Exam 1

Ecology

scientific study of interactions between organisms and their environments

Negative human impacts on the environment

habitat modification, greenhouse gas emissions/climate change, invasive species introduction, overfishing, wildlife trade, waste

Positive human impacts on the environment

habitat restoration, successful translocations, ex situ breeding programs, nature reserves, sustainable agriculture

Habitat restoration

taking an area that has been degraded by agriculture, deforestation, or urbanization and bringing it back to health

Individual scale

single organism of a particular species, behavioral and physiological ecology

Population scale

group of individuals that live in a particular area and interact with one another, evolutionary and population ecology

Community scale

an association of interacting populations of different species that live in the same area, community ecology

Ecosystem scale

collection of communities of organisms plus the physical environment in which they live, ecosystem ecology

Landscape scale

areas that vary substantially from one place to another, typically including multiple ecosystems, landscape ecology

Biosphere

all living organisms and their environments, global and climate change equality

What determines where organisms can live?

the physical environment including soil, climate, and elevation

Weather

short-term state of the atmosphere on a temporal scale of minutes, hours, days

Climate

long-term patterns of weather at a given location measured over years, decades, centuries

What is the primary driver of climate?

the sun

Causes of back radiation

clouds, aerosols, atmospheric gases, reflective surfaces

Back radiation

atmosphere traps the radiation close to the earth

Sensible heat loss

changing the temperature of an object

Latent heat loss

changing the physical state or phase of an object

Types of sensible heat loss

conduction and convention

Convection

energy transferred by movement of air and water currents

Conduction

energy transferred through the exchange of kinetic energy between molecules in direct contact

Types of latent heat loss

evaporation and transpiration

Evaporation

liquid turning into vapor

Transpiration

evaporation of water from inside plants

Why are temperatures warmer at the equator and colder at the poles?

solar radiation is not absorbed evenly due to earth’s curvature, so toward the poles the sun’s rays are spread over a larger area and take a longer path through the atmosphere

Uplift

rising of warm, less dense air in the atmosphere due to the heating of earth’s surface

Atmospheric pressure

force exerted by the molecules of air on the air and surface below it

Subsidence

sinking, downward movement of air in the atmosphere, usually over a broad area

Hadley cell

driven by heat, air is uplifted at the equator and subsides at about 30 degrees north and south

Polar cell

driven by lack of heat, air subsides at the poles, moves toward the equator when it reaches earth’s surface, and is replaced by air moving through the upper atmosphere from lower latitudes

Ferrel cell

located in mid latitudes between Hadley and polar cells, rotate in the opposite direction of polar and Hadley cells and function as gears

Surface winds

air flows from high pressure to low pressure

Downwelling

when warm surface waters reach the poles, they become cooler, denser, and more saline, leading them to sink to deeper depths and move toward the equator

Upwelling

when prevailing winds blow parallel to a coastline, surface waters flow away from the coast, leading to deep ocean water rising to the surface

Precipitation at the equator

low pressure causes heavy precipitation

Precipitation pattern of Hadley cells

low precipitation due to high pressure

Rain shadow effect

mountains force moving air upward causing it to cool and release precipitation on the windward slope resulting in lower levels of precipitation and soil moisture on the leeward side

Climatic variations within latitudes is caused by

ocean currents, distribution of land and water, elevation

How does distribution of land and water impact climate?

water has a higher heat capacity than land, so air temperatures show greater seasonal variation than air temperatures over the ocean

How does the el nino southern oscillation work?

when trade winds drop, warm surface water flows eastward toward South America. Low pressure formed by warm, moist air rising near South America causes condensation and heavy rainfall. Dry air sinks over Australia leading to clear skies, increase in temperature, and decrease in rainfall.

Biome

major division of the terrestrial environment distinguished by predominant plants’ morphology and adaptation

Aspects of plants that define biomes

size, deciduous/evergreen/succulent

Deciduous

plants that seasonally drop their leaves

Succulent

specialized tissues for holding onto water

Why do we define biomes based on plant life?

primary producers, can’t move between biomes, more visible, highly adaptable

Tropical rainforest

high temperature and precipitation biome found between 0-10 degrees, generally absent seasonality, dominated by broad-leaved evergreen and deciduous trees in the canopy and shrubs/forbs on the forest floor

Tropical/seasonal forest/savanna

high temperature, seasonal precipitation biome found between 0-23.5 degrees, seasonality driven by precipitation (wet vs. dry season), dominated by drought deciduous trees, thorn woodlands, grasses, shrubs

Desert

high temperature, low precipitation biome found around 30 degrees, some temperature seasonality, dominated by succulents, drought deciduous shrubs, grasses, short-lived annuals

Temperate grassland

seasonal temperature and precipitation biome found between 30-50 degrees with warm, wet summers and cold, dry winters, dominated by grasses

Temperate shrubland

seasonal (mild) temperatures and seasonal precipitation biome found between 30-50 degrees with warm, dry summers and cold-ish wet winters, dominated by an open canopy of short evergreen trees and shrubs

Temperate deciduous forest

seasonal temperatures and precipitation biome found between 30-50 degrees with hot, wet summers and cold, wet-ish winters, dominated by deciduous trees, smaller trees, shrubs/forbs below the canopy

Temperate evergreen forest

seasonal (mild) temperatures and precipitation biome found between 30-50 degrees with variable but often warm, wet summers and mild, wet winters, dominated by evergreen trees

Boreal forest

seasonal (cold) temperatures and low precipitation biome found between 50-60 degrees north with warm-ish summers and cold winters, dominated by conifers and deciduous birches

Tundra

seasonal (cold) temperatures and low precipitation biome found between 65-90 degrees north with cold dark winters, warm-ish bright summers, dominated by sedges, forbs, grasses, low-growing shrubs, lichens, mosses

What are aquatic biomes determined by?

velocity, temperature, clarity, salinity, oxygen concentration, nutrient status, pH

Lotic

flowing water

What order streams are considered major rivers?

6th order or higher

Benthic zone

just above the floor of the stream where invertebrates feed on detritus

Detritus

freshly dead or partially decomposed remains of organisms

Hyporheic zone

on the floor of a stream where rotifers, copepods, and insects live

Characteristics of lower order streams

fast flowing, CPOM is the main energy input, high oxygen content

CPOM

course particulate organic matter

Characteristics of intermediate order streams

deeper portions flow more slowly, finer sediments, main energy input is from algae and FPOM

FPOM

fine particulate organic matter

Characteristics of high order streams

photosynthesis is the main energy input so detritus is less important, richer communities

What type of rivers does the river continuum apply to the best and why?

temperate because of the freezing temperatures and seasonality

Lentic

still

Formation of lentic waters

glacial processes, geological events, biological processes

What depth of lakes are the most nutrient rich?

shallow

Littoral zone

close to the shore, tons of plant and animal life

Photic/epilimion

close to the surface, lots of algae and fish

Thermocline

transitional part

Aphotic zone

light cannot penetrate so there is no phytoplankton

Human impacts on aquatic ecosystems

sediment deposition, fertilizer run off, invasive species, dam construction, pollution, habitat destruction, overfishing, extreme weather, overuse of water

What are marine zones categorized by?

physical distance to shorelines and the ocean bottom

Nearshore

environments close to the shore that are influenced by local climate, tides, wave action and influx of freshwater

Estuary

freshwater from rivers meets saltwater from rising ocean tides, biological communities adapted to varying salinity

Primary threats to estuaries

pollution

Salt marshes

shallow zones rich in terrestrial sediments, dominated by vascular plants, biological communities adapted to salinity gradient

Primary threats to salt marshes

sea level rise, erosion, extreme weather

Mangrove forest

assemblages of salt-tolerant trees in shallow coastal estuaries and mudflats, the mangroves trap sediments and provide nutrients and shelter for many species

Primary threats to mangrove forests

coastal development, shrimp farming, pollution, diversion of inland freshwater sources, wood harvesting

Rocky intertidal zone

ocean meets land between high and low tides, large rocks, biological communities adapted to alternating marine and terrestrial conditions with tolerance for temperature changes, salinity, desiccation, wave action

Primary threats to rocky intertidal zones

coastal development, pollution, sea level rise, extreme weather

Sandy shores

dynamic coastal environment characterized by fine sands and sediments, limited biological communities due to sandy substrate, tidal fluctuations, and wave action

Primary threats to sandy shores

coastal development, erosion, rising sea levels

Shallow ocean zones

highly productive marine biological zones where sunlight reaches the ocean bottom leading to the establishment of sessile and mobile organisms

Coral reefs

colonies of coral polyps held together by skeletons made of calcium carbonate extracted from sea water

Coral and algae relationship

coral are reliant on photosynthetic algae that live on their bodies for food, and the coral provides protection/nutrients to the algae

Seagrass beds

meadows of submerged flowering plants found on subtidal marine sediments composed of mud or fine sand

Primary threats to coral reefs

ocean acidification, coral bleaching, invasive species, destruction

Primary threats to seagrass beds

pollution, disease, destructive fishing

Kelp beds

large stands of kelp anchored to solid substrate in shallow water

Primary threats to kelp beds

coastal development, pollution, extreme weather, changing water temperatures, predator removal

Pelagic zone

open ocean beyond continental shelves, vastness and depth make it hard to characterize distinct biological communities

Primary threats to the pelagic zone

overfishing, plastic pollution, changing water temperatures, ocean acificiation

Marine benthic zone

ocean bottom subject to near-freezing temperatures and high pressures

Threats to marine benthic zone

bottom contact fishing practices, seabed mining, acidification

Autotrophs

source energy from inorganic chemical compounds or sunlight

Heterotrophs

acquire energy from eating autotrophs