BIO 373 1st Edition Lecture 5 Outline of Last Lecture I Biosphere a Case Study American Serenget II Terrestrial Biomes a Tropical rainforest b Hot deserts c Temperate grassland d Temperate deciduous e Boreal forests f Tundra III Mountain biological zones Outline of Current Lecture I Freshwater Biological Zones a Lotic systems b Lentic systems c Human impact II Marine Biological Zones a Intertidal regions b Coral reef c Pelagic zone d Human impact III Texas biomes IV Temperature Variation and Water Availability a Physiological ecology Current Lecture Freshwater Biological Zone Lotic moving o Rivers and streams Lentic still o Lakes and other still bodies Lotic System o Continuum concept large scale First order stream close to beginning of water shed These 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 System o Determined by depth and degree of light penetration Litorial zone Main channel benthic hyporheic Human impact o Sewage industrial waste o 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 energy o Deforestation o Dams Can change a lotic system into a lentic system altering the ecology Marine Biological Zones Determined by ocean depth light availability stability of bottom substrate o See slide for images of levels Intertidal region o Estuaries junction between rivers and oceans o Tides Earth moon and sun interaction movement of water into intertidal and coastal regions Tidal fluctuations affect salinity High tides increased salinity Higher elevation increased salinity o Due to accumulation of sediment o Salt marshes salt tolerant vascular plants are adapted to salinity changes Rocky intertidal region o 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 shore o Substrate is not stable little available food due to wave action o Organisms typically are adapted to go underneath sand and filter feed Coral reef o Animals and algae here interact Limitation needs Algae needs light availability to photosynthesize Animals need algae Kelp forests o Brown algae o Won t find in sandy regions o Bottom dwellers are accustomed to less light Human Impact o Over fishing o Terrestrial impact Agriculture fertilizers and pollution CO2 carbonic acid Texas Biomes Defined by precipitation gradient o West is drier easy gets more precipitation Temperature Variation and Water Availability Physiological ecology o Interaction between organisms and physical environments that influence their survival persistence o Adaptation growth of population geographical range of species responses to changes in climate etc Tolerance and avoidance responses to stress o 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 low o Acclimation short term behavioral or physiological response of an individual to stress reversible Return to original processes when conditions revert o Adaptation long term response of a population to an environmental stress Behavioral or morphological Variance in Temperature o Impacts metabolic function Proteins enzymes chemical reactions o Birds mammals tolerate a very small range of internal temperature o Bacteria also tolerate a small range but among different species can tolerate a wide variety of extremes o 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 saturated o avoidance through physiological morphological and behavioral responses adjust by less interaction with external environment o 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 out