Biogeochemical Cycles (Chapter 5) PDF

MIDTERM TOPIC (CHAPTER 5) BIOGEOCHEMICAL CYCLE BioGeoChemical Cycles- refers to the overall chemical cycles through both the biological and geological world. Each chemical has its own unique cycle, but all of the cycles do have some things in common. COMPO...

MIDTERM TOPIC (CHAPTER 5) BIOGEOCHEMICAL CYCLE BioGeoChemical Cycles- refers to the overall chemical cycles through both the biological and geological world. Each chemical has its own unique cycle, but all of the cycles do have some things in common. COMPONENTS OF BIOGEOCHEMICAL CYCLES RESERVOIRS- are those parts of the cycle where the chemical is held in large quantities for long periods of time. (oceans, lakes, and other bodies of water). EXCHANGE POOLS- parts of the cycle where chemical is held for only a short time. (clouds, lungs) 4 DIFFERENT CYCLES IN BIOGEOCHEMICAL CYCLES WATER CYCLE CARBON-OXYGEN CYCLE NITROGEN CYCLE PHOSPHOROUS CYCLE WATER CYCLE-Also known as hydrologic cycle, it is the path water takes through its various states, - vapor, liquid, soil – as it moves throughout the ocean, atmosphere, groundwater, streams and etc. In the water cycle, energy is supplied by the sun, which drives evaporation PROCESSES IN THE WATER CYCLE ✓ Evaporation- Is the reverse process in which the liquid water becomes gaseous. It occurs when the physical state of water is changed from a liquid state to a gaseous state, with considerable amount of heat ✓ Transpiration-A Biological process that occurs mostly in the day. Water inside of plants is transferred from the plant to the atmosphere as water vapor through numerous individual leave openings. ✓ Condensation-Is a process by which water vapor changes its physical state from a vapor, most commonly to a liquid. It condenses onto small airborne particles to form dew, fog, or clouds.  ✓ Precipitation-Occurs when water condenses from gaseous state in the atmosphere and falls to earth. Any and all forms of particles fall from the atmosphere and reach the ground. CARBON-OXYGEN CYCLE-Is the movement of carbon, in its many forms, between biosphere, atmosphere, oceans and geosphere. PROCESSES IN THE CARBON-OXYGEN CYCLE ✓ RESPIRATION-Takes carbohydrates and oxygen and combines them to produce carbon dioxide, water, and energy (𝑂2 +Carbohydrates = 𝐶𝑂2 + 𝐻2 𝑂 + energy) ✓ PHOTOSYNTHESIS-Obtain carbon dioxide and water to produces oxygen. NITROGEN CYCLE- A process of converting nitrogen gas into nitrogen compounds through the atmosphere, soil and organisms. PROCESSES ON THE NITROGEN CYCLE ✓ NITROGEN FIXATION-ATMOSPHERE – A process by which nitrogen gas is fixed into nitrates with lightning. ✓ NITROGEN FIXATION-SOIL – Rhizobium bacteria have a symbiotic relationship with legumes to convert atmospheric nitrogen (N 2) to a plant-available form to convert into ammonia. ✓ NITRIFICATION- A biological conversion of ammonia to nitrate by a nitrifying bacterium. ✓ ASSIMILATION - the process by which plants and animals incorporate the NO3- and ammonia formed through nitrogen fixation and nitrification. ✓ AMMONIFICATION – The process of converting ammonia from dead animals, waste products and decaying materials ✓ DENITRIFICATION - the process in which the nitrogen compounds make their way back into the atmosphere by converting nitrate (NO3-) into gaseous nitrogen (N). This process of the nitrogen cycle is the final stage of the cycle. PHOSPHOROUS CYCLE- the simplest cycle in the BIOGEOCHEMICAL CYCLE, the cycle that describes the transformation and translocation of phosphorus in soil, water, and living and dead organic material. Has only one form which is phosphate. PROCESSES IN PHOSPHOROUS CYCLE ✓ WEATHERING - Phosphorus is found in the rocks in abundance. That is why the phosphorus cycle starts in the earth’s crust. The phosphate salts are broken down from the rocks. These salts are washed away into the ground where they mix in the soil. ✓ ABSORPTION BY PLANTS- The phosphate salts dissolved in water are absorbed by the plants. However, the amount of phosphorus present in the soil is very less. That is why some of the plants turns into yellow because of the lack of phosphorous. ✓ ABSORPTION BY ANIMALS- The animals absorb phosphorus from the plants or by consuming plant-eating animals in a food chain cycle ✓ RETURN OF PHOSPHORUS BACK TO THE ECOSYSTEM - When the plants and animals die they are decomposed by microorganisms During this process, the organic form of phosphorus is converted into the inorganic form, which is recycled to soil and water. ✓ Soil and water will end up in sediments and rocks, which will again release phosphorus by weathering. Thus, the phosphorus cycle starts over.