Ch.6: Terrestrial and Aquatic Biomes Flashcards
Convergent evolution
2 species descended from unrelated ancestors look similar bc of similar selective forces
Biome
unique geographic region w/ communities composed of organisms w/ similar adaptations; based on plants (must have); terrestrial
- depends on soil type
- defined by plants in that area
2 characteristics that determine biome
avg annual precipitation and temperature
Climate diagrams
visualize patterns of temp and precipitation associated w/ particular biome
Growing season
months that are warm enough and have enough precipitation to allow plant growth
Tundras:
coldest biome; treeless, permafrost (permanently frozen soil)
- Low precipitation
- Acidic soil bc of slow decomposition
- Nutrient-poor
- Upper soils thaw during summer growing season
Alpine tundras
@ high elevation = longer growing season
Boreal forests (Taiga)
biome densely populated by evergreen needle-leaved trees w/ short growing season and severe winters
- Avg temps < 5°C
- Soil is acidic and podzolized
- low evaporation, long growing season
- low temps, slow decomposition, accumulates large waste reservoir (carbon)
- few species can survive harsh winters (-60°C)
- source for lumber and paper (low species diversity)
o keystone species: wolves
Temperate rainforests
biome known for mild temps and high precipitation
- Dominated by evergreen forests
- Warmer conditions bc of warm ocean nearby
- Mild, rainy winters and foggy summers
- Historic plant communities; low species diversity
Temperate seasonal rainforests
biome w/ moderate temp and lots of precipitation
- Dominated by deciduous trees (maple, beech, oak)
- Low fluctuations
- Soils support a layer of small plants beneath dominant trees (slightly acidic)
- Warmer and drier parts are dominated by pines
Woodlands/shrublands
biome w/ hot/dry summers and mild/wet winters
- Favors growth of drought-tolerant grasses and shrubs
- 12-month growing season
- Frequent fires
Sclerophyllous
vegetation w/ small, durable leaves
Temperate grasslands/cold deserts
hot/dry summers, cold/harsh winters
- Prairies
- Soil has low acidity and is nutrient-rich
- Plant growth limited by lack of precipitation in summer and cold temps in winter
- Contains the badlands (things can’t really grow) and buffalo
Tropical rainforests
warm/rainy biomes w/ multiple layers of lush vegetation
- Continuous canopy of 30-40 m trees w/ understory
- Highest species diversity
- Matter decomposes quickly; vegetation rapidly takes up nutrients
- Trees have wide-spread, shallow roots to get rainwater (not a lot of soil nutrients)
Tropical seasonal forests/savannas
biome w/ warm temps, pronounced wet and dry seasons (bc of intertropical convergence zone)
- Deciduous trees that shed their leaves during the dry season
- Rapid decomposition and nutrient cycling
- Favors growth and reproduction
- Fire and grazing maintain savannas
Subtropical deserts
biome w/ hot temps, little rainfall, long growing seasons, and little vegetation
- Hot deserts north and south of equator
- Descending air of Hadley cells
- Low rainfall, neutral pH
Aquatic ecosystems categorized by…
flow/current, depth and salinity
Lotic systems
flowing fresh water
Lentic systems
nonflowing fresh water
Stream/Creek
narrow channel of fast-flowing fresh water
River
wide channel of slow-flowing fresh water
Riparian zone
band of terrestrial vegetation along rivers and streams
- Influenced by seasonal flooding and elevated water tables
Allochthonous
inputs of organic matter (ex: leaves) that come from outside an ecosystem
Autochthonous
inputs of organic matter produced by algae and aquatic plants w/in ecosystem
Photic zone
area of neritic and oceanic zones w/ sufficient light for photosynthesis by algae
- Intertidal
- Extends across entire ocean
- Where light can penetrate
Neritic zone
intertidal zone –> open ocean ~200 m deep
- Edge of zone = end of continental shelf (submerged portion of continental plate)
- Only photic zone
Oceanic zone
ocean zone beyond neritic zone
Abyssal zone
not very productive, characterized by organism w/ chemosynthesis
ocean: aphotic and photic zones
Euphoric zone
filled w/ free moving organisms
Intertidal zone
along the shore (b/w high and low tide); consists of rocky, sandy, and muddy beaches
- Tides come through twice a day
- Gravitational pull from moon and sun causes tidal differences
- Organisms have to be adapted to be covered by water and exposed to air
Estuaries
area along coast where mouths of freshwater rivers mix w/ salt water from oceans
o Where stream and ocean meet
o Highly productive
Coral reefs
one of most productive environments; tiny animals in mutualistic relationship w/ algae; produce CO2, algae produce sugars
- Hollow tubes w/ exoskeletons and tentacles that collect detritus and plankton
- Live in colonies
- Climate change = increased acidification = threat
- 20°C year round
Coastal wetlands (salt/tidal marshes)
saltwater biome w/ nonwoody emergent vegetation
o Found at continental coasts and in estuaries
Mangrove swamp
biome occurs along tropical and subtropical coasts
- Trees have roots submerged in salt-water; tolerant
- Atlantic east pacific = ~ 8 species
- Indo west pacific = ~40 species
- Highest high tide = last species of mangrove
3 types of mangroves
fringe
dwarf (red mangroves)
landward (white and black mangroves)
Which are most salt tolerant mangroves?
landward (white mangroves, peg roots)
- Salt deposits as high tides come/go and water evaporates
Plankton
free floating producers
o Ex: clam larvae
Nekton
free swimming consumers
Benthos
bottom dwellers
o Ex: adult clams
Decomposers
bacteria
Ponds
aquatic biome smaller than a lake
- Nonflowing freshwater w/ some area too deep for plants to rise of above surface
Lake
aquatic biomes larger than pond
- Nonflowing freshwater w/ some area too deep for plants to rise above surface
Littoral zone
shallow area around edge of lake of pond w/ rooted vegetation
Limnetic zone (Pelagic zone)
open water beyond littoral zone; where photosynthetic organisms = floating algae
Benthic zone
area w/ sediments at bottoms of lakes, ponds, and oceans
o Habitat for burrowing organisms
Profundal zone
area in lake too deep to get sunlight; low O2 levels
3 types of circulation:
epilimnion, thermocline, hypolimnion
Epilimnion circulation
surface layer of water in lake/pond
Thermocline circulation
middle depth of water; experiences rapid change in temp over short distance
Hypolimnion circulation
deeper layer of water
Stratification
condition of lake/pond when the warmer, less dense surface water floats to cooler, denser water
Fall turnover
vertical mixing of lake; occurs in fall, assisted by winds that drive surface currents
Oligotrophic lake
small limnetic zone, sparce fish population, most life in littoral zone (narrow), low concentration of nutrition and plankton, little shore vegetation
Eutrophic lake
small limnetic zone w/ dense fish population, wide littoral zone, a lot of shore vegetation, lots of plants on top
Natural eutrophication
every lake or body of water will eventually eutrophicate; natural cycles
Cultural eutrophication
human caused eutrophication (fertilizer)
- Algae don’t allow for oxygenation = fish die
Freshwater wetland
aquatic biome w/ standing freshwater, or soil saturated w. fresh water
- Shallow enough to have emergent vegetation throughout all depths
- Swamps, marshes, bogs
historical biogeograhpy
the current geographic location of species with evolutionary relationships to infer their evolutionary history through space and time
ecological biogeography
considers distribution of extant species as a function of modern conditions
biomes are classified by
the types of plants there
tropical rainforests are responsible for more than ___% of biodiversity on earth
more than 50% of biodiversity on earth
intertidal zone productivity
high productivity bc of readily available nutrients and light
spring tide is the…
greatest tidal difference
3-4 zonations of intertidal zone:
- Subtitle zone- below lowest tides
- Low tide zone- lowest the tide will get; almost always wet
- Middle tide zone- submerged ½ day, exposed to air ½ day
- Higher tide zone- exposed for majority of day
