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Ecology Midterm

Terms in this set (80)

Biotic
Living
Abiotic
Non-living
Distinguish between ecosystem, population, community, biosphere, & habitat
Ecosystem: Organisms interacting in an environment
Population: Organisms of the same species living in a specific area
Community: Groups of different species interacting
Biosphere: Global ecosystem of living & nonliving things
Habitat: Area an organism lives
Explain how plants, protists, fungi, and animals obtain food
Plants: photosynthesis
Protists: absorbing molecules from the environment
Fungi: live on other organisms
Animals: eating other organisms
Distinguish between herbivores, carnivores, & omnivores
Herbivores: only plants
Carnivores: only meat
Omnivores: Both plants & meat
predator & prey
When one organism feeds on another organism
The effect removing an herbivore would have on food web?
Cause a collapse for the entire food web.
Biomass
The energy in living organisms and decreases with each trophic level.
Scavenger
A carnivore that feeds on the bodies of dead organisms
Decomposer
An organism that breaks down wastes and dead organisms
Three examples of decomposers
Fungi, Worms, & Bacteria
Main energy source for plants
Sun
Difference between autotroph and Heterotroph
Autotrophs/producers make their own food, unlike heterotrophs
Consumer
An organism that obtains energy by feeding on other organisms
Food webs and Food chains
Food Chains depict energy flow in a single chain of organisms.
Food Webs depict the flow of energy through a larger amount of species.
Photosynthesis and Cellular respiration
Converts carbon dioxide & water to oxygen and glucose
Converts oxygen and glucose to carbon dioxide and water
What matter cycle is photosynthesis and cellular respiration apart of?
C cycle
Humans impact on the water cycle
withdraw lots of water
Humans impact on the Carbon Cycle
-fossil fuels
-Forest fires
Humans impact on nitrogen cycle
- deforestation releases a lot of Nitrogen
- Runoff from fertilizer
Which gas makes up 78% of our atmosphere
Nitrogen
Humans impact on Phosphorus cycle
- Mining it for fertilizer
- runoff causes increase in algae
Plant tropisms
Hydrotropism: growth in response to water
Geotropism: growth in response to gravity
Thigmotropism: Growth in response to touch
Kinesis
movement
Taxis
Movement toward or away from a stimulus.
Symbiosis
A relationship in which two different organisms live in close association with each other
Compare parasitism, mutualism, and commensalism
Parasitism: One organism benefits the other does not
Mutualism: both organisms benefit
Commensalism: One species neither helps or harms the other
Coevolution
Process by which two species evolve in response to changes in each other
Camouflage
So prey can hide from predators
Migration
Form of relocation diffusion involving a permanent move to a new location.
Niche
Full range of physical and biological conditions in which an organism lives and the way in which the organism uses those conditions
What happens if two or more species occupy a niche
Compete for limited resources and one would eventually exclude the other
Competitive exclusion
Ecological rule that states that no two species can occupy the same exact niche in the same habitat at the same time
Fundamental niche
The full potential range of the physical, chemical, and biological factors a species can use if there is no competition from other species.
Realized niche
the range of abiotic and biotic conditions under which a species actually lives
Generalized species
species that can survive in a variety of ecological niches
Specialized species
A species closely fitted to a specific niche
Biome
A group of ecosystems with similar climates and organisms
Factors to determine types of terrestrial biomes
differences in average annual precipitation and temperature
Limiting factors in tundra
No plants can grow in the winter
Prairies
flat, open grasslands
Savannas
Areas of tall grasses and scattered trees and shrubs
Desert pavement
A layer of coarse pebbles and gravel created when wind removed the finer material.
Types of deciduous trees
Oak, Birch, & maple
Biome located in temperate zone
Temperate deciduous forest
Desert
An extremely dry area with little water and few plants
Steppe
sparse, dry, treeless grassland
Desert rainfall
less than 10 inches per year
Grassland rainfall
10-30 inches
Deciduous forest rainfall
Varies with seasons
Why can grassland grasses withstand fire
Have a heavy root system
Examples of conifers
pines, sequoias, and junipers
Tundra vs. Taiga
Taiga: thick forest
Tundra: has no trees
Temperate vs Tropical forest
Temperate: near cooler areas
Rain forest: located near equator so hot & humid
Deciduous vs Taiga
Taiga: non-needle shape trees that fall off in the fall
Deciduous: wax coated leaves that stay on year long
Factors to determine aquatic systems
Water depth, water salinity, and the flow of water
Wetland
A land area that is covered with a shallow layer of water during some or all of the year
Marsh
A wetland typically covered with grasses
Swamp
A wetland ecosystem in which shrubs and trees grow
Humans impact on wetlands
Agricultural runoff
Esturary
water passage where the tide meets the current of a stream
Humans impact on lakes
Cultural Eutrophication: caused by excess nutrients from fertilizers, leads to death of body of water
Humans impact on rivers
Run off puts pesticides into river
Biotic potential
The maximum rate at which the population of a given species can increase when there are no limits on its rate of growth.
Environmental resistance
All the limiting factors that tend to reduce population growth rates and set the maximum allowable population size or carrying capacity of an ecosystem
Emigration &. Immigration
Emigration- Migration from a location
Immigration- Migration to a new location
Exponential vs Logistic Growth
Exponential growth: when a populations size increases dramatically over a period of time
logistic growth: when a population begins with slow growth followed by a period of exponential growth then leveling off stably
Carrying capacity
The largest population that an area can support
K-selected species
a species with a low intrinsic growth rate that causes the population to increase slowly until it reaches carrying capacity
R-selected species
a species that has a high intrinsic growth rate, which often leads to population overshoots and die-offs
Density dependent factors
limiting factor that depends on population size
Density independent factors
limiting factor that affects all populations in similar ways, regardless of population size
Clumped population distribution
large group, feeding opportunities & protection from predators
Uniform population distribution
Evenly spaced individuals
Random population distribution
no pattern
Top-down population control
Higher levels in the food chain (predator) affects the prey population. Predators control the population levels of the prey
Bottom-up control
Productivity of the species on the lower layer sets the bounds on the population sizes of the species on the higher layer
Benthos examples
Mussels, worms
Nekton examples
fish, turtles, whales
Plankton examples
phytoplankton, zooplankton
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