Communities, Biomes, and Ecosystems Chapter 3 Communities, Biomes, and Ecosystems

Community A group of interacting populations that occupy the same area at the same time. Plants, animals, bacteria, etc.

limiting factor Any biotic or abiotic factor that restricts the numbers, reproduction or distribution of organisms.

Food Water Space Disease Predation Shelter Nesting sites Examples include: Food Water Space Disease Predation Shelter Nesting sites Atmosphere (temp)

Range of Tolerance the upper and lower limits of what an organism can survive! Temperature pH (acidic or basic) oxygen

Would an organism with a wide or narrow range of tolerance be more likely to survive better when abiotic factors are greatly changed?

ecological succession The change in an ecosystem that happens when one community replaces another as a result of changing abiotic or biotic factors.

primary succession The establishment of a community on an area of exposed rock that does not have top soil.

Usually starts with lichens and mosses that break down rock. Volcanic areas! These pioneer organisms produce dead decaying material to help create soil.

Lichen = a combination of fungus and algae

A seedling saltbush pioneers volcanic cinders Sagebrush and a single pine colonize the cinder barrens left from an eruption

Primary succession

Secondary succession (not after primary, after an event that changes the ecosystem!) The change that takes place after a community has been removed but the soil has remained intact from an event such as fire, flood or windstorm. Pioneer species are the first to grow in this process . These are different from primary pioneer species. It is faster because soil is already present.

Example of secondary succession.

Secondary succession

Climax community A mature community that results when there is little change in the composition of species. The end result of primary succession.

Desert Climax Community

Rainforest

Arctic tundra

Disturbances in a community: Fire Flood Windstorm Hurricane Landslide

Lake Eyre Basin Australia Following periodic heavy rainful, the natural-flowing rivers that make up the region overfill with water and travel thousands of miles inland to the lowest part of the continent, Lake Eyre basin. What happens next is a marvel of nature. The basin–covering one-sixth of the continent–collects water flowing from these rivers, particular the three largest—Cooper Creek, Diamantina and Georgina rivers. The water in turn awakens dormant wildlife and attracts water birds from across the country to breed and feed.

Human Impact??

Tree Harvesting

Replanting after tree harvesting.

Biomes A large group of ecosystems that share the same climate and have similar types of plant communities. (9 -10) These are determined by latitude and climate. Generally found at the same latitude and altitude.

Latitude The distance of any point on the surface of Earth north or south of the equator.

As you go to higher latitudes the temperature decreases due to the decrease in the sun’s intensity this is due to the curvature of the earth.

Climate The average weather conditions in an area including temperature and precipitation. Factors affecting climate: Latitude Proximity to water Shape of land (topography) Direction of prevailing winds (Jet Stream)

3 climate zones: polar, temperate, tropical

Proximity to water can affect climate: City B is closer to a large body of water. Its temperature line is flatter (moderated).

What factors determine the 9 biomes What factors determine the 9 biomes? Defined primarily according in the characteristics of their plants and animals. These are determined by latitude and climate!

Terrestrial Biome = on land

Tundra: treeless, permanently frozen soil permafrost.

Boreal Forest: evergreens coniferous forest, taiga.

Temperate Forest: deciduous trees, 4 seasons

Temperate woodland: mixed shrubs, less rainfall

Temperate grassland: fertile soil, drought, prevents large trees

Desert: rate of evaporation exceeds rate of precipitation, on every continent except Europe

Tropical Savanna: grasses, scattered trees, low precipitation

Tropical seasonal forest: dry, trees drop leaves to conserve water

Tropical Rain Forest: Large amounts of rainfall, tall broad leaved trees.

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Aquatic Ecosystems (3) Grouped based on abiotic factors: Water flow Depth (related to light) Distance from shore Salinity Latitude

1. Freshwater Ecosystems Ponds, lakes, streams, rivers, and wetlands Low salt content 2.5 % water on earth is freshwater Almost 70% of fresh water is frozen in glaciers.

Lakes are divided into zones: Littoral zone: shallow near the shore, allows sunlight to penetrate through. Limnetic zone: open water: plankton free floating Profundal zone: deepest part, no light

Lake Zones

2. Transitional Aquatic Ecosystems Transitional = where land and water meet or where salt and fresh water meet Wetlands: marshes, swamps, bogs Estuaries: transitional very diverse, freshwater and saltwater mix.

A bog!

2,400 yrs old

Apalachicola Estuary Estuaries: transitional very diverse, freshwater and saltwater mix.

3. Marine Ecosystems Intertidal: where ocean meets land Photic: a zone in the ocean water to a depth of about 200 meters also called the euphotic zone, the area shallow enough for sunlight to penetrate! Large numbers of organisms can be found in the photic zone!

Phytoplankton (plants) Zooplankton (animals) Fish Turtles Jellyfish What lives in the photic zone? Phytoplankton (plants) Zooplankton (animals) Fish Turtles Jellyfish Dolphins ??????

Phytoplankton

Zooplankton

Basking shark

Aphotic: Below the photic zone, sunlight can not penetrate! Benthic: on the ocean floor. Abyssal: deepest part of the ocean These categories are based on the depth of the ocean.

Know these zones! Be able to label them!!!!

What lives in the aphotic zone? Octopus Eels Angler Fish Hagfish Squid ***The cold, deep water has more nutrients. Why? Things die and sink!

Hydrothermal tube worm