ENR SCI: Unit 3 - Ecology & Biodiversity

Vocab: Density Dependant & Density Independent (Define & Examples)

Dependant: Birthrate falls with rising population density

- Food supply, Parasites, Disease, Competition, Predations

Independent: Birth & death rate changes but independently from the size of the population

- Rainfall, flood, acidity, drought ("weather conditions"/natural disasters"

Ecological Aucceasion

Sequence of community changes

—> transition in species composition over time

TWO TYPES:

1. Primary succession (takes hundreds of years)

2. Secondary succession (takes ~150)

PANDA PAWS (Density Factors/Population Regulation)

Dependant:

Predators

Availability of resources (e.g. water, shelter)

Nutrient supply (i.e. food source)

Disease/Pathogenic spread (sickness spread in population)

Accumulation of wasters

Independant:

Phenomena (e.g. natural disasters)

Abiotic factors (e.g. temperature, CO2 levels)

Weather conditions (e.g. floods, storms)

Vocab: Community

Group of organisms living in the same space

Berries Picked Slowly Died Grass Never Stopped Growing Down Town

Bare (rock) Pioneer Species Decomposition Grass (growth) Nutrient (soil) Shrub Growth Depth (soil) Trees

First law of thermodynamics

Energy cannot be created or destroyed, only transformed

Second law of thermodynamics

Energy conversions are NOT completely efficient —> Some energy is always lost as heat

Dicholoro Diphenyl Trichororoethane (DDT)

-Chemical used to kill lice & other pests-

—> Usage stoped by RACHEL CARSON (biologist)

- Usage was killing birds & fish

- Published book "Silent Spring" -> VERY controversial and well-known

- Introduced idea of "bioaccumulation"

—> Impaced Peregone Falcon eggs (became thinner w/ HIGH DDT exposure)

Vocab: Bioaccumulation

Build up of a substance (usually a toxin) as it passes through a food chain

Vocab: Biomagnification

Increase in chemical concentration in animal tissues as the chemical (often toxins) moves up the food chain

Vocab: Climax forest

Mature, stable ecosystem

Vocab: Population Dynamics (define)

Complex interactions between biotic & abiotic factors that cause variations in population size

Vocab: Population Cycles

Changes in carrying capacity

-->P redator-prey interactions

--> Time lags result from delay in reproduction time

Vocab: Lag Time

Initial adjustment period when organisms/cells are placed in a new environment ^ have NOT yet begun actively growing

Vocab: Limiting Factors

Limit the size of the population

Vocab: Autotrophs ("self-feeders")

Build organic moleules themself using:

- Energy from the sun (photosynthesis) OR

- Chemical energy from inorganic chemical reactions (chemosynthesis)

Vocab: Heterotrophs ("different-feeders")

Depend on biosynthetic output of other organisms

--> CANNOT utilise energy from the sun OR inorganic chemical reactions

Ex. Consumers:

- Herbivores, omnivores, carnivores

Vocab: Intrinsic

Occurring as a natural part of something ("inevitable")

Vocab: K-selected

- Late reproduction, few offspring

- Invest a lot in RAISING OFFSPRING

Ex. chimp, human

Vocab: r-selected

- Early reproduction, many offspring

- Little parental care

Ex. Fish

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