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 living in 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 sizeM = individuals marked on first sampling effortC = individuals marked on second sampling effortR = individuals captured both times

Distribution

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 Growth

Fur Seals on Saint Paul Island, off the coast of Alaska

Limiting Factors & Carrying Capacity

Population Cycles: Predation

Human Population Growth

Survivorship Curves

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 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

Dutch Elm Disease

Species Interactions

Examples of Species Interactions

• Commensalism

•Mutualism

•Parasitism

Keystone Species

Competition

Competitive Exclusion

Resource Partitioning, Anolis lizards

Creating or Repairing: Succession

Succession in Iceland

Periodic Disturbances

Increased sunlight and soil nutrients released from the tress that burned in a forest fire in Yellowstone National Park greatly contributed to the recolonization of the land.

Energy in Ecosystems

Food Chain

Food Web

Trophic Levels

Energy Pyramids

Carbon Cycle

Nitrogen Cycle

Where do Organisms Live?Climate is a major Influence

Biomes: In General

Tropical Rain Forest

Temperate Deciduous Forest

Taiga

Savanna

Temperate Grassland

Chaparral

Desert

Tundra

Lakes

River

Wetland

Estuary

Intertidal Zone

Oceans

Coral Reefs

Benthic Zone