The Organization

of LifeEcosystems and Diversity

Chapter 4

Ecosystem

All of the organisms living in an area together with their physical environment

2 types of ecosystemsAquatic- waterTerrestrial- land

SurvivalIn order to survive, an ecosystem

needs 5 basic components 1. Energy- usually from the sun 2. Mineral nutrients 3. Water 4. Oxygen 5. Living organisms

Factors

Biotic factors- the living and once living parts of an ecosystem

Abiotic factors- The nonliving parts of the ecosystem (air, water, rocks)

Components of an Ecosystem

Organism- a living thing (multi-celled or single celled); anything that can carry out life processes independently

All organisms live in a particular place called a habitat

For example:Cactus live in the desertDolphins live in the ocean

Components

Species- organisms that are closely related and are capable of producing fertile offspring

Population- members of the same species living in the same area at the same time

Community- two or more populations living in the same area at the same time

o Ecosystem- all the organisms living in an environment; includes abiotic and biotic factors

o Biosphere - The Earth- All land, water and air where life exists

Diversity of Living Things

*Classify organisms by fossil records *Evolutionary Characteristics *Hierarchy of Matter: atom, molecule, organelle, cell, tissue, organ, organ system, and

organism

6 Kingdoms

o  Archaebacteria Eubacteria Fungi Protists Plants Animals

Biodiversity

The number and variety (sum) of all organisms in a given area

Approx 2 million known species (most insects)

Estimate more than 9 million not yet discovered

Benefits of Biodiversity

Stability of ecosystems and sustainability of populations

Balances energy and nutrients/food security

Increases genetic diversity and decreases chances of genetic disease

Biodiversity at Risk

Extinction - the last member of a species dies and the species ceases to exist (can be a natural event)

Extirpation – the extinction of a certain population from a given area, but not the entire species globally

Causes of Biological Loss

Invasive/Exotic Species (species not belong in area)

PollutionOver-harvesting, Hunting, and

PoachingClimate change**Habitat destruction, loss, and

fragmentation = BIGGEST THREAT

Ways to Save Biodiversity

Captive Breeding Programs Preserving Genetic Material (storing to

be used in future)Artificial Selection (done under human

direction)Zoos , Parks, Aquariums, and GardensConservation

Areas of Critical Biodiversity

Hotspots – pinpoint areas of high diversity; support an especially great diversity of endemic (native) species

Examples:Tropical Rain ForestsCoral Reefs and Coral EcosystemsIslands