• Chapter 50 ~

An Introduction to Ecology and the Biosphere

I am the Lorax.I speak for the trees.I speak for the trees, for the trees have no tongues.

EcologyEcology is the scientific study of the is the scientific study of the interactions between organisms and interactions between organisms and their environment. their environment.

What is Ecology?What is Ecology?

Distribution and Abundance of organisms is not homogenous

In Georgia, the legend saysThat you must close your windowsAt night to keep it out of the house.The glass is tinged with green, even so...

From the poem, "Kudzu,"by James Dickey

Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings

Fig. 50.1

Distribution and Abundance of organisms is determined by:

AbioticAbiotic factors: non-living chemical and factors: non-living chemical and physical factors such as temperature, light, physical factors such as temperature, light, water, and nutrientswater, and nutrients

BioticBiotic factors: the living components factors: the living components

Factors Affecting the Distribution of Organisms

European Honeybee Africanized honey bee

The swelling continued over the next day until the whole left of my face was a puffy red useless mass. I was unable to open my eye properly again for about two more days.

Factors Affecting the Distribution of Organisms

Food eaten by 1 locust swarm = Food eaten 1000 people

Factors Affecting the Distribution of Organisms

2006

2005

Culex Pipiens – Mosquito: West Nile Virus Carrier?

Factors Affecting the Distribution of Organisms

Species Dispersal, Biotic Factors, Abiotic Factors, Behavior and Habitat Selection

Factors Affecting the Distribution of Organisms-Introduced Species or Non-native species - newbies to an area

Abiotic factors: temp, light, wind, water (these 4 make up climate), oxygen, salinity, pH, fire, moisture, rocks/soil…

Biotic factors: competition, predation, disease, …

-Species Dispersal - Can the species ‘get’ to a particular location?

-Habitat Selection - Even if the habitat is suitable, does the species“select” it to breed/build nests…

-Behavior - Is the behavior of the species amenable to its spreadingin the chosen location?

-Abiotic Factors - Are the nonliving factors condusive?

-Biotic Factors - Are the living factors condusive?

-For each of the three examples: identify which of these made it easyto colonize/immigrate and distribute in a new location

Factors Affecting the Distribution of Organisms

Tens Rule - Only 1 out of 10 introduced species make it!

Ecological time - Ecological time - (minutes, (minutes, months, years) months, years)

Evolutionary time -Evolutionary time - (decades, (decades, centuries, millennia, and centuries, millennia, and longer).longer).

Organismal ecologyOrganismal ecology is concerned is concerned with the behavioral, physiological, with the behavioral, physiological, and morphologicaland morphologicalways individualsways individualsinteract with theinteract with theenvironment. (chp 51)environment. (chp 51)

Levels of Organization in Ecological Study

PopulationPopulation:: a population is a group a population is a group of individuals of the of individuals of the samesame speciesspecies living in a particular geographic living in a particular geographic area.area.

Population Ecology - Chp 52Population Ecology - Chp 52

Community:Community:all the organisms thatall the organisms thatinhabit a particularinhabit a particulararea.area.

Community Ecology -Community Ecology -

chp 53chp 53 Any ‘abiotic factors’ in Any ‘abiotic factors’ in

a community?a community? No!No!

Fig. 50.2c

EcosystemEcosystem: : all the all the abiotic factorsabiotic factors + + entire entire community of speciescommunity of species that that exist in a certain area.exist in a certain area. Biomes – major ecosystems of the Biomes – major ecosystems of the

worldworld Terrestrial Biomes and Acquatic Terrestrial Biomes and Acquatic

BiomesBiomes

Fig. 50.2d

Aquatic Biomes-Marine Biome (3% salt; 75% of earth covered by this biome)-Freshwater Biome (<1% salt)

PHOTIC ZONE (light)

APHOTIC ZONE (no light)

BENTHIC ZONE - ooze (sediments from top), benthos (organism communities), and detritus (dead matter - food for benthos)

Aquatic Biomes - Vertical Stratifiction based on light - why is this important?

PHOTIC ZONE

APHOTIC ZONE

BENTHIC ZONE

Aquatic Biomes

Algae + cyanobacteria = PhytoplanktonVery Important - Make oxygenZooplankton - live on phytoplankton

Worms, Bacteria - Use oxygen which has to come from surface; decomposers - release nutrients back by breaking down dead material

Thermocline - area of rapid change in temperature

Thermocline - seen in summer (stratification=layers) ; prevents Thermocline - seen in summer (stratification=layers) ; prevents oxygen from sinking to lower areas and nutrients (after decomposers oxygen from sinking to lower areas and nutrients (after decomposers break down dead matter) from rising up to the surfacebreak down dead matter) from rising up to the surface

Turnover or mixing occurs in spring and fall due to Turnover or mixing occurs in spring and fall due to changing surface temperatureschanging surface temperatures

Figure 50.15 Lake stratification and seasonal turnover - compare the temperature on Figure 50.15 Lake stratification and seasonal turnover - compare the temperature on the top of the lake (0the top of the lake (0ooc-ice) to lower layers (4c-ice) to lower layers (4ooc). Look at the oxygen in the different c). Look at the oxygen in the different layers. What trend do you notice ? Why is the top layer at a lower temp? What layers. What trend do you notice ? Why is the top layer at a lower temp? What signiicance does it have to living organisms? signiicance does it have to living organisms?

Figure 50.15 Lake stratification and seasonal turnover - What is happening in spring? Figure 50.15 Lake stratification and seasonal turnover - What is happening in spring? What is turnover and why is it important? What is turnover and why is it important?

Figure 50.15 Lake stratification and seasonal turnover - What is happening in Figure 50.15 Lake stratification and seasonal turnover - What is happening in summer? Is there any turnover - why/why not? summer? Is there any turnover - why/why not?

Figure 50.15 Lake stratification and seasonal turnover - You get it by now - what Figure 50.15 Lake stratification and seasonal turnover - You get it by now - what does fall bring to the lake?does fall bring to the lake?

Aquatic Biomes: Freshwater vs. Ocean

Littoral - rooted aquatic plantsLimnetic - phytoplankton (floating)

Intertidal - waves + tides; crabs, barnacles,algaeOceanic - phytoplankton (floating), nekton (free swimming fish, tutles, mammals,..

Aquatic Biomes: Oceans/Neritic Zone

Coral reefs

Symbiont -Dinoflagellate Algae- is expelled when temperature rises and causes coral bleaching! Reef ‘dies’ as a result.

Cnidarians-Animals!!

Aquatic Biomes: Oceans/Abyssal zone

Abyssal Zone -Hydrothermal Vents (Origin of Life Here??)

Tube-dwelling worms!! + chemoautotrophic prokaryotes (extremophiles)

Aquatic Biomes: Algal Blooms

               

           

Algae eventually die and sink to bottom

Bacteria grow in large numbers and reduce oxygen available to all life forms in the water

Eutrophication (addition of fertilizers) causes algal blooms

Algae start reproducing heavily due to increase in nutrients (fertilizers) or temperature

Types Of LakesTypes Of Lakes Oligotrophic Lake: Oligotrophic Lake: narrow and deep narrow and deep

(more stratification); has few photosynthetic (more stratification); has few photosynthetic organisms, nutrient poor, oxygen rich deep organisms, nutrient poor, oxygen rich deep

waterswaters

Eutrophic Eutrophic Lake: Lake: wide and not wide and not very deep; has a lot of very deep; has a lot of photosynthetic photosynthetic organisms, nutrient rich, organisms, nutrient rich,

oxygen poor deep watersoxygen poor deep waters

Cultural Eutrophication

(addition of fertilizer- runoff from farms or wastes)

Aquatic BiomesAquatic Biomes

Wetlands: area covered with water; can Wetlands: area covered with water; can filter toxins/pollutants out of water; has filter toxins/pollutants out of water; has low oxygen and high nutrient content; low oxygen and high nutrient content; humans have destroyed them (90%)humans have destroyed them (90%)

Estuary: transition Estuary: transition area beween river and area beween river and sea; salinity varies; sea; salinity varies; also very productive; also very productive; animals have to adapt animals have to adapt to variations in to variations in salinity, currents-salinity, currents-worms, oyesters, worms, oyesters, crabs, fishcrabs, fish

Terrestrial Biomes Terrestrial Biomes (look up(look up abiotic abiotic factors and biotic factors that are the factors and biotic factors that are the hallmarks of each biome)hallmarks of each biome)

Terrestrial BiomesTerrestrial Biomes Tropical Rain ForestTropical Rain Forest

Vertical Stratification - Vertical Stratification - plants show intense plants show intense competition for lightcompetition for light

High rainfall, warm tempHigh rainfall, warm temp Highest animal diversityHighest animal diversity

Terrestrial BiomesTerrestrial Biomes SavannaSavanna Tropical GrasslandsTropical Grasslands Long dry season, Long dry season,

warmwarm Scattered treesScattered trees Fire - benefit is Fire - benefit is

renewal of grasses renewal of grasses as grass seed needs as grass seed needs fire to fire to germinate/sproutgerminate/sprout

Grazing animalsGrazing animals

Terrestrial BiomesTerrestrial Biomes DesertDesert

Hot and DryHot and Dry Extremes in Extremes in

temperature temperature between day and between day and nightnight

Plants like cacti Plants like cacti store water store water (succulents), (succulents), reduced leaf areareduced leaf area

Terrestrial BiomesTerrestrial Biomes ChaparralChaparral Hot summers and Hot summers and

Wet winters Wet winters (California)(California)

Shrubs, small treesShrubs, small trees FireFire

Terrestrial BiomesTerrestrial Biomes Temperate GrasslandsTemperate Grasslands

Converted into Converted into agricultural landagricultural land

Dry winters, wet Dry winters, wet summerssummers

FireFire

Terrestrial BiomesTerrestrial Biomes Temperate Temperate DeciduousDeciduous

ForestsForests

Leaves are shed Leaves are shed in winter (hence in winter (hence deciduous)deciduous)

Fall colors!Fall colors!

Terrestrial BiomesTerrestrial Biomes Coniferous ForestsConiferous Forests

Cone bearing Cone bearing trees like trees like pine, spruce- pine, spruce- evergreenevergreen

Taiga – Taiga – Northern Northern Coniferous Coniferous ForestsForests

Terrestrial BiomesTerrestrial BiomesTundraTundra Permafrost- Permafrost-

permanent ice on permanent ice on ground, high windsground, high winds

Lichen, moss, small Lichen, moss, small shrubs, few treesshrubs, few trees

Caribou, reindeerCaribou, reindeer

Factors Affecting the Distribution of Organisms

• The range of the American Beech can be predicted under 2 climate-change scenarios.

Fig. 50.16

DDT ActivityDDT ActivityPrecautionary Precautionary principleprinciple

EEcology helps evaluate cology helps evaluate environmental issuesenvironmental issues

Fig. 50.3