- Slides: 162
What is ecology? l Ecology is the scientific study of interactions between ______ l term ecology comes from the Greek oikos, _______, and logos, to study .
biotic and abiotic factors What are biotic factors? Give examples. What are abiotic factors? Give examples. .
climate What is climate? What abiotic factors are the major components of climate? .
climate What effects do bodies of water have on climate? What effects do mountains have on climate? Include descriptions of how elevation affects temperature, and of rain shadows. .
Fig. 52 -12
Fig. 52 -13
climate What effects do seasons have on climate? Describe what causes seasons; include the terms solstice and equinox in your description. .
Fig. 52 -10 c 60ºN 30ºN 0º (equator) June solstice March equinox 30ºS December solstice Constant tilt of 23. 5º September equinox
What are biomes? .
aquatic biomes List the major aquatic biomes and their defining physical features. define the following: photic zone aphotic zone benthic zone.
Fig. 52 -16
Lakes • Oligotrophic lakes are nutrient-poor and generally oxygen-rich • Eutrophic lakes are nutrient-rich and often depleted of oxygen if ice covered in winter • Rooted and floating aquatic plants live in the shallow and well-lighted littoral zone • Water is too deep in the limnetic zone to support rooted aquatic plants; small drifting animals called zooplankton graze on the phytoplankton Copyright © 2008 Pearson Education, Inc. , publishing as Pearson Benjamin Cummings
Fig. 52 -18 a
Fig. 52 -18 b
Fig. 52 -18 c
Wetlands • A wetland is a habitat that is inundated by water at least some of the time and that supports plants adapted to water-saturated soil • Wetlands can develop in shallow basins, along flooded river banks, or on the coasts of large lakes and seas • Wetlands are among the most productive biomes on earth and are home to diverse invertebrates and birds Copyright © 2008 Pearson Education, Inc. , publishing as Pearson Benjamin Cummings
Fig. 52 -18 d
Fig. 52 -18 e
Streams and Rivers • The most prominent physical characteristic of streams and rivers is current • A diversity of fishes and invertebrates inhabit unpolluted rivers and streams • Damming and flood control impair natural functioning of stream and river ecosystems Copyright © 2008 Pearson Education, Inc. , publishing as Pearson Benjamin Cummings
Fig. 52 -18 f
Estuaries • An estuary is a transition area between river and sea • Salinity varies with the rise and fall of the tides • Estuaries are nutrient rich and highly productive • An abundant supply of food attracts marine invertebrates and fish Video: Flapping Geese Copyright © 2008 Pearson Education, Inc. , publishing as Pearson Benjamin Cummings
Fig. 52 -18 g
Intertidal Zones • An intertidal zone is periodically submerged and exposed by the tides • Intertidal organisms are challenged by variations in temperature and salinity and by the mechanical forces of wave action • Many animals of rocky intertidal environments have structural adaptations that enable them to attach to the hard substrate Copyright © 2008 Pearson Education, Inc. , publishing as Pearson Benjamin Cummings
Fig. 52 -18 h
Oceanic Pelagic Zone • The oceanic pelagic biome is a vast realm of open blue water, constantly mixed by winddriven oceanic currents • This biome covers approximately 70% of Earth’s surface • Phytoplankton and zooplankton are the dominant organisms in this biome; also found are free-swimming animals Video: Shark Eating a Seal Copyright © 2008 Pearson Education, Inc. , publishing as Pearson Benjamin Cummings
Fig. 52 -18 i
Coral Reefs • Coral reefs are formed from the calcium carbonate skeletons of corals (phylum Cnidaria) • Corals require a solid substrate for attachment • Unicellular algae live within the tissues of the corals and form a mutualistic relationship that provides the corals with organic molecules Video: Coral Reef Copyright © 2008 Pearson Education, Inc. , publishing as Pearson Benjamin Cummings Video: Clownfish and Anemone
Fig. 52 -18 j A deep-sea hydrothermal vent community
Marine Benthic Zone • The marine benthic zone consists of the seafloor below the surface waters of the coastal, or neritic, zone and the offshore pelagic zone • Organisms in the very deep benthic, or abyssal, zone are adapted to continuous cold and extremely high water pressure Copyright © 2008 Pearson Education, Inc. , publishing as Pearson Benjamin Cummings
• Unique assemblages of organisms are associated with deep-sea hydrothermal vents of volcanic origin on mid-oceanic ridges; here the autotrophs are chemoautotrophic prokaryotes Video: Hydrothermal Vent Copyright © 2008 Pearson Education, Inc. , publishing as Pearson Benjamin Cummings Video: Tubeworms
aquatic biomes Describe the process of turnover in a lake, and why it is important. What is eutrophication, and what are some likely consequences of it? .
Fig. 52 -17 -1
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terrestrial biomes List the major terrestrial biomes and their characteristic vegetation types and climate. .
terrestrial biomes define the following: climograph ecotone Be sure that you can interpret a climograph. .
Fig. 52 -19
Terrestrial Biomes • Terrestrial biomes can be characterized by distribution, precipitation, temperature, plants, and animals Copyright © 2008 Pearson Education, Inc. , publishing as Pearson Benjamin Cummings
Fig. 52 -21 a
Tropical Forest • In tropical rain forests, rainfall is relatively constant, while in tropical dry forests precipitation is highly seasonal • Tropical forests are vertically layered and competition for light is intense • Tropical forests are home to millions of animal species, including an estimated 5– 30 million still undescribed species of insects, spiders, and other arthropods Copyright © 2008 Pearson Education, Inc. , publishing as Pearson Benjamin Cummings
Fig. 52 -21 b
Desert • Precipitation is low and highly variable, generally less than 30 cm per year; deserts may be hot or cold • Desert plants are adapted for heat and desiccation tolerance, water storage, and reduced leaf surface area • Common desert animals include many kinds of snakes and lizards, scorpions, ants, beetles, migratory and resident birds, and seed-eating rodents; many are nocturnal Copyright © 2008 Pearson Education, Inc. , publishing as Pearson Benjamin Cummings
Fig. 52 -21 c A savanna in Kenya
Savanna • Savanna precipitation and temperature are seasonal • Grasses and forbs make up most of the ground cover • Common inhabitants include insects and mammals such as wildebeests, zebras, lions, and hyenas Copyright © 2008 Pearson Education, Inc. , publishing as Pearson Benjamin Cummings
Fig. 52 -21 d
Chaparral • Chaparral climate is highly seasonal, with cool and rainy winters and hot dry summers • The chaparral is dominated by shrubs, small trees, grasses, and herbs; many plants are adapted to fire and drought • Animals include amphibians, birds and other reptiles, insects, small mammals and browsing mammals Copyright © 2008 Pearson Education, Inc. , publishing as Pearson Benjamin Cummings
Fig. 52 -21 e
Temperate Grassland • Temperate grasslands are found on many continents • Winters are cold and dry, while summers are wet and hot • The dominant plants, grasses and forbs, are adapted to droughts and fire • Native mammals include large grazers and small burrowers Copyright © 2008 Pearson Education, Inc. , publishing as Pearson Benjamin Cummings
Fig. 52 -21 f
Northern Coniferous Forest • The northern coniferous forest, or taiga, extends across northern North America and Eurasia and is the largest terrestrial biome on Earth • Winters are cold and long while summers may be hot Copyright © 2008 Pearson Education, Inc. , publishing as Pearson Benjamin Cummings
• The conical shape of conifers prevents too much snow from accumulating and breaking their branches • Animals include migratory and resident birds, and large mammals Copyright © 2008 Pearson Education, Inc. , publishing as Pearson Benjamin Cummings
Fig. 52 -21 g
Temperate Broadleaf Forest • Winters are cool, while summers are hot and humid; significant precipitation falls year round as rain and snow • A mature temperate broadleaf forest has vertical layers dominated by deciduous trees in the Northern Hemisphere and evergreen eucalyptus in Australia Copyright © 2008 Pearson Education, Inc. , publishing as Pearson Benjamin Cummings
• Mammals, birds, and insects make use of all vertical layers in the forest • In the Northern Hemisphere, many mammals hibernate in the winter Copyright © 2008 Pearson Education, Inc. , publishing as Pearson Benjamin Cummings
Fig. 52 -21 h
Tundra • Tundra covers expansive areas of the Arctic; alpine tundra exists on high mountaintops at all latitudes • Winters are long and cold while summers are relatively cool; precipitation varies Copyright © 2008 Pearson Education, Inc. , publishing as Pearson Benjamin Cummings
• Permafrost, a permanently frozen layer of soil, prevents water infiltration • Vegetation is herbaceous (mosses, grasses, forbs, dwarf shrubs and trees, and lichen) and supports birds, grazers, and their predators Copyright © 2008 Pearson Education, Inc. , publishing as Pearson Benjamin Cummings
population ecology Population ecology is the study of populations in relation to _____ A population is: define the following: density dispersion range.
population ecology How does the mark-recapture method to estimate population size work? Include the formula and definition of the terms in the formula. .
population ecology What is demography? define and be able to use/interpret: l life tables l survivorship curves l reproductive tables .
Life Tables • A life table is an age-specific summary of the survival pattern of a population • It is best made by following the fate of a cohort, a group of individuals of the same age • The life table of Belding’s ground squirrels reveals many things about this population Copyright © 2008 Pearson Education, Inc. , publishing as Pearson Benjamin Cummings
Table 53 -1
Survivorship Curves • A survivorship curve is a graphic way of representing the data in a life table • The survivorship curve for Belding’s ground squirrels shows a relatively constant death rate Copyright © 2008 Pearson Education, Inc. , publishing as Pearson Benjamin Cummings
Fig. 53 -5
• Survivorship curves can be classified into three general types: – Type I: low death rates during early and middle life, then an increase among older age groups – Type II: the death rate is constant over the organism’s life span – Type III: high death rates for the young, then a slower death rate for survivors Copyright © 2008 Pearson Education, Inc. , publishing as Pearson Benjamin Cummings
Fig. 53 -6
Reproductive Rates • For species with sexual reproduction, demographers often concentrate on females in a population • A reproductive table, or fertility schedule, is an age-specific summary of the reproductive rates in a population • It describes reproductive patterns of a population Copyright © 2008 Pearson Education, Inc. , publishing as Pearson Benjamin Cummings
Table 53 -2
population ecology define and be able to use/interpret the exponential population growth model .
Exponential Growth l Exponential population growth is population increase under idealized conditions l Under these conditions, the rate of reproduction is at its maximum, called the intrinsic rate of increase .
l Equation growth: of exponential population d. N rmax. N dt .
l The J-shaped curve of exponential growth characterizes some rebounding populations .
Fig. 53 -11
population ecology define and be able to use/interpret the logistic population growth model define and understand the terms K and r .
l Exponential growth cannot be sustained for long in any population l. A more realistic population model limits growth by incorporating carrying capacity l Carrying capacity (K) is the maximum population size the environment can support.
The Logistic Growth Model l In the logistic population growth model, the per capita rate of increase declines as carrying capacity is reached l We construct the logistic model by starting with the exponential model and adding an expression that reduces per capita rate of increase as N approaches K (K N) d. N rmax N dt K.
Table 53 -3
l The logistic model of population growth produces a sigmoid (S-shaped) curve .
population ecology describe K-selection and r-selection l What sort of life tables and survivorship curves would you expect for each type? l Give examples of organisms of each type. l If given a typical life history for an organism be able to categorize it as Kselected and r-selected. .
l K-selection, or density-dependent selection, selects for life history traits that are sensitive to population density l r-selection, or density-independent selection, selects for life history traits that maximize reproduction .
Fig. 53 -13
Fig. 53 -14
population ecology List and describe six density-dependent factors known to affect population growth rates. Describe how population cycles may be linked between predators and their prey. .
Competition for Resources l In crowded populations, increasing population density intensifies competition for resources and results in a lower birth rate .
Territoriality l In many vertebrates and some invertebrates, competition for territory may limit density l Cheetahs are highly territorial, using chemical communication to warn other cheetahs of their boundaries .
Fig. 53 -17 a .
Fig. 53 -17 b (b) Gannets .
Disease l Population density can influence the health and survival of organisms l In dense populations, pathogens can spread more rapidly .
Predation l As a prey population builds up, predators may feed preferentially on that species .
Toxic Wastes l Accumulation of toxic wastes can contribute to density-dependent regulation of population size .
Intrinsic Factors l For some populations, intrinsic (physiological) factors appear to regulate population size .
Human population history and future Be sure that you understand figures 53. 22 -26. What was industrial revolution and how did it affect human population growth? What is the demographic transition and how does it affect human population growth? What is the global carrying capacity for humans? .
The Global Human Population l The human population increased relatively slowly until about 1650 and then began to grow exponentially .
Fig. 53 -23
l To maintain population stability, a regional human population can exist in one of two configurations: l Zero population growth = High birth rate – High death rate l Zero population growth = Low birth rate – Low death rate l The demographic transition is the move from the first state toward the second state.
Birth or death rate per 1, 000 people Fig. 53 -24 50 40 30 20 10 Sweden Birth rate Death rate 0 1750 1800 Mexico Birth rate Death rate 1850 1900 Year 1950 2000 2050
l The demographic transition is associated with an increase in the quality of health care and improved access to education, especially for women l Most of the current global population growth is concentrated in developing countries .
Age Structure l One important demographic factor in present and future growth trends is a country’s age structure l Age structure is the relative number of individuals at each age .
Fig. 53 -25
l Age structure diagrams can predict a population’s growth trends l They can illuminate social conditions and help us plan for the future .
Infant Mortality and Life Expectancy l Infant mortality and life expectancy at birth vary greatly among developed and developing countries but do not capture the wide range of the human condition .
Global Carrying Capacity l How many humans can the biosphere support? .
Estimates of Carrying Capacity l The carrying capacity of Earth for humans is uncertain l The average estimate is 10– 15 billion .
Limits on Human Population Size l The ecological footprint concept summarizes the aggregate land water area needed to sustain the people of a nation l It is one measure of how close we are to the carrying capacity of Earth l Countries vary greatly in footprint size and available ecological capacity.
Fig. 53 -27
l Our carrying capacity could potentially be limited by food, space, nonrenewable resources, or buildup of wastes .
community ecology Community ecology is the study of: A biological community is: .
community ecology describe the following interspecific interactions in general terms of the +/-/0 system l competition l predation l herbivory l parasitism l mutualism l commensalism.
community ecology define the terms (ecological) niche resource partitioning character displacement .
Ecological Niches l The total of a species’ use of biotic and abiotic resources is called the species’ ecological niche l An ecological niche can also be thought of as an organism’s ecological role l Ecologically similar species can coexist in a community if there are one or more significant differences in their niches.
Resource partitioning l Resource partitioning is differentiation of ecological niches, enabling similar species to coexist in a community .
Character Displacement l Character displacement is a tendency for characteristics to be more divergent in sympatric populations of two species than in allopatric populations of the same two species l An example is variation in beak size between populations of two species of Galápagos finches .
Fig. 54 -4
predation Describe how these defenses can help animals avoid predation: l camouflage l warning coloration l Batesian mimicry l Müllerian mimicry.
mutualism What is the difference between obligate and facultative mutualism? .
community ecology l What is symbiosis? l Which interspecific interactions are types of symbiosis? .
community ecology l What is keystone species and a pivotal niche? .
community ecology l What is a food web? l How do energetic limits affect food webs/chains? .
community ecology Describe l ecological succession l primary succession l secondary succession.
ecosystems Diagram the biogeochemical cycles of l water l carbon l nitrogen l phosphorus.
Fig. 55 -14 a
Fig. 55 -14 b
Fig. 55 -14 c
Fig. 55 -14 d
ecosystems Describe how biomagnification (biological magnification) of a toxin works in an ecosystem. .
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How we almost killed ourselves: the ozone hole story Describe the importance of the ozone layer. .
How we almost killed ourselves: the ozone hole story Describe how human activities led to depletion of the ozone layer. .
Fig. 55 -24
How we almost killed ourselves: the ozone hole story Describe what humans have done about the depletion of the ozone layer. .
How we still might kill ourselves: global warming Describe the greenhouse effect and why CO 2 is called a greenhouse gas. .
AP story realclimate. org Global cooling myth debunked
How we still might kill ourselves: global warming Describe how human activities increase CO 2 in the atmosphere, the logic behind how that leads to global warming, and the evidence that global warming is occurring. .
How we still might kill ourselves: global warming Describe what effects global warming may have. What is the feed-forward effect of thawing tundra? Describe what humans have done about global warming. .
biodiversity Define l ecosystem biodiversity l species biodiversity l genetic biodiversity .
Fig. 56 -3
biodiversity Describe the value of biodiversity in l maintaining the global ecosystem and biogeochemical cycles l providing unique resources such as food, remediation, drugs l intrinsic value of biodiversity.
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The sixth extinction. . . or how we are killing lots of things (and perhaps ultimately ourselves as well) l What is habitat loss and how is it affecting life on Earth today? l What are introduced species and how are they affecting life on Earth today? l What is overexploitation and how is it affecting life on Earth today? .
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Fig. 56 -8 (a) Brown tree snake (b) Kudzu
The sixth extinction. . . or how we are killing lots of things (and perhaps ultimately ourselves as well) l What is overexploitation and how is it affecting life on Earth today? .
Fig. 56 -9 http: //www. nmfs. noaa. gov/fishwatch
What is the sixth extinction? What can humans do about it? .