Ecology practice set

Population

Population

A group of individuals of a single species living in the same general area

Uniform dispersion

Even dispersion because of territoriality and intraspecific competition

Random dispersion

Lack or absence of strong attractions or repulsions

Clumped dispersion

Resource clumping leading to Protection or Cooperation

Selected K traits

• Traits are favored at high densities

• Like Humans produce few but take care

• Survivorship curve type 1

K population

Near carrying capacity and density dependent

R population

Per capita rate away from carrying capacity and is density independent

R traits

• Traits maximize reproduction

• Like clams produce many but do not take care of them

• Survivorship curve type 3

Density dependent factors

Territoriality, competition for resources, disease, predation, toxic wastes, and intrinsic factors

Density independent factors

Natural disasters and Weather

Exponential Growth

J shaped curve with unlimited resources due to no carrying capacity

Logistic Growth

S shaped graph and limited resources due to Carrying capacity (K)

Community

A group of populations of different species living close enough to interact

Competitive exclusion Principle

2 species competing for the same limiting resources cannot coexist in 1 place

Resource Partitioning

Differentiation of ecological niches enabling similar species to coexist in a community

Character Displacement

Differences of Niches in similar species that are present when they are both in the same place but not when they are in different places

Optimal Diversity

Maximum richness and equal relative abundance

Energetic Hypothesis

10% of energy in one trophic level is utilized in the next so top trophic level species cannot obtain enough energy, limiting the length of the food chain.

Dynamic Stability Hypothesis

Long food chains are less stable than short food chains because if one species decreases the food chain/web collapses

Fundamental Niche

Potential functions in an environment without Competition

Realized Niche

Actual functions in an environment with Competition

Primary Succession

When the environment starts without soil

Secondary Succession

When the environment starts with soil

Ecosystem 1

All the organisms in a given area as well as the abiotic factors with which they interact

Ecosystem 2

one or more communities and the physical environment around them

Matter vs Energy Flow

Matter Cycles while Energy Flows

Energy changing forms

Sunlight reaches the earth, then is turned to chemical energy by Autotrophs, and released as heat

Trophic energy flow

Photoautotrophs with consume light energy → Chemoautotrophs turns energy into chemicals → Heterotrophs consume the chemical energy and excrete it → Is now waste for Detritivores

Gross Primary Production

Amount of energy producers obtain, then photosynthesize into chemical energy

Net Primary Production

Amount of biomass left for Consumers after Producers use GPP for respiration

Eutrophication

Increased levels of nutrients (N and P) caused by intense primary production that cause aquatic algae to grow rapidly and deoxygenate the entire aquatic area or community

Reservoir

Where elements exist and processes that transfer elements between them → sedimentation and erosion

Biogeochemical cycles

Any of the various chemical cycles, which involve both biotic and abiotic components of ecosystems

Nitrogen fixation

Carbon fixation