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Download Ecology: The Biosphere - BIOLOGY
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Ecology: The Biosphere We talked about cellstissuesorgansorgan systemsorganisms What do animals need to survive? -food source -water -shelter Keeping those 3 things in mind, think of an animal that lives in this area. What are it’s: --food source(s)? --water source(s)? --types of shelter? So… Animals need these things to survive and they have to interact with them daily. This branch of biology is called ecology. Ecology can be defined as: -scientific study of interactions among organisms and between organisms and their environment. Biospherecontains the combined portions of the planet in which ALL LIFE EXISTS [land, water, air (atmosphere)] Organisms in the biosphere (everything) are interdependent of each other and the environment. always changing! Levels of Organization Range in complexity from a single individual to the entire biosphere 6 levels (from most specific to least specific): 1. Individual 2. Population 3. Community 4. Ecosystem 5. Biome 6. Biosphere 1. Individual -Individual organisms (species) -able to interbreed because so similar to one another 2. Population -groups of individuals that belong to the same species -live in the same area 3. Community -different populations that live together in one area 4. Ecosystem -collection of organisms that live in a particular place -live in a certain area with living and non-living/physical environment 5. Biome -group of ecosystems that have the same climate and communities 6. Biosphere: the combined portions of the planet in which ALL LIFE EXISTS [land, water, air (atmosphere)] So… We have all these organisms living together and relying on each other… How to these organisms survive (use food, water, shelter etc. but what do they need to make use of these things)? They need energy! >>What is energy? The ability to do work. Energy makes the world go ‘round>> The flow of energy through an ecosystem is one of the most important factors that determine a system’s capacity to sustain life. WHY? -energy gives organisms the ability to survive (get food, reproduce, daily functioning!) Ecosystems are open systems in which energy flow is one way, and materials and nutrients are recycled. What is the main energy source for life on Earth? -The big yellow one Sun -less than 3% of the Sun’s energy that reaches the Earth is actually used by living things What types of organisms use this energy to MAKE their own energy? -Plants, some types of algae, and some types of bacteria How? -Photosynthesis -return back to this later on this quarter >>We call these organisms that use energy from the environmentAUTOTROPHS [auto- means self] We also call autotrophs PRODUCERS Not all organisms get their energy from sunlight. What are some types of organism that get their energy elsewhere? Organisms that get their energy by relying on other organisms are called HETEROTROPHS We also call heterotrophsCONSUMERS Thinking back to those organisms we talked about above, where do they get their energy from? -eating plants -eating animals -eating plants and animals -animal remains and other dead matter -break down organic matter (things around them in the soil etc.) >>Herbivores obtain energy by eating only plants Examples: Cows, Caterpillars, Deer >>Carnivores obtain energy by eating only animals Examples: Snakes, Dogs, Owls >>Omnivores obtain energy by eating both plants and animals Examples: Humans, Bears, Crows >>Detritivores obtain energy by feeding on plant and animal remains/dead matter Examples: Mites, Earthworms, Snails >>Decomposers obtain energy by breaking down organic matter (soil, plants etc.) Examples: Bacteria, Fungi >>So which are producers and which are consumers?<< So… If the energy begins in a simple plant then how does a carnivore get its energy? -By eating other organisms which eventually leads back to the sun. Ecosystems are open systems in which energy flow is one way, and materials and nutrients are recycled. The energy stored by PRODUCERS can be passed through an ecosystem to CONSUMERS along a food chain. Trophic Levels: each step in a food chain/food web. >>Producers make up the 1st trophic level >>Primary consumers [consumers that eat plants] make up the 2nd trophic level >>Secondary consumers [consumers that eat primary consumers] make up the 3rd trophic level And so on and so forth… >What are the ingredients/parts of a cheeseburger? meat patty bun lettuce cheese tomato mustard/ketchup >>Where did the meat patty come from? >>What did the cow need to grow? >>What kind of food did the cow eat? >>What did the grass need to grow? Food Chain of a Cheeseburger Do these types of relationships exist in nature? What is the problem with a food chain? Food Chain [1 path of energy] Food Web [Multiple paths of energy] Food Webs In nature, feeding relationships aren’t as simple as a food chain. Most animals feed on various types of organisms and are preyed upon by multiple animals. Keystone species species that have, for various reasons, a substantial effect disproportionate to their numbers - on the rest of the community. The sea otter, at the top of the diagram, acts as a "keystone species" in the community. >>Because they lack the blubber of other marine mammals, individual sea otters need to consume a huge amount of food each day to stay warm and healthy. >>While a population of otters may eat many things, sea urchins are their favorite prey. Since sea urchins can have major effects on other species in the community, otter predation on them exerts a controlling influence on the ecosystem. >>The impact of sea urchins is relatively well understood. Sea urchins, endowed with strong jaws and very hard teeth (see photo below), are tireless grazers, capable of consuming tough, woody kelps and mineralized invertebrate skeletons. Studies have shown that, in the absence of otters, some urchin populations can grow so dense that they consume nearly all the bottom cover of edible algae and sessile invertebrates.
