Ecology - C. 18The study of the interactions between organisms and the living and nonliving components of their environment.
Levels of Organization• Biosphere-everything living• Ecosystem-living and nonliving in an area• Community-group of populations• Population- # same species in an area• Organism-an individual Theme: Interconnectedness. No organism is isolated!
Coevolution of Species
Population DynamicsPopulation: Members of the same species livingin a particular place at the same time.
Measuring Population Density:The Mark-Recapture Method Formula for calculating population size: N = (M * C) / R N = population size M = individuals marked on first sampling effort C = individuals marked on second sampling effort R = individuals captured both times
Measuring Populations• Demographics-study of population dynamics. How populations grow and what factors limit growth.• Per Capita Growth: BR-DR = GR
Models of Growth• Exponential Growth • Logistic Growth
Exponential Growth of Bacteria
Logistic GrowthFur Seals on Saint Paul Island, off the coast of Alaska
Limiting Factors & Carrying Capacity
Population Cycles: Predation
Human Population Growth
Ecosystem Components• Abiotic Factors: non-living components such as sunlight, water, temperature, wind, natural disasters and rocks and soil.• Biotic Factors: living components (or biota) such as plants, animals, and microorganisms.
Communities- C. 19• All interacting organisms living in one area.
Biodiversity• The biodiversity of an area is a way of describing how many different organisms live there• Low biodiversity is a major problem that can occur to decrease the aesthetic and/or utilitarian value of an ecosystem• A variety of indices can be used to describe an area’s biodiversity
Invasive Species• An invasive species is one Dutch Elm Disease that when brought to a new area or part of an area is likely to cause or will cause environmental harm• Most often, the harm caused is a loss of biodiversity or loss of some other species• An exotic or alien species is one that is not native to an area
Examples of Species Interactions •Mutualism• Commensalism •Parasitism