Populations and Ecosystems Flashcards
Eukaryote
Organism with enclosed nucleus and other complex organelles.
Prokaryote
Organism without enclosed nucleus and other complex organelles.
Within an ecosystem, there exist…
individuals –> populations –> communities
Individuals are classified as species if they…
- have shared characteristics
2. produce fertile offspring
To be classified as a populations, three factors must exist…
- number of same species
- in the same place
- at the same time
What determines the number of individuals in a given area?
abiotic and biotic factors
What does it mean that “an ecosystem is dynamic”
There exist changing biotic factors in response to changing abiotic factors
Taxonomy
the classifying of organisms which is understood around the world
Order of Classification
domain kingdom phylum class order family genus species
How is the order of classification determined?
organized according to shared physical characteristics from the broadest similarities to the most specific, where all individuals in that classification share all the same physical characteristics.
Dichotomous key
a series of steps classifying organisms. Each step offering two options to move from step to step until the organisms are separated into distinct groupings.
How to label a Genus species
- both are always italicized
- Genus is always capitalized
- species is always lower case
- referred to as bionomial nomenclature
Four zones of a lake or pond:
- Littoral
- Limnetic
- Profundal
- Benthos
Littoral
- area nearest the shore which is warm and shallow
- high biodiversity due to greater abundance of a variety of plants
Limnetic
- open water near the surface and home to phytoplankton and zooplankton (feeds off phytoplankton) and fish that are top feeders.
Profundal
- deep region of lake below the limnetic zone
- darker with less sun penetration where floating dead matter is found
Benthos
- bottom of the lake
Estuary
- where salt and freshwater biomes meet
- aquatic biome with the greatest biodiverstiy
Two types of lakes:
- Oligotrophic lakes
2. Eutrophic lakes
Oligotrophic lakes
- deep and cold
- change little over time and have low nutrient levels
Eutrophic lakes
- shallow and warm and high nutrient levels due to high abundance of photosynthetic organisms (including algae)
- undergo eutrophication - the build up of matter on the bottom of the lake, causing the lake to fill and become even more shallow
- eventually the lake disappears (natural succession of lake to meadow)
Terrestrial Biomes
- Tundra
- Taiga
- Temperate deciduous
- Temperate grassland
- Tropical grassland/ Savanna
- Tropical rainforest
- Desert
Desert
can be hot or cold. area with very little precipitation, therefore low vegetation
Tropical rainforest
The tropical rainforest is a hot, moist biome found near Earth’s equator. Low light penetration.
Tropical Grassland AKA SAVANNA
A savanna or savannah is a mixed woodland-grassland ecosystem characterised by the trees being sufficiently widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach the ground to support an unbroken herbaceous layer consisting primarily of grasses.
Temeprate grassland
Temperate grasslands are characterized as having grasses as the dominant vegetation. Trees and large shrubs are absent. Temperatures vary more from summer to winter, and the amount of rainfall is less in temperate grasslands than in savannas.
Temperate deciduous
Temperate deciduous or temperate broad-leaf forests are a variety of temperate forest ‘dominated’ by trees that lose their leaves each year. They are found in areas with warm moist summers and cool winters.
Taigai (boreal forest)
Taiga, generally referred to in North America as boreal forest or snow forest, is a biome characterized by coniferous forests consisting mostly of pines, spruces, and larches. The taiga or boreal forest is the world’s largest land biome.
Tundra
Tundra is the coldest of all the biomes. It is noted for its frost-molded landscapes, extremely low temperatures, little precipitation, poor nutrients, and short growing seasons. Dead organic material functions as a nutrient pool.
Ecotone
transition zone between biomes
ecological niche
role organisms play in its ecosystem
habitat
area where an organism carries out its daily function
range
area where individuals of a species can be found
limiting factors
abiotic and biotic factors which limit the number of individuals in population
- abiotic limiting factors
- aquatic: temp., pH, O2 concentration
- terrestrial: temp., wind, moisture, pH of soil, fire, altitude. - biotic limiting factors: competition, predator prey, parasites, etc.
Symbiotic relationships
- parasitism - one benefits, the other loses
- commensalism - one benefits, the other neither benefits nor loses
- mutualism - both benefit
Biome
community of flora and fauna and anamalia that have common characteristics for the environment they exist in.
Succesion
gradual change in vegetation of an area as it develops toward a final stable community; the climax community is the final dominant vegetation found in the area.
Primary succesion
occurs when no community existed before
Secondary succesion
follows parietal or complete destruction of a community
Pioneer community
first plant and animals that appear
Climax community
final stable domination plant and animals comunities
Two factors of introduced species
a. no predators in new area
b. outcompete native species
Population estimation methods
- quadrat method
- line transect
- aerial survey - for large bird populations
- mark and recapture
4 Factors reducing biodiversity
- invasive species
- habitat loss
- competition for resources
- damage to environment
Why do economics and ecological demands conflict?
For example, for St. Albert to expand, we must destroy land to build cities. The pros, are that we would have more people paying taxes. Costco is on the best land to plant crops in the province, but the farmer sold it to make money, etc.
