Ecology Chapter 13.1

Biodiversity Is the amount of different species found in different areas. The more biodiversity, the more differences in species found. The most biodiverse area of the world are ecosystems on and near the equator. The next maps support this idea by showing the equatorial regions usually containing the highest species diversity. Biodiversity is key to having life continue under many different circumstances.

The “richness” described in this map shows where there is a higher diversity and variation of species of freshwater fish around the world. You can see some trends of where we see the highest levels of biodiversity. Roughly, what regions do you see that have the most diverse populations? What regions of earth to you find the few diverse species?

A similar map, but this time showing vascular plant species diversity A similar map, but this time showing vascular plant species diversity. Where do you see the highest levels of plant species diversity? Where do you see the least?

Ecology Ecology is the study of interactions among living things and their surroundings. It’s not just the living things (biotic), but also the non-living things. (abiotic) EX: Water, air, pollution, and weather – these all matter, but are not alive Ecology was a newer concept because scientists didn’t really think about relationships between different organisms.

Factors to Ecology Abiotic Factors Biotic Factors Non-living things in an ecosystem Biotic Factors Living things in an ecosystem Can you identify the abiotic and biotic factors in the following photos?

Name the factors!

Organization Individual – an single living thing (organism) Population – a group of the same species in the same area. Community – group of different populations interacting together. Ecosystem – all organisms and non-organisms in an area that are trying to maintain homeostasis. Biome – major global region of all living and non-living things. Biosphere – all the interactions on Earth

Different levels of organization exist for describing ecosystems Different levels of organization exist for describing ecosystems. Individuals and Populations should be fairly easily understood. Communities differ because it’s the interactions between various species. Ecosystems are generally larger and account for abiotic factors as well. Biomes cover major earth regions based largely on climate and organisms. The whole earth is referred to as the biosphere.

Measuring ecosystems Scientists use many methods to study these interactions/ecosystems. Observation is a vital tool. Direct surveys = watch animals with their own eyes and see how they interact Indirect surveys = check for signs of animals and try to guess interactions For plants we use quadrat sampling. Check a small sample area and calculate larger number

Field scientists might use simple tools to create the quadrant method Field scientists might use simple tools to create the quadrant method. Simply throw the grid out and find an average number of organisms with some basic math. (We will do this in class later)

Other methods Ecologists sometimes perform experiments in the lab or the field. Field experiments can help to make sure subjects are real and accurate. Sometimes ecologists use modeling to predict patterns in nature. Mostly computer modeling can be used to track large amount of data at once. Done pretty well using human populations

GPS tracking Mark recapture Radio telemetry

More Ecology Chapter 13.3 – 13.4

Species Keystone Species Species that are so important to an ecosystem that if they something happens to them it has an unusually large effect. Beavers are a good example because: They eat fish and control fish population Knock down trees (producers) Block water flow with dams What about wolves? http://www.yellowstonepark.com/wolf-reintroduction-changes-ecosystem/

Energy in Ecosystems Energy is distributed to all animals in an ecosystem, but they differ in how they get that energy Producers – get energy from non-living sources. (Also called autotrophs) Consumers – must eat other living sources for energy. (Also called heterotrophs) Producers provide energy for other organisms in the ecosystem.

Energy for Producers Chemosynthesis Photosynthesis Organisms that live in extreme environments like hot sulfur springs might not depend on sunlight, but chemicals. Almost all producers get their energy from sunlight (photosynthesis).

Food Chains This is a sequence that shows the relationships between animals in what they eat. They begin with a producer, and then those are eaten by consumers. Then those consumers are eaten by other consumers.

Types of Consumers Herbivores – Eat only plants Carnivores – Eat only animals Omnivores – Eat both plants and animals Detritivores/ Decomposers – Eat dead organic matter from plants and animals Scavengers – Eat the remains of dead animals

Decomposer Herbivore Omnivore Omnivore Detritivore Carnivore

Consumers Can become either specialized or generalized. Specialist – consumer that eats one or two specific organisms. Generalist – consumer that eats from many different sources. Primary consumers – are usually your herbivores, they eat the producers Secondary consumers – usually carnivores, eat the primary consumers Tertiary consumers – usually omnivores, eat multiple producers and consumers

Trophic Levels Levels of nourishment in a food chain. Energy flows UP the food chain from lowest trophic level to highest. Producers -> Primary Consumers -> Secondary Consumers -> Tertiary Consumers. Sometimes a species and move into different places in different food chains. (Like humans)

Food Web Food Webs are just collections of different food chains that interact. Think of all the relationships animals have with other animals and plants. Then think about how all those other animals relate to each other.

Populations Mostly Chapter 14

Communities Communities of organisms interact constantly. Predation and competition are common methods of this interaction Predation Process of one organisms capturing and eating another organism Competition When two organisms fight over the same limited resources

Predation Competition is vital in controlling size of populations. Just image what would happen to some populations if they were not regulated by such activities.

Community based relationships Mutualism – interspecies interaction where both organisms see benefits. Symbiosis - so close of a relationship that they live in direct contact with each other. ****Usually associated with mutualism. Commensalism – one species receives benefit other isn’t really effected. Parasitism – One benefits and one is harmed. Predation – One hunts the other, only one is benefited.

This is an example of what? Why?

Population Density This is a measurement of the number of individuals living in a defined space. Simple formula: # of individuals / area (units) = pop. Density Example: 12,000,000 mice over an area of 2 million square kilometers 6 mice per square kilometer

Population Dispersions This is how individuals of a population are spread around. Clumped – Individuals live in close groups Uniform – Individuals live spaces apart Random – Individuals live over a random area.

Population Dispersions

Carrying Capacity This is the maximum number of individuals an environment can hold. After this is reached the population will experience a crash. In mathematical formulas it is represented as “K” Population Crash – Sudden and dramatic drop in size of a population. Many things might cause carrying capacity to be reached: Lack of food Lack of water Disease No more room

Survivorship Curve Is a generalized diagram showing the number of surviving members of a population over the number of births over time. Three types: Type 1, Type 2, Type 3. Type 1 = Long life span, but low birth rate Type 2 = moderate life span and birth rate Type 3 = high birth rate but with very little survive

4 Factors 4 factors contribute to a population’s size. Immigration – # of indiv. moving into a population Emigration - # of indiv. Moving out of a population Births – # of indiv. Born into a population Deaths - # of indiv. That die in a population Deaths Births Total population Emigration Immigration

Available Resources Population growth depends on the environment and resources available. 2 kinds of growth: Exponential growth – when a population increases in size rapidly Logistic growth – slow growth followed by fast growth, then slow growth again. Has reached carrying capacity.

Exponential Growth

logistic Growth

Tomorrow’s lab You will measure populations in a few ways: Mark recapture method Direct survey – (hand counting) Indirect survey – (looking for signs of the animals) Quadrat method – (finding the average number of organisms in a given area)