Ecology.pdf

Ecology BIOL-2101 Prof. Dan Mennill Department of Integrative Biology, University of Windsor ‹#› Lecture 8: Physiological Ecology Today: Chapter 7 Thermobiology Gas exchange Ecophysiology of plants ‹#› look inside...

Ecology BIOL-2101 Prof. Dan Mennill Department of Integrative Biology, University of Windsor ‹#› Lecture 8: Physiological Ecology Today: Chapter 7 Thermobiology Gas exchange Ecophysiology of plants ‹#› look inside organisms Ecophysiology Physiology: the study of the functions of organisms and their parts Physiological ecology (or ecophysiology):Loading… the study of how organisms function in their environment ‹#›  Ecophysiology Ecophysiology is an integrative field that strives to unite multiple subdisciplines of biology to solve ecological problems Ecophysiology: “Ecology provides the questions, and physiology provides the tools to determine the mechanisms.” ‹#›  Areas of ecophysiology The areas of focus on ecophysiology in Chapter 7: Thermobiology = 3 Water and ion balance Gas exchange Ecophysiology of Loading… animals or plants Acid-base balance Secondary metabolites ‹#›  Perfect zone Thermobiology Limited temperature range supports life On Earth, the extremes are found between the polar regions and the - tropics and hot springs - - Some lichens in Antarctica can photosynthesize at temperatures < 0°C Snowshoe hare can Some deep sea bacteria maintain 39°C body temp at temperatures of -40°C live at temperatures > 100 ° C ‹#›  100°C Metabolism Heterotrophic organisms need other organisms to fulfill energy and nutritional requirements Metabolism: the chemical processes within living organisms that maintain life Plants survive with only light, C02, H20, and mineral nutrients; animals require energy from plants ‹#›  Aerobic vs anaerobic metabolism Aerobic metabolism: oxygen is involved in converting carbohydrates, lipids, proteins to ATP in mitochondria - > muscles - move Anaerobic metabolism: lower efficiency production of ATP without oxygen Ex - -. intense exercise Measure metabolic rate as oxygen consumption (aerobic) or heat production (anaerobic) ‹#›  Ectothermy OUTSIDE um Ectotherms: organisms that rely on the external environment as the primary source of heat They have slower metabolic rates - I - They can survive long periods with little food Ectotherms in cool climates have cold- Ectotherms like frogs are adapted enzymes inactive during winter ‹#›  Ex. Humans Endothermy Endotherms: organisms that rely on their own metabolism for warmth They have faster metabolic rates, and can - remain active in cool - environments of layer Fat Retain heat by insulation air and circulatory system Use considerable energy Chipmunks eat almost constantly to maintain for thermoregulation body temperature keeping body at temperature ‹#›  Heterothermy and homeothermy Homeotherms: organisms that maintain constant body Ex Humans temperature. Heterotherms Loading… (poikilotherms): organisms that cannot maintain a steady body temperature ambient environment changing Heterotherms often bask to maintain body temperature ‹#›  Endothermy/homeothermy in insects & metabolism la maintain constant body temp rely on own for warmth Sphynx moths maintain a body temperature around 38-41°C due to high wingbeat frequency Sphynx moths can raise their thorax temperature within minutes, by muscle contraction cookinguodyp if distance engaging in long locomotion FIGURE ‹#› 7.10 Endo/ecto- and hetero/homeo- thermy Endothermy - Heterothermy Poikilothermy Homeothermy Ectothermy FIGURE ‹#› 7.3 Heat production Three quarters of metabolized energy is released as heat bringboyat z Some mammals have brown brown adipose add tissue (fat), whic which releases all Aenergy as heat without - producing ATP - brown at release Fatty tissue 100 % heat - none Converted to Ap Small mammals - winter metabolize brown adipose tissue to maintain body temperature ‹#›  Insulation Fat insulation middle of > - keep Whale at 3839 % Effective thermoregulation requires ability to conserve heat: insulation > - trap air molecules Hair and feathers work - by trapping stagnant air - Fat is also a good insulator (mostly in aquatic organisms) ‹#›  Heron sitting in frigid water Counter-current exchange heat is flowing in different direction than the blood is Counter-current exchange minimizes heat loss in extremities flowing body flowing warm Sits arterial next back blood to into Venus the blood from the body heat from the jump arteries veins to recycling into some heat energy veins heat s maintainenergy de the FIGURE body ‹#› 7.8 Responses to cold and heat Responses to cold: Rapid muscle contractions (shivering) produce heat vibrating - Vasoconstriction reduces heat loss arteries Small become > - flow body less O2 Muscles contract to fluff up feathers or fur when cold (e.g. goose bumps) Cold animals may shiver, vasoconstrict, erect feathers/fur for warmth ‹#›  Responses to cold and heat Responses to heat: Sweating and panting (evaporation cools) rapid more heat transfer Vasodilation, especially in large-area organs such as ears warmblood shedding got > - 02 Reduction of metabolic rate minimize energy expended Seeking shade Warm animals may sweat, pant, vasodilate, become less active, and seek shade ‹#›  Torpor, hibernation, estivation Torpor: relatively short- term condition of decreased activity Hibernation: long-term condition of decreased activity in cold temperatures Estivation: decreased activity in hot temperatures Bats reduce body burrow into ground - escape heat temperature during inactive times of day ‹#›  Hibernation In hibernating animals, heart rate - and breathing - slow down and body temperature - - lowers to near - freezing - FIGURE ‹#› 7.9 bear is still Sleep metabolizing body temp does not drop Bear physiology does not - like seen in hibernation change during the winter; they are not true - hibernators, and can be - awoken in winter - But bears also eat a lot in the fall to build up fat reserves comes our thinner all of that having brown used tissue in adipose order to keep at ideal temperature ‹#›  shut and down metabolism Antifreeze to physiological lowest level systems Freezethemselves matching the ambient temp of ground Antifreeze proteins: toplasm substances which reduce the freezing point Polar marine fish can live in waters