Ecology: Exam 1

Ecology

study of relationships between organisms and the environment; derived from Charles Darwin

(Disciplines) Large/small taxa or reactions

Abiotic interactions, organisms, populations, communities, biomes, earth

Evolution

the process by which different kinds of living organisms are thought to have developed and diversified

Natural Selection

organisms adapt to their environment to survive; survived genes are passed on to the next generation

Yellow Stone Wolves

drastic changes to: animal populations, animal movements, and vegetation; before reintroduction little to no trees and more elk, after reintroduction increase in trees and control on elk population

Trophic cascade

removal of top predators results in reciprocal changes in the relative populations of predator and prey through a food chain

Biosphere

the combination of all ecosystems of the planet (all life and the area where life is found)

Determining natural factors for physical environment

temperature, water, sunlight, soil

Biota

sum of all living things

Biota influence

physiographic features: climate, soil, geography

Ecotone

transitional zone where 2 different ecological communities, ecosystems, or biomes meet and integrate

climate

a region’s long-term atmospheric conditions

soil

the loose top layer of the earth’s surface where plants grow, made of minerals, organic matter, air, and water

What do climate and soil dictate?

plant and animal life

How is climate determined?

rotation of earth: tilted earth axis causes seasons, causes movement of air, water circulation (ocean currents)

What dictates climate?

earth’s rotation and tilt drives air circulation patterns and consequently precipitation patterns

ocean currents

continuous directed movements of sea water that flow throughout the ocean like rivers

Coriolis effect

As earth rotates, the tangential velocity at the equator is greater than the poles; Objects travelling from the equator (north or south) has greater velocity than the earth underneath

Warm surface ocean currents

carry less dense water away from the equator toward the poles

Cold deep ocean currents

carry denser water away from the poles towards the equator

What are ocean currents driven by?

Surface currents:
- wind
- topography

Deep ocean currents:
- density-dependent
- colder and saltier = more dense

If ocean currents are driven by density (salinity) how could the melting of polar regions from global climate change influence ocean currents?

Melting polar ice adds more fresh water to the ocean, which lowers water salinity, decreases density, and can slow down or stop water circulation; Hot places get hotter (EX: Equator, Midwest) and rapid cooling in place like Europe that rely on ocean circulation

topography

the study and detailed description of surface features, shape, and physical layout of a land area (both natural formations and artificial structures

elevation

the height of a place or object above a fixed reference point, usually sea level; Higher up = colder, less diversity

Ecological Partitioning

niche/resource partitioning; the process where competing species use different resources, areas, or times in an ecosystem so they can survive together instead of one driving the other to extinction

Change over time

Global average temperatures have risen by about 2 degrees Fahrenheit driven by fossil fuel use; effects include: sea levels rising as warm water expands and glaciers melt, mass ice shrinkage, and extreme weather (heavy downpours, intense heatwaves, and severe droughts)

Can humans change biomes?

Yes- conversions of natural biomes to “used” biomes; “Unused” land declined 95% in 1700 to 61% in 2000; predominantly land consists of urbanization, agriculture, wildlands- deserts stayed deserts (undesirable), woodlands declined and grasslands become agriculture

Soil

complex mixture of living and non-living material

Soil Classification

based on vertical layering (soil horizons); soil structure in constant state of flux; Layers: O, A, B, C in order

How is soil (not dirt) created?

parent material, climate, time, living organisms, topography

Soil- parent material

earthy materials, both mineral and organic

Soil- climate

parent material is broken down by climate

Soil- time

the age of a soil is considered in thousands or millions of years

Soil- living organisms

plants and animals die and add to the matter of weathered material

Soil- topography

hilliness, flatness, or slope of land

Soil- O horizon

Organic Layer freshly fallen organic material- most superficial layer

Soil- A horizon

mixture of minerals, clay, slit, and sand

Soil- B horizon

Clay, humus, and other materials leached from A horizon- often contains plant roots

Soil- C horizon

Weathered parent material; often rock fragments or bedrock

Biome Equation

Climate + Soil = specific plant species = specific animal species

biosphere

the global ecological system where all living things exist and interact with earth’s land, water, and air

Water percentages

Biosphere: 71% of surface water
Ocean: 97% of water in biosphere
Polar ice caps/Glaciers: 2% (about)
Freshwater (groundwater, lakes, rivers): <1%

Natural lakes

a large naturally occurring body of standing water; formed by geologic forces

Geologic force

volcanism, glacial activity

Volcanism

the process where molten rock, gases, and other materials break through the surface of a planet from its hot interior

Glacial activity

the slow movement and changing of giant masses of ice that shape the earth’s surface through erosion and the dropping of rocks and dirt

Lentic systems

a body of standing or relatively still freshwater, such as a lake, pond, or wetland; not flowing

Littoral zone

the shallow, warm edge near the shore where rooted plants grow

Limnetic zone

the open, sunlit surface water away from the shore where algae and plankton thrive

Profundal zone

the deeper, darker area where sunlight cannot reach

Benthic zone

the bottom layer of water body, home to decomposers and scavengers

Thermocline

a layer of water that divides temperature fluctuation in large water bodies

Thermal stratification

the separation of a body of water into distinct temperature layers based on water density

Epilimnion

the top, warmest layer; wind and waves mix this layer, and it has the highest oxygen levels

Metalimnion (thermocline)

the middle transition zone; temperature drops very fast as it deepens, acting as a barrier to mixing

Hypolimnion

the deep, cold, and dense bottom layer; this water stays isolated from the surface and often loses oxygen over time

Oligotrophic

having a low concentration of plant nutrients and low primary productivity, usually paired with clear water and high oxygen levels; (well oxygenated, lots of life); Lake Superior, Lake Tahoe

Eutrophic

rich in nutrients (especially nitrogen and phosphorus) leading to heavy plant and algae growth in body of water (oxygen depleted, less life)

Lake turn over

the natural (sometimes seasonal) profess where a lake’s water mixes completely from top to bottom; mixes nutrients and energy

Lake Erie

crazy input of phosphorus; result: led to an increase in phytoplankton and zooplankton—→ leads to poor water quality and low oxygen levels (from dead things)

phytoplankton

microscopic plant-like organisms that drift in the sunlit surface layers of oceans and freshwater bodies

zooplankton

tiny, drifting animals that live in oceans, lakes, and rivers