Principles of Ecology PDF

Unit - 2 Principles of Ecology  Principles of Ecology - Segments of the Environment - Atmosphere, Lithosphere, Hydrosphere, Biosphere - Ecosystem: Biotic and Abiotic Factors - Organization of the Ecosystem - Types of Ecosystems - Structure of the Ecosystem - Ecologic...

Unit - 2 Principles of Ecology  Principles of Ecology - Segments of the Environment - Atmosphere, Lithosphere, Hydrosphere, Biosphere - Ecosystem: Biotic and Abiotic Factors - Organization of the Ecosystem - Types of Ecosystems - 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 - Ecosystems Services - Economical values of Ecosystem Services - Threats to Ecosystems - Ecosystems Conservation 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 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://www.youtube.com/watch?v=NHetWkxhpAg Organization of the Ecosystem ref Individual, Species, Organism: An individual living thing, genetically similar enough to breed and produce live, fertile offspring in nature ref Population: All members of a individual that live in the same area at the same time ref Biological Community: All populations living and interacting in an area ref Ecosystem: A biological community and its physical environment ref Biome: is a set of ecosystems sharing similar characteristics with their abiotic factors adapted to their environments ref Biosphere: A biosphere is the sum of all the ecosystems established on planet Earth. It is the living (and decaying) component of the earth system ref Types of Ecosystems ref Natural, Artificial Aquatic Ecosystem: An ecosystem which exists in a body of water is known as an aquatic ecosystem. Majorly two types, Freshwater ecosystems and Marine ecosystems ref Terrestrial Ecosystem: The ecosystem which is found only on landforms is known as the terrestrial ecosystem. The main types of terrestrial ecosystems are forest ecosystems, desert ecosystems, grassland ecosystems and mountain ecosystems. ref 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  [ref], [ref] Ecosystem Functions 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:AN d9GcRzjOz_0Z0hjtz-ioqM43GrS3M9qDzOnXmtwQP p0BA6TFDfDpFC7g https://encrypted-tbn1.gstatic.com/images?q=tbn:ANd9GcTsDoYoxXGLYH2SGytHwsD2fyUZEuA232wDRu4pn 9AfnbGF-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-%2BBiog eochemical%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 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 hydrosphere (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. Mild warming due to CO2 emissions → warmer 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_hypo thesis_graphic_1_AYool.png Global Conveyer Belt https://upload.wikimedia.org/wikipedia/commons/4/4c/Thermohaline_Circulation_2.pn g Video: The Gulf Stream Explained (5 min) Excessive warming due to massive CO2 emissions → melting of ice caps → Meltwater pouring into the oceans → stalling of thermohaline ocean currents → ocean stratification → less transport of nutrients from ocean bottom to 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 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 CO is the main utilizable 2 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 CO solubility (reduced C-sink 2 capacity of the ocean) ○ Ocean Acidification reduces C-sequestration in the form of CaCO 3 ○ 740ppm CO in water by 2100. Reduction in population of 2 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 CO , methane, SO , NO , etc. leads to 2 X X 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 N 2 gas. The N=N triple bond is relatively difficult to break, requires special conditions. As a result most ecosystems are N-limited. N dissolves in water, cycles through air, water 2 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 - NH to NO 3 2 ○ Bacteria of the genus Nitrobacter oxidize the - nitrites to NO 3 - Denitrication Anaerobic respiration of NO to 3 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 (N O) released by the action of 2 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 – NO poor sorption to 3 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 Eutrophication (1.54mm) Credit:Fuse School - Global Education Source https://youtu.be/6LAT1gLMPu4  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 CO 2 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 SO from industry and combustion (e.g. coal, 2 petrol). SO2 from Refine industry convert the Petroleum to Gasoline Products SO2 from Metallic ore Industries. SO2 from Mining industries - Acid mine drainage Gaia Theory By James Lovelock; Greek Earth Goddess Earth with all intricate and interacting systems is like a Super-Organism Gaia Hypothesis - James Lovelock (4.29mm) 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 Ecosystem Services ref Ecosystem ‘services’ are provided free-of-charge as a gift of nature. purification of air and water regulation of rainwater run-off and drought waste assimilation and detoxification soil formation and maintenance control of pests and disease plant pollination, seed dispersal and nutrient cycling  maintaining biodiversity for agriculture, pharmaceutical research and development and other industrial processes protection from harmful ultraviolet radiation climate stabilization (for example, though carbon sequestration) moderating extremes of temperature, wind, and waves. Major Ecosystem Types and Services ref Source: https://www.cbd.int/doc/case-studies/inc/cs-inc-iucn-nc-wb-en.pdf Economic Value of Ecosystem Services ref Economists typically classify ecosystem goods and services according to how they are used Source: https://www.cbd.int/doc/case-studies/inc/cs-inc-iucn-nc-wb-en.pdf Direct use values: Consumptive uses ref harvesting of food products timber for fuel or construction medicinal products hunting of animals for consumption non-consumptive uses ref enjoyment of recreational and cultural activities that do not require harvesting of products Indirect use values ref: from ecosystem services Natural water filtration - which often benefits people far downstream Storm protection - function of mangrove forests which benefits coastal properties and infrastructure Carbon sequestration which benefits the entire global community by abating climate change. Option values: preserving the option to use in the future ecosystem goods and services (provisioning, regulating, and cultural services ) that may not be used at present ref. Non-use values: refer to the enjoyment people may experience simply by knowing that a resource exists This kind of value is usually known as existence value (or, sometimes, passive use value) ref. Benefits from forests in Mediterranean countries Source: https://www.cbd.int/doc/case-studies/inc/cs-inc-iucn-nc-wb-en.pdf Human System vs Ecosystem Anthroposystem Ecosystem Very simple ecosystem; Often highly complex max. 3 trophic levels food webs Open system; minimal Often closed systems recycling with significant recycling High efficiency of transfer of Low efficiency of transfer biomass to higher trophic of biomass to higher level trophic level Monoculture; high density High biodiversity Few favored species Natural balance in encouraged; weeds species populations destroyed achieved adapted to Static, highly unstable conditions Few people feed the Robust, stable, dynamic, rest-agriculture adaptable, evolving Problems with Human Systems Dependent on very few species ○ 80% of world food from 15 species. ○ Human consume only 150 out of the estimated 50,000 edibles. ○ Out of 10,000 cereals, not one new has been cultivated in the past 2000 yrs. Inherently unstable ○ Irish Great potato famine (1845-47) wind-borne potato blight fungus; near total crop failure ○ 1 million dead due to starvation, typhoid and cholera Require constant inputs; pesticides, fertilizers, etc. Prone to pest attacks and failures Pollute soil, air, water Soil degradation and topsoil loss Threats to Ecosystems Ecosystems Conservation ref ref Habitat Destruction Establishment of protected areas Pollution Rules that prohibit farming Eutrophication on sloping land or the use of pesticides Invasive species Adopt more Overharvesting environmentally friendly land uses UV Radiation Discouraging them from adopting more harmful Thank You Extra Slides 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