Introduction to Ecology: Ecosystems Components PDF

Introduction to Ecology Ecosystems: Components “All things come from earth, and to earth they all return”—Menander SCIENTIFIC METHOD Hypothetico – deductive method Steps: Observation – direct or indirect Definition of the Problem – should be within the domain of science; usually no...

Introduction to Ecology Ecosystems: Components “All things come from earth, and to earth they all return”—Menander SCIENTIFIC METHOD Hypothetico – deductive method Steps: Observation – direct or indirect Definition of the Problem – should be within the domain of science; usually not a “Why?” question Formulation of Hypothesis – temporary working explanation for the problem Experimentation/Data gathering – a “series” of experiments Formulation of Theory (not speculation as used in ordinary English) BRANCHES OF SCIENCE  Ecology and the levels of organization of matter Ecology—Greek oikos meaning home Study of how organisms interact with one another and their non-living environment (biotic and abiotic components) Studies connections in nature on the thin life supporting membrane of air, water, and soil Levels of Organization of Matter Subatomic particles to universe Subatomic particles Atoms Molecules Protoplasm Cells Tissues Organs Organ Systems Organisms Population Community Ecosystem Biosphere Planet (Earth) Solar System Galaxy Universe Ecosystem Organization Biosphere Organisms Made of cells Eukaryotic vs Prokaryotic Ecosystems Species Groups of organisms that resemble one another in appearance, behavior, and genetic make up Sexual vs Asexual reproduction Communities Production of viable offspring in nature 1.5 million named; 10-14 million likely Populations Genetic diversity Populations Communities Ecosystems Organisms Biosphere Fig. 4.2, p. 66  Subdivisions of Ecology 1. Autecology- study of individual organism, it’s life histories & behavior to adapt to environment 2. Synecology- study of groups of organisms that are associated together as a unit  Fields of Ecology 1. Population Ecology- deals with population growth and fluctuations 2. Chemical Ecology- concern on the use of chemicals in animal recognition, trail making, courtship and defense 3. Physiological Ecology- responses of individual organisms to temperature, moisture, light and other environmental conditions 4. Evolutionary Ecology- natural selection & evolution of population 5. Behavioral Ecology- concern on the role of imprinting and instinct in the social life of animals  Scientists Who Made Contributions in Ecology Theophrastus (300BC)- wrote about the relations between organisms and the environment; father of Botany Ernst Haeckel- Father of Ecology, he coined the word Ecology from greek word “oikos” during 1869 Thomas Malthus (1766-1834)- he pioneered on the study about populations Charles Darwin (1809-1882)- authored on the theory about “Natural Selection”  Laws of Ecology 1. Law: Nature knows best Principle: Balance of nature 2. Law: All forms of life are important Principle: Diversity and Stability 3. Everything changes Principle: Change 4. Law: Everything is connected to everything else Principle: Interdependence  Laws of Ecology 5. Law: Everything goes someplace, somewhere Principle: Pollution and Accumulation 6. Law: Our’s a finite resources Principle: Finiteness of resources 7. Law: There is no such thing as free lunch Principle: Energy 8. Law: Nature is beautiful and we are the stewards of God’s creation. Principle: Stewardship  Major Ecosystem Components Abiotic Components Biotic Components temperature, water Producers, consumers, & moisture, light, decomposers soil, wind or air, Plants, animals, precipitation, salinity, bacteria/fungi time Biotic interactions with Sets tolerance limits biotic components for populations and include predation, communities competition, symbiosis, Some are limiting parasitism, factors that structure commensalism etc. the abundance of populations  Biotic Components of Ecosystems Producers=autotroph Source of all food Photosynthesis Abiotic chemicals (carbon dioxide, Heat Heat Solar oxygen, nitrogen, energy Consumers=heterotroph minerals) Aerobic respiration Heat Anaerobic respiration Methane, H2S Decomposers (bacteria, fungus) Producers (plants) Decomposers Matter recyclers… Consumers Release organic compounds Heat (herbivores, Heat into soil and water where they carnivores) can be used by producers  Producers: the first trophic level Autotrophs (“self-feeders”) = organisms that capture solar energy for photosynthesis to produce sugars Green Plants Cyanobacteria Algae Chemosynthetic bacteria use the geothermal energy in hot springs or deep-sea vents to produce their food Photosynthesis: Function of Producers 1. Light Reaction- use light, produced ATP & NADPH, release of Oxygen gas; happens in grana 2. Dark Reactions (Calvin Cycle- use ATP and NADPH plus the presence of CO2 to produce sugar; happens in stroma  Overall Reaction 6CO2 + 12 H2O + light energy → C6H12O6 + 6O2+ 6H2O Carbohydrate made is glucose Water appears on both sides because 12 H2O molecules are required and 6 new H2O molecules are made Water is split as a source of electrons from hydrogen atoms releasing O2 as a byproduct Electrons increase potential energy when moved from water to sugar therefore energy is required Consumers: organisms that consume producers Primary consumers = second trophic level Organisms that consume producers Herbivores consume plants Deer, grasshoppers Secondary consumers = third trophic level Organisms that prey on primary consumers Carnivores consume meat Wolves, rodents Consumers occur at even higher trophic levels Tertiary Consumers = fourth trophic level Predators at the highest trophic level Consume secondary consumers Are also carnivores Hawks, owls Omnivores = consumers that eat both plants and animals Cellular Respiration Overview Transformation of chemical energy (organic compound) in food into chemical energy cells can use: ATP These reactions proceed the same way in plants and animals. Process is called cellular respiration (1.glycolysis(cytoplasm); 2. Kreb Cycle & 3. Electron Transport (mitochondria)) Overall Reaction: C6H12O6 + 6O2 → 6CO2 + 6H2O  Detritivores and Decomposers Organisms that consume nonliving organic matter Enrich soils and/or recycle nutrients found in dead organisms Detritivores = scavenge waste products or dead bodies Millipedes Decomposers = break down leaf litter and other non-living material Fungi, bacteria Enhance topsoil and recycle nutrients  Detritivores vs Decomposers Detritus feeders Decomposers Bark beetle Carpenter Termite and engraving ant carpenter galleries ant Long-horned work beetle holes Dry rot fungus Wood Mushroo reduced m to powder Powder broken down by decomposers Time progression into plant nutrients in soil Fig. 4.15, p. 75  Abiotic Components 1. Temperature - affects living things in 2 ways: (1) affects internal processes (2) affects behavior of an organism in ecosystem - Living things function within temperature range of 0-50 degrees Celcius - Minimum temp.- lower limit of temp. in which organisms can still function - Maximum temperature- highest limit of temp. in which organisms can still function - Optimum temperature- the temp. in which organisms functions best http://www.nrel.colostate.edu/projects/century/CENTURY%20Parameterization%20Workbook.pdf )  Abiotic Components Temperature and Animals: In terms of the ability of animals to maintain their body temperature, they can be divided into: 1. Homeotherm- “warm-blooded”- maintain constant body temp. ex. birds & mammals 2. Poikilotherm- “cold-blooded”- they control their body temperature by external means; exs. fishes, amphibians & reptiles 3. Heterotherms- can be a homeotherm or a poikilotherm depending on environmental conditions; exs. bees, humming birds & bats  Abiotic Components Temperature and Plants: In Cold areas: - Plants survive by means of insulation - Possess hairs or thick barks Frostbite- happens when ice crystals are formed in between cells Physiological drought- at very low temp. roots of plants become less permeable for water In High Temp. Areas: (suffer from dehydration) - Plants are impregnated with cuticle - Cactus no longer grow leaves  Abiotic Components 2. Water Plants and animals must maintain a favorable water balance. Plant Adaptation to Water Condition: 1. Xerophytes- plants growing in arid condition; possess succulent tissue 2. Hydrophytes- may be found submerge or floating in water; with air spaces in its body to float in water 3. Halophytes- plants present in marine water; have a succulent body  Abiotic Components Water Balance in Animals: Water intake- drinking water, water in food and metabolic water Water loss- urine, feces, perspiration Adaptation in Arid Condition: - Animals become nocturnal - Tolerate dehydration and elevated temp., like the camels (can survive 8 days without water, tolerate water loss of 25% to 40%)  Abiotic Components 3. Light - main source of energy in all ecosystem - important during photosynthesis - for the formation of Vit. D in animals - 2 Ecological Characteristics of Light: 1. Shade Tolerance- ability of plants to survive & grow in shade 2. Photoperiodism- reactions of living organisms to changes in day length - Ozone- protects the earth from too much solar radiation - Ozone Depletion- it is depleted by CFC’s & NO  Abiotic Components 4. Soil - formed by mechanical or chemical weathering of rocks plus addition of humus - Soil Properties: 1. Soil texture Clay- fine particles Sand- coarse particles Silt- medium sized particles Loam- mixture of clay, sand and silt  Abiotic Components 2. Soil Moisture- water content of the soil, affected by: - texture - amount of rainfall - slope of the land - underlying rock types 3. Soil Acidity- large amount of lime makes the soil basic while large amount of granite makes it acidic  Abiotic Components 4. Soil Structure- proper arrangement of soil particles; build up of larger soil structure called peds which allows good drainage of water & gases  Abiotic Components 5. Soil Color- iron is responsible for its reddish or brownish color; gray color lacks iron 6. Soil Profile Horizon O Horizon A Horizon B Horizon C Horizon R  Abiotic Components 5. Wind or Air - It is an agent pollination and seed dispersal - Transpiration in plants proceeds faster because of wind - Evaporation in animals proceeds faster in the presence of wind - Very strong winds results to destruction of nature  Abiotic Components 6. Time - an ecosystem does not only exist in space but also in time - the following processes are affected by time: 1. food hunting and gathering- starving predator subjected to reduction in searching time for prey will lead to catastrophic results 2. reproduction & finding mate- organisms whose reproductive cycle is short needs to find a mate the fastest possible time 3. locomotion- the speed of motion of an organism determines the distance it can travel in a unit time Limiting Factors on Land & in H2O Terrestrial Aquatic/Marine Sunlight Light penetration Temperature Water clarity Precipitation Water currents Soil nutrients Dissolved nutrient Fire frequency concentrations Esp. N, P, Fe Wind Dissolved Oxygen Latitude concentration Altitude Salinity