Five Common Graphs
1 / 26

- PowerPoint PPT Presentation

  • Uploaded on

Five Common Graphs. Several graphs are commonly seen in ecology. for example. Linear progressions J - CURVES S - CURVES Climb and collapse Bell shaped curve. An arithmetic number sequence grows by repeated additions of like amounts. and produces a linear graph. Examples.

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
Download Presentation

PowerPoint Slideshow about '' - EllenMixel

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

Slide2 l.jpg

Several graphs are commonly seen in ecology

for example

  • Linear progressions

  • J - CURVES

  • S - CURVES

  • Climb and collapse

  • Bell shaped curve

Slide3 l.jpg

An arithmetic number sequence grows by repeated additions of like amounts

and produces a linear graph





Slide4 l.jpg




Each of these

arithmetic progressions when graphed,produces a straight-line graph

Such number sequences are predictable and easy to understand

Slide5 l.jpg

An exponential progression

produces a classical J – CURVElike the one shown here

Slide6 l.jpg

J-curves are both powerful and deceptive

They result from number sequences that growby repeated multiplications by like amounts




Slide7 l.jpg

Most of the growth in an exponential sequence

occurs at the end of the sequence


  • A graph of a nuclear detonation

  • Populations undergoing ecological release

  • A graph of human population growth between 8000 BC and 2000 AD

An s curve is also known as a logistic growth pattern l.jpg
An S-curve is also known as a Logisticgrowth pattern

  • Takes into account environmental factors limiting growth.

  • Contains 5 stages.

  • Initial Growth/slow

  • Exponential Growth/fast

  • Slowing Growth

  • Slower Growth

  • Steady State, which will fluctuate moderately.

Slide10 l.jpg

During the early stages of a population’s growth,theS-CURVE follows an exponential pattern

As the population grows larger, competition and other limiting factors begin to slow its rate of growth

Slide11 l.jpg


birth rates and death rates become equal

and the population stabilizesnear the carrying capacity of its environment

Slide12 l.jpg

We often see


in k-strategists

such as whales and gorillas

..... unless they undergo ecological release .....

Slide13 l.jpg

This graph depicts a population pattern known as

Climb and Collapse

Can you see why?

Slide14 l.jpg

The population shown here grew exponentially for many generations

This was eventually followed by a catastrophicdie-off over a relatively short span of time

Slide15 l.jpg

This graph shows the climb-and-collapse of a reindeer population

on St. Matthews Island, Alaska

In 1944, 29 reindeer were placed on the island

Slide16 l.jpg

Since the island had no competitors or predators population

The reindeer herd underwent

ecological release


Slide17 l.jpg

By 1963, more than 6000 reindeer populationdamaged the vegetation needed to survive

Slide18 l.jpg

More than 99% of the herd died during the winter of 1963-1964

… only 42 individuals survived …

Slide22 l.jpg

Such data often involve producepatterns of variation within a population

Slide23 l.jpg

Example produce

Suppose we analyze all the oranges on a given tree for their vitamin Ccontent per gram

Slide24 l.jpg

Some will have a very high amount of vitamin C per gram produce


will have very little

vitamin C

per gram

But most will have some average amount of vitamin C per gram

Slide25 l.jpg

producing a producebell-shaped curve when graphed

Slide26 l.jpg

C’s produce




Bell shape curves are what we often use in education when evaluating student work.

What’s fair about this? What’s not?