ecosystem in environment.pptx

ECOSYSTEMS AND BIOMES ecosystems Ecosystems An ecosystem is a self-sustaining association of living plants and animals and their non-living physical environment Key is interactions between the biotic and abiotic Ecology is the study the relationships between organisms and their environment, and amon...

ECOSYSTEMS AND BIOMES ecosystems Ecosystems An ecosystem is a self-sustaining association of living plants and animals and their non-living physical environment Key is interactions between the biotic and abiotic Ecology is the study the relationships between organisms and their environment, and among the various ecosystems in the biosphere Ecosystem components and cycles An ecosystem is a complex of many variables, all functioning independently yet in concert, with complicated flows of energy and matter Key is to understand the linkages and interconnections within and between systems “The effects of what you do in the world will always spread out like ripples in a pond” components Biotic and abiotic Energy Nearly all ecosystems depend on a direct input of solar energy growth, tissue replacement, movement, and reproduction. Solar energy chemical energy in food production mechanical energy in the form of physical activity A few limited ones exist in dark caves, wells or ocean floor depend on chemical reactions (chemosynthesis) Earth’s Structure Core, mantle, outer layer Outer layer (ecosphere) lithosphere, hydrosphere and atmosphere provide conditions for life on land and water The Atmosphere Atmosphere- gases surrounding the lithosphere and hydrosphere Troposphere- (17km from the surface of the earth) 99% of water vapour, up to 90% of the air, and responsible for our weather, Oxygen 21%, Nitrogen 78%, trace gases 1%, Stratosphere (from 17km to about 50km) main area for ozone Mesosphere (50km-85km) Thermosphere *The higher you go the lower the pressure and density of the Layers of Earth’s atmosphere ENERGY Definition- capacity to do work, measured in calories Types of energy- radiant energy, chemical energy, heat, mechanical energy, electrical energy, potential energy, and kinetic energy. Low-quality energy (dispersed at low temperature) vs. highquality energy (quick dispersal at high temperatures) Laws of Thermodynamics 1. Law of conservation of energy: energy cannot be created or destroyed; it is transformed from one form to another. 2. Law of Entropy: when an energy is transformed from one form into another, there is always a decrease in the quality of the usable energy. In any transformation, some energy is lost as lower quality, dispersed energy that is dissipated into the surrounding environment, often as heat. Inverse relationship between the quality of energy and entropy As energy disperses through transformation, entropy increases. budget Energy The law of entropy (balance of energy expense and replacement) is important for organisms for preservation. Example: Baleen whale Energy consumption, humans and environmental problems Energy cannot be recycled (as energy is transformed, more is dispersed into the atmosphere, becoming less useful, due to increase in entropy) ?? implications for advanced societies as energy consumers and sustainability Humanity contribution of energy into the atmosphere and to environmental problems Ecosystems as subsystems and energy flows Ecosystems are divided into subsystems Biotic subsystem- producers (plants), consumers (animals) and detritus feeders and decomposers (worms, mites, bacteria, fungi) Abiotic flows- gaseous, hydrologic, and mineral cycles Biotic and abiotic components of ecosystems Christopherson, Byrne and Giles, 2013 Food chains and food webs Chain of how is energy is passed down from producers (autotrophs) to consumers (heterotrophs) and then detritivores/decomposers. Producers-herbivores-carnivores-omnivoresdecomposers Trophic levels- primary, secondary and tertiary levels Marine food chain Carnivorous plants Pitcher plant web Food Simplified Great Lakes food web Energy efficiency Energy pyramid Individuals, Population, Community Convenient biotic subdivision within an ecosystem Community is formed by interactions among populations of living animals and plants at a particular time NB: An ecosystem is the interaction of many communities with the abiotic physical components of its environment Populations- a group individuals of the same species Individual species Communit y vs. ecosyste m Habitat and niche Two important concepts of community Habitat – where an organism resides or is biologically adapted to live Physical and natural factors, most species have specific habitat requirements with definite limits and a specific regimen of sustaining nutrients Niche- refers to the function, or occupation, of a life form within a given community. It is the way an organism obtains and sustains the physical, chemical and biological factors it needs to survive Niche facets: habitat niche, trophic (food) niche, reproductive niche Competition vs. interdependenc e Competitive exclusion principle Symbiosis- co-existence of two or more species in interdependence (mutualism vs. parasitism) Humans and earth systems-mutualism or parasitism; sustainable or unsustainable Acacia species distribution in Argentina Mutualism pitcher plant, bat and insect Plants: essential biotic component of the ecosystem critical biotic link between solar energy and the biosphere Land plants (and animals) became common about 430 million years ago Vascular plants developed conductive tissues and true roots for internal transports of fluids and nutrients About 270, 000 species of plants are known to exist, mostly vascular About 20 species of plants provide 90% of the world’s food 3 species (wheat, corn and rice provide 50% of food Photosynthesis and Respiration The chemical process by which plants combine energy from the sun, with carbon dioxide and water in plants to produce glucose and oxygen. Chlorophyll absorbs light energy for the process Respiration Respiration is opposite of photosynthesis Process where plants convert stored energy (carbohydrates) through oxidization to release carbon dioxide, water and heat energy Net photosynthesis vs. Net Primary productivity Net photosynthesis- difference between photosynthesis energy production and respiration energy loss (Energy budget of the biosphere) Net photosynthesis determines overall plant growth Limiting growth factors: light, water, temperature, soil quality, plant’s site, elevation, and competition from other plants and animals Net Primary Productivity- net photosynthesis for an entire plant community The amount of stored chemical energy that community generates for the ecosystem Measured as fixed carbon per square metre per year Biomass is the net dry weight of all this organic material and its stored chemical energy Terrestrial net primary productivity map Marine Net Primary Productivity Abiotic ecosystem components Light Temperature Water Climate ecosystems microclimate Biogeochemical Cycles Recycling of gases and sedimentary (nutrients) materials that are involved in chemical reactions necessary for growth and development of living organism Gaseous cycles (hydrogen, oxygen, carbon and nitrogen) Sedimentary cycles (mineral/solid elements e.g. phosphorus, calcium, potassium and sulphur) Oxygen Cycle Atmosphere as major reserve Earth’s crust- silicate (SiO2) and carbonate (CO3) Unoxidized in fossil fuel reserves and sediments Carbon Cycle Oceans primary reserve (About 42900 billion metric tons) In the form of CO2, CaCO3 etc. Atmosphere- 700 billion metric tons at any point Fossil fuels and oil shales 13200 metric tons as hydrocarbon molecules Living and dead organic matter 2500 billion metric tons CO2 absorption through Phytoplankton photosynthesis Excessive CO2 leads to acidification affecting plankton, corals & organisms CO2 enters the atmosphere by respiration of plants and animals, volcanic activity, and combustion of fossil fuel Carbon cycle Human contribution 400% carbon greater than 1950s level 8.2 billion tons in 2007, 1.47 billion tons 1950, 4.75 billion in 1980 About 50% of carbon from the Industrial Revolution is not absorbed by oceans and organisms Dead zones Global dead zones Great Lakes Eutrophication Lake Erie Ecozones and Biomes Ecozones- Similar ecosystems grouped together Biomes -groups of dominant plants and animals based on vegetation and adaptations 6 biomes globally recognized- marine. Freshwater, forest, grassland, desert and tundra Canada’s ecozones Canada biomes Global biomes