Unit 2 Ecology Ch. 3 The Biosphere

What Is Ecology?  Like all organisms, we interact with our environ.  To understand these interactions better & to learn how to control them, we turn to the science of ecology  Like all organisms, we interact with our environ.  To understand these interactions better & to learn how to control them, we turn to the science of ecology

Interactions & Interdependence  Ecology - the study of interactions between organisms & their environ. or surroundings  Biosphere - the portions of the planet in which all life exists (including: land, water, & air or atmosphere)  The highest level of organization  Ecology - the study of interactions between organisms & their environ. or surroundings  Biosphere - the portions of the planet in which all life exists (including: land, water, & air or atmosphere)  The highest level of organization

Interactions & Interdependence  Interactions within the biosphere produce a web of interdependence between organisms & the environ. in which they live  Interdependence - relying on one another to survive  Interactions within the biosphere produce a web of interdependence between organisms & the environ. in which they live  Interdependence - relying on one another to survive

Levels of Organization  To understand relationships within the biosphere, ecologists ask questions about events & organisms

Levels of Organization  Some ecologists study interactions between a particular kind of organism & its surroundings  These studies focus on the species level  Species - a group of organisms so similar to 1 another that they can breed & produce fertile offspring  Some ecologists study interactions between a particular kind of organism & its surroundings  These studies focus on the species level  Species - a group of organisms so similar to 1 another that they can breed & produce fertile offspring

Levels of Organization  Other ecologists study populations  Population - groups of individuals that belong to the same species & live in the same area  Other ecologists study populations  Population - groups of individuals that belong to the same species & live in the same area

Levels of Organization  Still others study communities  Community - different populations that live together in an area  Still others study communities  Community - different populations that live together in an area

Levels of Organization  Ecosystem - a collection of all the living & nonliving (physical) components of an envrion.  Biome - group of ecosystems that have the same climate & similar communities  Ecosystem - a collection of all the living & nonliving (physical) components of an envrion.  Biome - group of ecosystems that have the same climate & similar communities

Levels of Organization

Energy Flow  At the core of every organism’s interaction with the environ. is its need for energy to power life’s processes  The flow of energy through an ecosystem is an important factor in determining the system’s capacity to sustain life  At the core of every organism’s interaction with the environ. is its need for energy to power life’s processes  The flow of energy through an ecosystem is an important factor in determining the system’s capacity to sustain life

Producers  Without a constant supply of energy, living systems cannot function  Sunlight is the main energy source for life on Earth  Without a constant supply of energy, living systems cannot function  Sunlight is the main energy source for life on Earth

Producers  Autotrophs - organisms that can capture energy from sunlight & use it to produce food  Includes: plants, some algae, & certain bacteria  Also called producers - they can make their own food  Autotrophs - organisms that can capture energy from sunlight & use it to produce food  Includes: plants, some algae, & certain bacteria  Also called producers - they can make their own food

Producers  Autotrophs use light energy to power chemical reactions that convert carbon dioxide & water into oxygen & energy-rich carbs. - photosynthesis

Consumers  Heterotrophs - (consumers) - organisms that rely on other organisms for their energy & food supply  There are 5 different types of heterotrophs: herbivores, carnivores, omnivores, detritivores, & decomposers  Heterotrophs - (consumers) - organisms that rely on other organisms for their energy & food supply  There are 5 different types of heterotrophs: herbivores, carnivores, omnivores, detritivores, & decomposers

Consumers  Herbivores - eat plants  Carnivores - eat animals  Omnivores - eat both plants & animals  Detritivores - feed on plant & animal remains & other dead matter  Decomposers - break down organic matter (bacteria & fungi)  Herbivores - eat plants  Carnivores - eat animals  Omnivores - eat both plants & animals  Detritivores - feed on plant & animal remains & other dead matter  Decomposers - break down organic matter (bacteria & fungi)

Feeding Relationships  Energy flows through an ecosystem in 1 direction, from the sun to autotrophs (producers) & then to various heterotrophs (consumers)  The energy stored by producers can be passed through an ecosystem along a food chain  Energy flows through an ecosystem in 1 direction, from the sun to autotrophs (producers) & then to various heterotrophs (consumers)  The energy stored by producers can be passed through an ecosystem along a food chain

Feeding Relationships  Food chain - a series of steps where organisms transfer energy by eating & being eaten  Food chains show the 1-way flow of energy in an ecosystem  Food chain - a series of steps where organisms transfer energy by eating & being eaten  Food chains show the 1-way flow of energy in an ecosystem

Feeding Relationships  Food web - links all the food chains in an ecosystem together  Trophic level - each step in a food chain or food web  Producers make up the 1st trophic level, consumers make up the 2nd, 3rd, etc.  Each consumer depends on the trophic level below it for energy  Food web - links all the food chains in an ecosystem together  Trophic level - each step in a food chain or food web  Producers make up the 1st trophic level, consumers make up the 2nd, 3rd, etc.  Each consumer depends on the trophic level below it for energy

Food Web

Ecological Pyramids  Energy pyramid - a diagram that shows the amount of energy in each trophic level in a food chain or food web  Organisms use about 10% of the energy for life processes, the rest is lost as heat  Energy pyramid - a diagram that shows the amount of energy in each trophic level in a food chain or food web  Organisms use about 10% of the energy for life processes, the rest is lost as heat

Cycles of Matter  Unlike the 1-way flow of energy, matter is recycled within & between ecosystems  Matter can cycle through the biosphere because biological systems do not use up matter, they transform it  Unlike the 1-way flow of energy, matter is recycled within & between ecosystems  Matter can cycle through the biosphere because biological systems do not use up matter, they transform it

The Water Cycle

Nutrient Cycles  Nutrients - all the chemical substances that an organism needs to sustain life  Every living organism needs nutrients to build tissues & carry out essential life functions  Like water, nutrients are passed between organisms & the environ. through cycles  Nutrients - all the chemical substances that an organism needs to sustain life  Every living organism needs nutrients to build tissues & carry out essential life functions  Like water, nutrients are passed between organisms & the environ. through cycles

Nutrient Limitation  Primary productivity - the rate that organic matter is created by producers  1 factor that controls PP is the amount of available nutrients  Primary productivity - the rate that organic matter is created by producers  1 factor that controls PP is the amount of available nutrients

Nutrient Limitation  If a nutrient is in short supply, it will limit an organism’s growth  Limiting nutrient - when an ecosystem is limited by a single nutrient that is scarce  If a nutrient is in short supply, it will limit an organism’s growth  Limiting nutrient - when an ecosystem is limited by a single nutrient that is scarce

Nutrient Limitation  When an aquatic ecosystem receives a large input of a limiting nutrient, it often results in an immediate increase in the amount of algae & other producers - algal bloom