PrinciplesofEcology_2.pdf

Unit - 2 Principles of Ecology Principles of Ecology - Segments of the Environment - Atmosphere, Lithosphere, Hydrosphere, Biosphere - Ecosystem: Biotic and Abiotic Factors - Structure of the Ecosystem - Ecological Pyramids - Functions of Ecosystems - Productivity - Food Production - Energy Flow - Food Chain and Food Web - Nutrient Recycling - Biogeochemical Cycles - Water Cycle, C, N, P, S Cycles - Development and Stabilization - Community Associations - Community Adaptations - Ecological Succession Ecology - Ikos—dwelling; Logos—study Study of the inter-relationships among living beings and their interactions with the physical environment [ref]. Autoecology - study of an individual species including behavior, adaptation and interaction with environment[ref] Synecology - study of communities and their interactions with the environment[ref] The Physical and biological habitat surrounding us is the in Environment, it has a four segments[ref] Atmosphere: small reservoir, efficient transporter. Lithosphere: Earth’s Crust, rocks, minerals. Huge reservoir, less transport (conveyer), Pedosphere: soil Hydrosphere: oceans and water, huge reservoir and transporter Biosphere: small reservoir, moderate transporter; huge impact on the environment. Atmosphere http://view.ge/page/sience/15-atmosphere-of-earth?lang=english Exosphere: 500 – 1000 km up to 10,000 km, Thermosphere: from 80 – 85 km to 640+ km temperature increasing with height. Ionosphere: auroras, long distance radiowave propagation. Mesosphere: 50 km to 80 to 85 km temperature decreasing with height. Meteors burn up when entering the atmosphere. Stratosphere: 7 to 17 km range to about 50 km Temperature increases with height. Ozone—few ppm (Mainly 15 to 35 km) Troposphere: Surface to between 7 km at the poles and 17 km at equator. Weather variations , vertical mixing http://www.theozonehole.com/atmosphere.htm The Atmosphere (12.53min) Water Resources (11.38min) Inside the Earth (5.05min) Credit:MT Paul, Bozeman Science, The Atmosphere. Source https://youtu.be/6LkmD6B2nc Credit:MT Paul, Bozeman Science, Water Resources. Source https://youtu.be/IDAj5T1ST7o Credit:Mexus Education Pvt.Ltd, Inside the Earth. Source https://youtu.be/N9ncfAsmiSg Ecosystem Ecosystem is a functional unit consisting of living and non-living components[ref]. Abiotic factors[ref]: - Climatic: temperature, rainfall, snow, light levels, wind, humidity - Edaphic (Soil) Factors: pH, mineral and organic matter, texture Biotic Factors[ref]: - Producers (Autotrophs): green plants; chlorophyll - Consumers (Heterotrophs) pri., sec., ter. consumers - Decomposers (Saprotrophs): Bacteria, fungi Ecosystems: Biotic and Abiotic Factors (21.35min) Credit: Sam Holloway Knowles Science Teaching Foundation, Ecosystems: Biotic and Abiotic Factors. Source: https://youtu.be/NHetWkxhpAg Structure of the Ecosystem - Ecological Pyramids or Trophic Pyramids https://en.wikipedia.org/wiki/Food_web Types of Ecological Pyramids or Trophic Pyramids: Terrestrial Vs Aquatic Ecosystem http://scienceaid.co.uk/biology/ecology/food.html Variations in Ecological Pyramid https://en.wikipedia.org/wiki/Food_web Ecosystem Functions[ref], [ref] Productivity - Food Production Energy Flow - Food Chain, Food Web Nutrient recycling - Biogeochemical Cycles Development and Stabilization - Associations, Adaptations, Succession Productivity - Food Production https://upload.wikimedia.org/wikipedia/commons/a/a2/Phot https://en.wikipedia.org/wiki/Photosynthesis osynthesis_Block_diag.gif Energy Flow https://upload.wikimedia.org/wikipedia/commons/thu mb/3/3a/Ecological_Pyramid.svg/2000px- Ecological_Pyramid.svg.png https://encrypted- tbn1.gstatic.com/images?q=tbn:ANd9GcRzjOz_0Z0 hjtz- ioqM43GrS3M9qDzOnXmtwQPp0BA6TFDfDpFC7g https://encrypted- tbn1.gstatic.com/images?q=tbn:ANd9GcTsDoYoxXGLYH2SGytHwsD2fyUZEuA232wDRu4pn9AfnbGF-xRh8w Flow of Chemical and Pollutants through Food Chain http://iasmania.com/wp-content/uploads/2015/12/Bioacc-VS-Biomag1.png Detritus Food Chain Less dependent on direct sunlight Depends on influx of organic matter from another system Generally small E.g. Mangrove leaves (detritus)— microorganisms—crabs E.g. Caves: bat colonies—guano—organisms (salamanders) E.g. Ocean floor—dead carcasses—organisms feeding on it. https://en.wikipedia.org/wiki/Food_web Nutrient recycling - Biogeochemical Cycles http://1.bp.blogspot.com/-sSscHv8Kmtw/VUQHMBL1rSI/AAAAAAAAB18/YKOplqNSdTM/s1600/1A%2B- %2BBiogeochemical%2BCycle%2BComponents.jpg Biogeochemical Cycles Biogeochemical Cycling (22.23min) (10.04min) Jane Poynter: Life in Biosphere 2 (15.50min) Credit:Sam Holloway Knowles Science Teaching Foundation, Biogeochemical Cycles. Source https://youtu.be/dJazhP4cnR8 Credit:MT Paul, Bozeman Science, Biogeochemical Cycling. Source https://youtu.be/09_sWPxQymA Credit:TED, Jane Poynter: Life in Biosphere 2. Source https://youtu.be/a7B39MLVeIc Hydrological Cycle & Earth’s Albedo Evaporation—cloud formation Increased albedo or reflection coefficient is a measure of the ‘whiteness’ of the earth when viewed through space. Greater the albedo→lower is the solar radiation absorbed by the earth→lower is the temperature of the globe (Greater cooling). https://upload.wikimedia.org/wikipedia/commons/thumb/1/18/Albedo-e_hg.svg/549px-Albedo-e_hg.svg.png Albedo and Tree Cover Trees tend to have a low albedo ○ Deciduous trees: 0.15-0.18 (15-18%) ○ Coniferous trees 0.09-0.15 (9-15%) Hence, removing forests → increases albedo →localized climate cooling. However, trees also provide local evaporative cooling and carbon sequestration; loss of trees reduces these cooling effects. Cloud feedbacks and snow cover further complicate the issue. Studies of new forests indicate: ○ A net cooling effect in tropical and mid-latitude areas ○ A net neutral or slightly warming effect in high latitudes (e.g. Siberia) Betts, Richard A. (2000). "Offset of the potential carbon sink from boreal forestation by decreases in surface albedo". Nature 408 (6809): 187–190. doi:10.1038/35041545.PMID 11089969. Phytoplankton, Clouds, Albedo Phytoplankton produce dimethylsulfoniopropionate (DMSP) Converted to Dimethyl sulfide (DMS) in ocean Escapes to atmosphere, oxidizes to SO2 and nucleates clouds. This is an example of how the biosphere (plankton) regulates the hydosphere (global precipitation), earth’s albedo and global temperature. CLAW Hypothesis: negative feedback; regulation of global temperature. Anti-CLAW Hypothesis: positive feedback; escalation of global warming. warm oceans→more phytoplankton → more DMS → More clouds → cooling (negative feedback; regulation) https://upload.wikimedia.org/wikipedia/en/thumb/f/f5/CLAW_hypothesis_graphic_1_AYool.png/598px- CLAW_hypothesis_graphic_1_AYool.png warm oceans → stalling of thermohaline ocean currents→ocean stratification → less nutrients from ocean bottom in euphotic zone → less phytoplankton → less DMS → less clouds → more heating (positive feedback; escalation) https://upload.wikimedia.org/wikipedia/en/c/cc/CLAW_hypothesis_graphic_2_AYool.png Global Conveyer Belt https://upload.wikimedia.org/wikipedia/commons/4/4c/Thermohaline_Circulation_2.png Plants: Significance in Water Cycle Taproots go upto 100x deeper than canopy Short-circuit pathways for soil water redistribution In dry spells, water from below brought to surface, to increase nutrient extraction, photosysnthesis and transpiration. In wet spells, promote percolation Plants: Significance in Water Cycle Plants pump huge quantities of water from soil to air. ○ 100s to 1000s L/day ○ Regulate T and humidity. In a clearing in Nigeria, soil T upto 5°C higher; humidity reduced by 50% compared to adjacent forest. Evapo-transpiration of trees—nature’s pump and cooler Drop in Amazon’s temperature in June/July is due to transpiration. Transpiration: 40% of Amazonian rain is from transpiration Afforestation efforts: appropriate types and density. /http://www.i-sis.org.uk/LOG4.php Importance of Rainforests 25% of rain never reaches the ground.; wets canopy and evaporates 25% of total—runoff 50% of total pumped up and transpired by plants. 75% of rainwater is returned to the atmosphere; new clouds, new rain, Colossal heat pump—energy of six million atom bombs/day; redistributes energy to higher latitudes Up to 80% incident solar energy carried by hot, humid air; ○ rises rapidly and develops into thunder clouds that simultaneously ○ ater areas further downwind ○ releases latent heat Importance of Rainforests Absorb 2 billion tonnes of CO2/yr; about 20-30% of fossil C emissions Destruction of the Amazon: ○ May stall the heat pump ○ Accelerate drought and desertification (positive feedback) ○ Loss of CO2 sink; accelerate global warming. ○ Reforestation cannot replace natural stands. Loss of soil carbon. Sources: Prof. Eneas Salati from the University of São Paulo, Piracicaba – Brasil http://www.fgaia.org.br/texts/e- rainforests.html http://www.hydrogen.co.uk/h2_now/journal/articles/1_global_warming.htm http://www.hydrogen.co.uk/h2_now/journal/articles/2_global_warming.htm http://www.greendiary.com/entry/increasing-global-warming-decreases-forests-co2-absorption-capacity http://www.i-sis.org.uk/LOG4.php Availability of Carbon Earth’s C content = 0.19% (0.032% in lithosphere) Atmospheric CO2 is the main utilizable reservoir 18% in biomass Main reservoirs air, rocks (carbonates), oceans. http://image.slidesharecdn.com/biogeochemicalcycles-120914165417-phpapp01/95/biogeochemical-cycles-6- 728.jpg?cb=1347641775 Potential contributors to climate change Complex interactions in the climate puzzle Feedback mechanisms Some interesting twists ○ Increasing temp. reduces CO2 solubility (reduced C-sink capacity of the ocean) ○ Ocean Acidification reduces C-sequestration in the form of CaCO3 ○ 740ppm CO2 in water by 2100. Reduction in population of mussels by 25% and oysters by 10% ○ At 1800ppm, shells will dissolve Human Impacts on Carbon Cycle Burning of Fossil fuels Deforestation and Poor Agricultural practices Increase in atmospheric greenhouse gasses such as CO2, methane, SOX, NOX, etc. leads to Greenhouse effect, global warming and climate change. Nitrogen Reservoir N is an essential component of proteins, nucleic acids and other cellular constituents. Reservoirs – 79% of the atmosphere is N2 gas. The N=N triple bond is relatively difficult to break, requires special conditions. As a result most ecosystems are N-limited. N2 dissolves in water, cycles through air, water and living tissue. Nitrogen Fixation Abiotic: lightning (very high T and P) 107 metric tons yr-1 ~ 5-8% of total annual N fixation. (weathering of rocks is insignificant) Biotic: Nitrogen fixation by microbes, 1.75 x108 metric tons yr-1 (symbiotic bacteria: azobacter or rhizobium- legumes Industrial: The Haber-Bosch process (1909) 5x107 metric tons yr-1 – high P & T, Fe catalyst to convert N2 to NH3;& NH4NO3 Combustion Side Effect: 2x107 metric tons yr-1. High T and P oxidizes N2 to NOx Nitrification-Denitrification Nitrification by chemoautotrophs ○Bacteria of the genus Nitrosomonas oxidize NH3 to NO2 - ○Bacteria of the genus Nitrobacter oxidize the nitrites to NO3 - - Denitrication Anaerobic respiration of NO3 to dinitrogen gas by several species of Pseudomonas, Alkaligenes, and Bacillus Human Impacts on Nitrogen Cycle Burning of Fossil fuels add Nitrogen Oxides (NO2) and Nitric Acid vapor (HNO3). Nitrous Oxide (N2O) released by the action of anaerobic bacteria on Livestock waste. Nitrogen stored in Soil and Plants released by destruction of forestlands, grassland and wetlands. Upset the nitrogen cycle in aquatic ecosystem by adding excess of nitrates to the body Harvest nitrogen-rich crops, irrigate crops, wash out nitrogen from topsoils Fate of N Sources of anthropogenic N loads: Fertilizers, Legume Crops, Combustion and forest burning, livestock. In most terrestrial and freshwater ecosystems N is a limiting nutrient, gets cycled efficiently. What happens when plants have enough N (i.e. greater 16:1 N:P ratio)? When N saturation of ecosystem occurs, excess N tends to leave the system in the form of nitrate. Flushing/erosion – dissolved and particulate matter in streamwater, (DIN, DON, TN, Org N) - Leaching to groundwater – NO3 poor sorption to clays, highly water soluble. Effects of Increased N loading Since 1940s amount of N available for uptake has more than doubled. Anthropogenic N inputs are now equal to biological fixation. Eutrophication in aquatic systems, coastal algal blooms and “Dead Zone”, fish kills, increased turbidity, Selective pressures in terrestrial systems favoring species-poor grasslands and forests Nitrate MCL – 10 mg/L … Nitric oxide – precursor of acid rain and smog Nitrous oxide – long lived greenhouse gas that can trap 200 times as much heat as CO2 Phosphorus Cycle Ref One of the longest cycles Essential nutrient; DNA, ATP, ADP, fat, cell membranes Human Impacts on Phosphorus Cycle P-containing detergents Mining phosphate rock P-containing fertilizer use P in water leads to eutrophication Sulphur Cycle Human Impacts on Sulfur Cycle SO2 from industry and combustion (e.g. coal, petrol). SO2 from Refine industry convert the Petroleum to Gasoline Products SO2 from Metallic ore Industries. SO2 from Mining industries - Acid mine drainage Group Work 1 - Discuss human influence on Biogeochemical Cycles and Impacts to our Environment Group Work 2 - How do we maintain the Biogeochemical Cycles to balance our ecosystem Gaia Theory By James Lovelock; Greek Earth Goddess Earth with all intricate and interacting systems is like a Super-Organism Gaia Hypothesis - James Lovelock (28.46mm) Credit:Naked Science. Source https://youtu.be/GIFRg2skuDI Self regulation: chemistry of oceans, atmosphere, temperature, living beings Earth behaves as if it had a purpose Purpose is to nurture life and maintain life-friendly conditions. This perspective brings a new awareness that can be the foundation of all future development It will enable the further evolution of mankind Development and Stabilization Associations Succession Populations (11.12mm) Biology 2-01 Ecological Succession (21.05mm) Animal and plant Adaptation adaptations (4.00mm) Credit:Bozeman Science Source https://youtu.be/KFViSog6ZJw Credit:Holloway Science Source https://youtu.be/WyqCQq6SZKQ Credit:MsBrewerFlipped Source https://youtu.be/5WECs5-jNlc Interaction In Ecosystem Interaction In Ecosystem YouTube URL: http://www.youtube.com/watch?v=XJ6VtduDSyY Earth's Atmosphere Learn About Planet Earth - Earth's Atmosphere YouTube URL: http://www.youtube.com/watch?v=fyfN9t_E0w8 Layers of the Atmosphere-Temperature, Pressure Reference Table Page 14-Layers of the Atmosphere-Hommocks Earth Science Department YouTube URL: http://www.youtube.com/watch?v=jV8u7ki5LUk The Water Cycle The Water Cycle YouTube URL: http://www.youtube.com/watch?v=al-do-HGuIk NASA | Earth's Water Cycle NASA | Earth's Water Cycle YouTube URL: http://www.youtube.com/watch?v=oaDkph9yQBs The Gulf Stream Explained The Gulf Stream Explained YouTube URL: http://www.youtube.com/watch?v=UuGrBhK2c7U Carbon Cycle in Nature Carbon Cycle in Nature YouTube URL: http://www.youtube.com/watch?v=4vOPD9lH-MQ The Carbon Cycle The Carbon Cycle YouTube URL: http://www.youtube.com/watch?v=nzImo8kSXiU NITROGEN CYCLE NITROGEN CYCLE YouTube URL: http://www.youtube.com/watch?v=LbBgPekjiyc Phosphorus Cycle Phosphorus Cycle YouTube URL: http://www.youtube.com/watch?v=_IBx0zpNoEM Eutrophication Video Eutrophication Video YouTube URL: http://www.youtube.com/watch?v=IsXtsR1llk0 Sulfur Cycle Sulfur Cycle YouTube URL: http://www.youtube.com/watch?v=CeH-f-cmCkc Oxygen Cycle Oxygen Cycle YouTube URL: http://www.youtube.com/watch?v=mUVX5rg1E0I Ecological pyramids YouTube URL: http://www.youtube.com/watch?v=NJplkrliUEg Components of the Ecosystem YouTube URL: http://www.youtube.com/watch?v=MWPj2IkeklI Natural Ecosystems Of The World YouTube URL: http://www.youtube.com/watch?v=q8njvpw_y0k Biodiversity How Wolves Change Rivers YouTube URL: http://www.youtube.com/watch?v=ysa5OBhXz-Q

PrinciplesofEcology_2.pdf

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