Bio 354 Exam 1 Flashcards

Ecology

the scientific study of the biotic and abiotic interactions which govern the abundance and distribution of organisms

Major processes of ecology

reproduction, photosynthesis, nutrient cycling, decomposition, metabolism

Main factors of ecology

Temperature and precipitation (abiotic), competition and predation (biotic)

Scale of Ecology:

Individual, Population, Community, Ecosystem, Landscape, Region, Biosphere

Individual

physiological and behavioral processes within individual organisms

Population

differences among groups of individuals due to differences in behaviors, geography

Community

association of interacting populations/species

Ecosystem

physical and chemical factors that influence communities

Landscape

exchanges in materials among ecosystems

Region

landscapes subjected to largescale and long-term processes

Biosphere

largest scale, regions of the Earth that support life

Steps in scientific method

Information, Question, Hypothesis, Prediction, Testing Hypothesis, Data

Regional scale variation in temperature

uneven heating of Earth’s spherical surface by the sun = latitudinal variation in temperature, with temperatures highest along equator and lowest at poles

Local scale variation in temperature

caused by the differences in elevation, with cold air draining where cold (denser) air sinks to the basin of mountains (temperature and pressure decrease with increasing elevation)

Regional scale variation in seasonality

constant axial tilt (23.5 degrees towards Polaris) = different amounts of solar energy in the North and South Hemispheres

Local scale variation in seasonality

slope aspect - south facing slopes get more incident solar radiation, making vegetation more dry (xeric); north facing slopes get less, making vegetation more moist (mesic)

Regional scale variation in Atmospheric Circulation and Precipitation

differential heating of Earth’s surface - drives patterns of precipitation

Local scale variation in Atmospheric Circulation and Precipitation

“rain shadow effect” - area of low rainfall on Leeward side of mountains; moist air from coast rises along Windward side = decrease in pressure and temperature = rain, while on Leeward side air mass drops = increase in pressure and temperature = dry

Coriolis Effect

“apparent” deflection of the wind direction due to the differences in speed of Earth’s rotation between high and low latitudes

Prevailing winds

results from deflection of air caused by Coriolis effect

Regional scale variation of Biomes as products of temperature and precipitation

interaction between temperature and precipitation results in the diversity of biomes

Local scale variation of Biomes as products of temperature and precipitation

Microclimate - Ground color: darker soil absorbs more sunlight leading to warmer temperature, Vegetation: shading leads to cooler temperatures, Ground Cover: leaf litter provides insulation

Soil

foundation for terrestrial biomes, complex mix of living and non-living material, formed by the interaction among organisms, climate, and topography

Horizons include:

O (organic), A and B, C (bedrock)

O (organic) Horizon

fragmented plant litter

A & B Horizon

mineral and organic matter gradually leeched from A to B horizons

C (bedrock)

weathered parent material

Major soil types are distinguished on:

Mineral and humus composition/pH and drainage capacity

Drainage capacity

Clay to silt to sand, low to high water conducting capacity

Tropical rain forest:

• Climate - high temperatures and high precipitation, low variability in both

• Soils - nutrient poor; acidic; lots of leeching

• Biology - high species richness; lots of tall trees; epiphytes (plants that live on other plants)

Desert:

• Climate - high temperatures and low precipitation, moderate/high (cold deserts) variability in temperature

• Soils - coarse grained; low in organic matter

• Biology - sparse vegetation; drought adapted plants

Mediterranean Woodland:

• Climate - moderate temperature and moderate precipitation, low variability in both; hot dry summers and cold wet winters

• Soils - like desert, but more rich in organic matter and fertile

• Biology - high diversity, lots of drought adapted plants, trees, plants, evergreen vegetation, fire-adapted plants

Temperate Grassland:

• Climate - low temperatures; moderate precipitation; high variability in both

• Soils - nutrient rich; deep; high in organic matter

• Biology - herbaceous vegetation and grasses (important for herbivores)

Temperate Forest:

• Climate - low temperatures and moderate variability in temperature; high-ish precipitation and low/high variability in precipitation

• Soils - fertile and acidic

• Biology - harsh winters and dry summers

  • Coniferous - short growing season

  • Deciduous - wet and long growing season

Coniferous vs. Deciduous

• Coniferous - cone-bearing trees, evergreen

• Deciduous - loses leaves in winter

Tundra:

• Climate - temperatures are low and variable; low/moderate precipitation

• Soils - thin; permafrost (frozen ground); low fertility, high in organic matter

• Biology - low rates of decomposition; perennial plants, lichens (mutualism between algae and fungi)

Ocean:

• Structure - neritic zone, littoral zone, pelagic zone (epipelagic, mesopelagic, bathypelagic)

• Light - 80% of sunlight absorbed in first 10 meters

• Temperature - thermal stratification with warm water above cold water

• Movement - wind drives currents, nutrient cycling by upwelling

• Salinity - when precipitation is greater than evaporation, there is a decrease in salinity and vice versa

• Oxygen - higher near surface and decreases with depth

• Biology - photic zone (phytoplankton and zooplankton), invertebrates and fishes, then deep sea fishes with bioluminescence, and then chemosynthetic organisms

Shallow marine:

• Structure - kelp forest and coral reef

• Light - shallow water means more light for photosynthesis

• Temperature - kelp forests limited to cold water and coral reefs limited to warm water

• Movement - currents flush oxygen and nutrients/remove wastes

• Salinity - fairly stable

• Oxygen - well oxygenated

• Biology - among the most productive and diverse communities, zooxanthellae (photosynthetic algae, coral mutualism)

Intertidal:

• Structure - exposed vs sheltered, rocky shore vs sandy shore, zones: supratidal, intertidal (upper, middle, lower), and subtidal

• Light - highly variable; depends on zone and tide

• Temperature - highly variable depending on zone and tide

• Movement - waves and tides (caused by gravity force), spring tides, neap tides, “semi-diurnal”: two high and low tides per day

• Salinity - more variable than open ocean; evaporation in low tide increases salinity

• Oxygen - not limited; air exposure and wave mixing increases oxygen

• Biology - zonation of species due to differences in exposure to air, light, and disturbances

Wetland/Estuary:

• Structure - salt marsh: between land and ocean, estuary: between river and ocean, Freshwater wetland: between land and lake

• Light - highly variable, depends on tides

• Temperature - highly variable, shallow water so water temperature varies with air temperature

• Movement - driven by ocean currents and tides; important for cycling nutrients and oxygen, removes wastes

• Salinity - fluctuates widely, stratification with low salinity over high salinity

• Oxygen - highly variable; decomposition depletes oxygen but tides restore it

• Biology - very productive; high abundances of relatively few species; important for fish nurseries, migratory birds, “ecosystem services”

Rivers/streams

• Structure: zones: wetted channel, active channel (flooded once or more per year), phreatic zone (ground water), riparian (trees and shrubs that border river)

• Light - depends on clarity of water; light reduced by organic matter, algae

• Temperature - depends on flow rate and depth and tracks air temperature

• Movement - currents cycle nutrients and remove wastes; flow depends on precipitation

• Salinity - reflects the conditions of soil and history of leeching

• Oxygen - depends on the temperature; higher temperature means lower oxygen

• Biology - high in fish diversity

Lakes:

• Structure: zones: littoral (shore), vs. limnetic (open water): epilimnion, metalimnion, hypolimnion

• Light - depends on surrounding landscape; lots of organic matter means lots of nutrients, which means more phytoplankton that reduce light penetration

• Temperature - thermal stratification

• Movement - wind-driven mixing of water, vertical currents (upwelling)

• Salinity - lower salinity than ocean, but more variable

• Oxygen - well mixed clear water, “oligotrophic” with less productivity but have increased light penetration and so higher oxygen, vs.  “eutrophic” with high productivity but decreased light penetration and so less oxygen

• Biology - some lakes have high species diversity, such as cichlid fishes of African lakes