Ecology and Ecology and BiodiversityBiodiversity

EcologyEcologyEcology is the study of relationships

between all organisms and their environment.

BiosphereBiosphereThe largest environment we focus

on at one time is the biosphere.The biosphere consists of the thin

layer of the earth’s surface where all organisms live.

The biosphere can be divided into various biomes which are the world's major communities, classified according to the predominant vegetation and characterized by adaptations of organisms to that particular environment.

BiomesBiomes

BiomesBiomesEach biome supports certain varieties of organisms that are adapted to that environment such that they are getting their needs met and are successfully reproducing offspring.

ExamplesExamples of Biomes of BiomesTerrestrial Biomes (Land Biomes)

◦Forests – Coniferous, Deciduous, Rain◦Grasslands◦Desert◦Taiga◦Tundra

Aquatic Biomes (Water Biomes)◦Freshwater Lakes, Ponds or Rivers◦Saltwater Oceans◦Brackish Water Wetlands

Levels of OrganizationLevels of OrganizationEcosystem – a self-sustaining

collection of organisms and their environment.

Community – all organisms that live in a particular place

Population – all members of a particular species that live in a particular place.

Organism – one member of a particular species that lives in a particular place.

Habitat vs. NicheHabitat vs. NicheA habitat is the place in which an

organism lives (this can be big like the desert or small like your backyard)◦for example – a frog lives near a pond-

like habitat.A niche is the job or function of an

organism within its ecosystem◦for example – the frog eats insects and

is eaten by small animals and birds.

Components of an Components of an EcosystemEcosystem

Nonliving components of an ecosystem are called abiotic factors.◦Examples: sunlight, rocks, slope of the

land, temperatureLiving components of an ecosystem

are called biotic factors.◦Examples: all living organisms – plants,

animals, protists, bacteria, etc.

Describing Biotic FactorsDescribing Biotic FactorsThere are many ways to describe

living things. Be sure you are familiar with the following terms:◦Producer◦Consumer◦Herbivore◦Carnivore◦Autotroph◦Heterotroph

Interactions of Biotic Interactions of Biotic FactorsFactors

One example of interactions of biotic factors is predation. An organism that consumes others is called a predator and the organism that it consumes is called its prey.

Interactions of Biotic Interactions of Biotic FactorsFactors

Another example of interactions of biotic factors is symbiosis which is a close, often long-term, interaction between two different biological species. This includes:◦Mutualism – both organisms benefit◦Commensalism – one benefits and the

other derives neither benefit nor harm◦Parasitism – one benefits at the expense

of the other.

• • Biodiversity refers to the number and variety of species in a given area and it is always changing! The number of known species on Earth, for instance, is about 1.6 million, most of which are insects. (This differs from the actual number of species on Earth, which may be closer to 13 million!)

BiodiversityBiodiversity

The greater the biodiversity (both in different types of species and species numbers), the more sustainable the ecosystem.

Biodiversity = Biodiversity = SustainabilitySustainability

Diverse, thusSustainable

NOT Diverse, thusDifficult to Sustain

Each species has a role or niche to play in its ecosystem so when an ecosystem changes, hopefully there will be some organisms that possess adaptations or genetic variations (from sexual reproduction) enabling their species, or at least some of their species, to survive. Otherwise, the ecosystem may be in jeopardy!

Biodiversity = Biodiversity = SustainabilitySustainability

Sexual vs. Asexual Sexual vs. Asexual ReproductionReproduction

Variety within a species is the result of sexual reproduction.

Having species richness and species numbers is a good thing for sustainability.

Asexual reproduction does NOT promote biodiversity.

Example of BiodiversityExample of Biodiversity Mt. St. Helens’ Gopher. When Mt. St.

Helens volcano erupted in 1980, it devastated an entire mountain of life; however, there was one mammal that survived. A small furry gopher species had tunneled underground and eventually found its way to the surface, after the lava cooled. Because this small gopher has adaptations such as fast burrowing claws, and did not require much food, it was able to survive. Hundreds of other gophers died in the devastation, but this particular type survived.

Danger of Limited Danger of Limited BiodiversityBiodiversity

The tundra is a very fragile environment. It can only support a limited number of consumers because its cold climate limits the growing and reproduction cycles of plants (the producers); therefore, there is very LIMITED biodiversity. Should a disaster arise (like melting of glaciers, etc.), it could damage this fragile ecosystem forever!