CYCLING IN NATURE

Wed Sept 4/Thurs Sept 5 If you have supplies to turn in, please place them under the window. AGENDA Collect signature pages Set up science notebook. This will be a TESTGRADE! Stamp and review homework Notes: Nutrient Cycles HOMEWORK Complete Pre-Lab: Using a Compound Light Microscope QUIZ NEXT CLASS- Flow of Energy and Matter in Ecosystems

Ecosystem structure is influenced by the availability of nutrients and energy. The five main elements plants use include: carbon oxygen hydrogen nitrogen phosphorous. Cycles, Alright!

The elements essential for life tend to move in cycles. Elements are transferred from the environment, to organisms, then back to the environment. Organisms Environment

Elements, chemical compounds, and other forms of matter are passed from one organism to another and from one part of the biosphere to another through biogeochemical cycles. Connect biological, geological, and chemical cycles of the biosphere. Organisms Environment

Cold and warm ocean currents, clouds, winds, and rainfall are all a part of the global hydrologic cycle. The hydrologic cycle is driven by solar energy.

What are two ways water moves into the atmosphere? Evaporation- water changes from liquid form to an atmospheric gas. Transpiration: evaporation of water from leaves of plants. It remains as water vapor, clouds, and ice crystals until it falls back to earth.

How does water fall back to Earth? Condensation- water cools and forms clouds. Precipitation- water falls to earth and remains on land for about 10 to 120 days. Then some of it evaporates or is carried by rivers and streams to the seas where, with evaporation, the cycle begins.

Water is an important way in which nutrients move into and out of ecosystems. As the water goes through the hydrologic cycle, it carries the nutrients with it. Raise your hand if you love the hydrologic cycle!!!

Carbon moves in through the atmosphere and oceans, through organisms, and then back to the environment as dead organisms deteriorate. Carbon enters the atmosphere through –respiration, –fossil fuel burning, and –volcanic eruptions, which release carbon from rocks deep in the earth’s crust.

Carbon exists as gas in the atmosphere- CO 2 (carbon dioxide). About half of all the carbon entering the atmosphere each year will move into two large “holding stations”. The two places where most of the CO 2 is housed are: 1) oceans 2) plant biomass

Each year photosynthesiz ers capture airborne CO 2 and turn it into organic compounds, like food.

In aquatic food webs, carbon is turned into the shells and other hard parts of marine organisms. When the shelled organisms die, they sink to they bottom where they can remain buried for millions of years. This carbon may slowly be converted into “fossil fuel”: –gas, –petroleum –coal

Of all of the nutrients influencing the growth of land plants, nitrogen is often in the shortest supply. The atmosphere is the largest supply of nitrogen, but it is in a form that cannot be used by organisms.

Nitrogen Fixation: process of converting nitrogen gas (N 2 ) into ammonia (NH 3 ) Bacteria that are found in the soil and on the roots of legumes undergo this process.

Nitrogen fixing bacteria can convert N 2 into forms that can be used in ecosystems. The N 2 is turned into ammonia NH 3 by the bacteria. The ammonia is then used in the production of proteins by plants. N 2  NH 3 (nitrogen fixation!) Plants use the nitrogen in their tissues, the nitrogen is then transferred to animals when they consume the plant. !!! The Nitrogen Cycle Yipee!!!

Nitrogen is returned to the environment when bacteria and fungi break down nitrogen- containing wastes and the remains of plants and animals. Denitrification: conversion of nitrates into nitrogen gas (N 2 )

Nutrient Cycles and Acid Rain Acid rain is caused by a chemical reaction that begins when compounds like sulfur dioxide and nitrogen oxides are released into the air. These substances can rise very high into the atmosphere, where they mix and react with water, oxygen, and other chemicals to form more acidic pollutants, known as acid rain

Volcanoes and acid rain Volcanoes are a natural source of acid.

Acid Rain

pH Scale pH scale- measuring system that indicates the concentration of H + ions in solution Acids- Are compounds that donate H + (below pH of 7) Bases- are compounds that donate OH - (above pH of 7) Neutral pH is 7 s/6-_FAQs/pHscale.jpg