Chapter 3 4 Ecology Ecosystems Communities Ms Carballosa
Chapter 3 & 4: Ecology, Ecosystems, & Communities Ms. Carballosa Biology
What is ecology? The study of interactions among organisms They study the biosphere – from Earth’s atmosphere to the trenches of the ocean and everything inbetween
What is ecology? These interactions are interdependent: between environments, everything is connected We are constantly changing our surroundings by our habits (eating, driving, creating houses, etc).
Levels of Organization Organism Planet Earth Group of ecosystems that share similar climates and organisms Species: group of similar organisms that can breed and reproduce Population Group of species Biome Community Ecosystem Different populations together All organisms in an area & their non-living parts
Levels of Organization
Biotic vs. Abiotic Biotic: Living -Ex: Animals, plants, bacteria Abiotic: Non-living -Ex: Sunlight, water, heat, soil Which levels of organization including abiotic factors?
Biotic vs. Abiotic Would bean seeds grow better in sand or soil? ? What are some abiotic factors you can find it soil that you can’t find in sand?
Energy, Producers & Consumers We need energy in order to survive… to get out of bed in the morning! You can get your energy from a poptart, but where did the poptart get it?
Energy, Producers & Consumers The ultimate source of energy is the sun! -Photosynthesis: Plants converting energy from the sun into “food” Sometimes, organisms get energy from chemicals: Chemosynthesis -Bacteria that use sulfur deep in the ocean, or in volcanoes.
Energy, Producers & Consumers Autotrophs: use solar / chemical energy to produce “food”. - “Food” is an inorganic substance turned organic (it now contains Carbon) -Also known as Primary Producers They store this energy to pass on to others. Without them, our ecosystem wouldn’t have any energy and you wouldn’t have any food!
Reminder! Energy cannot be created nor destroyed, it can only be transferred and converted!!
Energy, Producers & Consumers We cannot make our own energy, we have to get it from other organisms -Known as Heterotrophs or Consumers
Energy, Producers and Consumers Different kinds of Consumers: -Carnivores: kill and eat other animals (lion) -Scavengers: eat bodies of dead animals (hyenas) -Decomposers: break down organic matter (bacteria) -Herbivores: eat plant parts (birds) -Omnivores: eat both plants and animals (us) -Detritivores: eat decomposers (shrimp)
Discovery Education Elements of Biology: Ecosystems: Organisms and their environment
Community Interactions Organisms live in different places depending on the range of conditions that let it live… we wouldn’t survive Antarctica right? -Known as the range of tolerance Range of tolerance determines the species’ habitat: the general place where an organism lives Penguins tolerance is only in cold temperatures and near water for fishing… they would not tolerate the Sahara desert.
Community Interactions Niche: describes the organism’s role and interaction with the biotic and abiotic factors of its environment -Think jobs Important to understand how organisms interact to form communities… the jobs should benefit everyone in some way to keep the community flowing.
Community Interactions Important parts of a niche: -Resources: Any necessity of life (water, nutrients, food or space) -Physical aspects: Abiotic factors it requires to survive (frogs need moist areas to survive) -Biological aspects: Food it eats
Community Interactions What happens when more than one organism has the same niche? ? Competition!! -For food, water, mates, space, etc. -Usually fight to the death and one species dies out while the other survives. Sometimes, the other can adapt to a new niche.
Community Interactions
Community Interactions Competitive Exclusion Principle: No two species can have the exactly the same niche, in the same habitat, at the same time. -One will ALWAYS die out -Perhaps why some of us adapted to being omnivores?
Community Interaction Figure 4 -7 on Pg. 101: Dividing Resources In other words, learn to share!!
Predation
Predation Very important in shaping communities: helps keep the number of plants and animals in check! Predator: the one that kills and eats the animal Prey: the one that is eaten Their relationship determines where the prey can live and feed.
Predation Herbivore / Plant relationship is also predation! Only this time, there is no hunting and killing Affects the size and distribution of plant populations Can completely wipe out plant populations if too many herbivores are in the area
Keystone Species Changes in one important organism, called the keystone species, can have dramatic effects on the ecosystem Otters Sea Urchins Kelp
Symbioses Any relationship in which 2 organisms live close together 3 main types: Mutualism, Parasitism, & Commensalism.
Mutualism Both species benefit Nemo! -The anemone guards the clownfish with its stingers, and the clownfish chase away fish much bigger than themselves to protect its home.
Parasitism One organism benefits (usually by living inside it and taking its energy) and the other gets harmed Ex: Mosquitos, tapeworms, leeches
Commensalism One organism benefits and the other is neither helped nor harmed Ex: Barnacles on whales
Conditions Underwater What factors affect life in aquatic ecosystems? Aquatic organisms are affected primarily by: Ø Water’s depth Ø Temperature Ø Flow Ø Amount of dissolved nutrients Due to runoff from land, distance from shore also shapes marine communities Are these biotic or abiotic factors?
Water depth Identify the producer and the consumer in the photic zone. Photic zone: the sunlit region near the surface photosynthesis can occur. as deep as 200 meters – tropical seas A few meters deep or lessrivers, swamps Home to: Photosynthetic algaephytoplankton Zooplanktontiny free-floating animals eat phytoplankton Proprofs. com phytoplankton Firstlook. pnas. org
Water depth Below the photic zone is the dark aphotic zone Where photosynthesis cannot occur En. wikibooks. org
Water depth benthos: aquatic organisms living on, or in, rocks and sediments on the bottoms of lakes, streams, and oceans. Benthic zone: The bottoms of lakes, streams, and oceans ØIn shallow water or photic zone, algae and rooted aquatic plants can grow in the benthic zone ØWhen the benthic zone is below the photic zone, chemosynthetic autotrophs are the only primary producers. Studyblue. com
Temperature and Currents In aquatic habitats temperatures are: Warmer near equator colder near the poles. Warmer in the surface waters colder in the deepest parts Currents also play a role in the temperature of water. Carry water significantly warmer or cooler than would be typical for any given: Ø Latitude Ø Depth Ø Distance from shore
Nutrient Availability Organisms need certain substances to live such as: Ø Oxygen Ø Nitrogen Ø Potassium Ø Phosphorus Type and availability of substances vary between bodies of water. This greatly affects the types of organisms that can survive there
Freshwater Ecosystems What are the major categories of freshwater ecosystems?
Freshwater Ecosystems 3% of Earth’s water! Can be divided into three main categories: 1. Rivers and streams 2. Lakes and ponds 3. Freshwater wetlands
The Everglades are wetlands in southern Florida
Freshwater Ecosystems Rivers and Streams Originate from underground water sources in mountains or hills. Near a source, water has plenty of dissolved oxygen but little plant life. Downstream, sediments build up and plants establish themselves. Animals depend on terrestrial plants and animals living along their banks for food.
Freshwater Ecosystems Lakes and Ponds Freshwater wetlands Food web based on phytoplankton Water covers the soil… may travel or stand still Water circulates between surface and benthos to distribute heat, oxygen and nutrients Nutrient rich and highly productive Purify water of pollutants Made up of bogs, marshes and swamps
Estuaries • Special wetland where river meets the sea (mix of what kind of water? ) • Usually shallow, supports plenty of life • Spawning and nursing grounds for important fish and shellfish (crabs, shrimp, bass) • Examples: salt marsh (Chesapeake Bay) and mangrove swamp (Everglades!)
Marine Ecosystems Divided by depth and distance from shore into zones 1. Intertidal zone 2. Coastal zone 3. Open Ocean
Intertidal Zone • Submerged during high tide, open at low tide • Mostly barnacles and seaweed grow here • Closest to shore
Coastal Ocean • Begins at low tide to the shallow border of the ocean • Here, you find kelp forests and coral reefs – lots of life
Open Ocean • More than 90% of our ocean is considered open ocean • Ranges from 500 m to 10, 000 m deep • 2 areas: Photic and Aphotic (what do these mean again? ? ) Photic animals: Sharks, Whales Aphotic animals: Squids, Creepy fish
Succession • A series of predictable changes that occur in a community over time, usually after a disturbance • 2 types: 1. Primary succession 2. Secondary succession
Primary vs. Secondary • Begins in an area with no remains of the older community (volcanic eruption) • • Pioneer species: first species to colonize the barren area -Usually grass or fungus • Begins in an area where some of the community is still left behind (fire, hurricane, human interference) Much faster that primary succession / no pioneer species
Climax Communities • The maximum amount of organisms a community can hold • After natural disturbances, usually reaches its previous climax community • After human disturbances, the ecosystem may or may not recover
Biodiversity
Biodiversity The total of all genetically based variations of organisms in the biosphere 3 types of biodiversity: 1. Ecosystem diversity 2. Species diversity 3. Genetic diversity
Ecosystem Diversity Variety of habitats, communities, and ecological processes in the biosphere
Species Diversity Different species in the biosphere or in a particular area
Genetic Diversity Different genetic forms carried by a particular species
Valuing Biodiversity contributes to medicine, agriculture, and ecosystems We get some of our medicines from species We get different kinds of foods – different potatoes, for example Keystone species: otter! Without it, we lose the biodiversity in the ecosystem!
Threats to Biodiversity We are pushing animals to extinction at 1000 times the rate it naturally is! If we kill off genetic diversity, we kill species diversity, and eventually ecosystem diversity!
Human Impact We destroy habitats, hunt, introduce invasive species, release pollution into food webs, and contribute to climate change (global warming!)
What can we do to protect biodiversity? Protect individual species Preserve habitats and ecosystems Have benefits for human neighbors of conservation areas
What can we do to protect biodiversity? Target ecological hotspots: areas that are in immediate danger of extinction
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