Ecological Succession Ecological Succession &&

Cycles of MatterCycles of Matter

► Regrowth of a ForestRegrowth of a Forest Succession: replacement of one type of Succession: replacement of one type of

communitycommunity by another at a single place by another at a single place over a period of timeover a period of time

Example: burned areas of Example: burned areas of Yellowstone National Park started to Yellowstone National Park started to regrow small, green plants by the regrow small, green plants by the next next yearyear

► Primary SuccessionPrimary Succession Small organisms Small organisms

start to grow in start to grow in areas where other areas where other organisms had not organisms had not previously previously livedlived

No soil in this area, No soil in this area, just just bare rockbare rock

Over long period of Over long period of time, organisms time, organisms live and die on live and die on rock, and rock is rock, and rock is slowly transformed slowly transformed into into soilsoil

FirstFirst organisms to live in an area are called organisms to live in an area are called pioneer speciespioneer species

Example: slowly retreating glacier exposes new Example: slowly retreating glacier exposes new rockrock over many years there is enough soil for over many years there is enough soil for mosses to growmosses to grow soil deepens and mosses are soil deepens and mosses are replaced by replaced by grassesgrasses and wildflowers and wildflowers

►Secondary SuccessionSecondary Succession Sometimes, existing community is Sometimes, existing community is

destroyed by destroyed by natural disastersnatural disasters, such as , such as fire or floodfire or flood

If soil is left intact, the original community If soil is left intact, the original community may regrow through a series of stages may regrow through a series of stages called called secondarysecondary succession succession

Example: first year after farmer stops Example: first year after farmer stops growing crops, weeds start to growgrowing crops, weeds start to grow by by second year, new weed appearsecond year, new weed appear forests forests may form over many yearsmay form over many years

►Mature Communities and BiodiversityMature Communities and Biodiversity In early stages of In early stages of successionsuccession, only , only

few species grow in an area few species grow in an area These species grow quickly and These species grow quickly and

make many make many seedsseeds that scatter easily that scatter easily As community matures, it many be As community matures, it many be

dominated by well-adapted, dominated by well-adapted, slow-slow-growinggrowing climax speciesclimax species

Variety of species that are present in Variety of species that are present in an area is referred to as biodiversityan area is referred to as biodiversity

MatureMature community may community may not always be a not always be a forest; it simply forest; it simply has organisms has organisms that are well that are well adapted to live adapted to live together in the together in the same area over same area over timetime

Cycles of MatterCycles of Matter

►Carbon CycleCarbon Cycle Exchange of Exchange of carboncarbon between the between the

environment and living thingsenvironment and living things PhotosynthesisPhotosynthesis is the basis of carbon cycle is the basis of carbon cycle Carbon returns to the environment when Carbon returns to the environment when

sugar molecules are broken down to sugar molecules are broken down to release energy—process is called release energy—process is called respirationrespiration

Carbon dioxideCarbon dioxide and water are released as and water are released as byproducts of respirationbyproducts of respiration

►Nitrogen CycleNitrogen Cycle Organisms Organisms

need need nitrogen to nitrogen to build build proteins and proteins and DNA for new DNA for new cellscells

About About 78%78% of Earth’s of Earth’s atmosphere atmosphere is nitrogen is nitrogen gasgas

Bacteria in Bacteria in soil soil change nitrogen gas change nitrogen gas into forms that plants into forms that plants can use—process can use—process called nitrogen called nitrogen fixationfixation

When organisms When organisms dies, dies, decomposersdecomposers break down remains break down remains and release form of and release form of nitrogen into soil that nitrogen into soil that plants can useplants can use

Certain types of Certain types of bacteria in soil bacteria in soil convert nitrogen into convert nitrogen into a a gasgas that returns to that returns to atmosphereatmosphere

►Water CycleWater Cycle Movement of water between the Movement of water between the

oceansoceans, atmosphere, , atmosphere, landland, and living , and living thingsthings

During evaporation, sun’s heat causes During evaporation, sun’s heat causes water to change from liquid to water to change from liquid to vaporvapor

During condensation, water vapor During condensation, water vapor cools and returns to cools and returns to liquidliquid state state

Water that falls to oceans and land is Water that falls to oceans and land is precipitationprecipitation

Groundwater is Groundwater is precipitation that precipitation that seeps into the seeps into the ground and slowly ground and slowly flows back into flows back into soil, streams, soil, streams, rivers, and rivers, and oceansoceans

Plants release a Plants release a large amount of large amount of water water vaporvapor transpirationtranspiration

Let’s Review!Let’s Review!

What is the precipitation that is stored What is the precipitation that is stored between or within rocks?between or within rocks?

Ground waterGround water

What is the burning of a substance What is the burning of a substance called? (Think of the carbon cycle called? (Think of the carbon cycle picture with the factories…)picture with the factories…)

CombustionCombustion

What is the gradual development of What is the gradual development of a community over time called?a community over time called?

SuccessionSuccession

What process is the basis of the What process is the basis of the carbon cycle?carbon cycle?

PhotosynthesisPhotosynthesis