ECOLOGY CH. 1 & 2

ECOLOGY Def: the study of how living things interact with their environment Habitat – where an organism gets the things it needs to survive Biotic Factors  Living Abiotic Factors  Non-living Levels of Organization Organism – individual Population – members of same species Species – similar organisms that are capable of producing offspring that are similar to parents Community – all the populations in an area Ecosystem – the community plus non-living parts of the area Biome – A large Ecosystem based on precipitation and temperature Tundra, Taiga, Deciduous Forest, Rain Forest, Desert Biosphere – all the ecosystems of the world

Studying Populations Population – number of individuals Methods Population Density – individuals/ unit of area How crowded it is Methods Direct Observation – actually seeing Indirect Observation – seeing evidence without seeing individuals Ex. Sampling – average of smaller areas to estimate total population Mark and Recapture (# Marked X # captured 2nd time)/ # caught 2nd time with marks

Studying Populations Changes to population Birth rate vs. Death rate Immigration (in) vs. Emigration (exit) Limiting Factors – environmental factors that prevent a population from increasing Ex. Carrying Capacity – the maximum number of individuals an area can support Based on limiting factors

Interactions Among Populations Niche – how an organism interacts and uses its habitat The role or job of an organism Adaptations – Physical characteristic or behavior that make an organism more likely to survive (better able to use habitat) Keeps niches different from other species Natural Selection – survival of the fittest Forms adaptations Competition – struggle for limited resources Hurts both species Can be members of same species (intraspecific) or members of different species (interspecific)

Interactions Among Populations Predation – A specie hunts, kills, and eats another Predator Adaptations: Prey Adaptations: Mutualism – Both species benefit (+/+) Commensalism – One species benefit, the other is unaffected (+/0) Parasitism – one species (parasite) lives off from another (host) causing it harm Doesn’t usually kill host

Energy Flow through an Ecosystem Food Chain  single path Food Web  many, interconnected food chains Trophic Levels Producer – autotrophs Photosynthesis Consumer – heterotrophs Primary consumer Herbivores – only eat producers Secondary Consumer – Carnivore – only eat other consumers Omnivore – sometimes primary, sometimes secondary 3rd level, 4th level etc. Scavengers – carnivore that eats the already dead

Energy Flow through an Ecosystem Decomposers – detritivores Almost all energy passes here last Exception: stored energy in fossil fuels Energy Pyramid – shows total amount of energy in each trophic level for an ecosystem Most energy in producers 10% is passed onto next trophic level Each trophic level has less individuals Not many top carnivores Limit to number of levels in food chain

MATTER CYCLES Hydrologic – Water Cycle Evaporation – liquid to gas (water vapor) Purifies; only water goes up Transpiration –trees/plants evaporating water Condensation – water vapor to liquid Clouds & fog Precipitation Rain, snow, sleet, hail, ice What happens next? Surface Run-off – ditches  streams  lakes, rivers  oceans Aquifer – ground water Ends up in living organisms Evaporation – returns directly to atmosphere

MATTER CYCLES Carbon Cycle Found in atmosphere as Carbon Dioxide (CO2) .03% Linked to global warming as environmental concern Needed by organisms to form organic compounds Converted by plants through the process of photosynthesis Returned to atmosphere Respiration – breaking down carbon compounds for energy Decomposition – dead organisms broken down by fungi/bacteria Combustion – burning fossil fuels or plant products Double Whammy! – Deforestation Can’t take carbon out Burning puts carbon in Fossil Fuels – carbon stored deep in Earth Past organisms Oil, natural gas, coal

MATTER CYCLES Nitrogen Cycle Found in the air as atmospheric nitrogen (N2) 78% of air; most abundant substance Can NOT be used directly by most organisms Nitrogen fixation – changing atmospheric nitrogen into a usable form Needed by organisms to make proteins Rhizobium (bacteria) or lightning Found on root nodules in Legumes (alfalfa, clover, beans) Atmospheric nitrogen is changed into ammonia (NH3) or nitrates (NO4) Can be added to soil through fertilizers or decomposition of organisms Denitrification changes nitrogen compounds back into atmospheric nitrogen by bacteria.

WATER CYCLE Hydrologic Cycle– Water Cycle Evaporation – liquid to gas (water vapor) Purifies; only water goes up Transpiration –trees/plants evaporating water Condensation – water vapor to liquid Clouds & fog Precipitation Rain, snow, sleet, hail, ice What happens next? Surface Run-off – ditches  streams  lakes, rivers  oceans Aquifer – ground water Ends up in living organisms Evaporation – returns directly to atmosphere

CARBON CYCLE Carbon Cycle Found in atmosphere as Carbon Dioxide (CO2) .03% of air Linked to global warming as environmental concern Needed by organisms to form organic compounds Converted by plants through the process of photosynthesis Returned to atmosphere Respiration – breaking down carbon compounds for energy Decomposition – dead organisms broken down by fungi/bacteria Combustion – burning fossil fuels or plant products

CARBON CYCLE Double Whammy! – Deforestation Can’t take carbon out Burning puts carbon in Fossil Fuels – carbon stored deep in Earth Past organisms Oil, natural gas, coal

NITROGEN CYCLE Nitrogen Cycle Found in the air as atmospheric nitrogen (N2) 78% of air; most abundant substance Can NOT be used directly by most organisms Nitrogen fixation – changing atmospheric nitrogen into a usable form Atmospheric Nitrogen is changed into nitrates (NO3) or ammonia (NH4) Needed by organisms to make proteins

NITROGEN CYCLE Legumes or Lightning Cycle within a cycle Legumes are plants (alfalfa, clover, beans, etc) that have bacteria called Rhizobium on their roots that turn N2 into Nitrates Crop Rotation Cycle within a cycle Nitrates can be returned directly to the soil through decomposition Can be added to soil through fertilizers or decomposition of organisms Denitrification changes nitrogen compounds back into atmospheric nitrogen by bacteria. Must be returned to complete cycle

Succession Read Section 2-5 (p. 76-78) Topics (Objectives): Key Terms: Read Silently Take a break after each section and ask, “what did I just read?” Write down Topics or Objectives you should be able to accomplish after reading Make a list of key terms and key ideas (these are the notes) Topics (Objectives): Know the definition of succession Know the difference between primary and secondary succession Know the order of change that occurs during succession Key Terms: Succession, pioneer species, biome

Succession Def: the change of an ecosystem back to its climax community Climax community – the natural state of an ecosystem Based on climate (weather, temp), altitude, soil etc. Biomes Pioneer species – first to arrive after disturbance Lichens, weeds Animation Primary – no pre-existing ecosystem Secondary – return after disturbance Can be human or natural disturbances.  ex: