Lecture Presentation by Nicole Tunbridge and Kathleen Fitzpatrick Discovering Ecology Ecology is the scientific study of the interactions between organisms and the environment small scale geological events affect evolution over generations ID: 1021028
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1. 52An Introduction to Ecology and the BiosphereLecture Presentation by Nicole Tunbridge andKathleen Fitzpatrick
2. Discovering EcologyEcology is the scientific study of the interactions between organisms and the environment*small scale geological events affect evolution over generations.These interactions determine the distribution of organisms and their abundanceModern ecology includes observation and experimentation
3. The discovery of two new frog species in Papua New Guinea raises many ecological questionsWhat environmental factors limit their geographic distribution?What factors (food, pathogens) affect population size?
4. Figure 52.1
5. Figure 52.1a
6. Environment includes: Biotic (living) -> both affect Abiotic (nonliving) distrib./abundance
7. The Scope of Ecological ResearchEcologists work at levels ranging from individual organisms to the planet
8. Figure 52.2Global ecologyLandscape ecologyEcosystem ecologyCommunity ecologyPopulation ecologyOrganismal ecology
9. Levels of Organization of Biosphere:Organism (one of one species)Population (all of same species in an area)Community (all organisms in area)Ecosystem (living and non living in area)Biome (similar ecosystems)Biosphere (all life on Earth)
10. Figure 52.2aGlobal ecology
11. Landscape Ecology A landscape (or seascape) is a mosaic of connected ecosystemsLandscape ecology focuses on the exchanges of energy, materials, and organisms across multiple ecosystems
12. Figure 52.2bLandscape ecology
13. Ecosystem Ecology An ecosystem is the community of organisms in an area and the physical factors with which they interact (biotic AND abiotic)Ecosystem ecology emphasizes energy flow and chemical cycling among the various biotic and abiotic components
14. Figure 52.2cEcosystem ecology
15. Community Ecology A community is a group of populations of different species in an areaCommunity ecology examines the effect of interspecific interactions on community structure and organization
16. Figure 52.2dCommunity ecology
17. Population Ecology A population is a group of individuals of the same species living in an areaPopulation ecology focuses on factors affecting population size over time
18. Figure 52.2ePopulation ecology
19. Organismal Ecology Organismal ecology (species) studies how an organism’s structure, physiology, and (for animals) behavior meet environmental challengesOrganismal ecology includes physiological, evolutionary, and behavioral ecology
20. Figure 52.2fOrganismal ecology
21. Concept 52.1: Earth’s climate varies by latitude and season and is changing rapidlyThe long-term prevailing weather conditions in an area constitute its climateFour major abiotic components of climate are temperature, precipitation, sunlight, and windMacroclimate consists of patterns on the global, regional, and landscape levelMicroclimate consists of very fine patterns, such as those encountered by the community of organisms underneath a fallen log
22. Global Climate PatternsGlobal climate patterns are determined largely by solar energy and Earth’s movement in spaceThe warming effect of the sun causes temperature variations, which drive evaporation and the circulation of air and waterThis causes latitudinal variations in climateWHO CAN EXPLAIN TO ME WHY WE HAVE THE 3 CLIMATE ZONES AND WHAT THEY ARE? (treat!)
23. Latitudinal Variation in Sunlight IntensityThe angle at which sunlight hits Earth affects its intensity, the amount of heat and light per unit of surface areaThe intensity of sunlight is strongest in the tropics (between 23.5° north latitude and 23.5° south latitude) where sunlight strikes Earth most directly
24. Figure 52.460N30N0 (equator)September equinox30SMarch equinoxJune solsticeDecembersolsticeConstant tiltof 23.5
25. Figure 52.3aLow angle of incoming sunlightSun overhead at equinoxesLow angle of incoming sunlightAtmosphereLatitudinal variation in sunlight intensity90°N (North Pole)23.5°N (Tropic of Cancer)0° (Equator)23.5°S (Tropic of Capricorn)90°S (South Pole)
26. Global Air Circulation and Precipitation PatternsGlobal air circulation and precipitation patterns play major roles in determining climate patternsWater evaporates in the tropics, and warm, wet air masses flow from the tropics toward the poles
27. Figure 52.3b66.5N (Arctic Circle)30N60 N30N060S30S66.5S (Antarctic Circle)WesterliesNortheast tradesSoutheast tradesWesterliesDescendingdry airabsorbsmoisture.Ascendingmoist airreleasesmoisture.0ARID ZONEGlobal air circulation and precipitation patterns
28. Rising air masses release water and cause high precipitation, especially in the tropicsDry, descending air masses create arid climates, especially near 30° north and southAir flowing close to Earth’s surface creates predictable global wind patternsCooling trade winds blow from east to west in the tropics; prevailing westerlies blow from west to east in the temperate zones
29. Regional and Local Effects on ClimateClimate is affected by seasonality, large bodies of water, and mountains
30. Bodies of WaterOceans, their currents, and large lakes moderate the climate of nearby terrestrial environmentsCurrents flowing toward the equator carry cold water from the poles; currents flowing away from the equator carry warm water toward the poles
31. Figure 52.5Labrador CurrentCalifornia CurrentNorth PacificSubtropical Gyre30NEquatorIndianOceanSubtropicalGyreAntarctic Circumpolar CurrentSouth PacificSubtropical GyreGulfStreamNorth AtlanticSubtropical GyreSouth AtlanticSubtropicalGyre 30S
32. During the day, air rises over warm land and draws a cool breeze from the water across the landAs the land cools at night, air rises over the warmer water and draws cooler air from land back over the water, which is replaced by warm air from offshore
33. Figure 52.6Cool air flowPrecipitationMountainrangeLeeward sideof mountainsRain shadowOcean123
34. MountainsRising air releases moisture on the windward side of a peak and creates a “rain shadow” as it absorbs moisture on the leeward sideMountains affect the amount of sunlight reaching an areaIn the Northern Hemisphere, south-facing slopes receive more sunlight than north-facing slopesEvery 1,000 m increase in elevation produces a temperature drop of approximately 6C
35. Global Climate ChangeChanges in Earth’s climate can profoundly affect the biosphereOne way to predict the effects of future global climate change is to study previous changesAs glaciers retreated 16,000 years ago, tree distribution patterns changedAs climate changes, species that have difficulty dispersing may have smaller ranges or could become extinct
36. Concept 52.2: The structure and distribution of terrestrial biomes are controlled by climate and disturbanceBiomes are major life zones characterized by vegetation type (terrestrial biomes) or physical environment (aquatic biomes)Climate is very important in determining why terrestrial biomes are found in certain areas
37. Figure 52.8Tropic of CancerTropic of CapricornEquatorTropical forestSavannaDesertChaparralTemperate grassland30N30STemperate broadleaf forestNorthern coniferous forestTundraHigh mountainsPolar ice
38. A climograph plots the annual mean temperature and precipitation in a regionBiomes are affected not just by average temperature and precipitation, but also by the pattern of temperature and precipitation through the year
39. Figure 52.9DesertTemperategrasslandTemperatebroadleafforestTropical forestNorthernconiferousforestArctic andalpinetundraAnnual meantemperature (C)Annual mean precipitation (cm)0 100 200 300 40030150−15
40. General Features of Terrestrial BiomesTerrestrial biomes are often named for major physical or climatic factors and for vegetationTerrestrial biomes usually grade into each other, without sharp boundariesThe area of intergradation, called an ecotone, may be wide or narrow
41. Vertical layering is an important feature of terrestrial biomes, and in a forest it might consist of an upper canopy, low-tree layer, shrub understory, ground layer of herbaceous plants, forest floor, and root layerLayering of vegetation in all biomes provides diverse habitats for animalsThe species composition of each kind of biome varies from one location to another
42. Disturbance and Terrestrial BiomesDisturbance is an event such as a storm, fire, or human activity that changes a communityFor example, frequent fires can kill woody plants and maintain the characteristic vegetation of a savannaFor example, hurricanes create openings in forests that allow different species to growIn many biomes, even dominant plants depend on periodic disturbance
43. Tropical ForestDistribution is in equatorial and subequatorial regionsIn tropical rain forests, rainfall is relatively constant, while in tropical dry forests precipitation is highly seasonalTemperature is high year-round (25–29C) with little seasonal variation
44. Figure 52.11aA tropical rain forest in Costa Rica
45. Tropical forests are vertically layered, and competition for light is intenseTropical forests are home to millions of animal species, including an estimated 5–30 million still undescribed species of insects, spiders, and other arthropodsRapid human population growth is now destroying many tropical forests
46. DesertDeserts occur in bands near 30 north and south of the equator, and in the interior of continentsPrecipitation is low and highly variable, generally less than 30 cm per yearTemperature is variable seasonally and dailyDeserts may be hot or cold
47. Figure 52.11bOrgan Pipe Cactus National Monument, Arizona
48. Desert plants are adapted for heat and desiccation tolerance, water storage, and reduced leaf surface areaCommon desert animals include many kinds of snakes and lizards, scorpions, ants, beetles, migratory and resident birds, and seed-eating rodents; many are nocturnalUrbanization and conversion to irrigated agriculture have reduced the natural biodiversity of some deserts
49. SavannaDistribution includes equatorial and subequatorial regionsPrecipitation is seasonal with dry seasons lasting 8–9 monthsSavanna temperature averages (24–29C) but is more seasonally variable than in the tropics
50. Figure 52.11cA savanna in Kenya
51. Grasses and forbs(non woody) make up most of the ground coverThe dominant plant species are fire-adapted and tolerant of seasonal droughtCommon inhabitants include insects and mammals such as wildebeests, zebras, lions, and hyenasFires set by humans may help maintain this biome
52. ChaparralChaparral occurs in midlatitude coastal regions on several continentsPrecipitation is highly seasonal with rainy winters and dry summersSummer is hot (30C); fall, winter, and spring are cool (10–12C)
53. Figure 52.11dAn area of chaparral in California
54. The chaparral is dominated by shrubs, small trees, grasses, and herbs; many plants are adapted to fire and droughtAnimals include amphibians, birds and other reptiles, insects, small mammals, and browsing mammalsHumans have reduced chaparral areas through agriculture and urbanization
55. Temperate GrasslandTemperate grasslands are found on many continentsPrecipitation is highly seasonalWinters are cold (often below 10C) and dry; summers are hot (often near 30C) and wet
56. Figure 52.11eA grassland in Mongolia
57. The dominant plants, grasses and forbs, are adapted to droughts and fireNative mammals include large grazers such as bison and wild horses and small burrowers such as prairie dogsMost grasslands have been converted to farmland
58. Northern Coniferous ForestThe northern coniferous forest, or taiga, spans northern North America and Eurasia and is the largest terrestrial biome on EarthPrecipitation varies; some have periodic droughts and others, especially near coasts, are wetWinters are cold; summers may be hot (e.g., Siberia ranges from 50C to 20C)
59. Figure 52.11fA coniferous forest in Norway
60. Conifers such as pine, spruce, fir, and hemlock dominateThe conical shape of conifers prevents too much snow from accumulating and breaking their branchesAnimals include migratory and resident birds and large mammals such as moose, brown bears, and Siberian tigersSome forests are being logged at an alarming rate
61. Temperate Broadleaf ForestDistribution is primarily at midlatitudes in the Northern Hemisphere, with smaller areas in Chile, South Africa, Australia, and New ZealandSignificant amounts of precipitation fall during all seasons as rain or snowWinters average 0C; summers are hot and humid (near 35C)
62. Figure 52.11gA temperate broadleaf forest in New Jersey
63. A mature temperate broadleaf forest has vertical layers, including a closed canopy, understory trees, a shrub layer, and an herb layer The dominant plants are deciduous trees in the Northern Hemisphere and evergreen eucalyptus in Australia
64. Mammals, birds, and insects make use of all vertical layers in the forestIn the Northern Hemisphere, many mammals hibernate in the winterThese forests have been heavily settled on all continents but are recovering in places
65. TundraTundra covers expansive areas of the Arctic; alpine tundra exists on high mountaintops at all latitudesPrecipitation is low in arctic tundra and higher in alpine tundraWinters are cold (below 30C); summers are relatively cool (less than 10C)
66. Figure 52.11hDovrefjell National Park, Norway, in autumn
67. Vegetation is herbaceous (mosses, grasses, forbs, dwarf shrubs and trees, and lichen) Permafrost, a permanently frozen layer of soil, restricts the growth of plant rootsMammals include musk oxen, caribou, reindeer, bears, wolves, and foxes; many migratory bird species nest in the summerSettlement is sparse, but tundra has become the focus of oil and mineral extraction
68. Concept 52.3: Aquatic biomes are diverse and dynamic systems that cover most of EarthAquatic biomes are characterized by their physical environmentThey show less latitudinal variation than terrestrial biomesAquatic biomes defined by ABIOTIC factors.Marine biomes have salt concentrations of about 3% The largest marine biome is made up of oceans, which cover about 75% of Earth’s surface and have an enormous impact on the biosphere
69. Zonation in Aquatic BiomesMany aquatic biomes are stratified into zones or layers defined by light penetration, temperature, and depthThe upper photic zone has sufficient light for photosynthesis, while the lower aphotic zone receives little lightThe photic and aphotic zones make up the pelagic zoneDeep in the aphotic zone lies the abyssal zone with a depth of 2,000 to 6,000 m
70. The organic and inorganic sediment at the bottom of all aquatic zones is called the benthic zone The communities of organisms in the benthic zone are collectively called the benthosDetritus, dead organic matter, falls from the productive surface water and is an important source of food
71. Figure 52.12(a) Zonation in a lake(b) Marine zonationLittoralzoneLimneticzonePhoticzoneBenthiczoneAphoticzonePelagic zone0200 mContinentalshelf2,000–6,000 mNeriticzonePhoticzoneBenthiczoneOceaniczoneAphoticzonePelagiczoneAbyssalzoneIntertidal zone
72. In oceans and most lakes, a temperature boundary called the thermocline separates the warm upper layer from the cold deeper waterMany lakes undergo a semiannual mixing of their waters called turnoverTurnover mixes oxygenated water from the surface with nutrient-rich water from the bottom
73. Figure 52.13WinterSpringSummerAutumn4C4C4C4C244022188Thermocline
74. LakesSize varies from small ponds to very large lakesTemperate lakes may have a seasonal thermocline; tropical lowland lakes have a year-round thermoclineOligotrophic lakes are nutrient-poor and generally oxygen-richEutrophic lakes are nutrient-rich and often depleted of oxygen in deep zones or throughout if ice covered in winter
75. Figure 52.14aAn oligotrophic lake in JasperNational Park, AlbertaA eutrophic lake in theOkavango Delta, Botswana
76. Oligotrophic lakes have less surface area relative to depth than eutrophic lakesRooted and floating aquatic plants live in the shallow and well-lighted littoral zone close to shoreWater is too deep in the limnetic zone to support rooted aquatic plants; small drifting animals called zooplankton graze on the phytoplankton
77. WetlandsA wetland is a habitat that is inundated by water at least some of the time and that supports plants adapted to water-saturated soilWetlands have high organic production and decomposition and have low dissolved oxygenWetlands can develop in shallow basins, along flooded river banks, or on the coasts of large lakes and seas
78. Figure 52.14bA basin wetland in the United Kingdom
79. Wetlands are among the most productive biomes on Earth Plants include lilies, cattails, sedges, tamarack, and black spruceWetlands are home to diverse invertebrates and birds, as well as otters, frogs, and alligatorsHumans have destroyed up to 90% of wetlands; wetlands purify water and reduce flooding
80. Streams and RiversThe most prominent physical characteristic of streams and rivers is currentHeadwaters are generally cold, clear, turbulent, swift, and oxygen-rich; they are often narrow and rockyDownstream waters form rivers and are generally warmer, more turbid, and well oxygenated; they are often wide and meandering and have silty bottoms
81. Figure 52.14cA headwater stream in WashingtonThe Loire river in France,far from its headwaters
82. EstuariesAn estuary is a transition area between river and seaSalinity varies with the rise and fall of the tidesEstuaries are nutrient-rich and highly productiveEstuaries include a complex network of tidal channels, islands, natural levees, and mudflats
83. Figure 52.14dAn estuary in southern Spain
84. Saltmarsh grasses and algae are the major producersAn abundant supply of food attracts marine invertebrates, fish, waterfowl, and marine mammalsHumans consume oysters, crabs, and fishHuman interference upstream has disrupted estuaries worldwide
85. Intertidal ZonesAn intertidal zone is periodically submerged and exposed by the tidesIntertidal organisms are challenged by variations in temperature and salinity and by the mechanical forces of wave actionOxygen and nutrient levels are highSubstrate varies from rocky to sandy
86. Figure 52.14eA rocky intertidal zone on theOregon coast
87. Sandy zones protected from vigorous waves support sea grass and algae; rocky zones support attached marine algaeIn rocky zones, many animals have structural adaptations for attaching to the hard substrateIn sandy zones, worms, clams, and crustaceans bury themselves in sandOther animals include sponges, sea anemones, echinoderms, and small fishesOil pollution has disrupted many intertidal areas
88. Oceanic Pelagic ZoneThe oceanic pelagic zone is constantly mixed by wind-driven oceanic currentsOxygen levels are highTurnover in temperate oceans renews nutrients in the photic zones; year-round stratification in tropical oceans leads to lower nutrient concentrationsThis biome covers approximately 70% of Earth’s surface
89. Figure 52.14fOpen ocean near Iceland
90. Phytoplankton and zooplankton are the dominant organisms in this biome; also found are free-swimming animalsZooplankton includes protists, worms, copepods, krill, jellies, and invertebrate larvaeOther animals include squids, fishes, sea turtles, and marine mammalsOverfishing has depleted fish stocksHumans have polluted oceans with dumping of waste
91. Coral ReefsCoral reefs are formed from the calcium carbonate skeletons of corals (cnidarians)Shallow reef-building corals live in the photic zone in warm (about 20–30C), clear water; deepsea corals live at depths of 200–1,500 mCorals require high oxygen concentrations and a solid substrate for attachmentA coral reef progresses from a fringing reef to a barrier reef to a coral atoll
92. Figure 52.14gA coral reef in the Red Sea
93. Corals form a mutualistic relationship with unicellular algae, which provide them with organic moleculesIn addition to corals, other invertebrates and fish are also exceptionally diverseCollection of coral skeletons, overfishing, global warming, pollution, and aquaculture are threats to coral reef ecosystems
94. Marine Benthic ZoneThe marine benthic zone consists of the seafloor below the surface waters of the coastal, or neritic, zone and the offshore pelagic zoneOrganisms in the very deep benthic (abyssal) zone are adapted to continuous cold and extremely high water pressureSubstrate is mainly soft sediments; some areas are rocky
95. Figure 52.14hA deep-sea hydrothermal vent community
96. Shallow areas contain seaweeds and filamentous algaeDeep-sea hydrothermal vents of volcanic origin on mid-oceanic ridges are surrounded by unique chemoautotrophic prokaryotes, as well as echinoderms and arthropodsNeritic benthic communities include invertebrates and fishesOverfishing and dumping of waste have depleted fish populations
97. Concept 52.4: Interactions between organisms and the environment limit the distribution of speciesSpecies distributions are the result of ecological and evolutionary interactions through timeEcological time is the minute-to-minute time frame of interactions between organisms and the environmentEvolutionary time spans many generations and captures adaptation through natural selection
98. Events in ecological time can lead to evolutionFor example, Galápagos finches with larger breaks were more likely to survive a drought as they could eat the available larger seedsAs a result, the average beak size was larger in the next generationThis resulted in an evolutionary change
99. Both biotic and abiotic factors influence species distributionFor example, temperature, water availability, and interspecific interactions, affect the distribution of the saguaro cacti
100. Dispersal (movement from high pop. Center outward) Distribution (where organisms are located)*Not all species occupy their potential range due to many reasons (interactions, choice, abiotic factors…)Climograph-plot of temp. and precip.Stratification-layering of species into zones.
101. Figure 52.15Sonoran desertSaguaro cacti observed100 kmNCALIFORNIABAJACALIFORNIAARIZONASONORABAJACALIFORNIASURGULF OF CALIFORNIA
102.
103. Dispersal and DistributionDispersal is the movement of individuals or gametes away from centers of high population density or from their area of originDispersal contributes to the global distribution of organisms
104. Figure 52.17Current19701966196519601961195819511943193719561970
105. Figure 52.18Sea urchinLimpetBoth limpetsand urchinsremovedOnly urchinsremovedOnly limpets removedControl (both urchinsand limpets present)August1982Seaweed cover (%)February1983August1983February1984100806040200
106. Species TransplantsSpecies transplants include organisms that are intentionally or accidentally relocated from their original distributionIf a transplant is successful, it indicates that its potential range is larger than its actual rangeSpecies transplants can disrupt the communities or ecosystems to which they have been introduced
107. Behavior and Habitat SelectionSome organisms do not occupy all of their potential rangeSpecies distribution may be limited by habitat selection behavior
108. Biotic FactorsBiotic factors that affect the distribution of organisms may includePredationHerbivoryFor example, sea urchins can limit the distribution of seaweedsCompetitionMutualismParasitism
109. Abiotic FactorsAbiotic factors affecting the distribution of organisms includeTemperatureWaterOxygenSalinitySunlightSoilMost abiotic factors vary in space and time
110. Figure 52.UN03aData from the Field ExperimentAverage Biomass (g/100 cm2)Spartina patensTypha angustifoliaWithneighborsWithoutneighborsSaltMarshesFreshwaterMarshesSaltMarshesFreshwaterMarshes810320001833
111. Figure 52.UN03bData from the Greenhouse ExperimentSalinity (parts perthousand% maximum biomass(Spartina patens)8010200017% maximum biomass(Typha angustifolia)204060801004077299000
112. Figure 52.UN03cSpartina patens
113. Figure 52.UN03dTypha angustifolia
114. Figure 52.UN05
115. Figure 52.UN06Seed collection sitesSierra NevadaGreat BasinPlateauAltitude (m) Mean height (cm)75502503,0002,0001,0000