Introduction to Ecology

Introduction to Ecology Notes
 Ecology: study of relationships among living organisms
and interactions with the physical environment
 Biodiversity: total variety of living organisms in an area
What affects biodiversity?
 Changes in habitat
o Climate changes
o Fire
o Flood
 Birth rate: Births/ Year
 Death rate: Deaths/Year
 Invasion of other organisms
 Immigration: organisms moving in
 Emigration: organisms moving out
 ↑ Biodiversity = ↑ Resilience to change
Population analysis: when ecologists look at birth rate, death
rate, immigration and emigration numbers; allows for a critique
of populations and their communities
 Population: interbreeding group of species
 Community: interacting population
Two models resulting from population analysis
Exponential Growth: growth pattern where a population
grows as it increases in size
Logistic Growth: growth pattern that depends on density;
reflects competition
 Logistic Growth Vocabulary
o Carrying Capacity: number of organisms an
environment can support
 Births < Deaths until carrying capacity is
o Density-independent factors:
 Abiotic factors
 Weather
 Pollution
 Soil Type
o Density-dependent factors:
 Disease
 Competition
 Parasites
 Food