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LECTURE PRESENTATIONS For CAMPBELL BIOLOGY, NINTH EDITION Jane B. Reece, Lisa A. Urry, Michael L. Cain, Steven A. Wasserman, Peter V. Minorsky, Robert.

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Presentation on theme: "LECTURE PRESENTATIONS For CAMPBELL BIOLOGY, NINTH EDITION Jane B. Reece, Lisa A. Urry, Michael L. Cain, Steven A. Wasserman, Peter V. Minorsky, Robert."— Presentation transcript:

1 LECTURE PRESENTATIONS For CAMPBELL BIOLOGY, NINTH EDITION Jane B. Reece, Lisa A. Urry, Michael L. Cain, Steven A. Wasserman, Peter V. Minorsky, Robert B. Jackson © 2011 Pearson Education, Inc. Lectures by Erin Barley Kathleen Fitzpatrick An Introduction to Ecology and the Biosphere Chapter 52

2 Overview: Discovering Ecology Ecology is the scientific study of the interactions between organisms and the environment These interactions determine the distribution of organisms and their abundance © 2011 Pearson Education, Inc.

3 Tropic of Cancer 30°N 30°S Tropic of Capricorn Equator Tropical forest Savanna Desert Chaparral Temperate grassland Temperate broadleaf forest Northern coniferous forest Tundra High mountains Polar ice Figure 52.9

4 The rediscovery of the nearly extinct harlequin toad in Costa Rica raises many ecological questions –What environmental factors limit their geographic distribution? –What factors (food, pathogens) affect population size? © 2011 Pearson Education, Inc.

5 Ecology Big Idea 1 Geographic Distribution of Species -Dependent on environment Population size -Food supply, pathogens, natural predators

6 Climate determine the distribution of an organism © 2011 Pearson Education, Inc. Macroclimate Solar energy Bodies of water Seasonality Mountains Microclimate Abiotic Factors Biotic Factors

7 Latitudinal Variation in Sunlight Intensity The angle at which sunlight hits Earth affects its intensity, the amount of heat and light per unit of surface area The intensity of sunlight is strongest in the tropics (between 23.5° north latitude and 23.5° south latitude) © 2011 Pearson Education, Inc.

8 Figure 52.3a Latitudinal variation in sunlight intensity 90°N (North Pole) 60°N 30°N 23.5°N (Tropic of Cancer 60°S 90°S (South Pole) 0° (Equator) 23.5°S (Tropic of Capricorn) 30°S Low angle of incoming sunlight Atmosphere Sun overhead at equinoxes Low angle of incoming sunlight

9 Large Bodies of Water Effect on Climate Water has a high specific heat It takes longer to heat up and cool down. Result: -Lower temperature in summer and winter © 2011 Pearson Education, Inc.

10 Comparing Climate – Do Now Which of these two graphs is showing a city that is near a large body of water, AND how do you know that is the case?

11 Global Climate Change Changes in Earth’s climate can profoundly affect the biosphere One way to predict the effects of future global climate change is to study previous changes As glaciers retreated 16,000 years ago, tree distribution patterns changed As climate changes, species that have difficulty dispersing may have smaller ranges or could become extinct © 2011 Pearson Education, Inc.

12 Figure 52.7 Current range Predicted range Overlap (a) 4.5°C warming over next century (b) 6.5°C warming over next century

13 Figure 52.8 Sweden Finland Expanded range in 1997 Range in 1970

14 Mountains

15 Concept 52.2: The structure and distribution of terrestrial biomes are controlled by climate and disturbance Biomes 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 © 2011 Pearson Education, Inc.

16 Tropic of Cancer 30°N Tropic of Capricorn Equator Figure 52.9

17 Interactions between organisms and the environment limit the distribution of species Species distributions are the result of ecological and evolutionary (natural selection) interactions Ecological time is the minute-to-minute time frame of interactions between organisms and the environment Evolutionary time spans many generations and captures adaptation through natural selection © 2011 Pearson Education, Inc.

18 Events in ecological time can lead to evolution For example, Galápagos finches with larger beaks were more likely to survive a drought as they could eat the available larger seeds As a result, the average beak size was larger in the next generation This resulted in an evolutionary change © 2011 Pearson Education, Inc.

19 Both biotic and abiotic factors influence species distribution –For example, climate, interspecific interactions, and other factors affect the distribution of the red kangaroo © 2011 Pearson Education, Inc.

20 We will look at Kangaroo distribution and biomes on the next 2 slides. While you look at this map and distribution think of the following things. –What part of the country has the most kangaroos/km 2 ? –What factors would a biologist look for to identify why kangaroos are more plentiful in other areas? –What information would we need to know about biomes and the kangaroos to answer these questions? © 2011 Pearson Education, Inc.


22 Kangaroos/km 2 0– –1 1–5 5–10 10–20 > 20 Limits of distribution Figure 52.17

23 Figure Why is species X absent from an area? Does dispersal limit its distribution? No Yes No Does behavior limit its distribution? Do biotic factors (other species) limit its distribution? Do abiotic factors limit its distribution? Habitat selection Area inaccessible or insufficient time Predation, parasitism, competition, disease Water Oxygen Salinity pH Soil nutrients, etc. Physical factors Chemical factors Temperature Light Soil structure Fire Moisture, etc. Ecologists ask questions about where species occur and why species occur where they do

24 Dispersal of Species Dispersal is the movement of individuals away from centers of high population density or from their area of origin. © 2011 Pearson Education, Inc. Natural Range Adaptive Radiation Species Transplant Behavior Biotic Factors

25 Natural Range Expansions and Adaptive Radiation Natural range expansions show the influence of dispersal on distribution –For example, cattle egrets arrived in the Americas in the late 1800s and have expanded their distribution In rare cases, long-distance dispersal can lead to adaptive radiation –For example, Hawaiian silverswords are a diverse group descended from an ancestral North American tarweed © 2011 Pearson Education, Inc.

26 Figure Current

27 Species Transplants Species transplants include organisms that are intentionally or accidentally relocated from their original distribution If a transplant is successful, it indicates that its potential range is larger than its actual range Species transplants can disrupt the communities or ecosystems to which they have been introduced © 2011 Pearson Education, Inc.

28 Behavior and Habitat Selection Some organisms do not occupy all of their potential range Species distribution may be limited by habitat selection behavior © 2011 Pearson Education, Inc.

29 Biotic Factors Biotic factors that affect the distribution of organisms may include –Predation –Herbivory For example, sea urchins can limit the distribution of seaweeds –Competition © 2011 Pearson Education, Inc.

30 Both limpets and urchins removed Only urchins removed RESULTS Seaweed cover (%) Only limpets removed Control (both urchins and limpets present) Sea urchin Limpet February 1983 August 1983 August 1982 February 1984 Figure 52.20

31 Abiotic Factors Abiotic factors affecting the distribution of organisms include –Temperature –Water –Sunlight –Wind –Rocks and soil Most abiotic factors vary in space and time © 2011 Pearson Education, Inc.

32 Temperature Environmental temperature is an important factor in the distribution of organisms because of its effects on biological processes Cells may freeze and rupture below 0°C, while most proteins denature above 45°C Mammals and birds expend energy to regulate their internal temperature © 2011 Pearson Education, Inc.

33 Water and Oxygen Water availability in habitats is another important factor in species distribution Desert organisms exhibit adaptations for water conservation Water affects oxygen availability as oxygen diffuses slowly in water Oxygen concentrations can be low in deep oceans and deep lakes © 2011 Pearson Education, Inc.

34 Salinity Salt concentration affects the water balance of organisms through osmosis Most aquatic organisms are restricted to either freshwater or saltwater habitats Few terrestrial organisms are adapted to high- salinity habitats © 2011 Pearson Education, Inc.

35 Sunlight Light intensity and quality (wavelength) affect photosynthesis Water absorbs light; as a result, in aquatic environments most photosynthesis occurs near the surface In deserts, high light levels increase temperature and can stress plants and animals © 2011 Pearson Education, Inc.

36 Figure 52.21

37 Rocks and Soil Many characteristics of soil limit the distribution of plants and thus the animals that feed on them –Physical structure –pH –Mineral composition © 2011 Pearson Education, Inc.

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