A5 Balance of Matter and Energy Exchange PDF

A5 - Balance of Matter and Energy Exchange I can… Explain the interrelationship of energy & matter in maintaining homeostasis, and how human activity impacts this balance in different ecosystems Balance of Matter and Energy Exchange The biosphere is constantly exchanging energy wit...

A5 - Balance of Matter and Energy Exchange I can… Explain the interrelationship of energy & matter in maintaining homeostasis, and how human activity impacts this balance in different ecosystems Balance of Matter and Energy Exchange The biosphere is constantly exchanging energy with its surroundings - receiving energy input from sun and giving off energy output in form of radiant energy (heat) Sustainability is achieved when each of these aspects are balanced, or in a state of homeostasis Balance in Biosphere Inside our bodies, we maintain homeostasis (state of balance) ○ Also called equilibrium In 1979, James Lovelock proposed the Gaia Hypothesis (homeostasis on a global level) ○ His hypothesis suggests that Earth is self-regulating - can maintain its environment within certain limits ○ All living things on Earth (biosphere) function as one superorganism that can James Lovelock self-regulate Gaia Hypothesis and Living Things It is a controversial perspective in the scientific community, but emphasizes how all living things are interconnected Each part must be in a state of balance or equilibrium with every other component. Gaia Hypothesis and Living Things Life itself plays a large role in maintaining conditions of the biosphere that allow organisms to survive ○ The composition of our atmosphere, for instance would be very different if living organisms had not modified it through cellular respiration and photosynthesis Larger composition of our atmosphere would be made up of CO2 with little to no O2 Gaia Hypothesis and Living Things In the past, the atmosphere lacked O2 ○ Bacteria were able to grow and formed thick mounds in lagoons and lakes ○ As they died, their cells piled up, trapping and precipitating sediments - eventually formed sedimentary rock (also called stromatolites) Early stromatolite layers show that there was large amounts of O 2 trapped in iron oxides Later layers indicate that this O2 was no longer being trapped ○ Had moved out of oceans and into atmosphere Replicating Earth’s Biosphere Scientists have tried to replicate the biosphere on a smaller scale However, these experiments were not very successful - our biosphere is extremely complex Biosphere 2. A research facility designed to be a closed system for 100 years, Future Projects NASA programs such as ALS (Advanced Life Support) are being studied to see how plants may be grown in a space colony for food and oxygen gas Such programs also look for ways to recover useable material from waste Future Projects Haughton-Mars Project ○ In the Canadian Arctic, NASA sponsors a research station that is intended to stimulate the conditions of Mars’ surface ○ Purpose of this was to study what factors need to be in place for sustainable manned missions to other planets Haughton-Mars Project Human Interference Humans have significant ability to change surroundings Sometimes, these changes cause disruption in flow of matter and energy - which interrupts delicate natural balance of ecosystems Much work is being done into looking for ways to reduce environmental impact Examples of Human Interference Dead zones: Regions or lakes in which aquatic life has suffocated due to algal blooms ○ Approximately 150 dead zones in oceans Algal blooms occur seasonally due to turnover of nutrient rich waters in warmer temperatures Nutrient rich sediments have caused an algal bloom in Lake Erie. This has created a dead zone in the lake. Examples of Human Interference Various types of pollution contribute to algal bloom, such as: ○ Nutrients in soil being exposed by deforestation and being washed into rivers by rain ○ Sewage carrying significant amounts of phosphate (PO43-) and nitrate (NO3-) promote algae growth ○ Surface run-off and snowmelt carry manure from livestock operations ○ Run-off from fertilized agricultural fields and lakes Preserving Natural Balance Development of alternative energy sources is one possible method of reducing impact we have on our planet ○ Ex. Wind turbines May need to reconsider how we use land and resources to prevent damage to the ecosystems Transfer of matter and energy through biosphere is closely linked Wind energy ○ Ex. Tap water in Whitecourt may contain water molecules that were once transpired by a tree in a tropical rainforest