Ecology ecology - The study of living things and how they relate to their environment Levels of Organization in Ecology organism lowest level one living thing population collection of organisms of the same species living in the same general area example: all the black bears living in Cook Forest community all the populations of different species in an area this includes plants, animals, fungi ecosystem all communities (living things) and non-living things in an area example: animals, plants, rocks, wind, temperature, rainfall biome collection of ecosystems that have similar properties around the world biosphere all biomes on Earth Biosphere Biome Ecosystem Community Population Organism Ecosystems are made and changed by living and nonliving things in them Living alive or was alive Non-living never alive Biotic factor living, once living, or came from a living thing Tree, animal, rotting log, manure, etc. Abiotic factor never alive, nonliving Rocks, water, air, shade, sun, weather
Ecosystem Classes Terrestrial land-based Aquatic water-based Terrestrial Ecosystems Forest Biome Large variety of plants and animals in a small space Tropical Evergreen (includes rainforest) near equator Tropical Deciduous outside of the tropics Temperate Evergreen between Temperate Deciduous Taiga (Boreal Forest) near the North Pole Forest Vocabulary Tropical hot and humid Temperate mild Evergreen leaves (needles) stay green all year Deciduous leaves turn color and fall off Desert Biome Defined by the lack of precipitation Less than 10 of rain per year Can be hot or cold Wide temperature swings between day and night 17% of all terrestrial ecosystems Low biodiversity Includes the typical desert ecosystems and tundra ecosystems Tundra Biome Defined by the lack of precipitation Less than 10 of rain per year Low biodiversity Harshest biome Arctic region
Mountain Biome Wide range of habitats Lowland areas usually evergreen forests Highland areas usually don t have trees or large (if any) plants above the tree line. Colder as elevation increases. Organisms adapt to the temperature depending on what part they live in. Grassland Biome Tropical and temperate Few, if any, trees and shrubs Mainly grasses with herbivores, grazers, and insect-eating animals High likelihood of seasonal fire Usually flat, with very few terrain changes Two main types: Savannah and Prairie Savannah: Tropical, and seasonally dry Few trees Many predators and grazers Typical Africa stereotype with elephants, giraffes, etc. Prairie: Temperate No large trees or shrubs Can be tall grass, short grass, or mixed grass Mostly found in US and Canada Stereotypical Kansas or Midwest Aquatic Ecosystems Must be found in water Includes all living things, as well as abiotic factors such as ph, temperature, salinity, etc. More sensitive to changes than terrestrial ecosystems
Aquatic Ecosystems (continued) Two main types of aquatic ecosystems Freshwater Biome Covers only about 0.8% of Earth s surface Contains only about 1/100 th of a percent of total water on Earth but it s the only water we can drink Freshwater Biome (continued) Three classes of fresh water ecosystem Lentic slow moving pools, ponds or lakes Lotic fast moving creeks and streams Wetlands saturated soil with standing water that is not a lake or pond 41% of fish species live here Fast water = more oxygen = more diversity Marine Biome Saltwater Biggest type of ecosystem 71% of Earth s surface 97% of Earth s water Eight classes of marine ecosystem Oceanic top shallow part of the ocean Profundal deep ocean Benthic bottom sediment Intertidal between low and high tide Estuaries ocean tide meets the river Coral Reef Salt Marsh Hydrothermal Vent
Describing Populations Populations consist of a single species Individuals complete for the same resources and that controls the maximum size of the populations Limiting Resource resource that runs out first and prevents the population from growing food water shelter Can be different for different for different species All resources are found within the species habitat Habitat collection of resources Similar habitats can exist in different parts of the World Since not all species in a habitat use the same resources, some populations specialize Niche specie s role in a habitat Example: only eats a certain plant; lives in the wettest area Once a species finds its niche, it minimizes competition with the other species Population Size Population Size number of individuals of a certain species in a population Scientists use different methods for determining population Sampling Techniques Direct counting each organism Nest/Reproductive Sampling count the nests Random Sampling isolate an area, do direct counting and expand values Example: Sampling techniques allow for estimating population density
Population Density Population Density = population area Example: 3 black bears per square mile Large organisms usually have a lower density because they need more resources Low population Density Pros: More space per organism; More resources per organism Cons: Trouble finding a mate High population Density Population Distribution Population distribution Pros: Easier to find a mate; Easier to rely on others Cons: More competition; More disease; Vulnerable to predators How the population is distributed in the habitat What parts of the habitat are used the most/least 3 types: Random Uniform Clumped (clustered) Random distribution Uniform distribution Clumped distribution
Age Structure Most common because organisms are found around resources Distribution of ages in a population Shows the health of a population Predicts whether a population is likely to grow, shrink or stay the same 2010 Rural Valley Age Structure Ages Male Female 18-29 72 82 30-39 61 68 40-49 50 58 50-69 158 179 70 + 70 78 Totals 411 465 Total Population: 876 Number of people: n=876
2000 Rural Valley Age Structure Ages Male Female 15-19 27 28 20-24 26 26 25-34 44 44 35-44 72 74 45-54 58 59 55-59 31 32 60-64 24 24 65-74 51 53 75-84 38 39 85 + 7 7 Totals 378 386 Total Population: 922 Number of people: n=922
Ecological Interactions Members of a population interact with other community members As a result, members of the community compete with one another for resources: Shelter Food Heat Water Competition Multiple organisms trying to use the same limited resources Some will get the resources but others will do without Outcomes for those that do not get the resources: Death Move elsewhere Adapt (change resources) Do without Organisms also depend on each other Symbiotic Relationship Two organisms from different species that interact for the benefit of at least one 3 Types of symbiotic relationships: Mutualism both organisms benefit Example: cleaner fish and sharks Fish are fed Sharks are kept clean Commensalism One species benefits and the other species does not, but is not harmed Example: bird building nest in a tree Bird has protection Tree is not benefited but not harmed
Parasitism One species benefits and the other is harmed without the harmed species being killed Parasite/host Predation Example: Ticks on a dog Tick gets food Dog is harmed One species hunting and eating another Predator/prey Relationship Species 1 Species 2 Predation + - Competition + 0/- Mutualism + + Commensalism + 0 Parasitism + -