Ecosystems and Communities

What is Climate? Weather is the day-to-day condition of Earth’s atmosphere at a particular time and place Weather is the day-to-day condition of Earth’s atmosphere at a particular time and place Climate refers to the average, year- after-year conditions of temperature and precipitation in a particular region. Climate refers to the average, year- after-year conditions of temperature and precipitation in a particular region. 4-1

The Greenhouse Effect What is it? What is it? A natural situation in which heat is retained by a layer of greenhouse gases. A natural situation in which heat is retained by a layer of greenhouse gases. What causes it? Carbon dioxide, methane, water vapor, and a few other atmospheric gases trap heat energy and maintain Earth’s temperature range.

Effects of Latitude on Climate Because earth is a sphere that is tilted, solar radiation hits Earth at different angles Because earth is a sphere that is tilted, solar radiation hits Earth at different angles This creates 3 main climate zones This creates 3 main climate zones Polar zones = cold zones at the poles Polar zones = cold zones at the poles Tropical zones = warm zones around the equator Tropical zones = warm zones around the equator Temperate zones = in between the polar and tropical zones, vary from hot to cold throughout the year Temperate zones = in between the polar and tropical zones, vary from hot to cold throughout the year

Heat Transport in the Biosphere The unequal heating of earths surface drives winds and ocean currents spreading heat The unequal heating of earths surface drives winds and ocean currents spreading heat Warm air at the equator rises, cool air at the poles sinks creating wind currents Warm air at the equator rises, cool air at the poles sinks creating wind currents Warm water at the equator rises, cool water at the poles sinks creating ocean currents Warm water at the equator rises, cool water at the poles sinks creating ocean currents

What Shapes an Ecosystem? Biotic and Abiotic Factors Biotic and Abiotic Factors Niche Niche Community Interactions Community Interactions Ecological Succession Ecological Succession 4-2

Biotic Factors Ecosystems are influenced by a combination of biological and physical factors. Ecosystems are influenced by a combination of biological and physical factors. Biotic Factors are the biological (living) influences on organisms within an ecosystem. Biotic Factors are the biological (living) influences on organisms within an ecosystem. Examples: all living things it might interact with, birds, trees, mushrooms, bacteria… Examples: all living things it might interact with, birds, trees, mushrooms, bacteria…

Abiotic Factors Abiotic Factors are the physical (nonliving) factors that shape ecosystems Abiotic Factors are the physical (nonliving) factors that shape ecosystems Examples: temperature, precipitation, humidity, wind, nutrient availability, soil type, sunlight. Examples: temperature, precipitation, humidity, wind, nutrient availability, soil type, sunlight. Together, biotic and abiotic factors determine the survival and growth of an organism and the productivity of the ecosystem in which the organism lives. Together, biotic and abiotic factors determine the survival and growth of an organism and the productivity of the ecosystem in which the organism lives.

The Niche A niche is the full range of physical and biological conditions in which an organism lives and the way in which the organism uses those conditions. A niche is the full range of physical and biological conditions in which an organism lives and the way in which the organism uses those conditions. A niche includes the type of food it eats, how it obtains it, and which other species use the organism as food. It also includes the physical conditions it requires to survive and it includes when and how it reproduces. A niche includes the type of food it eats, how it obtains it, and which other species use the organism as food. It also includes the physical conditions it requires to survive and it includes when and how it reproduces. Everything an organism does to survive! Everything an organism does to survive!

The Niche No two species can share the same niche in the same habitat. No two species can share the same niche in the same habitat. Different species can occupy niches that are very similar Different species can occupy niches that are very similar Example Three species of North American warblers live in the same spruce trees, but they feed at different elevations and on different parts of the trees.

Community Interactions Community interactions, such as competition, predation, and various forms of symbiosis, can powerfully affect an ecosystem. Community interactions, such as competition, predation, and various forms of symbiosis, can powerfully affect an ecosystem.

Competition Competition occurs when organisms of the same or different species attempt to use an ecological resource in the same place at the same time. Competition occurs when organisms of the same or different species attempt to use an ecological resource in the same place at the same time. Resource refers to any necessity of life, such as water, nutrients, light, food, or space. Resource refers to any necessity of life, such as water, nutrients, light, food, or space. The competitive exclusion principle, states that no two species can occupy the same niche in the same habitat at the same time. The competitive exclusion principle, states that no two species can occupy the same niche in the same habitat at the same time.

Predation Predation is an interaction in which one organism captures and feeds on another organism. Predation is an interaction in which one organism captures and feeds on another organism. The predator is the organism that does the killing. The predator is the organism that does the killing. The prey is the food organism, the organism that is being hunted/eaten. The prey is the food organism, the organism that is being hunted/eaten.

Predation

Symbiosis is any relationship in which two species live closely together. Symbiosis means “living together” Three main classes of symbiosis: Mutualism Commensalisms Parasitism Symbiosis

Mutualism Mutualism is when both species benefit, they help each other. Example: many flowers depend on certain species of insects to pollinate them. The flowers provide the insects with food (nectar or pollen) and the insects help the flowers reproduce.

Mutualism

Commensalisms Commensalism is when one member of the association benefits and the other is neither helped nor harmed. Commensalism is when one member of the association benefits and the other is neither helped nor harmed. Example: barnacles attach themselves to a whale’s skin. Example: barnacles attach themselves to a whale’s skin. The barnacles don’t help or hurt the whale, but the barnacles benefit because as the whale swims, the constantly moving water carries the food the barnacles eat to them. The barnacles don’t help or hurt the whale, but the barnacles benefit because as the whale swims, the constantly moving water carries the food the barnacles eat to them.

Commensalisms

Parasitism Parasitism is when one organism lives on or inside another organism and harms it. Parasitism is when one organism lives on or inside another organism and harms it. The parasite obtains all or part of its nutritional needs from the other organism, called the host The parasite obtains all or part of its nutritional needs from the other organism, called the host Example: tape worms live in the intestine of mammals, Fleas, ticks, and lice live on the bodies of mammals, feeding on the blood and skin of the host Example: tape worms live in the intestine of mammals, Fleas, ticks, and lice live on the bodies of mammals, feeding on the blood and skin of the host

Parasitism

Ecological Succession Ecosystems are constantly changing in response to natural and human disturbances. As an ecosystem changes, older inhabitants gradually die out and new organisms move in, causing further changes in the community. These predictable changes that occurs in a community over time is called Ecological Succession.

Succession that occurs where no soil exists is called primary succession. Succession that occurs where no soil exists is called primary succession. When a disturbance of some kind changes an existing community without removing the soil, then secondary succession can take place. When a disturbance of some kind changes an existing community without removing the soil, then secondary succession can take place.

Primary Succession Stages The first species to populate the area are called pioneer species. It is usually lichens. Lichens break down rock, as they die they add organic material to help form soil in which plants can grow. After lichens, mosses appear, and grasses take root, then seedlings and shrubs can start to sprout.

Lichens and Mosses (pioneer species)

Succession

Secondary Succession Secondary succession happens when land is cleared and plowed for farming and is abandoned or when wildfire burns woodlands.