Exam #2 Flashcards
Herbivory
Feed on plants
Predation
Killing and consuming other organisms
Parasitism
Live in or on other organisms, depend on them for nourishment
Mutualism
A symbiotic relationship between two species in which both benefit (ex: plants and bees)
Commensalism
A symbiotic relationship between two species where only one species receive benefits, and other species remain unaffected (ex: hermit crabs and snail shells)
Intraspecific competition
Members of same species pursue limited resources (ex: one dung beetle species, if numbers increase, then competition increases)
Interspecific competition
Different species compete for shared resources (ex: zebras and wildebeest competing for grass, limits numbers of zebra and wildebeest)
Niche differentiation
Two species are potential competitors, but can coexist because they divide up fundamental nice
Fundamental niche
Each species has one, includes complete range of environmental conditions needed to support the species (ex: barnacles can ideally live in both deep and shallow intertidal zones)
Realized niche
Range of conditions where a species actually occurs given the constraints of competition (ex: coexistence of coyotes and wolves in North America –> coyotes could occupy more land + resources, but their reality is much smaller due to aggressive wolves)
Primary producers
Transform energy from sunlight into carbs (plants, algae)
Primary consumers
Eat the plants, feed on the primary producers (squirrels, insects)
Secondary consumers
Eat the herbivores and insects (birds eating insects, snakes)
Tertiary consumers
Eat the secondary consumers (fox)
Decomposers
An organism that decomposes organic material (bacteria)
Biomass pyramids
Visual depiction of total living organisms present at different trophic levels in an ecosystem
Keystone species
A species that other species in an ecosystem largely depend on. If it were removed the ecosystem would change drastically
Trophic cascade
An phenomenon triggered by the addition or removal of top predators and involving reciprocal changes in the relative populations of predator and prey through a food chain, which often results in dramatic changes in ecosystem structure and nutrient cycling
Ex of trophic cascade
No carnivores, too many herbivores, herbivores eat all the shrubs
Biomes
Major assemblages of similar organisms found in particular environments
Climatograph
Graphical snapshot of seasonal changes for a location
Three climate zones for terrestrial biomes
Tropical, temperate, polar
What separates one tropical biomes from another tropical biome?
Amount of precipitation during dry season
Tropical rainforest
- More plant and animal species than any other biome
- Different layers (forest floor, canopy, etc.)
- High biodiversity as a result of evolution that produced specialized ecological niche
- Ex: The Amazon
Tropical zone
Tropical rainforest, tropical seasonal forest, tropical savanna, tropical deserts
Temperate zone
Temperate deciduous forest, temperate evergreen forest, chaparral, grassland
Polar zone
Boreal forest, tundra
Tropical seasonal forest
- Seasonal drought (dry season)
–> Determines the distribution of these forests (50/50, each about 6 months a year) - During dry season, trees lose leaves to reduce need for water and survive drought (deciduous)
Ex: Caracas, Venezuela
Tropical savanna
- Highly seasonal rainfall (drought for more than half of year)
- Open grasslands = few trees, which are deciduous
- Ex: The Serengeti
What separates one temperate biome from another one?
Seasonal changes in temperature and rainfall
Temperate deciduous forest
- Moderate summers + cold winters
- Broad-leafed trees that lose their leaves in autumn, grow new leaves in spring
- Even precipitation throughout the year
- Growing season: hard frost end in spring through hard frost start in autumn
- Ex: Eastern U.S.
Temperate evergreen forest
- Trees keep their leaves throughout the year
- Less precipitation and warmer temperatures than temperate deciduous
- Summer months drier than winter months
- Trees can live for thousands of years
- Ex: Pacific Northwest
Chapparal
- Defined by summer drought
- Composed of evergreen shrublands and low woodlands
- Winters: mild temperature, high precipitation
- Summers: high temperature, no precipitation
- Diverse vegetation, many sclerophyllous plants (“stony leaves”) resistant to water loss, ex: rosemary, thyme
- Ex: Santa Barbara
Temperate grassland
- Too little precipitation to support forest, woodland, or shrubland, but enough precipitation to not be a desert
- Low precipitation throughout the year
- Long/cold winters + hot summers
- Tall grasses
Ex: Prairie in Easter Kansas
Polar biomes
- Very cold annual temperatures, less than 5C (41F)
- Short growing season
- Limited abundance/diversity of organisms
Ex: Areas near both the North and South pole
Boreal forest
- Growing season less than four months
- Winter are long/dry/cold
- Open coniferous forests
- Cold temperature slows evaporation
- Wet/boggy soils during growing season
Ex: Alaska
Tundra
- Northernmost polar regions
- Winters longer than in boreal forests
- Growing season shorter than boreal forests
- Dominated by grasses, herbs, low shrubs
- Receives less precipitation than many deserts
- Permafrost: permanently frozen layer in soil
Ex: Greenland
Deserts
- Occur in all three climatic zones
- Most common in transition between tropic and temperate zones
- Defined by low precipitation (annual rainfall below 10 in)
- Temperatures fluctuate daily and seasonally
- Expand when precipitation is low
- Expand when grasslands are overgrazed
Streams
All natural bodies of flowing water
Primary production in streams
Detritus and algae
Detritus
Organic matter (leaves, soil) washing in from terrestrial ecosystems, part of primary production in streams
Algae
Attached to rocks and provides primary production for stream food chains
Primary consumers in streams
Scrapers, shredders, and filter-feeders
Scrapers
Eat algae attached to rocks, use rasping mouth or tongue to scrape algae (ex: snails, some fish)
Shredders
Eat leaves, twigs, and detritus (ex: insect larvae)
Filter-feeders
Use gills or net-like structures to collect detritus (ex: freshwater mussels, worms)
Riparian zone
Region where stream meets terrestrial ecosystem
Characteristics of riparian zone
- Plants are tolerant to flooding, saturated soils, low oxygen
- Small but high biodiversity
- Soils filter groundwater heading to stream
- Plants slow flooding
Characteristics of lakes and ponds
- Habitat varies according to depth of water
- Short life span (less than 1 million years)
- Inland bodies of water (streams) that feed basins
- Little to no current or flow
- Become wetlands when they are old and filled with sediments
Closed basin lakes
Lakes with no outlet stream. They lose water through evaporation, which leaves behind minerals (ex: salt, Great Salt Lake)
Wetlands
Ecosystems where soil is saturated all year or most of the year. They soak up water during floods and soil is low in oxygen (ex: Amazon River Basin).
Estuaries
Partially enclosed basins of water where fresh and salt water mix. Serves as a transition from freshwater to salt water, where rivers feed into seas (ex: the Bay!).
Intertidal zone
Area along coast, beaches, rocky outcrops, tidepools
Benthic zone in ocean
The ocean bottom (coral reefs, kelp forests, thermal reefs)
