Matter Cycles through Ecosystems ALL ECOSYSTEMS NEED CERTAIN

Matter Cycles through Ecosystems. • ALL ECOSYSTEMS NEED CERTAIN MATERIALS. • WATER CYCLES THROUGH ECOSYSTEMS • CARBON CYCLES THROUGH ECOSYSTEMS • NITROGEN CYLCLES THROUGH ECOSYSTEMS

• All Ecosystems Need Certain Materials Living things depend on their environment to meet their needs. • All of the materials an organism takes in are returned to the ecosystem, while the organism lives or after it dies. • The movement of matter through the living and nonliving parts of an ecosystem is a continuous cycle. Matter never leaves an ecosystem, it just changes form. The most important cycles in ecosystems are: WATER, NITROGEN and CARBON DIOXIDE.

Water Cycles thru Ecosystem • Water is stored on Earth’s surface in Lakes, Rivers, & Oceans. Also found underground, & a lot in glaciers and polar ice sheets. • Water is part of living things, and is constantly moving through the environment: WATER CYCLE. • Water is made of Hydrogen & Oxygen; it constantly is changing form (gas-liquid-solid). Usually is gas in atmosphere (vapor), condenses to fall as precipitation (snow, sleet, rain, hail), and evaporates back to vapor into atmosphere. • Animals release water vapor when breathing (respiration) and plants do it through transpiration.

Carbon Cycles thru Ecosystem • Carbon is an element found in all living things. It is through Carbon Dioxide gas (CO 2) that carbon enters the living parts of an ecosystem. • Plants use CO 2 to make sugar (in photosynthesis). Sugars are carbon compounds important as a food source to supply energy to organisms for growth & life. Energy is released from food via respiration in organisms. Carbon then gets cycled back into atmosphere as CO 2 gas. When living things die, the rest of carbon that makes up living matter gets released. • Earth’s ocean has a lot more carbon in it than air does. CO 2 is dissolved in water, used by algae to make food via photosynthesis. • Marine organisms also release CO 2 through respiration and carbon on the ocean floor when they die.

Nitrogen Cycles thru Ecosystem • Nitrogen is another element important to life that cycles thru ecosystems. 4/5 of air you breathe is clear, colorless nitrogen gas. But we can’t get it from the air, instead we get it from plants. • Plants absorb compounds of nitrogen with roots from soil (also can’t get pure N from air). • Lightning “fixes” or breaks apart pure nitrogen into a form plants can use (it falls to ground with rain). But most soil nitrogen comes from “nitrogen-fixing bacteria” that live around roots of plants & in oceans to change gas nitrogen into usable nitrogen compounds. • Also, decomposers break down dead matter in oceans & soil to release nitrogen, used again by living things. • Some nitrogen goes back to atmosphere by certain bacteria, releasing nitrogen gas.