Define ecology and distinguish among the following ecological levels: population, community, ecosystem, landscape, and biosphere.
Define population density and dispersion and describe the main type of population dispersion.
Explain the four factors (natality, mortality, immigration and emigration) that produce changes in population size and solves simple problems involving this changes.
Define intrinsic rate of increase and explain the J-shaped growth curves (exponential population growth).
Biological organizations: hierarchical functional structure
Ecology: the science that studies interactions among organisms (biotic factors) and between organisms and their non living physical environment (abiotic factors: water, temperature, pH, wing, chemical nutrient).
Abiotic factors: Earth scinece, geology, chemistry, oceanography, climatology, and meteorology
Mathematical models describe population growth:
On a global scale: 2 factors determine the population size:
natality: the rate at which individuals produce offspring (the average per capita birth rate) : e.g. number of birth per 1000 people per year).
mortality:the rate at which individuals die (the average per capita deah rate): e.g. number of death rate per 1000 people per year.
On a local population size determined by:
the average per capita birth rate (b)
the average per capita death rate (d)
the average per capita immigrant rate (i)
the average per capita emigrant rate (e)
The average growth rate:
N/t = N (b-d)
N: the changes in number of individuals in the population
t : the change in time
N : the number of individuals in the existing population
The growth rate (r) : the rate of change (increase or decrease) of a population on a per capita basis is the birth rate minus the death rate.
r = (b – d)
Example: N = 10,000 people, 200 birth rate per year ( 20 birth per 1000 people) and 100 death per year (10 death per 1000 people).
r = 20/1000 – 10/1000
= 10/1000 = 0.001 (1% per year)
r = (b– d ) + (i –e)
Example: A population of 10,000 that has 200 birth (20 per 1000), 100 death (10 per 1000), 10 immigrants (1 per 1000), and 100 emigrants (10 per 1000) in a given year.
r = ((0.02 – 0.010) + (0.001 – 0.010)
= 0.001 or 0.1% per year
Instantaneous growth rate:
dN/dt = rN
solving for N: Nt = No. ert
Nt : number of individuals in at t time
No : number of individuals at the beginning ( t = 0)
r : instantaneous growth rate
e : base of natural logarithms ( 2.71828).
solving for r:
ln Nt – ln No
r = —————-
Characterize a community and distinguish between a community and ecosystem.
Define ecological niche, distinguish between an organism’s fundamental niche and its realized niche. and give several examples of limiting resources that might affect an organism’s ecological niche.
Community structure : ?
Communities contain autotrophs and heterotrophs
Primary producers (autotrophs)
Primary consumers (herbivores)
Secondary consumers (carnivores)
Tertiary consumers (carnivores)
Detritus feeders (detritivores)
Ecosystems and Biosphere
Compare how matter and energy operate in ecosystems.
Summarize the concept of energy flow through a foodweb.
Draw and explain typical pyramids of numbers, biomass and energy.
cycling of nutrients,
effects of natural & human induced disturbances
EOLOGY AND THE GEOGRAPHY OF LIFE
Define biome and briefly describe the nine major terrestrial biomes, giving attention to the climate, soil and characteristic plants and animals of each.
Describe at least one human effect on each of the biomes discussed.
Climate: temperature and precipitation many different
Natural selection: organism’s to survive and reproduce
abiotic & biotic factors act to eliminate the least-fit
individuals in a given population better adapted
Biomes are largely distinguished by their dominant form of vegetation.
biome: a large, relatively distinct terrestrial region
characterized by similar climate, soil, plants, and animals regardless of where it occurs.
a number of interacting ecosystems
temperature and precipitation: the most important factors ! (Fig. 54-1, p. 1206).
Near the poles: temperture is the most overriding climate factors.
Temperate & tropical regions: precipitation more significant than temperature (Fig. 54-2, p.1207).
Climate factors to which biomes are sensitive:
rapid temperature changes
Charachteristics in terms of:
Nine major biomes:
Temperate rain forest
Temperate deciduous forest
Tropical rain forest
Tundra in Summer
Tropical Rain Forest
Tropical Rain Forest