AP Biology- Chapter 54 and 55

A group of populations of different species living close enough to interact

Include competition, predation, herbivory, symbiosis

• -/-
• occurs when individuals of different species compete for a resource that limits their growth and survival

the concept that when populations of two similar species competes for the same limited resources, one population will use the resources more efficiently and have a reproductive advantage that will eventually lead to the elimination of the other population

The sum of a species' use of the biotic and abiotic resources in its environment

The division of environmental resources by coexisting species such that the niche of each species differs by one or more significant factors from the niches of all coexisting species

The fundamental niche is the entire area of an environment that a populatoin can inhabit even though the species may not live in the entire area. The realized niche is the actual area that a population inhabits

When characteristics of two closely related spices diverge while they are living in close proximity

• +/-
• interaction between species in which one species, the predator, kills and eats the other, the prey

When unrelated organisms begin to look like each other

Harmless species that mimicsa harmful model

Two or more species that look like each other

• "Camouflage"
• Makes prey difficult to spot

• "Warning Coloration"
• Uses bright colors to warn a predator of danger
• ex. Poison Dart Frog

• +/-
• Interaction in which organisms eats parts of plant or algae

when individuals of two or more species live in direct and intimate contact with one another

• A symbiotic interaction where a parasite derives nourishment from a host
• ex. tapeworms(parasite) lives off of humans(host)

• +/+
• a relationship where both species benefit
• ex. bacteria living on the root nodules of legumes

• +/0
• An interaction where one species benefits but neither helps or harms the other

• the variety of different kinds of organisms that make up the communtiy
• greater diversity= greater stabiltiy

the number of different species in the community

the proportion each species represents of all individuals in the community

• Play a key role in the environment
• Have a strong effect on the compostion of a community
• Influence ecological role
• exert inportant regulating effect on other species in a communtiy
• not nessacarily the largest population
• ex. Beavers change the flow of water from streams to standing ponds

After a disturbance, the disturbed area may be colonised by a variety of species. which are gradually replaced by other species. which are inturn replaced by still other species. Can take years or decades

• Begains with a virtually lifeless are without soil, due to a volcanic eruption
• 1.Bacteria come and make soil by decompostion of rock (prioneer species)
• 2.Grasses then grow quickly in high sunlight
• 3.Shrubs grow after which now allow for shade tolerant species to grow
• 4.Trees mostly shade tolerant plants now
• **The communtiy is now stable

Exsisting community is cleared but the soild is still intact, usually due to fire

• Tolerance- early species are weedy and r-selective as well as tolerant to harsh environments
• Faciliation and Inhibation- early species allow for haitat changes, change in soil pH, change in soil fertility, change in light levels(shade from trees). Allows other species to outcompete

• Plant communtiy dominated by trees
• Representing final stage of natural succession for a specific location. Has a stable plant community, remains essentially unchanged in species compostion as long as site remains undistribed, the species mix of climax forests is dependent on the abiotic factors of the region

• Disturbances are often necessary for community development and survival
• -Release of nutrients
• -Increases Biodiversity
• -Increases baitats
• -Rejuvenates communities

• All the organisms in a communtiy plus the abiotic factors
• Ecosystems are transformers of energy & processors of matter
• Ecosystems are self-sustaining
• Capture energy
• Transfer energy
• Cycle Nutrients

• Energy- sun gives a constant input of energy -Energy flows through the ecosystem
• Nutrients- Cycle around the ecosystem -Nutrients can ONLY cycle

• Sunlight -> Producers -> Primary Consumers -> Secondary Consumers
• **There is a loss of energy at all levels

• Never enters the atmosphere
• Cycles between animals, plants, rocks, soil
• Is passed by decompostion and waste

• Can be in the atmosphere
• Can't enter soil without help from bacteria and is put by into the air by bacteria
• Plants require nitrogen

Water leaving plants through leaves and bark

• Nutrient run off in soil
• Turns a forest to a desert
• Ground water is not transpired so less precipition is created
• 40x increase in water run off
• 60x loss of nitrogen
• 10x loss of calcium

• Greenbelt Movement
• Planting trees to rebuild the forests of Kenya
• Restoring a sustainable ecosystem

• the feeding relationships
• start with energy from the sun
• captured by plants, at the first level all chains. Aquatic and Terrestrial
• Food chains usually go up only 4 or 5 levels at most, due to the inefficiency of energy transfer
• All levels connect with decomposers

• Loss of energy between levels of food chain
• ex. Plants loss, 33% to cellular respiratoin, 50% to waste, only 17% moves to the next trophic level through growth
• Energy is lost as the cost of daily living
• usually only 10% is passed on

• loss of energy between levels of food chains
• can feed fewer at each level- 10% less

• Dynamic of energy through ecosystems have important implications for human populations
• Humans have a smaller ecological footprint as vegatarians