ap biology an introduction to ecology
TRANSCRIPT
An Introduction to Ecology
Objective
What are the abiotic and biotic components of ecosystems and how do they affect living organisms?
What is ecology?
The study of the interactions between organisms and the environmentEcology and evolution are very closely related topics
What is ecology?The environment an organism inhabits includes all the abiotic components – water, soil, sunlight, temperature, etc. AND all the biotic components – other organisms that must compete, defend, prey upon, etc.When studying ecology and organisms, we often want to know what effect a particular component has on a population
What factors affect the kangaroo distribution?Temperature?Water?Predators?Competition?
The hierarchy of ecology
OrganismPopulationCommunityEcosystemBiosphere
Ecology is complex!It is difficult to know all the connections between organisms and their environmentBut decisions must be made…The precautionary principal is usually followed – cautions us to consider carefully the consequences of our actions and work to prevent problems rather than try to fix them after the fact
When a course of action might have a potentially serious impact, one approach is to adopt the precautionary principle. Rather than assuming something is safe until proven otherwise, the precautionary principle argues the opposite: that something should be considered potentially harmful unless shown to be safe.While the precautionary principle aims to protect us against possible dangers, an excessively 'safety-first' approach may have its own drawbacks. For example, we may lose the benefits that a new technology might provide.With Tibbs the cat, doubts about the safety of FelineFine may persuade us to stop using it. That may stop Tibbs being poisoned, but it might harm her in other ways.
The environment limits the distribution of species
– or – not everyone can live everywhereDispersal – movement out of a high density area
Natural range expansions Species transplants – intentional or accidental introduction of a species to a new area
Actual range vs. potential range
Climate Major components:
TemperatureWaterSunlightWind
Macroclimate – global/regionalMicroclimate – very small
(like under a fallen log)
MacroclimateAffected by
WaterLarge bodies of water have a moderating effectCurrents carry warm or cold air
Climate
Affected by Mountains
Windward vs. leeward sides
ClimateAffected by
Seasonality
BiomesA biome is an ecosystem type, classified by dominant vegetation and organism adaptations
Aquatic BiomesLakesCoral ReefsRiversOpen OceanEstuariesIntertidal ZonesAbyssal Zones
Aquatic BiomesMany are physically and chemically stratifiedPhotic zone - where light is absorbedAphotic zone - little to no light penetratesBenthic zone - the bottom
Organisms that live here called benthic or benthos
They eat detritus
Terrestrial BiomesTropical forestSavannaDesertChaparralTemperate grassland
Temperate broadleaf forest Coniferous forestTundraHigh mountainsPolar ice
Terrestrial BiomesInfluenced mostly by climateSince climate varies by latitude, we see latitudinal patterns of distribution in biomes
Terrestrial BiomesVertical stratification importantPlants provide the stratification
CanopyLow treesShrubsLitter layer (forest floor)
Many organisms adapted to a particular layer
Terrestrial BiomesDon’t have clear, defined boundariesEcotone - area where one biome grades into another
Find different organisms here
Find your animal buddy