2Biotic and Abiotic Factors Biotic Factors – the biological influences on organisms within an ecosystemAbiotic Factors – the physical or nonliving factors that shape an ecosytemTogether biotic and abiotic factors determine the survival and growth of an organism and the productivity of the ecosystem in which the organism lives
3HabitatHabitat – is the area where an organism lives
4NicheNiche – is the full range of physical and biological conditions in which an organism lives and the way in which the organism uses those conditionsFor example the niche of owl is all of the following biotic and abiotic factors:Lives in treesFeeds at nightFeeds on miceLives in cool climateWhich of the following above are biotic and abiotic?
5Niche No two species can share the same niche in the same habitat Different species can occupy niches that are very similar
6Niche Example What is the Niche in Baseball? What is the Niche of different local businesses?
7Community Interactions Competition occurs when organisms compete for a resourceResource – is any necessity of life, such as water, nutrients, light, food, or spaceDirect competition results in a winner and a loser (the loser doesn’t survive)Competitive Exclusion Principle – state that no two species can occupy the same niche in the same habitat at the same time
9Community Interactions Predation – where one organism captures and feeds on another organism (lion and gazelle)Symbiosis – any relationship in which two species live closely together (3 forms as follows)Mutualism – both species benefit from the relationship (ex. bee and flower)Commensalism – one member of the association benefits and the other is neither helped or harmed (ex. barnacles attached to a whale)Parasitism – one organism lives on or inside another organism and harms it (ex. tick and dog)Can you think of any other example for all of these?
10Ecological Succession Ecosystems are constantly changing in response to natural and human disturbancesAs an ecosystem changes, older inhabitants gradually die out and new organisms move in, causing further changes in the communityThis series of predictable changes that occurs in a community over time is called Ecological Succession
11Primary SuccessionPrimary succession is the first time life appears on a new surface of landOccurs after volcanic activity or melting of glaciersWhen primary succession begins there is no soil, just ash and rockThe first species to populate the areas are called Pioneer Species
12Primary Succession The primary species on volcanic rock are lichen Lichen is made up of a algae and fungus that can grow on rockThe lichen grow on the rock and break it downWhen the lichen die they add organic material to help form soil for plants to grow on
13Secondary SuccessionDisturbances such as Fire or farming can alter an ecosystemWhen the disturbance is over, community interactions tend to restore the ecosystem to its original condition through Secondary SuccessionFor ex. Lightning in woodlands causes a fire burning the woodlands down, the fire also causes pine cones to explode and spread their seed to allow the forest to re-grow once the disaster is over