The Biosphere Chapter 3 Ecology The scientific study

The Biosphere Chapter 3

Ecology The scientific study of interactions among organisms and between organisms and their environment n Biosphere n

Levels of Organization n n n Biosphere Largest (World) Biome (Certain Characteristics, Desert) Ecosystem (Living and Non-living) Community (Different Populations Interacting) Population (All One Type of Organism) Species (Smallest) Individual

Energy Flow n Producers: n n n sunlight Autotrophs – make their own food EX: plants

n Consumers: n Heterotrophs: n n n Herbivores: Carnivores: Omnivores: Detritivores: Decomposers:

Feeding Relationships Food chains: series of steps in which organisms transfer energy by eating and being eaten. n Food webs: the network formed from the feeding relationships among the various organisms in an ecosystem n n Trophic level

Ecological Pyramid Three different kinds Energy pyramid: shows the amount of energy available at each level

n Biomass pyramid: amount of living organic matter at each trophic level

n Pyramid of numbers: shows the relative number of individual organisms at each level

Recycling in the Biosphere Matter is recycled within and between ecosystems n Biogeochemical Cycles: elements, chemical compounds, and other forms of matter are passed from one organism to another n Do not use up matter, they transform it n

Nutrient Limitation A limited amount of a nutrient hinders the productivity of the environment n Primary productivity: the rate at which organic matter is created by producers n n n Controlled by amount of available nutrients EX: in the ocean, nitrogen is not abundant, so it is the limiting factor

n Algal bloom: when an ecosystem receives a large input of a limiting nutrient n n Causes the producers to grow more quickly and produce more Can sometimes disrupt the equilibrium of an ecosystem