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Ecology and the Biosphere Chapter 50 Ecology is the scientific study of the interactions between organisms and their environment.

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Presentation on theme: "Ecology and the Biosphere Chapter 50 Ecology is the scientific study of the interactions between organisms and their environment."— Presentation transcript:

1 Ecology and the Biosphere Chapter 50 Ecology is the scientific study of the interactions between organisms and their environment



4 Emphasis scientific study interactions environment

5 Environmental Components Abiotic Components (non-living chemical and physical factors) Temperature Light Water Nutrients Biotic Components (other organisms) Predators and their Prey Pathogens and their Hosts Competitors …same species or other Organisms that modify the environment

6 Broad Range of Research Adaptatons of Organisms Ecosystem Dynamics

7 Four Major Sub disciplines Organismal Ecology Population Ecology Community Ecology Ecosystem Ecology Increasing complexity adaptations of individuals to their environment all of the individuals of a species in a site all of the populations in a site all of the biotic (community) and abiotic factors in a site

8 Ecology

9 Biomes of the Biosphere

10 Abiotic factors of Biosphere Temperature Water Sunlight Wind Substrate: Rocks and soil Disturbances

11 Temperature Temperature influences biological processes …chemistry and physiology a) freezing can rupture cells b) high temperatures denature proteins & NAs Organisms can only regulate body temperatures within narrow ranges of temperature a) metabolism slows down at low and high temperatures b) endotherms and extreme specialists are exceptions, but still operate within ranges of acceptable temperatures

12 Water Aquatic and marine organisms face challenges of maintaining osmotic balance Terrestrial organisms confront the problem of dessication, which has been an vital factor in the evolution of many lineages

13 Sunlight Virtually all ecosystems rely on sunlight for energy But sunlight is not the prime determinent of plant distribution Light can be limiting under canopies and in aquatic environments …both are shade conditions Sunlight heats the earth uneavenly, resulting in climate variation

14 Wind Wind chill exacerbates cold temperatures Wind can exacerbate water loss by increasing evaporation Wind moves air masses and moisture, influencing the distribution of temperature and moisture variation

15 Rocks and Soil physical structure, pH, nutrient content limits the distribution of plants and the animals that feed on them …resulting in patchiness of biotic communities

16 Disturbance Fires, extreme stroms, volcanic eruptions Disturbance can devastate biota Resets community, resulting in succession Succession of biota, emphasizing disperal early, then competitive ability later …major trade-off

17 Climate Sunlight Temperature Water Wind

18 Climograph of Biomes (major ecosystems) overlap indicates that other factors are involved too

19 Climograph of Biomes (major ecosystems) identify at least three patterns in this climograph

20 Biomes of the Biosphere

21 Causes of Global Climate Patterns


23 Solar energy incident to planet's surface Movement of planet through space

24 Solar Energy Half of the solar radiation is aborbed in the atmosphere, especially high energy wave lengths (e.g., UV radiation absrobed by ozone) Solar radiation heats the planet's surface unevenly Which creates patterns of atmospheric activity Which influences where moisture is captured or deposited






30 Why does the falling air at 30° move to the west if it moves toward the equator, and to the east if it moves to the poles? 30° 60° 90° 0° 30° 60° 90°


32 Biome Distributions


34 Effects of Mountains Rain shadows Slopes facing the equator are warmer Increases in altitude mimic increases in latitude: 6° C per 1000m altitude or 880 km latitude

35 Aquatic Biomes


37 Turnover mixes stratified lakes and ponds, moving oxygen down and nutrients up

38 Biotic Zonation in Lakes and Ponds

39 Nutrient Conditions Deep lakes are often nutrient poor oligotrophic Lakes in between are mesotrophic Shallow lakes are often nutrient rich eutrophic

40 Zonation in Marine Communities

41 Organismal Ecology Concepts

42 Regulators & Conformers Regulators: use physiological & behavioral mechanisms to achieve homeostasis in variable environments e.g., Salmon: marine/aquatic conditions, osmoregulation Conformers: allow body conditions to vary with those of external environment, usually in stable environments e.g., spider crabs (Libinia): doesn't osmoregulate

43 Tradeoffs Energy is the limiting currency Competing functions

44 Regulators and Conformers


46 Principle of Allocation Organisms have limited energy to invest in competing needs ◊ growth, survival & reproduction (maintenance) ◊ homeostasis Homeostasis is costly ◊ grasshoppers (moderately active ectotherms): 70/30 ◊ weasel (active endotherms): 97.5 versus 2.5 % ◊ wren (very active endotherms): 99.5 versus 0.5 % Results in Tradeoffs ◊ Regulators: Generalists with broad distributions over variable conditions ◊ Conformers: Specialists with narrow distributions under stable conditions

47 Responses to Environmental Change Physiological Morphological Behavioral

48 Physiological Responses: Tolerance and Acclimation

49 Morphological Responses sometimes reversible occurs over developmental time

50 Behavioral Responses Can be almost instantaneous, often reversible Examples: ◊ desert animals that burrow in the day to escape heat ◊ seasonal migration ◊ hibernation ◊ honey bees cool their hives by fanning their wings or heat them up by through their activity

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