Ms. Harvey 2016 BIOGEOCHEMICAL CYCLES

 An ecosystem survives by a combination of energy flow and matter recycling TWO SECRETS OF SURVIVAL: ENERGY AND MATTER RECYCLING

 What happens to energy in an ecosystem?  What happens to matter in an ecosystem? BIOGEOCHEMICAL CYCLES

 Nutrient cycles: Global Recycling 1.Global cycles recycle nutrients through the earth’s air, land, water, and living organisms 2.Nutrients are the elements and compounds that organisms need to live, grow, and reproduce. 3.Biogeochemical cycles move these substances through air, water, soil, rock, and living organisms. ECOSYSTEMS

We alter the water cycle by:  Withdrawing large amounts of freshwater.  Clearing vegetation and eroding soils.  Polluting surface and underground water.  Contributing to climate change. EFFECT OF HUMAN ACTIVITIES ON THE WATER CYCLE

Water can be in the atmosphere, on the land, in the ocean, and even underground. It is recycled over and over again through the water cycle. In the water cycle water changes state between a liquid, solid (ice), and gas(water vapor). WATER CYCLE

 Most water vapor gets into the atmosphere by a process called evaporation  This process turns the water that is at the top of the oceans, rivers, lakes, into water vapor in the atmosphere using energy from the Sun  The water vapor rises in the atmosphere and cools forming tiny water droplets -- this process is called condensation  Those water droplets make up clouds  As those water droplets combine with each other they grow larger and become too heavy to stay in the air. Eventually they fall as precipitation – rain, snow, sleet  Most of the precipitation that falls becomes part of the oceans, rivers, lakes once again  Some that falls in the form of snow and ice stays at the Earth’s surface in glaciers and other types of ice  And some precipitation seeps into the ground and becomes part of the groundwater from which we tap into for our drinking water WATER CYCLE

 Carbon moves from the atmosphere to plants  Carbon moves from plants to animals  Carbon moves from plants to animals to the ground  Carbon moves from living things to the atmosphere  Carbon moves from fossil fuels to the atmosphere when fuels are burned  Carbon moves from the atmosphere to the oceans CARBON CYCLE

We alter the carbon cycle by adding excess CO 2 to the atmosphere through:  Burning fossil fuels  Clearing vegetation faster than it is replaced EFFECTS OF HUMAN ACTIVITIES ON CARBON CYCLE

THE NITROGEN CYCLE

 Nitrogen makes up 80% of our atmosphere part of our abiotic environment  Nitrogen is also found in living things – it is an element that makes up proteins and DNA  All animals and plants need nitrogen BUT the nitrogen in the atmosphere is triple bonded and a very tough molecule to break – not useable to us in that form  So what breaks it apart? – lightning strikes or fires AND our very tiny friends… BACTERIA!  Once bacteria “fix” the nitrogen in a useable form plants can then soak it up through their root system  The nitrogen becomes assimilated throughout the plant into “edible” organs and lucky for us (and other critters too) when we eat the organs of a plant we ingest the nitrogen that we need to make proteins which our body needs for cellular function  Once animals die, decomposers help to break apart matter, once again releasing nitrogen back into the soil  Bacteria help once again by releasing nitrogen back into the atmosphere NITROGEN CYCLE

We alter the nitrogen cycle by:  Adding gases that contribute to acid rain  Adding nitrous oxide to the atmosphere through farming practices which can warm the atmosphere and deplete ozone. EFFECTS OF HUMAN ACTIVITIES ON THE NITROGEN CYCLE

We alter the nitrogen cycle by:  Contaminating ground water from nitrate ions in inorganic fertilizers  Releasing nitrogen into the troposphere through deforestation. EFFECTS OF HUMAN ACTIVITIES ON THE NITROGEN CYCLE

Solar energy, the cycling of matter, and GRAVITY sustain life on earth! WHAT SUSTAINS LIFE ON EARTH?