Ecology Day 6

IN pg. 40 Exponential Growth - Think Penny The initial population of bull snakes in northern Oklahoma was 100, this population under exponential growth will grow at a rate of 25% per year and we will follow this for 50 years. 1. Write the equation symbolically 2. Write the equation in numbers 3. Show the math – all of it.

Do it now pg. 40 Yearly Population Growth You are doing a study of the lions in Africa on January 1st 2011 there were 625 lions, during the year of 2011, 70 lions are born, 65 lions will immigrate into the pack, 20 deaths and 30 lions emigrated on December 31st 2011 how many lions were left to start January 1st 2012? 1. Write the equation symbolically 2. Write the equation in numbers 3. Show the math – all of it.

Thru 1 Staple tape or glue your calculation table onto page 39. Pg. 39 – Population calculation table Pg. 41 – line graphs from tables and naming your graphs Staple tape or glue your calculation table onto page 39. Do your calculations in pencil Line graphs only, no bar graphs, no pie charts Staple tape or glue onto page 41 Do calculation at bottom of page in pencil.

Do it again. Pg. 40 How are all of the formulas you have learned in the last 3 days related? How are they different? Which formula is the easiest, which formula is the most difficult and why?

Out pg. 40 Use top ten on page 3 – green paper. Use top ten number 5 – cartoon Concept = Biotic vs. Abiotic factors and how they influence population growth.

Cause of Death in an Elk Population IN Pg. 42 Cause of Death in an Elk Population What type of model is this? What predators eat elk? What is the main cause of death for 3-12 Y.O.? What age of elk do bears kill?

Do It now Pg. 42 Differences Similarities Differences Logistic growth Exponential growth Logistic growth Differences Similarities Differences

What is ecology? Ecology- the study of organisms and their environment. Reveals relationships between living (biotic) and nonliving (abiotic) parts of the environment. Abiotic factors include… Biotic factors include….

What are the two types of factors? Abiotic Factors Precipitation Temperature Soil Water Air Geographic features like mountains Biotic Factors Plants Animals Bacteria Fungus Microscopic organisms like plankton

The Biosphere

What are the Levels of organization in ecology? Biosphere- the portion of the earth’s surface that supports life. Ecosystem- all of the living (biotic) and nonliving (abiotic) factors interacting in the environment. Community- all of the populations that interact in an area. Population- a group of organisms of the same species that live at the same place at the same time. Organisms- individual living things.

What is the idea of an ecosystem? Eco=Greek “oikos” which means house. System=a set of interrelated parts that work together and DEPEND on each other.

Can you identify this image? Without knowing the scale the image was taken, you might guess it is a type of plant. This image was taken with an electron microscope and zoomed in 50X. You most likely would not guess that this is an image of human eyelashes.

Why is SCALE important? Ecosystems exist at different scales. Microscopic = consists of organisms not visible to the naked eye. Macroscopic = consists of organisms you can see with the naked eye. Can range from small areas like a tidal pool to large areas like the ocean. Regardless of scale, an ecosystem still consists of Abiotic and biotic factors Competition Predator/prey relationships

What is an example of a Microscopic Ecosystem? Photographer David Littschwager captured this amazing shot of a single drop of seawater magnified 25 times to reveal an entire ecosystem of crab larva, diatoms, bacteria, fish eggs, zooplankton, and worms. In this single drop of water we can find all of the observable features of an ecosystem: biotic and abiotic factors, competition for resources, and predator prey relationships. Seawater magnified 25X

What is an example of Macroscopic Ecosystems? Macroscopic ecosystems can also range in scale, from a small freshwater pond to an entire rainforest. Yet in either system, we will find biotic and abiotic factors, competition for resources, and predator prey relationships.

How do we describe a population? Population size is the total # of organisms. Population distribution is how the organisms are spaced in their environment. NO COUNTING…it’s a pattern. Population density is the # of organisms in a particular area at a given time. Regions with the highest population size do not necessarily have the highest population density, since land area is an important variable in calculating population densities China had a population in 2004 of 1,300,100,000 with a density of 136 people/square kilometer Japan had a population of 127,600,000 with a density of 338 people/square kilometer

Cornell notes Pg. 43 Populations continued

Rates Rate is a measure of an event during a specific amount of time Speed measures distance/time Birth/death rates are calculated in occurrences per 1000 usually during a year #births = birth rate x pop1 #births = 10 babies x 50,000 people = 500 babies 1000 people born

Populations Populations are all of the individuals of a species in an area or region.

Population growth rates A population growth rate describes how a population changes over time. Any population that increases in size is said to have a positive growth rate. A decreasing population has a negative growth rate. A population that remains the same size has a zero growth rate. What are the variables that determine a populations growth rate? The growth of populations is regulated by 4 different factors: birth rate, death rate and the movement of individual into(immigration) and out of the population(emigration).

How are Calculating growth rates figured? Population = Final pop. in year 10- Initial pop. in year 1 Growth rate Initial pop. in year 1 Remember If the population is increasing, it has a + number for its growth rate. Initial pop.=5000 Final pop.=15000 Growth rate = 15000-5000=10000= 2 5000 5000 If the population is decreasing, it has a - number for its growth rate. Initial pop.=6000 Final pop.=2000 Growth rate = 2000-6000= -4000= -.67 6000 6000

Population growth curve with all parts labeled – this is on your question sheet. The slope of a line tells you a population’s growth rate __ + # Of Indiv. Years

Carrying capacity = the number of organisms a particular habitat can sustain Exponential growth Carrying capacity Logistic growth # of individuals Time

Limiting factors determine the carrying capacity of the environment.

How are Populations Limited? Populations are limited in size by different factors: Density independent factors-not dependent on how many individuals of the species there are—fire, flood, weather. Density dependent factors-dependent on how many individuals there are in the population—competition for resources, disease, predation.

Demographic transition Less developed countries with higher death rates tend to have higher birth rates. This leads to a bottom heavy pyramid. This means there are lots of young people and fewer older people. As a countries develop, death rates decrease (normally due to better nutrition and health care), birth rates also decrease. This leads to a pyramid that is about equal at the top and bottom. This means there is an equal amount of younger and older people.

Demographic Pyramids

Population density is the # of organisms in a particular area at a given time. Regions with the highest population size do not necessarily have the highest population density, since land area is an important variable in calculating population densities China had a population in 2004 of 1,300,100,000 with a density of 136 people/square kilometer Japan had a population of 127,600,000 with a density of 338 people/square kilometer

Do it again: Pg 42 Copy this slide Density-average # of individuals per unit of area Size-the total # of individuals How Populations are Described Distribution-how the individuals are spread through the environment

Out: pg 42 Draw and label each type of distribution. 2. Come up with your own definition for each term & draw the distribution which matches the definition. Population Distribution= Clumped= Uniform= Random=