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Ecology. Study of relationships between organisms and their environments. Ecosystem Organization. Biosphere. Biome. Ecosystems. Communities. Populations. Organisms. Organism. A single living thing. Habitat (house). The place where an organism lives out its life. Niche (occupation).
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Ecology Study of relationships between organisms and their environments.
Ecosystem Organization Biosphere Biome Ecosystems Communities Populations Organisms
Organism • A single living thing
Habitat (house) • The place where an organism lives out its life Niche (occupation) • Strategies and adaptations a species uses in its own environment • How the species gets food and shelter
Population • A group of organisms that belongs to the same species • Population members breed with each other and live in the same area
Population dynamics • The study of the change in population numbers and the factors influencing those changes Population size Birth Immigration Death Emmigration
Models of Population Growth • Exponential Growth • Birth exceeds death • Population Size Explodes
Exponential growth – density independent Population size Time, in generations
Can this happen in nature? • Yes • Invasive species • Uniform habitat • No predators • No disease • Unlimited area
Logistic equation – density dependent K Population size Time, in generations
K = Carrying capacity • The maximum number of individuals that a habitat can support for a prolonged period of time • Not constant, it fluctuates.
Limiting Factors-factors that affect the carrying capacity • Density-independent factors • Weather (storms, cold, drought) • Some diseases (DDT poisoning) • Density-dependent factors • Food or Predators • Space or Shelter • Other diseases (rabies)
Population structure • A population that is 75% adults, 25% juveniles is very different from a population of 25% adults and 75% juveniles.
Population structure • Age structure – distribution of ages in a population. • Size structure – distribution of sizes in a population.
Community • Different populations in a certain area at a certain time. • Changes in one population cause changes in other populations
Symbiosis • living together • Three major kinds of symbiosis • Mutualism-both species benefit • Commensalism-one species benefits and the other is neither helped nor harmed • Parasitism-one species benefits at the expense of another • Predator-Prey Relationship
Ecosystem • All the different populations in a community and the community’s abiotic factors • There are two major kinds of ecosystems: terrestrial and aquatic
Biotic vs. Abiotic • Biotic factors – all living organisms in an environment • Abiotic Factors—nonliving factors in an environment • Air • Temperature • Water • Light • Soil
Biomes • The typical weather patterns over a long period of time is the climate.
Biomes are a group of ecosystems with similar climates (temperature and rainfall) and organisms.
Is the temperature of each Biome: Hot, moderate, or cold? • Tundra - • Desert - • Temperate Grassland - • Tropical savanna - • Taiga - • Temperate forest - • Tropical rainforest - • Tundra - Cold • Desert - Hot • Temperate Grassland - Moderate • Tropical savanna - Hot • Taiga - Cold • Temperate forest - Moderate • Tropical rainforest - Hot
Tundra • Found in Antarctica and the North Pole, North of the Arctic Circle. • Grass, lichen and herbs • Permafrost – layer of soil that is always frozen. • Very short warm season that is very wet • Many insects during warm season
Animals such as wolves, foxes, hares and caribou grow thick fur during the winter to keep warm.
Taiga • Found in Northern Hemisphere. • Spruce and Fir trees • Growing season very short • Nearly constant daylight in summer • Many lakes and swamps
Temperate Forest • climate and amount of sunlight can vary tremendously between each season. • four types: Deciduous forest, Evergreen forest, temperate rain forest, and mixed evergreen and deciduous forests.
Grasslands • Tall, perennial grasses and no trees. • Cover a quarter of the land on Earth.
Savannas are like the grasslands except that they do receive enough rain to support small trees.
Savanna • Found near equator between tropical rain forest and desert biomes • Grass, scattered trees, shrubs, many with thorns • Many grazing animals • Have a wet and dry season • Plants and animals most active during wet season.
Animals that appear in both include: bison, antelopes, giraffes and kangaroos.
Desert • Deserts take up 8.6 million square miles on Earth.
Desert • Get less than 25 cm of rain each year • Has little or no vegetation • Driest places on earth
In the Desert Biome, plants (cactus) have the ability to hold water for later use and most animals (scorpion) are nocturnal.
Rainforest • Found near the equator • Over half of the world's plant and animal species live here. All fit into only seven percent of the world's land.
Biosphere • Portion of Earth that supports life