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Ecology. You + the world around you. Some cool facts…. 75%. _______ of all animals are beetles. Cockroaches can live _______ without their head (and their heads can stay alive without their bodies!). ______ of the world’s fresh water is stored in Antarctica’s ice.
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Ecology You + the world around you
Some cool facts… 75% • _______ of all animals are beetles. • Cockroaches can live _______ without their head (and their heads can stay alive without their bodies!). • ______ of the world’s fresh water is stored in Antarctica’s ice. • Homeowners use _______________ toxic chemicals per acre than farmers • In Peru a single bush may contain more ant species than in the British Isles. • A single porcupine is known to kill 100 trees in one winter weeks 70% up to 10 times more
Ecology Buzzwords • Biosphere • Ecosystem • Community • Biotic • Abiotic • Ecological succession • Biome • Producers • Consumers • Decomposers • Water cycle • Carbon/oxygen cycle • Nitrogen cycle • Commensalism • Mutualism • Parasitism
What is Ecology? • Ecology is the study of the interactions of organisms with one another and with their physical environments. • Ecology studies the biosphere.
Biosphere Ecosystem Biome Community Population Individual
What is the Biosphere? • The biosphere is that part of the Earth in which life exists • This includes: - air - land - water - ALL organisms How many kilometres above the earth/below the ocean does the biosphere extend?
The biosphere is HUGE!!! And very complex so, instead we study… Ecosystems!
Biosphere Ecosystem Biome Community Population Individual
What is an Ecosystem? • An ecosystem is the combination of an area’s abiotic and biotic factors. What do you think abiotic and biotic mean?
Abiotic Biotic Physical features • air • water • rainfall • temperature • soil • rocks • elevation • humidity ALL living organisms
Can you name some of the biotic and abiotic features in this photo?
Time to think… • Name the abiotic and biotic features of your house as a mini “ecosystem”
As ecosystems change, they undergo ecological succession The process through which the existing community of organisms is replaced by a different community over periods of time
Succession (usually) leads to a climax community A fairly stable collection of organisms
So what have we learned about ecological succession? small things come first! depending on what happened, it can be (relatively) fast ORverrrrry slow sometimes, a whole new ecosystem is formed
Biosphere Ecosystem Biome Community Population Individual
What’s a biome? • An environment that has a CHARACTERISTIC climax community • There are 2 main types of biomes land aquatic
Can you name any types of biomes? Land Aquatic • tundra • taiga • temperate deciduous forests • grasslands • tropical rainforests • desert • rivers • streams • lakes • intertidal zone • neritic zone • open-sea zone • deep-sea zone • estuaries (freshwater) (marine)
Ecosystems and Energy • What is the primary source of ALL energy on Earth?
So… • Producers • Consumers • Decomposers • Produce their own food ex: plants, some bacteria • Consume food made by producers ex: animals • Decompose dead producers and consumers ex: fungi, bacteria
A note about consumers… • There are different levels of consumers! primary consumers = herbivores secondary consumers tertiary consumers quarternary consumers Omnivores and carnivores
A review of Energy Cycles(you should’ve seen these in Gr. 10…) • Water cycle • Nitrogen cycle • Carbon cycle • Oxygen cycle
Biosphere A community is all of the populations in a given area For example: All organisms living on a decomposing tree Biome Ecosystem Community Population Individual
symbiosis • A close relationship between two species in which at least one species benefits from the other. • parasitism • commensalism • mutualism
Which relationship? Aphids provide ants with a sugary substance . In return, ants defend their “herds” from predators.
Which relationship? • Shrimp live within the stinging tentacles of sea anemones. Shrimp are protected from predators. Anemones are not harmed, nor do they benefit.
Which relationship? • Ticks bite into the skin of animals and feed on their blood.
Biosphere A population is a group of individuals of the same species that live in a particular location. For example: All pine beetles living on a decomposing tree (larvae and adults) Biome Ecosystem Community Population Individual
But…why aren’t we buried in cats? There are factors that control populations Can you think of any factors that control population numbers?
Population growth is controlled by density-dependent limiting factors competition predation parasitism crowding and stress *Size of the group matters!*
The density-dependent limiting factors are all related to each other and can exacerbate each other. for example, crowding makes it easier for parasites to infect more hosts, which causes more stress to parasitized animals, which can make them more vulnerable to predation and less able to compete with other animals for resources
Populations are also controlled by density-independent limiting factors natural disasters extreme changes in temperature (frosts, heat waves), rainfall (floods, droughts), introducedpredators, etc *Size of the group DOES NOT matter!*
For example… In cooler climates, aphids go through a huge population increase during the summer months. In autumn, the population ‘crashes’ to much lower numbers. Name a density-dependent and a density-independent factor regulating the population Density-dependent:______________ Density-independent:_____________
Humans + the Environment • 63,000 square miles of rainforests are being destroyed each year. • The world is losing seven million hectares of fertile land each year due to soil degradation; overgrazing is the single most prominent cause • 80% of the world's forests are gone • 99% of all those things we buy are not in use after 6 months. • Up to 100 species become extinct every day
