Exam 2
Mutualism
(+,+) Both species benefit because both are able to secure resources better living together than separate
Predation
(+,-) Organisms hunt, kill, and consume prey Predators have adaptations to help them hunt (sharp teeth/strong jaw)
Parasitism
(+,-) Organisms live and feed in/on other organisms Typically does not kill hosts, but does harm
Commensalism
(+,0) One species benefits, the other is unaffected Ball moss & tree Cattle egret & cow Whale & barnacle Remoras & shark
Competition
(-,-) Interaction among organisms vying for the same limited resource in an ecosystem
Growth Rate
(births/1,000 individuals) - (deaths/1,000 individuals)
k-adapted species
- long life - slower growth - mature later - few, large offspring - high parental care/protection - adaptes to stable environment - predators - niche specialists
Nitrogen Cycle
1. Nitrogen fixing bacteria are needed to convert N2 to NH3, a form of nitrogen that can be used by many producers. 2. Microbes are needed to decompose organic matter, releasing NH4 as a waste product. 3. Bacteria are needed for nitrification to convert NH4 to NO3. 4. Denitrifying bacteria are needed to convert NO3 back to atmospheric nitrogen (N2).
Temperate Zone
25° to 60 ° N and S Annual precipitation 200 mm - > 2,000 mm Annual temperature 5 - 20° C Growing seasons 4-10 months Reliable rainfall year-round Most of the trees in this biome survive the cold winter by losing their leaves. Precipitation - 75-150 cm/yr Temperature: Hot summers and cold winters Topsoil is rich in organic material and underlain by clay Vegetation is primarily deciduous - Oak, maple, beech Animals: Deer, bear and small animals Most of this biome land area has been regenerated after farming & timber harvest
Mutualism
A butterfly finds nectar stored inside the flowers and eats it. In the process he gets pollen smeared on his body. When he is finished hunting for nectar, the butterfly flies to another flower of the same species to find more nectar. Some of the pollen gets scraped off onto the second flower.
Interspecific Competition
A giraffe and an elephant are both eating leaves from an acacia tree in the savanna. This is an example of:
Population
A group of individuals of the same species living and interacting in the same region
Solar Energy
A large amount, but not easily used by cells or not always available
Polar Zone
Above 60° N and S latitude Very cold, < 5° C Short growing seasons Limited abundance and diversity of life
Exponential Growth
Abundant growth factors produce ________
r-selected species
Adapt well to unpredictable environments High biotic potential (r) Can increase/decrease quickly in response to environmental changes Examples: Dandelions, deer mice, and spotted knapweed
Open-Pit Mining
Adds phosphorous and nitrogen to the hydrosphere, where they can alter plant growth and pollute aquatic ecosystems Same as animal waste and fertilizing
Density Independent Factors
Affect a population regardless of its size, and can decrease the population Storms, fires, floods, avalanches
Matter Cycles
All ecosystems function through two fundamental processes: __________ and energy flow
Energy Flow
All ecosystems function through two fundamental processes: matter cycles and __________
Population
All individuals of a species which live in the same geographic area and interbreed Fluctuate in size and have varied distributions
Community
All the different populations that live together in an area Plants, animals, and other species
Assimilation
Ammonium (NH4+ ) taken up by plants and consumed by animals to make biological molecules
Nitrogen Fixation
Bacteria converts atmospheric nitrogen into ammonium (N2) to (NH4+ )
Carbon Cycle
Balanced between respiration and photosynthesis
Interspecific
Between individuals in 2 different species
Intraspecific
Between individuals of the same species in a population
Grassland
Biome with the most nutrient-rich soil
Climatic Factors
Biomes are defined as distinctive types of ecosystems determined by:
Terrestrial Biomes
Biomes on land (forests, taiga, tundra, etc.) 10 major biomes plus mountainous regions are distributed across Earth's land masses
r-selected species
Can have sudden population growths which may overshoot carrying capacity and suddenly crash
Exponential Growth
Cannot last forever because growth rates decrease as a population fills its environment
Symbiosis
Close biological/ecological relationship between 2 species Mutualism Parasitism Commensalism
Grassland
Cold winters, hot summers Too dry for forests, too wet for deserts Precipitation 250 - 750 mm/yr. - too little to support trees Rich organic soil horizon Periodic fires keep grasses dominant, limit tree growth Grazing animals, small mammals, reptiles, birds of prey
Tundra
Cold winters; short summers Growing season < 3 months Precipitation 100-500 mm/yr
Boreal Forest
Cold, dry winters Growing season < 4 months Precipitation 500-1,500 mm/yr. Soils are acidic and mineral poor Vegetation comprised of drought resistant conifers: White spruce, Balsam fir, Eastern larch Mostly small animals and migrating birds Some large animals are present - Wolves, bear, moose
Species Interactions
Control population and maintain carrying capacity More Diversity = More Relationships
Nitrification
Converts ammonium into nitrates (NH4+ ) to (NO3-)
Denitrification
Converts nitrates back to atmospheric nitrogen gas (NO3-) to (N2)
Terrestrial Biome
Defined primarily by both temperature and precipitation
N-cycle
Depends on many types of soil bacteria Often limits nutrients for plants (I.e. burning fossil fuels, fertilizing, etc.)
Resource Partitioning
Division of resources so potential competitors may coexist
Consumers
Eat other organisms and take in their carbon
Primary Consumers
Eat producers on the trophic levels
Tertiary Consumers
Eat secondary consumers on the trophic levels Carnivores
Quaternary Consumers
Eat tertiary consumers on the trophic levels
Secondary Consumers
Eats primary consumers on the trophic levels Herbivores
Population Dynamics
Ecologists who study ___ ____ (changes in population size and makeup) find some population sizes change predictably while others fluctuate randomly.
Density-Dependent Factors
Effects increase as populations grow Disease, competition, predation
Mountain
Experience same biome transitions in altitude as continent does in latitude
Tropical Zone
Extends 25°N and S Average monthly temp > 20° C Annual precipitation varies
some
Fire is a natural element of terrestrial ecosystems in only ____ ecosystems
Predator Defense
Fleeing/Running Hard shell Quills (Porcupine) Living in groups Camouflage Chemical Defense (poison) Mimicry
Energy Flow
Flows from producers (TL1) to Quaternary Consumers (TL5) in a linear fashion
Food Webs
Food chains linked together to show connections in community More complex = Greater stability
Energy
Foundation of every ecosystem Captured through photosynthesis Passed from organism to organism through the food chain
7.2%
From 2009-2010, the Yellowstone wolf population increased from 320 to 343, a growth rate of:
Range
Geographic area where a species (or one of its populations) can be found Influenced by behavioral and ecological factors Reflects how individuals interact with each other and their environment.
Keystone Species
Impacts its community more than its mere abundance would predict
0.05
In 1920, the elk population was 10,000. In 1921 , it was 10,500. What was the population growth rate?
367
In 2010, the Yellowstone wolf population was 343, with a growth rate of 7%. We would predict that the population would be __________ in 2011 if the growth rate remains constant.
Assimilation
In the Nitrogen cycle, which step does not involve bacteria?
Clumped Distribution
In which population distribution pattern would individuals within the population experience the most competition with other individuals in their population?
Clumped Distribution
Individuals found in groups within the habitat Seen in social species (wolves, elk, prairie dogs, etc.)
Uniform Distribution
Individuals spaced evenly due to territorial behavior
Random Distribution
Individuals spread out irregularly Example: Wind-blown seeds that germinate where they land
Biomes
Influenced by physical and climatic characteristics Particularly precipitation and temperature
Reproductive Strategy
Influences the growth potential of a species' population aka Life-History Strategy
Competition
Intraspecific and Interspecific
Population Distribution
Location and spacing of individuals within their range
Biotic Potential
Maximum per-capita rate a population could increase under ideal conditions (no environmental limits) r
Carrying Capacity
Maximum population size that can be indefinitely supported in a particular environment Determined by growth factors and can increase/decrease as resources change (K)
Mediterranean Scrub
Mild, moist winters & hot, dry summers Precipitation 250 - 500 mm/ yr. Dominated by summer drought Thin soil, often not fertile Adapted to periodic fires Dense growth of evergreen shrubs, low woodlands Mule deer, chipmunks, many species of birds
Nitrogen
Most abundant element in the Earth's atmosphere Needed to make proteins and nucleic acids (DNA/RNA)
Heat
Most energy (~90%) is released as _____, while the remaining 10% supports metabolism
Nitrogen and Phosphorus
Move in cycles heavily dependent on a wide variety of bacteria Chemicals essential for life
Carbon Cycle
Movement of carbon from the non-living environment into living things and back
Matter Cycles
Movement of life's essential chemicals or nutrients through an ecosystem
Phosphorous Cycle
Needed by all organisms to make DNA Very slow cycle - no atmospheric component Dependent only on weathering of rock
Nitrogen
Needed to make protein and nucleic acids
Population Density
Number of individuals per unit area Example: Number of wolves distributed over Yellowstone Too High: More competitive (fighting) & disease spreads easier Too Low: Hard to mate
Tundra
Nutrient poor soils - little organic material Permafrost Treeless - mostly grasses, low shrubs Low species richness
Niche Generalist
Occupies a broad niche Can utilize a wide variety of resources
Boom and bust
Occur when predator and prey populations increase and decrease
Exponential Growth
Occurs in a population when there are no limits Typically seen when a species enters a new environment or there is a new resource J-Shape
Competitive Exclusion Principle
One species excludes another from a portion of the same niche as a result Less successful species can leave the area, switch niches, or die
Ecologists
Organize life from biosphere, biome, ecosystem, community, population, and individual (largest to smallest)
Carbon
Photosynthesis and cellular respiration are how ________ moves in and out of living things
Logistic Population Growth
Population growth rate slows as the size approaches the carrying capacity Exponential growth transitions to logistic growth S-Shaped Curve
Biome
Portion of the biosphere characterized by a distinct climate and a particular assemblage of plants and animals adapted to it
Resistance Factors
Predators, competition, and diseases decrease population growth rates, causing the J curve to transition to the S curve (logistic growth)
Nitrogen Fixation
Process of converting nitrogen gas into nitrogen compounds that plants can absorb and use
Cellular Respiration
Process that releases energy by breaking down glucose and other food molecules in the presence of oxygen
Cellular Respiration
Process that releases energy by breaking down glucose and other food molecules in the presence of oxygen Producers & Consumers
P-Cycle
Provides nutrients for plant growth Impacted by humans through open-pit mining and animal waste
Deforestation
Reduces carbon uptake from atmosphere into biotic reservoirs
Burning Fossil Fuels
Releases carbon, and nitrogen from fossil fuel sinks into the atmosphere
Trophic Levels
Represent feeding levels in a food chain Organized based on what consumers eat Some feed at multiple trophic levels
k-selected species
Reproduce slowly Has lower biotic potential (r) More likely to have a stable population close to carrying capacity Less adaptable to environmental change Examples: Elk, bears, and spruce trees
Sinks
Reservoirs that accept more nutrients than they release Time Nutrients Stay = Residence Time
Producers
Set the energy budget for food in a system through photosynthesis on the trophic levels
r-adapted species
Short life Rapid growth of individual Early maturity Many, small offspring Little parental care Adapted to unstable environment Prey Niche generalists
Individual
Single member of the population
Biome
Species within each _____ are specifically adapted to the particular environmental conditions of it
Ecosystem
Specific portion of a biome consisting of the living (biotic) and nonliving (abiotic) environmental components that interact
Community Ecology
Study of all the populations Plants, animals, human affect, and other living species
Equator
Temperature decreases when moving away from the ______ and with increasing elevation
Desert
Temperature varies -20 to > 40 °C Extremely arid Precipitation < 250 mm annually Defined by lack of precipitation Soils low in nutrients and high in salts Vegetation sparse - cactus and sagebrush Animals are very small to regulate temperature
Lynx
The animal most likely to be found in the Boreal forest would be:
1 & 3
The biological community that characterizes the arctic tundra is: 1) migrating herbivores, small mammals, and predatory birds 2) large trees 3) mosses, lichens, and dwarf woody plants 4) diverse amphibians and reptiles
Limiting Factor
The critical resource whose availability determines species population size distribution
Range of Tolerance
The range of a limiting factor within which a species can survive and reproduce Population concept
Biosphere
Total area on Earth (terrestrial, marine, and freshwater.) where living things are found
Nitrogen Cycle
Transfer of nitrogen from the atmosphere to the soil, to living organisms, and back to the atmosphere
Exponential Growth
Turns into logistic growth (S curve) as population size approaches carrying capacity (K) and resistance factors begin to limit survival
Photosynthesis
Use of solar energy to combine CO2 and H2O to make sugar, releasing O2 in the process Producers only
Species Diversity
Variety of species in an area Measured by species richness (# of different species) and species evenness (relative abundance of individual species)
Complex Structure
Vertical arrangement of foliage of different trees in the tropical rainforest creates a diverse array of habitats for animals
Niche Specialist
Very specific habitat or resource requirements
Savanna
Warm, constant temperature Drought for ½ the year Precipitation: 760 -1,200 mm/yr. Seasons regulated by precipitation Soil low in nutrients from leaching Expanses of grass with occasional Acacia trees Adapted to periodic fires Herds of hoofed animals & large predators
Tropical Rain Forest
Warm, constant temperatures Growing season year-round Precipitation > 2,000 mm/ yr. High plant / animal diversity Ancient, nutrient-poor soil 3 distinct canopy layers Estimated 5-50 million species Many unique niches and endemic species
Secondary
What kind of organisms are on trophic level (TL ) 3?
Resistant Factors
What might cause a population's size to transition from exponential to logistic growth?
Random
What population distribution pattern would you expect to see in a population of dandelions whose seeds are dispersed by the wind?
Phosphorus
Which cycle does not have an atmospheric phase?
Intraspecific competition
Which of the following is demonstrated by the bird of paradise's dance?
Annual Population Growth
[(# New Births)/(# of Individuals Prior Year)] * 100