What is Ecology? Ecology is the scientific study of interactions among organisms and between organisms and their environment. What does this mean? How do we study these interactions?
We have to ask questions about events and organisms that range in complexity from a single individual to the entire biosphere.
Levels of Organization
Organism An individual living thing
Population Members of one species that interbreed and live in the same place at the same time.
Compete for: –Food –Water –Shelter –Mates Population
Community Different populations that live together in a defined area. Several populations interacting together.
Ecosystem A collection of all of the organisms that live in a particular place, together with their nonliving, or physical environment.
Biotic Factors: living organisms within an ecosystem Abiotic Factors: nonliving factors that help shape an ecosystem Ecosystem
Biomes A group of ecosystems that have the same climate and similar dominant communities.
Biosphere The highest level of organization that ecologists study is the entire biosphere itself. The portion of the Earth that supports life.
ORGANISM POPULATION COMMUNITY ECOSYSTEM BIOSPHERE BIOME
Ecological Methods Ecologists use a wide range of tools and techniques to study the living world. Apply the scientific method to do ecological research: –Observing –Experimenting –Modeling
Interactions Between Organisms All organisms depend upon other living things and nonliving things to meet their needs, such as: FoodFood ShelterShelter ReproductionReproduction ProtectionProtection Thus, an interdependence exists among organisms and the environment
Energy Flow All living things need ENERGY to survive. Where does this energy ultimately come from?
Autotrophs Organisms that capture energy from sunlight or chemicals and use that energy to produce food. Ex. Bacteria, plants, and algae Also called producers
Heterotrophs Rely on other organisms for their energy and food supply Also called consumers
Types of Consumers Herbivores Carnivores Omnivores Detritivores Decomposers
Heterotrophs that eat plants (1 st order consumers)
Heterotrophs that eat animalsHeterotrophs that eat animals They come in many sizes!They come in many sizes!
Eat both plants and animals Ex: humans, raccoons, bears
Animals that feed on animal remains and dead matter (collectively called detritus) EX: mites, earthworms, snails, crabs
Break down decaying matter Ex: bacteria and fungi
Feeding Relationships What happens to the energy in an ecosystem when one organism eats another? –The energy moves along a one-way path. Energy flows through an ecosystem in one direction, from the sun to autotrophs and then to various heterotrophs
Food Chains The energy stored by producers can be passed through an ecosystem along a food chain, a series of steps in which organisms transfer energy by eating and being eaten.
A food chain shows how matter and energy move through an ecosystem Sun Grass Rabbit Snake Hawk The arrows show the direction that energy is transferred Natural Food Chain Each organism represents a trophic level, a step in the food chain.
Food Web Shows all of the possible feeding relationships at each trophic level in the community.
A diagram that shows the relative amounts of energy or matter contained within each trophic level in a food chain or food web. 3 types –Energy pyramids –Biomass pyramids –Pyramids of numbers
Only part of the energy that is stored in one trophic level is passed on to the next level…. why? –Organisms use much of the energy that they consume for life processes (reproduction, respiration, and movement). Only 10% of the energy available within one trophic level is transferred to organisms at the next trophic level.
The total amount of living tissue within a given trophic level is called biomass. A biomass pyramid represents the amount of potential food available for each trophic level in an ecosystem.
Pyramid based on the numbers of individual organisms at each trophic level.
The water cycle is the continuous movement of water between Earth and its atmosphere.
Carbon is an essential component of proteins, fats, and carbohydrates The carbon cycle is a process by which carbon is cycled between the atmosphere, land, water, and organisms.
The carbon cycle has been operating to keep the amount of carbon dioxide in balance between the atmosphere and Earth. HOWEVER, the burning of fossil fuels has added more carbon dioxide than can be removed by plants during photosynthesis.
Carbon dioxide is considered a greenhouse gas …it traps heat on Earth. This contributes to global warming, which has led to an overall increase in the Earth’s average temperature.
*78% of the atmosphere is composed of nitrogen *Living things cannot use nitrogen in the atmospheric form *Lightening and some bacteria convert nitrogen to usable forms, then producers use them to make proteins. Consumers then eat the producers and reuse the nitrogen to make their own proteins! *When organisms die, decomposers return nitrogen to the soil and it is either reused or converted into nitrogen gas and returned to the atmosphere.
Primary Productivity—rate at which an organic matter is created by producers Process can be limited by a lack of nutrients
A polar bear, its fur stained with algae, stands in its cage at Higashiyama Zoo in Nagoya, central Japan, Saturday, Sept. 6, Three polar bears at the zoo changed their colors in July after swimming in a pond with an overgrowth of algae, prompting many questions from visitors concerned about whether the animals are sick or carrying mold, a zoo official said. Credit: AP Photo/Kyodo News, Shuzo Shikano
50 4–1 The Role of Climate Words you need to know: –Weather –Climate –The Greenhouse Effect –Climate Zones polar zones (66.5° and 90° North and South latitudes) temperate zones (between the polar zones and the tropics) tropical zone (23.5° North and 23.5° South latitudes)
52 Heat Transport winds and ocean currents
53 4–2 What Shapes an Ecosystem? Biotic & abiotic factors Habitat = the area where an organism lives (biotic and abiotic factors that affect it) Niche = full range of physical and biological conditions in which an organism lives and the way in which the organism uses those conditions
54 no two species can share the same niche in the same habitat
55 Community Interactions Competition = organisms of the same or different species attempt to use an ecological resource in the same place at the same time –Resource = any necessity of life (water, nutrients, light, food, or space) competitive exclusion principle = ecological rule that states that no two species can occupy the same exact niche in the same habitat at the same time
58 Predation = interaction in which one organism captures (kills) and feeds on another organism –Predator / Prey
59 Symbiosis = Any relationship in which two species live closely together –mutualism –commensalism –parasitism
60 Mutualism = symbiotic relationship in which both species benefit from the relationship
62 4–1 The Role of Climate Words you need to know: –Weather –Climate –The Greenhouse Effect –Climate Zones polar zones (66.5° and 90° North and South latitudes) temperate zones (between the polar zones and the tropics) tropical zone (23.5° North and 23.5° South latitudes)
64 Heat Transport winds and ocean currents
65 4–2 What Shapes an Ecosystem? Biotic & abiotic factors Habitat = the area where an organism lives (biotic and abiotic factors that affect it) Niche = full range of physical and biological conditions in which an organism lives and the way in which the organism uses those conditions
66 no two species can share the same niche in the same habitat
67 Community Interactions Competition = organisms of the same or different species attempt to use an ecological resource in the same place at the same time –Resource = any necessity of life (water, nutrients, light, food, or space) competitive exclusion principle = ecological rule that states that no two species can occupy the same exact niche in the same habitat at the same time
70 Predation = interaction in which one organism captures (kills) and feeds on another organism –Predator / Prey
71 Symbiosis = Any relationship in which two species live closely together –mutualism –commensalism –parasitism
72 Mutualism = symbiotic relationship in which both species benefit from the relationship
74 Commensalism = symbiotic relationship in which one member of the association benefits and the other is neither helped nor harmed
76 Parasitism = symbiotic relationship in which one organism lives in or on another organism (the host) and consequently harms it –Host / parasite
77 Ecological Succession Ecosystems are constantly changing in response to natural and human disturbances. ecological succession = gradual change in living communities that follows a disturbance
78 Primary Succession primary succession = succession that occurs on surfaces where no soil exists –Volcano –Glacier
79 pioneer species = first species to populate an area during primary succession –Often lichens
80 Secondary Succession secondary succession = succession following a disturbance that destroys a community without destroying the soil –land cleared and plowed for farming is abandoned –Wildfires
81 climax community = mature, stable community that did not undergo further succession –Old growth forests
Chapter 5 Populations 5-1 How Populations Grow
Characteristics of Populations –Three important characteristics of a population geographic distribution Density growth rate
Geographic Distribution Geographic distribution, or range, is a term that describes the area inhabited by a population.
Population Density Population density is the number of individuals per unit area. Population density The population of saguaro cactus in the desert plant community has a low density, whereas other plants in that community have a relatively high density.
Populations Growth Population Growth Three factors can affect population size: number of births the number of deaths the number of individuals that enter or leave the population. * Simply put, a population will increase or decrease in size depending on how many individuals are added to it or removed from it
Immigration & Emmigration Immigration Immigration the movement of individuals into an area, is another factor that can cause a population to grow. Emigration Emigration the movement of individuals out of an area, can cause a population to decrease in size.
Word Origin Immigration is formed from the Latin prefix in-, meaning “in,” and migrare, meaning “to move from one place to another. If the Latin prefix e- means “out,” then which of the following means “migration out”? A.) emigration B.) migration C.) Immigration
Exponetial Growth Exponential Growth If a population has abundant space and food, and is protected from predators and disease, then organisms in that population will multiply and the population size will increase.
Exponential Growth Exponential growthExponential growth occurs when the individuals in a population reproduce at a constant rate. Under ideal conditions with unlimited resources, a population will grow exponentially.
Logistic Growth Logistic growth occurs when a population's growth slows or stops following a period of exponential growth. Logistic growth As resources become less available, the growth of a population slows or stops. The general, S-shaped curve of this growth pattern, called logistic growth
Carrying Capacity Carrying Capacity The number or the largest number of individuals that a given environment can support.
In the Belly of a Python Pythons have replaced alligators as the apex (top) predator in the Florida Everglades
What is a Python? Native to grassy marshes and jungles of Southeast Asia Can grow up 23 feet long Can weigh up to 200 lbs Excellent swimmers – can stay submerged in water up to 30 minutes Diameter can be about the same as a telephone pole Carnivores that kill by constriction (squeezing prey) On Threatened List in native lands, but not threatened in Florida
Burmese Pythons are an Invasive Species An invasive species is one that “invades” a habitat that is not its native habitat. In its native habitat it is part of an ecosystem that keeps its population in balance with other organisms.
An Invasive Species can Severely Damage an Ecosystem’s Balance But when it is imported into another environment that provides the right combination of climate and resources to live but where its population is NOT kept in check in the new ecosystem, it becomes an INVASIVE SPECIES that disrupts the balance of the ecosystem.
What are the Everglades? The Florida Everglades is a huge, wetland ecosystem. Over 4,500 miles of slow moving waters feed the sub- tropical habitats. Formed over thousands of years its waters and vegetation provides home to thousands of mammals, amphibians, birds, fish, insects, arachnids, reptiles and plants. The Everglades is America's only sub-tropical wilderness and visitors travel from all over the world over to experience its natural beauty. Has diverse habitats of pine and freshwater cypress forests, open prairie, and tropical saltwater mangrove swamps. Fragile ecosystems are easily disrupted by invasive species.
Images of the Everglades
Burmese Pythons Disturb the Ecosystems of the Everglades The non-native python has virtually no predators in the Everglades. It is a voracious eater. It disrupts the fragile balance of the ecosystems in the Everglades The following slides show some of the very different kinds of animals that have been found in stomachs of captured pythons.
Endangered Key Largo Woodrat Rare – only about 100 in the wild
White-tailed Deer White-tails have a home territory that is less than one square mile. If the deer in an area decrease because of python predation, how does that affect the ecosystem? Think – what else eats deer? What do deer eat? Think in both directions of the food chain.
Yes, Alligators in Python Digestive Systems!
Limpkins – southern marsh bird Feed almost exclusively on apple snails, which are voracious plant eaters. If the limpkin population goes down from python predation, what does the apple snail population do?
Wood Stork Wood Storks have been on the Endangered Species List since 1984
Little Blue Heron
How Many Pythons Are in Florida? An estimated 150,000 are slithering around the Evergaldes So let’s see – what’s the math? 72 mice x 150,000 = 4 gators x 150,000 = 1 racoon x 150,000 = 15 rabbits x 150,00 = And so on - you get the picture! Now multiply the above by the fact that they can live to be 30 years old and hatch 35 to 100 eggs a year! And some percentage of the babies live and continue eating and hatching more snakes! It’s a problem, alright.
Female with 59 Eggs When Captured and Killed
Ready to Watch Our Movie? What are we interested in picking up information about? How the invasion started What predators they replace What they eat Ways that they disrupt the ecosystem What can be done to solve the problem?
Images from The Nature Conservancy northamerica/unitedstates/florida/howwewor k/in-the-belly-of-a-python.xml northamerica/unitedstates/florida/howwewor k/in-the-belly-of-a-python.xml