An Introduction to Ecology: Distribution and Adaptations of Organisms

1. An Introduction to Ecology: Distribution and Adaptations of Organisms

2. Ecology (from the Greek oikos, “home” and logos, “to study”) • the scientific study of the interaction between organisms and their environments • ecology incorporates hypothetico-deductive methods, using observations and experiments to test hypothetical explanations of ecological phenomena

3. Ecology • Math • Genetics • Geology • Biology • Chemistry • Physics

4. Ecology • behavioral biology -entomology • physiology -land-use planning • public health - molecular biology • agriculture - agronomy • computer science - engineering • forestry - oceanography • evolution • bacteriology

5. Environment • all external conditions and factors, living and nonliving that affect an organism or other specified system during its lifetime • abiotic (temperature, light, water, nutrients, etc.) • biotic - organisms that are part of any individual’s environment

6. Ecology • autecology - concern with individual species • synecology - concerned with the group • kinds of ecology • aquatic -island • marine -paleoecology • freshwater - behavioral • desert - applied • forest - exotic

7. subatomic particles --->atoms ---> molecules --->protoplasm ---> cells ---> tissues ---> organs ---> populations ---> communities ---> ecosystems ---> biosphere ---> planets ---> solar systems ---> galaxies ---> universe

8. bioshpere - largest, most nearly self sufficient biological system • biome - large regional or subcontinental “biosystem” characterized by major vegetation type or other features • ecosystem - community + nonliving environment • community - all populations in a given area • population - groups of individuals of any one kind

9. Ecosystem • 1877 - Karl Mobius (Ger.) “biocenosis” used in description of organisms along an oyster reef • 1887 - S. A. Forbes (U.S.) “microcosm” used in relation to a lake • 1935 - A. G. Tansley (G.B.) coined “Ecosystem” • 1940’s - V.V. Dokuchaev (USSR) and G. F. Morozov (USSR) emphasized “biocenosis” • 1940’s “geobiocenosis” expanded from biocenosis

10. Abiotic Factors • light • soild • currents and pressures • nutrients • atmospheric gases • water • temperature • environmental effects, i.e. fire, flood, drought

11. Light • different responses to different wavelengths • photosynthesis (red and blue most efficient) • red algae (absorb green to aid in photosynthesis because water absorbs blue light) • color vision (fish, some reptiles, birds, most mammals) • cockroaches and other insects (uv)

12. photoperiodism - response to duration of light • latitude of 40N (Washington, DC) has day length range of 6 hours in winter to 18 hours in summer • affects daily, seasonal, annual balance • migration of birds (buzzards, swallows) • shedding of leaves in the fall • color changes in fur • blooming of flowers • long day (bloom in summer) • short day (bloom in spring and fall)

13. intensity • rate of photosynthesis • singing of birds • order in which birds sing • strength of song

14. Water • Precipitation • hydrologic cycle 97-99% of water transpired each day • succulents - 500 g water = 1 g glucose • Humidity • absolute (amount of water in air) • relative (% of water in air compared to how much air can hold at same temperature and pressure) • Aquatic environments • marine • freshwater

15. Hydrologic Cycle • transpiration • precipitation • condensation • evaporation • percolation • runoff • ground water

16. Temperature • plants and temperature • extremes in temperatures (more perennials) • affects transpiration • modifications to retard or speed up transpiration • animals (thermoregulation) • most plants and animals are poikilotheremic (cannot maintain a constant temperature - not cold blooded)

17. diapause (resting stage, i.e. insects during temperature extremes) • estivation (summer dormancy, i.e. frogs burrowing into mud during hot periods) • homeothermic (body temperature regulated internally and remains fairly constant) • turpor (suspended animation, i.e. bears body temp drops during cold weather to conserve energy • hibernation (severe reduction in body temperature for prolonged periods (ground squirrels, bats, ground hogs, whip-or-wills)

18. Thermoregulation • behavioral • turpor • hibernation • estivation • anatomical • ears of rabit and elephant dissipate heat • body hair • physiological • rete mirabile • capillaries • temperature

19. Atmosphere • trophosphere 0-17 km • 78% nitrogen • 21% oxygen • <1% Ar • 0.035% carbon dioxide • 0.01-5% water vapor • stratosphere 17-48 km • ozone layer 17-26 km • mesosphere 48-94 km

20. Pollutants in the Atmosphere • carbon oxides • carbon monoxide (CO) • carbon dioxide (CO2) • sulfur oxides • sulfur dioxide (SO2) • sulfur trioxide (SO3)

21. nitrogen oxides • nitric oxide (NO) • nitrogen dioxide (NO2) • nitrous oxide (N2O) • volatile organic molecules • methane • benzene • chlorofluorocarbons • bromine containing halons

22. suspended particulates • dust • soot • asbestos • lead • arsenic • cadmium • nitrates (NO3-) • sulfates (SO4-2)

23. droplets (liquids) • sulfuric acid (H2SO4) • oil • polychlorinated biphenyls (PCB’s) • dioxins • pesticides • photochemical oxidants • ozone (O3) • peroxyacyl nitrates (PAN’s) • hydrogen peroxide (H2O2) • aldehydes (formaldehyde)

24. radioactive substances • Radon 222 • iodine 131 • strontium 90 • plutonium 239 • heat • noise

25. Currents and Pressures • Wind • Krummholz structure on vegetation (gnarled, twisted, supine trees at tree-line) • flagging structure on vegetation • Water currents • structural adaptations of plants & animals • behavioral adaptations (rheotaxis) • Air & Water Pressure (33 feet, 1 atm) • Gravity • geotrophisms

26. Global Air Circulation and Rain Shadows to Form Deserts

27. Environmental Affects • Fires • fire ecology • slash, longleaf habitats • jack pines, sand pines • everglades • grasslands • pitcher plant bogs • scrub oaks • animals (scrub jays)

28. Floods • Drought • Tolerances in Plants • surface area of leaves • pubescence of leaves • hypodermis in pines • wax coatings • extra layers of epidermis • sunken stomata • Tolerances in Animals • uric acid and urine concentration • behavioral patterns

29. Nutrients • How do organisms obtain nutrients? • photosynthesis • food webs, food chains • cycles • carbon • phosphorus • nitrogen • water • oxygen • sulfur

30. Leibig’s Law of the Minimum • All organisms need minimum amounts of nutrients in order to survive, grow, and reproduce. • Also includes heat, light, water, etc.

31. Nutrients • Macronutrients • nitrogen • potassium • calcium • phosphorus • magnesisum • sulfur

32. Micronutrients • iron • chlorine • copper • manganese • zinc • molybdenum • boron • Elements Essential to Some Plants or Animals • sodium • cobalt

33. Soil Profile • humus (organic matter) • topsoil (decomposing organic material, live organisms, some minerals) • zone of leaching • zone of accumulation (iron, aluminum, organic matter, clays) • parent material (partially broken down inorganic material) • bedrock (impenetrable for most part)

34. Formation of Soil From Rock • Mechanical Weathering • frost action • frost wedging • frost heaving • abrasion • pressure release • plant growth (roots) • burrowing animals • crystalizations of salts • temperature extremes, i.e. forest fires

35. Chemical Weathering • oxygen 4FE + 3O2 ---> 2Fe2O3 (hematite) • acids • CO2 + H2O <=> H2CO3 <=> H+ + HCO3- (carbonic acid) (bicarbonate ion) • CaCO3 + CO2 + H2O <=> Ca+3 + 2HCO3- (calcite) or • CaCO3 + H+ + HCO3- <=> Ca+2 + 2HCO3- • solution weathering (see above) • lichens

36. Soil and Climate • due to climate, water movement affects soils • pedalfers (eastern U.S.) effective downward leaching due to high rainfall & acids produced by decaying humus. (high aluminum and iron oxides) - clay, minerals • pedocals (western U.S.) little leaching- evaporation pulls water out of ground (precipitation of salts, especially calcite) alkalai soils, heavy sodium salts • laterites (tropical) high rainfall, heavy leaching - red soils with iron and aluminum oxides (nonproductive soils because of excess leaching)

37. Alexander Von Humboldt(1769-1859) • German scientific explorer • extensive exploration in Mexico, down through Ecuador • realized species diversity of tropical rain forests • recognized plants occur in repeatable groups relating to soils, climate, and biological interactions • relationships between plant communities and latitude and altitude • influenced Thomas Jefferson’s exploration of Louisiana Purchase • Humboldt Current named after him

38. Altitude, Latitude and Plant Communities • snow • tundra • taiga (boreal forests) tall trees with spiphytic mosses, liverworts and lichens • temperate forest • tropical rain forest

39. Biotic Factors • symbioses • mutualism • commensalism • parasitism • predation • competition

40. Competitive Exclusion Principle • No two species can coexist indefinitely on the same resource. • Methods to avoid competition • live in separate areas (geographic separation) • live in different habitats within same geographical area • use same habitat differently (i.e. vertical or horizontal separation) • temporal separation • nocturnal • diurnal • reproductive cycles

41. Law of Tolerance • abudnance of organisms is greatest with tolerance to the environment. (There is not only a minimum but a maximum to environmental parameters

42. Gaia Hypothesis(Gaia Gk. = earth goddess) • developed by James Lovelock in conjunction with Lynn Margulis • states life (especially micro-organisms) have evolved with abiotic factors to produce a controlled system that maintains earth’s favorable condition for life • life maintains the physical environment which in turn maintains the biotic environment

43. Terrestrial Biomes • tropical forests • savannahs • deserts • chaparral • temperate grasslands • temperate deciduous forests • taiga • tundra

44. Freshwater Biomes • ponds and lakes • streams and rivers

45. Marine Biomes • estuaries • intertidal zones • coral reefs • oceanic pelagic • benthos

46. Homeostasis and the Principle of Allocation • homeostasis - the maintenance of a steady-state internal environment in the face of extremes in external environment • regulators • conformers • principle of allocation - each organisms has a limited amount of energy that can be allocated for obtaining nutrients, escaping from predators, coping with the environmental fluctuations, growth and reproduction