Tolerance & Succession What lives where & why

Limiting Factors factors that restrict the numbers or distribution of organisms Plant limiting factors: P & N water sunlight temperature Soil (type, amount, pH, salinity) Herbivores

Biome Type Determined by: Temperature & Water determine plants types Type of plants sets up food chain & shelter so….. determines types of animals

Temp & Water based on… 1) Latitude: 2) Altitude: Farther from equator = colder Weather patterns based on latitude determine precipitation 2) Altitude: Higher up = colder Windward side = lots of rain Leeward side = rain shadow

Rain shadow Windward side

Biomes of Rocky Mountains

More Terms: Biodiversity: # different species of organism more diversity = more stable system Dominant Species: Species with the most biomass Greatly affect other species Keystone Species: removal has major effects

Bottom up model of control: amount of energy at bottom of food chain controls number of consumers Top down model: number of predators keep the prey in check.

Biodiversity most affected by: 1) Evolutionary History: a) older ecosystems = more time for speciation b) tropical = older…fewer disturbances (glaciers) c) tropical = longer growing season = more time 2) Evapotranspiration: a) combined evaporation from plants & soil b) measure of rainfall, solar radiation & temp c) more evapotrans = more diversity 3) Latitude = #1 predictor of biodiversity

Invasive Species Non-native species invade an ecosystem Also called exotic species May have no predators in new ecosystem Represent a dead-end in the food chain Out-compete native organisms decreasing species diversity

Pioneer & Climax Communities Pioneer = first organisms to move in New area Disturbed area (after fire, plowing) Climax = last community to move in community stays same for long time very little change highest species diversity

Seres Successive communities that replace each other in ecological succession Each sere changes the environment making it easier for the next sere to move in = facilitation Each new sere outcompetes the previous sere (competitve exclusion)

Primary Succession First organisms to live on that piece of ground 1) volcanic islands 2) rock slides 3) a humans dig a lake

Secondary Succession 2nd time a community has grown there 1) after forest fire or flood 2) abandoned farmer’s fields 3) vacant lots

Traits of pioneer species A) Primary succession 1) very hardy 2) tolerate full sun, drought, little – no soil 3) low species diversity 4) r-selected (tolerate high mortality) 5) poor competitors in less hostile habitat

Traits of pioneer species B) Secondary succession 1) weeds – good dispersal fast growth 2) annuals 3) full sun, drought tolerant 4) r –selected 5) poor competitors - oportunistic

Seres of secondary Weeds- annuals Perennial grasses & flowers young shrubs Shrubs & sun loving trees (pines) Shade loving trees (deciduous) seedlings that can grow in shade replace sun-loving trees as older trees die

Biome determined by abiotic Very little water …succession ends with desert grasses/shrubs or cacti Dry seasons, low precipitation …. Succ ends with Grass lands/savanna (not enough water for trees) Water available long growing season but cold winter deciduous trees Water available but short growing season (cold) evergreen trees (tiaga or boreal forest) Water and warm all year – tropical rain forest

Wetlands Reduce flooding Filter sediment out of water Filter toxins out of water Provide nurseries for fish & shellfish Provide homes for many species High species diversity

Biological Control Use one organism to control the population of another organism. Protists: microsporidia to control insects Fungi: Bacteria: Insects: