The Biosphere Chapter 3

What is Ecology?

Ecology The study of the interactions among organisms and between organisms their environment.

Biosphere  All parts of the Earth where life can exist (land, water and air).

Biotic vs. Abiotic  Biotic: the living factors in an ecosystem  Abiotic: the nonliving factors in an ecosystem

Levels of Organization  Ecosystem: interactions among the community and abiotic factors  Community: group of interacting populations  Population: group of one species living in the same place at the same time  Ecosystem: interactions among the community and abiotic factors  Community: group of interacting populations  Population: group of one species living in the same place at the same time

Energy, Producers, and Consumers

Autotrophs An organism that can make its own food. Use photosynthesis or chemosynthesis. Also called producers.

Heterotrophs An organism that has to get its food from others. Also called consumers.

Types of Heterotrophs  Herbivores: eat only plants  Carnivores: eat only meat  Omnivores: eat both plants and meat  Detritovores: break down dead material; decomposers  Scavengers: eat dead animals  Herbivores: eat only plants  Carnivores: eat only meat  Omnivores: eat both plants and meat  Detritovores: break down dead material; decomposers  Scavengers: eat dead animals

Energy Flow in Ecosystems

Feeding Relationships Food chains: less complex Food webs: show all eating relationships in an ecosystem. BETTER! Food chains: less complex Food webs: show all eating relationships in an ecosystem. BETTER!

Trophic Levels Each step in a food chain. As you move up trophic levels, 90% of the energy is lost.

Ecological Pyramids Energy Pyramid (kCal) Energy Pyramid (kCal)

Cycles of Matter

The Water Cycle

Nutrient  Chemicals an organism needs to sustain life.  Carbon  Nitrogen  Phosphorous  Limiting nutrient: the nutrient whose supply limits productivity of producers  Chemicals an organism needs to sustain life.  Carbon  Nitrogen  Phosphorous  Limiting nutrient: the nutrient whose supply limits productivity of producers

Carbon Cycle

Nitrogen Cycle

Phosphorous Cycle

Ecosystems & Communities Chapter 4

Niches & Community Interactions

Niche Everything an organism does to survive. All physical and biological conditions. What it eats, where it lives (habitat), how it avoids predators, etc. Everything an organism does to survive. All physical and biological conditions. What it eats, where it lives (habitat), how it avoids predators, etc.

Competition  Occurs when two organisms want the same resource at the same time.  Competitive Exclusion Principle: No two species can occupy the same niche at the same time.  Occurs when two organisms want the same resource at the same time.  Competitive Exclusion Principle: No two species can occupy the same niche at the same time.

Predation An interaction where one organism captures and feeds on another organism. Predator: the “killer” Prey: the “killed” An interaction where one organism captures and feeds on another organism. Predator: the “killer” Prey: the “killed”

Keystone Species  A species that exerts strong control on the structure of a community so that changes to its population causes dramatic changes  Ex: sea otters  A species that exerts strong control on the structure of a community so that changes to its population causes dramatic changes  Ex: sea otters

Symbiosis Any relationship in which two species live closely together. Mutualism: both species benefit Ex: bees and flowers Commensalism: one species benefits while the other is not affected Ex: barnacles on a whale Parasitism: one species benefits, while the other is harmed Ex: tapeworms- YUK! Examples of Symbiosis Any relationship in which two species live closely together. Mutualism: both species benefit Ex: bees and flowers Commensalism: one species benefits while the other is not affected Ex: barnacles on a whale Parasitism: one species benefits, while the other is harmed Ex: tapeworms- YUK! Examples of Symbiosis

Succession

Ecological Succession The series of predictable changes that occur in an ecosystem over time. Primary Succession: occurs where there is no soil 1st: lichens; 2nd: mosses; 3rd tree seedlings appear Ex: after a volcano erupts Secondary Succession: occurs where there is soil Ex: after a forest fire The series of predictable changes that occur in an ecosystem over time. Primary Succession: occurs where there is no soil 1st: lichens; 2nd: mosses; 3rd tree seedlings appear Ex: after a volcano erupts Secondary Succession: occurs where there is soil Ex: after a forest fire

Climate

Weather vs. Climate Weather: the day to day condition of the Earth at a particular time and place Climate: the average, year-to-year conditions of temperature and precipitation Weather: the day to day condition of the Earth at a particular time and place Climate: the average, year-to-year conditions of temperature and precipitation

Effect of Latitude on Climate The tilt of the Earth creates climate zones based on latitude: Polar Temperate Tropical The tilt of the Earth creates climate zones based on latitude: Polar Temperate Tropical

Heat Transport in the Biosphere Unequal heating of the Earth drives winds and ocean currents. Air and water near the equator heats and rises. Unequal heating of the Earth drives winds and ocean currents. Air and water near the equator heats and rises.

Ozone Layer Layer of the Earth’s atmosphere (13-20 km above Earth) containing ozone (O 3 ). Absorbs 93-99% of UV light. Layer of the Earth’s atmosphere (13-20 km above Earth) containing ozone (O 3 ). Absorbs 93-99% of UV light.

The Greenhouse Effect Natural situation where gases trap the sun’s heat energy in the atmosphere. Maintains our climate. (Earth would be 30 ºC cooler without it.) Natural situation where gases trap the sun’s heat energy in the atmosphere. Maintains our climate. (Earth would be 30 ºC cooler without it.)

Humans in the Biosphere

Carrying Capacity  The maximum number of individuals of a particular species that a particular environment can support.

Resources  Renewable Resource: can be replaced by a healthy ecosystem  Ex: trees, wind  Nonrenewable Resource: can’t be replenished by natural processes in a reasonable amount of time  Ex: fossil fuels  Renewable Resource: can be replaced by a healthy ecosystem  Ex: trees, wind  Nonrenewable Resource: can’t be replenished by natural processes in a reasonable amount of time  Ex: fossil fuels

Biological Magnification  Increasing concentration of a harmful substance in organisms at higher trophic levels in a food chain

Biodiversity  All of the organisms in the biosphere  Ecological hot spot: a place where significant numbers of species and habitats are in immediate danger of extinction  All of the organisms in the biosphere  Ecological hot spot: a place where significant numbers of species and habitats are in immediate danger of extinction

Conservation  “wise use”  studying the loss of biodiversity & ways it can be prevented  “wise use”  studying the loss of biodiversity & ways it can be prevented

Ecological footprint  The total area of functioning land and water ecosystems needed to provide resources and absorb the wastes of an individual or population.  Used to calculate the biosphere’s carrying capacity for humans.  The total area of functioning land and water ecosystems needed to provide resources and absorb the wastes of an individual or population.  Used to calculate the biosphere’s carrying capacity for humans.