BIO 373 1st Edition Lecture 5 Outline of Last Lecture I. Biospherea. Case Study—American SerengetII. Terrestrial Biomesa. Tropical rainforestb. Hot desertsc. Temperate grasslandd. Temperate deciduouse. Boreal forestsf. TundraIII. Mountain biological zonesOutline of Current Lecture I. Freshwater Biological Zonesa. Lotic systemsb. Lentic systemsc. Human impactII. Marine Biological Zonesa. Intertidal regionsb. Coral reefc. Pelagic zoned. Human impactIII. Texas biomesIV. Temperature Variation and Water Availability a. Physiological ecologyCurrent LectureFreshwater Biological Zone- Lotic= movingo Rivers and streams- Lentic= stillo Lakes and other still bodies- Lotic Systemo Continuum concept large scale First order stream= close to beginning of water shedThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute. Second order= two first orders join Third order= two second orders join- Biological assemblage of vegetation and organisms can be categorized at each order o Physical locationsmall scale Main channel=larger fish Benthic zone= smaller organisms, decomposers Hyporheic zone= decomposers, vegetation- Lentic Systemo Determined by depth and degree of light penetration Litorial zone Main channel, benthic, hyporheic- Human impacto Sewage, industrial wasteo Fertilizer Can increase phytoplankton which causes less algae which causes a decrease in oxygen availability o Non-native species Introducing non-native species can alter the natural biome/disrupt flow of energyo Deforestationo Dams Can change a lotic system into a lentic system, altering the ecologyMarine Biological Zones- Determined by ocean depth, light availability, stability of bottom substrateo See slide for images of levels- Intertidal regiono Estuaries= junction between rivers and oceanso Tides= Earth, moon, and sun interaction movement of water into intertidal andcoastal regions Tidal fluctuations affect salinity- High tides increased salinity- Higher elevation increased salinityo Due to accumulation of sedimento Salt marshes= salt- tolerant vascular plants are adapted to salinity changes- Rocky intertidal regiono Stable substrate, changing condition Daily fluctuations in salinity, temperature, dryness (dessication) etc.o At low tides, you can see a variety of organisms and species- Sandy shoreo Substrate is not stable, little available food due to wave actiono Organisms typically are adapted to go underneath sand and filter feed- Coral reefo Animals and algae here interact Limitation/needs: Algae needs light availability to photosynthesize Animals need algae- Kelp forestso Brown algaeo Won’t find in sandy regionso Bottom dwellers are accustomed to less light- Human Impacto Over fishingo Terrestrial impact Agriculture (fertilizers) and pollution (CO2 carbonic acid)Texas Biomes- Defined by precipitation gradiento West is drier, easy gets more precipitationTemperature Variation and Water Availability- Physiological ecologyo Interaction between organisms and physical environments that influence their survival persistenceo Adaptation, growth of population, geographical range of species, responses to changes in climate, etc.- Tolerance and avoidance= responses to stresso Stress= lower than optimum physiological rate Affects survival, reproduction, and growth When variables are too low or too high, the rate of physiological processes is lowo Acclimation= short term behavioral or physiological response of an individual to stress, reversible Return to original processes when conditions reverto Adaptation= long term response of a population to an environmental stress Behavioral or morphological- Variance in Temperatureo Impacts metabolic function Proteins, enzymes, chemical reactionso Birds/mammals tolerate a very small range of internal temperatureo Bacteria also tolerate a small range but among different species can tolerate a wide variety of extremeso tolerance through biochemistry- stable/active enzymes at varying degree of temperatures- isozymes= similar enzymes that temporarily will be produced in order to function at a different temperature from normal- unsaturated lipids= increase production to keep membrane fluid, since unsaturated lipids do not pack as tightly as saturatedo avoidance through physiological, morphological, and behavioral responses- adjust by less interaction with external environmento ex: in plants change in heat is dependent upon solar radiation, infrared in and out, heat convection and conduction, and evapotranspiration plants can alter what goes in and