ecology exam 1

What is Ecology?

the study of how organisms affect- and are affected by- other organisms and their environment.

Life's hierarchy of organization

biosphere, biome, ecosystem, community, population, organism

Flow of Energy and Nutrients

Sun-producers-consumers-decomposers-START AGAIN

Do Natural systems necessarily return to their original state after a disturbance?

no not necessarily, even random perturbations can play a role in system health

Scientific Method

observations, questions, hypotheses, tests, observe results, conclusions

what is a controlled experiment?

Experimental groups are compared with a control group that lacks the factor being tested

What is needed for a successful testing/observation

replication and randomness. You must have randomness to prove causation

what is an ecological niche?

abiotic & biotic conditions needed by a species to survive, grow, & reproduce

What is the most fundamental component of the physical environment?

climate

how do organisms react with their environment?

by gathering inorganic nutrients and energy from the environment, interacting with temperature, through gas exchange, and through water and precipitation

what is weather?

Current conditions—temperature, precipitation, humidity, cloud cover

what is the climate?

Long-term description of weather, based on averages and variation measured over decades. this includes cycles and long-term trends

the global climate system is driven by what?

energy which is derived from solar radiation

of incoming radiation, where does it go?

1/3 reflected back by clouds and aerosols, 1/5 absorbed by ozone, clouds, vapor and 49% absorbed by Earth

what is the greenhouse effect?

a natural process existing since the beginning of time. a process that warms the Earth's surface and lower atmosphere by trapping heat from the sun

where is solar energy the most intense?

at the equators. energy is then spread poleward by winds and ocean currents

atmospheric circulation

low pressure, hot air rises, causing precipitation.

high pressure, cool air rises, dryness

prevailing winds

consistent patterns of air movements where wind travels from areas of high pressure to areas of low pressure

Coriolis effect

when the winds appear to be deflected due to the rotation of the Earth

what warms faster, land or water and why?

land warms faster than the ocean.. the ocean is denser so it takes more energy to heat

ocean circulation

two types, shallow and deep. shallow ocean circulation is when ocean surface currents are driven by surface winds, but modified by the presence of land masses. speed of ocean currents a lot slower. deep ocean circulation is determined by density

ocean currents in relation to climate

ocean currents largely impact climates. they are responsible for 40% of earth's heat exchange

down dwelling

colder, saltier(denser) water sinks

upwelling

when prevailing winds pull water away from coast

lapse rate

decrease in temperature with increasing height above the surface

Why does it get colder as you move up a mountain?

as elevation increases, density and pressure decrease which makes it colder

rain-shadow effect

warm air from ocean is carried by wind onto land and up mountain where it rains then comes down the other side of the mountain as dry air

Continental climate

Terrestrial areas in the middle of large continental land masses have greater variation in daily and seasonal temperatures

maritime climate

Coastal areas that are influenced by an adjacent ocean

Albedo

Amount of solar radiation a surface reflects; light-colored surfaces have highest albedo

Evapotranspiration

Water loss through transpiration by plants, plus evaporation from the soil.

Texture

smooth surface allows for less transfer of energy to the atmosphere by wind than a rough surface.

Salinity

Concentration of dissolved salts in water

biosphere

is the zone of life on Earth. It lies between the lithosphere and the troposphere.

what are Biomes and how are they categorized?

large-scale terrestrial communities shaped by the physical environment. they are characterized by the growth forms of the dominant vegetation

Convergence

Evolution of similar growth forms among distantly related species in response to similar selection pressures

what other type of land mass are mountain tops similar to from an evolutionary perspective

islands

tropical rainforests

79 inches of rain, most productive and diverse, light is a key limiting factor

Tropical Seasonal Forests and Savannas

wet and dry seasons, shorter trees, more grasses and shrubs

hot deserts

high temps, low moisture, sparse vegetation and animal population,

temperate grasslands

co-occuring wet and growing seasons, grass have extensive roots, high soil organic matter

Temperate Shrublands and Woodlands

Mediterranean type climate, separate wet and growing season, evergreen and shrubs can survive warm dry season

temperate deciduous forest

lower diversity than rainforest, norther hemisphere only, adequate water and soil fertility, leaves die in winter

temperate evergreen forests

coastal, continental, and maritime climates. acidic soil, conifers, FLORIDA

boreal forests

long, severe winters, permafrost, conifers, pines, cold wet conditions limit decomposition

tundra

cold and dry, plants have short growing season and survive by going dormant, low growing grasses and shrubs, permafrost

freshwater biological zones characterized by...

Characterized by both plants and animals, as well as physical characteristics

lotic vs lentic

lotic is flowing lentic is still

marine biological zones determined by...

ocean depth, light availability, and the stability of the bottom substrate

Nearshore zone

influenced by tides, local climate, and substrate stability.

Shallow ocean

high biodiversity and productivity, driven by photosynthesis

Pelagic zone

determined by light availability and proximity to the bottom

tolerance vs avoidance

Tolerance is the only strategy available for immobile species. Avoidance can include behavioral and/or physiological changes

Physiological Ecology

the study of interactions between organisms and the physical environment that influences survival and persistence

potential vs actual distribution

potential is determined by physical environment. actual is other real things like competition

Conduction

transfer of energy from warmer to cooler molecules. (d=diffusion)

Convection

heat energy is carried by moving water or air. (v=movement)

Latent heat transfer

water absorbs heat as it changes state from liquid to gas

Ectotherms

Primarily regulate body temperature through energy exchange with the external environment. high tolerance for temp variation, control temp with behavior, body size is constrained

endotherms

Rely primarily on internal heat generation, mostly birds and mammals. Maintain a constant resting metabolic rate over a range of environmental temperatures, called the"thermo neutral zone." have lower critical temp

homeotherm vs Poikilotherm

Homeotherm- Same body temp

Poikilotherm- Varying body temps with environment

Hypoosmotic

Water moves into high-solute cell and swells

Hyperosmotic

Water moves out of high-solute cell and swells

Isoosmotic

Water is in equilibrium (marine environments are normally isoosmotic with their inhabitants)

Water Balance in Terrestrial Animals

amphibians have thin skin so are water reliant, reptiles evolved thick outer skin in order to prevent water loss, mammals have hair and feathers to prevent evaporation, and insects have a cytoskeleton to prevent water loss.

water potential

sum of Ψo = osmotic potential (negative value), Ψp = pressure potential, and Ψm = matric potential (negative value)

energy is the basic need for what in organisms?

Cellular maintenance, Growth, and reproduction

three sources of energy

radiant energy (sunlight, the most prominent), chemical energy (stored in bonds of food molecules), and kinetic energy (movement of molecules)

autotrophs

organisms that assimilate energy from sunlight (photosynthesis), or from inorganic compounds (chemosynthesis)

heterotrophs

obtain their energy by consuming energy-rich organic compounds from other organisms

photosynthesis: light and carbon reactions

light-photons of light are absorbed and energy is used to split water and provide electrons to make ATP and NADPH.

carbon-carbon dioxide is fixed in the calvin cycle and carbs are synthesized

environmental constraints of photosynthesis

- light

- water availability

- nutrients

- temp

photorespiration

results in a net loss of energy for the plant. O2 is taken up, leading to breakdown of carbon compounds and release of CO2.

balance between photosynthesis and photorespiration is determined by...

1. Ratio of O2:CO2: high CO2 favors photosynthesis

2. Temperature: high temps favors photorespiration

different types of photosynthesis

C4- reduces photorespiration energy losses, grasses

CAM- enhances water conservation, common in arid and saline environments

C3

heterotrophs energy investment

their investment in finding resources typically mirrors the energy gain