{"id":808,"date":"2025-11-26T02:18:03","date_gmt":"2025-11-26T02:18:03","guid":{"rendered":"https:\/\/fourcornerseducation.net\/ESS2026\/?page_id=808"},"modified":"2025-11-26T02:18:04","modified_gmt":"2025-11-26T02:18:04","slug":"biogeochemical-cycles-core","status":"publish","type":"page","link":"https:\/\/fourcornerseducation.net\/ESS2026\/biogeochemical-cycles-core\/","title":{"rendered":"Biogeochemical cycles (Core)"},"content":{"rendered":"\n<p>The Ecosystem<\/p>\n\n\n\n<p><strong>The biogeochemical cycles.<\/strong><\/p>\n\n\n\n<p>Transfer of matter through the ecosystem is quite different that of energy.<\/p>\n\n\n\n<p>Energy travels from the sun, through food webs and is eventual lost to space as heat.<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Matter is recycled and reused. <\/li>\n\n\n\n<li>Organisms die are decompose and nutrients (matter) released<\/li>\n\n\n\n<li>Nutrients may become parts of living things again, when they are taken up by plants<\/li>\n\n\n\n<li>But they may also be combined into the lithosphere through fossilisation and sedimentation<\/li>\n\n\n\n<li>Matter may be released to the atmosphere through both natural and anthropogenic processes<\/li>\n<\/ul>\n\n\n\n<p>These are the <strong>BIOGEOCHEMICAL CYCLES<\/strong><\/p>\n\n\n\n<p>The Biogeochemical cycles ensure chemical elements continue to be available to living organisms. However human impact on these cycles can affect the sustainability of ecosystems.<\/p>\n\n\n\n<p>Biogeochemical cycles have stores, sinks and sources. <\/p>\n\n\n\n<h5 class=\"wp-block-heading\">Stores<\/h5>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Definition:<\/strong>\u00a0Also known as reservoirs, these are where elements are held for a period of time, ranging from seconds to millions of years.<\/li>\n\n\n\n<li><strong>Mechanism:<\/strong>\u00a0The element is in a state of balance, where the input equals the output. However, they can shift between being a store, sink, or source depending on the net flux.<\/li>\n\n\n\n<li><strong>Examples:<\/strong>\n<ul class=\"wp-block-list\">\n<li><strong>Carbon:<\/strong>\u00a0The atmosphere, oceans, and living organisms like plants and animals.<\/li>\n\n\n\n<li><strong>Water:<\/strong>\u00a0Lakes, rivers, and groundwater.<\/li>\n\n\n\n<li><strong>Nutrients:<\/strong>\u00a0Soil, biomass, and the atmosphere.\u00a0<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<h5 class=\"wp-block-heading\">Sinks<\/h5>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Definition:<\/strong>\u00a0Areas where an element accumulates over time, with total input exceeding total output.<\/li>\n\n\n\n<li><strong>Mechanism:<\/strong>\u00a0The net effect is a long-term removal of the element from the active part of the cycle.<\/li>\n\n\n\n<li><strong>Examples:<\/strong>\n<ul class=\"wp-block-list\">\n<li><strong>Carbon:<\/strong>\u00a0Fossil fuel deposits (like coal and oil), deep ocean, and some rock formations.<\/li>\n\n\n\n<li><strong>Phosphorus:<\/strong>\u00a0Sediments and rocks.\u00a0<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<h5 class=\"wp-block-heading\">Sources<\/h5>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Definition:<\/strong>\u00a0Areas where elements are released into the cycle.<\/li>\n\n\n\n<li><strong>Mechanism:<\/strong>\u00a0The rate of output is greater than the rate of input.<\/li>\n\n\n\n<li><strong>Examples:<\/strong>\n<ul class=\"wp-block-list\">\n<li><strong>Carbon:<\/strong>\u00a0Volcanic eruptions, burning fossil fuels, respiration, and decomposition.<\/li>\n\n\n\n<li><strong>Nitrogen:<\/strong>\u00a0Nitrification in soil, lightning.\u00a0<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<div class=\"wp-block-columns is-layout-flex wp-container-core-columns-is-layout-9d6595d7 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-vertically-aligned-center is-layout-flow wp-block-column-is-layout-flow\">\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"457\" height=\"396\" src=\"https:\/\/fourcornerseducation.net\/ESS2026\/wp-content\/uploads\/2025\/11\/biogeo.jpg\" alt=\"\" class=\"wp-image-812\" srcset=\"https:\/\/fourcornerseducation.net\/ESS2026\/wp-content\/uploads\/2025\/11\/biogeo.jpg 457w, https:\/\/fourcornerseducation.net\/ESS2026\/wp-content\/uploads\/2025\/11\/biogeo-300x260.jpg 300w\" sizes=\"auto, (max-width: 457px) 100vw, 457px\" \/><figcaption class=\"wp-element-caption\">Generalised model of the Biogeochemical cycles<\/figcaption><\/figure>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-vertically-aligned-center is-layout-flow wp-block-column-is-layout-flow\"><div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"553\" height=\"423\" src=\"https:\/\/fourcornerseducation.net\/ESS2026\/wp-content\/uploads\/2025\/11\/Store-Sink-Source.png\" alt=\"\" class=\"wp-image-813\" srcset=\"https:\/\/fourcornerseducation.net\/ESS2026\/wp-content\/uploads\/2025\/11\/Store-Sink-Source.png 553w, https:\/\/fourcornerseducation.net\/ESS2026\/wp-content\/uploads\/2025\/11\/Store-Sink-Source-300x229.png 300w\" sizes=\"auto, (max-width: 553px) 100vw, 553px\" \/><figcaption class=\"wp-element-caption\">System Models of Storage, Sinks and sources in the biogeochemical cycles. Consider which box on the left might be stores, sinks or sources.<\/figcaption><\/figure>\n<\/div><\/div>\n<\/div>\n\n\n\n<h4 class=\"wp-block-heading\">The Carbon Cycle<\/h4>\n\n\n\n<p>Carbon is an essential element in living systems, providing the chemical framework to form molecules that make up living organisms. Carbon makes up around 0.03% of the atmosphere as carbon dioxide, and is present in the Oceans as carbonate and bicarbonates and in rocks such as limestone and coal.<\/p>\n\n\n\n<p>Carbon cycles between living (biotic) and non-living (abiotic) chemical cycles: carbon is fixed by photosynthesis and released back to the atmosphere through respiration. Carbon is also released back to the atmosphere through combustion, including fossil fuels and biomass.<\/p>\n\n\n\n<p>Carbon can remain locked in either cycle for long periods of time. ie in the wood of trees or as coal and oil.<\/p>\n\n\n\n<p>Human activity has disrupted the balance of the global carbon cycle (carbon budget) through increased combustion, land use changes and deforestation.<\/p>\n\n\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-6\" class=\"h5p-iframe\" data-content-id=\"6\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"Carbon Cycle\"><\/iframe><\/div>\n\n\n\n<p>Organisms, crude oil and natural gas contain organic stores of organic carbon. The atmosphere, soils and oceans store inorganic carbon. The amount of time Carbon (or any molecule in the biogeochemical cycles) is held in storage, is called <strong>residence time. <\/strong>Humans have disrupted the residence time of geologically stored carbon through mining and extraction of fossil fuels: Coal, oil and gas. Without human interference the residence time would by hundreds of millions of years.<\/p>\n\n\n\n<p><strong>Carbon Sequestration<\/strong><\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"651\" height=\"469\" src=\"https:\/\/fourcornerseducation.net\/ESS2026\/wp-content\/uploads\/2025\/11\/Photosynthesis.png\" alt=\"\" class=\"wp-image-816\" srcset=\"https:\/\/fourcornerseducation.net\/ESS2026\/wp-content\/uploads\/2025\/11\/Photosynthesis.png 651w, https:\/\/fourcornerseducation.net\/ESS2026\/wp-content\/uploads\/2025\/11\/Photosynthesis-300x216.png 300w\" sizes=\"auto, (max-width: 651px) 100vw, 651px\" \/><\/figure>\n<\/div>\n\n\n<p>Environmental systems and societies guide<\/p>\n\n\n\n<p>Carbon sequestration is the process of capturing gaseous and atmospheric carbon dioxide and storing it in a solid or liquid form. Trees and other plants sequester carbon naturally by absorbing carbon dioxide and converting it into biomass. Organic matter is fossilised into coal, oil and natural gas.<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"777\" height=\"693\" src=\"https:\/\/fourcornerseducation.net\/ESS2026\/wp-content\/uploads\/2025\/11\/Fossilisation-1.png\" alt=\"\" class=\"wp-image-818\" srcset=\"https:\/\/fourcornerseducation.net\/ESS2026\/wp-content\/uploads\/2025\/11\/Fossilisation-1.png 777w, https:\/\/fourcornerseducation.net\/ESS2026\/wp-content\/uploads\/2025\/11\/Fossilisation-1-300x268.png 300w, https:\/\/fourcornerseducation.net\/ESS2026\/wp-content\/uploads\/2025\/11\/Fossilisation-1-768x685.png 768w\" sizes=\"auto, (max-width: 777px) 100vw, 777px\" \/><\/figure>\n<\/div>\n\n\n<p><\/p>\n\n\n\n<p>In an ecosystem, the difference between total inputs and outputs is the net accumulation or release of carbon. If photosynthesis exceeds cellular respiration in an ecosystem there is a net uptake of carbon dioxide, and if cellular respiration exceeds photosynthesis there is a net release of carbon dioxide. In a young forest, the trees act as a sink as net productivity is high, a mature forest acting as a store when photosynthesis equals respiration and when a forest is logged (deforestation) or following a forest fire  carbon is released to the atmosphere and the ecosystem becomes a carbon source.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"570\" src=\"https:\/\/fourcornerseducation.net\/ESS2026\/wp-content\/uploads\/2025\/11\/Carbon-cycle-forest-productivity-1-1024x570.png\" alt=\"\" class=\"wp-image-822\" srcset=\"https:\/\/fourcornerseducation.net\/ESS2026\/wp-content\/uploads\/2025\/11\/Carbon-cycle-forest-productivity-1-1024x570.png 1024w, https:\/\/fourcornerseducation.net\/ESS2026\/wp-content\/uploads\/2025\/11\/Carbon-cycle-forest-productivity-1-300x167.png 300w, https:\/\/fourcornerseducation.net\/ESS2026\/wp-content\/uploads\/2025\/11\/Carbon-cycle-forest-productivity-1-768x428.png 768w, https:\/\/fourcornerseducation.net\/ESS2026\/wp-content\/uploads\/2025\/11\/Carbon-cycle-forest-productivity-1-1536x855.png 1536w, https:\/\/fourcornerseducation.net\/ESS2026\/wp-content\/uploads\/2025\/11\/Carbon-cycle-forest-productivity-1-2048x1141.png 2048w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<p><\/p>\n\n\n\n<p>Agricultural systems can act as carbon stores, sources and sinks, depending on the techniques used.  Some agricultural methods, such as crop rotation, cover crops and no till, will promote the role, of soil as a carbon sink whereas drainage of wetland, monoculture and heavy tillage will promote the role of soil as a carbon source. Cropping over a longer timescale such as in forestry for timber production and the subsequent use of harvested products will also affect these roles (illustrated above).<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"640\" height=\"427\" src=\"https:\/\/fourcornerseducation.net\/ESS2026\/wp-content\/uploads\/2025\/11\/Lettuce-jersey.jpeg\" alt=\"\" class=\"wp-image-823\" srcset=\"https:\/\/fourcornerseducation.net\/ESS2026\/wp-content\/uploads\/2025\/11\/Lettuce-jersey.jpeg 640w, https:\/\/fourcornerseducation.net\/ESS2026\/wp-content\/uploads\/2025\/11\/Lettuce-jersey-300x200.jpeg 300w\" sizes=\"auto, (max-width: 640px) 100vw, 640px\" \/><figcaption class=\"wp-element-caption\">Organic small scale agricultural system, where natural composts (manure and composted plant material) is added to the soil and crop rotations used to improve soil fertility. <\/figcaption><\/figure>\n<\/div>\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"640\" height=\"360\" src=\"https:\/\/fourcornerseducation.net\/ESS2026\/wp-content\/uploads\/2025\/11\/Wheat.jpeg\" alt=\"\" class=\"wp-image-824\" srcset=\"https:\/\/fourcornerseducation.net\/ESS2026\/wp-content\/uploads\/2025\/11\/Wheat.jpeg 640w, https:\/\/fourcornerseducation.net\/ESS2026\/wp-content\/uploads\/2025\/11\/Wheat-300x169.jpeg 300w\" sizes=\"auto, (max-width: 640px) 100vw, 640px\" \/><figcaption class=\"wp-element-caption\">Large scale monoculture (wheat) with extensive use of chemical fertilisers. Increased soil erosion in dry conditions.<\/figcaption><\/figure>\n<\/div>\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"683\" src=\"https:\/\/fourcornerseducation.net\/ESS2026\/wp-content\/uploads\/2025\/11\/Scotts-pine-regrowth-1024x683.jpeg\" alt=\"\" class=\"wp-image-826\" srcset=\"https:\/\/fourcornerseducation.net\/ESS2026\/wp-content\/uploads\/2025\/11\/Scotts-pine-regrowth-1024x683.jpeg 1024w, https:\/\/fourcornerseducation.net\/ESS2026\/wp-content\/uploads\/2025\/11\/Scotts-pine-regrowth-300x200.jpeg 300w, https:\/\/fourcornerseducation.net\/ESS2026\/wp-content\/uploads\/2025\/11\/Scotts-pine-regrowth-768x512.jpeg 768w, https:\/\/fourcornerseducation.net\/ESS2026\/wp-content\/uploads\/2025\/11\/Scotts-pine-regrowth.jpeg 1200w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption class=\"wp-element-caption\">Clear felled (harvested) Scots Pine forestry, with replanting of young tress to be harvested in 60 years time.<\/figcaption><\/figure>\n<\/div>\n\n\n<h4 class=\"wp-block-heading\">Fossil Fuels and the Carbon Cycle<\/h4>\n\n\n\n<p>Fossil fuels were plant and animal matter laid down between sediments millions of years ago and through fossilisation become Coal, Oil and Natural gas &#8211; a period when ecosystems acted as net sinks of carbon. Geologically they have a very residence time. However when we burn them as fuel they become a carbon source.<\/p>\n\n\n\n<div class=\"wp-block-columns are-vertically-aligned-top is-layout-flex wp-container-core-columns-is-layout-9d6595d7 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-vertically-aligned-top is-layout-flow wp-block-column-is-layout-flow\"><div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"640\" height=\"361\" src=\"https:\/\/fourcornerseducation.net\/ESS2026\/wp-content\/uploads\/2025\/11\/azeri-oil-field.jpeg\" alt=\"\" class=\"wp-image-828\" srcset=\"https:\/\/fourcornerseducation.net\/ESS2026\/wp-content\/uploads\/2025\/11\/azeri-oil-field.jpeg 640w, https:\/\/fourcornerseducation.net\/ESS2026\/wp-content\/uploads\/2025\/11\/azeri-oil-field-300x169.jpeg 300w\" sizes=\"auto, (max-width: 640px) 100vw, 640px\" \/><figcaption class=\"wp-element-caption\">An Oilfield next to the Caspian sea in Azerbaijan which has been producing oil for over 150 years. <\/figcaption><\/figure>\n<\/div><\/div>\n\n\n\n<div class=\"wp-block-column is-vertically-aligned-top is-layout-flow wp-block-column-is-layout-flow\"><div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"640\" height=\"427\" src=\"https:\/\/fourcornerseducation.net\/ESS2026\/wp-content\/uploads\/2025\/11\/Motorbikes-hanoi.jpeg\" alt=\"\" class=\"wp-image-829\" srcset=\"https:\/\/fourcornerseducation.net\/ESS2026\/wp-content\/uploads\/2025\/11\/Motorbikes-hanoi.jpeg 640w, https:\/\/fourcornerseducation.net\/ESS2026\/wp-content\/uploads\/2025\/11\/Motorbikes-hanoi-300x200.jpeg 300w\" sizes=\"auto, (max-width: 640px) 100vw, 640px\" \/><figcaption class=\"wp-element-caption\">Urban Traffic in Hanoi, Vietnam. The mass of motorbikes in the city not only release carbon dioxide to the atmosphere they are also a major contributor to the smog and pollution problems of the city.<\/figcaption><\/figure>\n<\/div><\/div>\n<\/div>\n\n\n\n<h4 class=\"wp-block-heading\">Oceans as Carbon Sinks and Sources<\/h4>\n\n\n\n<p>Carbon dioxide is absorbed into the oceans by dissolving and is released as a gas when it comes out of a solution. While oceans act as a carbon sink, the human use of fossil fuels releases inorganic carbon at a faster rate than oceans can absorb it. Environmental systems and societies guide. Increases in concentrations of dissolved carbon dioxide cause ocean acidification, harming marine animals even small decreases in pH can interfere with calcium carbonate deposition in mollusc shells and 2.1 coral skeletons.<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-large\"><img decoding=\"async\" src=\"https:\/\/globalocean.noaa.gov\/wp-content\/uploads\/2022\/11\/pmel-research.003.jpg\" alt=\"\"\/><figcaption class=\"wp-element-caption\">Image from the National Oceanic and Atmospheric Administration. <a href=\"https:\/\/globalocean.noaa.gov\/wp-content\/uploads\/2022\/11\/pmel-research.003.jpg\" rel=\"lightbox[808]\">https:\/\/globalocean.noaa.gov\/wp-content\/uploads\/2022\/11\/pmel-research.003.jpg<\/a><\/figcaption><\/figure>\n<\/div>\n\n\n<div class=\"wp-block-columns is-layout-flex wp-container-core-columns-is-layout-9d6595d7 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\" style=\"flex-basis:33.33%\">\n<p>Open the link for a more detailed explanation of how the cceans act as a carbon sink, but also how man&#8217;s activities create a tension with this role. <\/p>\n\n\n\n<p><strong><a href=\"https:\/\/ocean-climate.org\/en\/awareness\/the-ocean-a-carbon-sink\/\" target=\"_blank\" rel=\"noreferrer noopener\">Ocean and Climate Platform<\/a><\/strong><\/p>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\" style=\"flex-basis:66.66%\">\n<figure class=\"wp-block-image size-full\"><a href=\"https:\/\/ocean-climate.org\/en\/awareness\/the-ocean-a-carbon-sink\/\" target=\"_blank\" rel=\" noreferrer noopener\"><img loading=\"lazy\" decoding=\"async\" width=\"879\" height=\"317\" src=\"https:\/\/fourcornerseducation.net\/ESS2026\/wp-content\/uploads\/2025\/11\/Screenshot-2025-11-26-at-09.14.41.png\" alt=\"\" class=\"wp-image-831\" srcset=\"https:\/\/fourcornerseducation.net\/ESS2026\/wp-content\/uploads\/2025\/11\/Screenshot-2025-11-26-at-09.14.41.png 879w, https:\/\/fourcornerseducation.net\/ESS2026\/wp-content\/uploads\/2025\/11\/Screenshot-2025-11-26-at-09.14.41-300x108.png 300w, https:\/\/fourcornerseducation.net\/ESS2026\/wp-content\/uploads\/2025\/11\/Screenshot-2025-11-26-at-09.14.41-768x277.png 768w\" sizes=\"auto, (max-width: 879px) 100vw, 879px\" \/><\/a><\/figure>\n<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>The Ecosystem The biogeochemical cycles. Transfer of matter through the ecosystem is quite different that of energy. Energy travels from the sun, through food webs and is eventual lost to space as heat. These are the BIOGEOCHEMICAL CYCLES The Biogeochemical cycles ensure chemical elements continue to be available to living organisms. However human impact on &#8230; <a title=\"Biogeochemical cycles (Core)\" class=\"read-more\" href=\"https:\/\/fourcornerseducation.net\/ESS2026\/biogeochemical-cycles-core\/\" aria-label=\"Read more about Biogeochemical cycles (Core)\">Read more<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-808","page","type-page","status-publish"],"_links":{"self":[{"href":"https:\/\/fourcornerseducation.net\/ESS2026\/wp-json\/wp\/v2\/pages\/808","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/fourcornerseducation.net\/ESS2026\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/fourcornerseducation.net\/ESS2026\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/fourcornerseducation.net\/ESS2026\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/fourcornerseducation.net\/ESS2026\/wp-json\/wp\/v2\/comments?post=808"}],"version-history":[{"count":11,"href":"https:\/\/fourcornerseducation.net\/ESS2026\/wp-json\/wp\/v2\/pages\/808\/revisions"}],"predecessor-version":[{"id":832,"href":"https:\/\/fourcornerseducation.net\/ESS2026\/wp-json\/wp\/v2\/pages\/808\/revisions\/832"}],"wp:attachment":[{"href":"https:\/\/fourcornerseducation.net\/ESS2026\/wp-json\/wp\/v2\/media?parent=808"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}