Ecology II Populations Population the total number of
Ecology II: Populations
Population: the total number of a certain species in a given area
Lt. 1: I can understand use all aspects of Population Dynamics
Wolves in Yellowstone
Size, Distribution, Density
Size - Number of individuals - Influenced by many factors -Growth = - (b-d)+ (i-e)
Distribution - Spatial arrangement of the populations 3 Types: 1. Clumped 2. Uniform 3. Random (rare)
Density - Number of individuals per unit area - May indicate resource availability
II. Population Demographics - The study of how population factors change over time
A. Density Dependent Factors - Affects populations as density varies Ex. -disease -predation -Limiting Resources 1. Food (nutrients) 2. Water 3. Space 4. Habitat
B. Density Independent Factors - Often abiotic - Natural disasters - Non-communicable disease
Sampling: estimating size and density Forms: 1. Quadrat: small section of land, count individuals, extrapolate 2. Transect: a line across different areas 3. Mark-and-recapture: Catch as many as possible, mark them, repeat, marked/new total
Lt. 2: I can analyze and interpret population growth curves
Population Growth Curves
III. Human Population Growth
History: -population grew slowly for thousands of years -disease kept the population low -most of history – 50% of children died -500 years ago human population began growing -invention of agriculture -increased food supply -improved sanitation, health care -exponential growth
Reasons for growth:
1. Invention of Agriculture
2. Increased food supply
3. Improved sanitation and healthcare
Result:
1. Increased Infant Survival
2. Decreased Death rate
3. Exponential Growth
Common Solutions to Human Population Growth:
-limiting family size (China)
-empowerment of women
Age Structure Diagrams: population profiles
IV. Conservation: the maintenance of genetic, species and ecosystem diversity -Protecting biodiversity
Value of Biodiversity:
1. Provides us with foods
2. Pharmaceuticals (40 – 50%)
3. Recreation
Lt. 5: I can state the two types of competition and what resoures are competed for.
Competition: when one or more individuals defend or use a resource; excluding others 2 Types: 1. Intraspecific: between members of the same species 2. Interspecific: between members of different species
Dispersal: Leaving a stressful ecosystem for a better ecosystem
Competitive Exclusion: Competition which leads to the local extinction of a species
- Slides: 56