * * * * * * * * * * * * * * * * * * * * *...
  • Celsus, -

    Celsus, -

    Scottish surgeon John Hunter inflammation is not a disease but a nonspecific response Julius Cohnheim (1839-1884) first used the microscope to observe inflamed blood vessels in thin, transparent membranes, such as in the mesentery and tongue of the frog.