Slide 1 / 131 Slide 2 / 131 AP BIOLOGY Ecology March 2013 www.njctl.org Slide 3 / 131 Table of Contents Click on the topic to go to that section Intro to Ecology · Population Ecology · Community Ecology ·
Slide 4 / 131 Intro to Ecology Click to return to the Table of Contents Slide 5 / 131 Ecology Ecology is the study of how organisms interact with each other and their environments. Clownfish interact with sea anemones in a manner that is positive to both. The sea anemone provides protection and nutrients to the clownfish. In return, clownfish fecal matter provides nutrients to the sea anemone. Slide 6 / 131 Biotic vs Abiotic Factors that ecologists study can be either biotic or abiotic. Biotic factors of this coral reef include fish, corals, sea anemones, and plankton. Abiotic factors of this coral reef include water temperature, water salinity, nutrient availability and sunlight. Use this information to define the parameters of biotic and abiotic factors.
Slide 7 / 131 Biotic vs Abiotic Biotic Factors Abiotic Factors Nonliving factors in an Living factors in an environment. environment. Animals Sunlight · · Plants Water · · Fungi · Temperature · Bacteria Nutrients · · Soil · Slide 8 / 131 Salt Marsh The salt marsh ecosystem is composed of land that is submerged by ocean water during high tide and is dry during low tide. Organisms that live in a salt marsh need to have the ability to survive in both wet/dry conditions and in high/low salinity conditions. Plants are composed of grasses and shrubs. Common animals include crabs, mussels and a variety of birds. Many fish use salt marshes as hatcheries. Describe three biotic and three abiotic factors that affect the salt marsh. Slide 9 / 131 Levels of Biological Organization Ecosystem Community Population Organism SMALLEST LEVEL
Slide 10 / 131 Levels of Biological Organization Organism: Any individual that has all the characteristics of life. Slide 11 / 131 Levels of Biological Organization Population: A group of organisms of the same species that live in the same geographic area. Remember: What are the characteristics of a species? Slide 12 / 131 Levels of Biological Organization Community: All of the populations that live in the same geographic area.
Slide 13 / 131 Levels of Biological Organization Ecosystem: All of the living organisms (communities) and the nonliving components of a geographic area. Slide 14 / 131 Groups of different species living together and 1 interacting in the same environment are referred to as a A Organism B Community C Ecosystem D Population Slide 15 / 131 2 All of the following are abiotic factors EXCEPT: A Algae B pH C Temperature D Nutrients
Slide 16 / 131 3 Which of the following levels of biological organization includes both abiotic and biotic factors? Species A B Population C Community D Ecosystem Slide 17 / 131 Habitat The term habitat describes the specific area - including biotic and abiotic factors - where an organism lives within an ecosystem. A habitat is like an organism's home within an ecosystem. Slide 18 / 131 Ecological Niches An organism's niche is a description of the role it plays in its habitat. A niche includes all aspects of where and how an organism lives including: * the type of food it eats * how it obtains food * where it lives in its environment (tree, nest, hive, etc.) * when and how it reproduces
Slide 19 / 131 Ecological Niches Komodo Dragon Niche Komodo dragons live in the Indonesian Islands. They hunt and ambush invertebrates, birds and mammals. They lay up to 20 eggs at a time in self-dug holes. The eggs incubate for eight months. Komodo dragons take nine years to mature and can live up to 30 years. Slide 20 / 131 Ecological Niches A population's habitat answers the question "Where do you live?". A population's niche answers the question "How do you make a living?". Click this picture to watch a video about niches in the North African river plains. Slide 21 / 131 Ecological Niches No two species can occupy the same niche in the same environment at the same time. This is called niche overlap . When this occurs, competition for resources will displace one of the species. The figure below shows three different species of warblers that have established different niches in the same tree.
Slide 22 / 131 Ecological Niches Niche overlap leads to a fundamental niche and a realized niche for a species. Realized niche - the actual Fundamental niche - the optimal niche of a species, in niche of a species, as a result of competition the absence of limiting factors Slide 23 / 131 4 Traditionally, a polar bear's diet consists mainly of seals that it hunts from the edges of sea ice. As the sea ice melts and humans encroach on the existing habitat, polar bears are now known to hunt through human trash for nutrition. Describe the difference between the polar bear's fundamental niche and realized niche. Students type their answers here Slide 24 / 131 Population Ecology Click to return to the Table of Contents
Slide 25 / 131 Populations Population ecology studies the interactions between populations and their environments. Factors that affect populations can be density dependent or density independent. Slide 26 / 131 Density Dependent Factors Density dependent factors affect populations based on the density of that population. Examples include predation, competition and disease. A low density population will suffer more from heavy predation than a high density population. Slide 27 / 131 Density Independent Factors Density independent factors affect a population, regardless of population density. Examples include weather and natural disasters. Severe weather that causes flooding will destroy both high density and low density populations.
Slide 28 / 131 5 In 2005, hurricane Katrina deposited over 5 cm of sediment on the coastal wetland ecosystem of the Gulf of Mexico, destroying 100 km 2 of wetland. Did hurricane Katrina have density dependent or density independent effects? A Density dependent B Density independent Slide 29 / 131 6 In a field of wildflowers, population size is limited by available nutrients in the soil. When the density of flowers reaches a certain level, the death rate increases due to lack of nutrients. Is this population affected by density dependent or density independent factors? A Density dependent B Density independent Slide 30 / 131 Population Size Population size is positively correlated with birth rate and immigration and negatively correlated with death rate and emigration. Draw two graphs illustrating the relationship between population size and 1) birth rate/immigration and 2) death rate/emigration. Answer Entering Leaving
Slide 31 / 131 Exponential Population Growth When a population has access to unlimited resources, it experiences exponential growth. Exponential Population Growth d N = r N dt where r = growth rate and N = population size Slide 32 / 131 Exponential Population Growth After elephants in Kruger National Park, South Africa, were protected from hunting, the population grew exponentially for 60 years. When population size threatened to destroy habitat and food supply, park managers implemented elephant birth control and exportation. Slide 33 / 131 Logistic Population Growth Most populations do not have unlimited resources. When a population becomes too large, it exhausts food supply, water supply and shelter. At this point, intraspecific competition causes the population to decrease. Intraspecific competition - competition among members of the same species. These two lions are competing for the same prey.
Slide 34 / 131 Logistic Population Growth The population size that can be maintained with a given amount of resources is called the carrying capacity . Populations that are limited in resources experience logistic growth . In logistic growth, the rate of increase approaches zero as the carrying capacity is reached. Source: Nature.com Slide 35 / 131 Case Study: Red Tail Hawk Consider a new population of red tail hawks that have been released by conservationists into a woodland in upstate New York. Six years ago scientists released 50 hawks into a 900 acre woodland. Slide 36 / 131 Case Study: Red Tail Hawk Consider a new population of red tail hawks that have been released by conservationists into a woodland in upstate New York. Since the hawks had no natural predators and plenty of prey in the environment, they showed exponential population growth.
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