Cycles of Matter

Earth is a closed system

Living organisms need matter to cycle because they are crucial for energy and structural building blocks

Essential Ecosystem Services $$$$$

WATER (hydrologic cycle) 71% of Earth is water. (So why wasn’t it called Aqua?)

The amount of water in the biosphere is finite. It is recycled through the hydrological cycle. (So you could be drinking dinosaur pee)

Hydrologic Cycle

WATER – ESSENTIAL FOR ALL LIFE Water is essential for humans and ecosystems. Drought and poor water quality can affect water availability and impact humans and the environment.

And only 3% of it is drinkable!

WATER’S SPECIAL PROPERTIES Water exists in the environment as a solid, a liquid, and a gas

WATER’S SPECIAL PROPERTIES Water is polar, allowing it to dissolve and transport a wide range of materials

The charged ends dissolve a wide variety of substances (nutrients, minerals, toxins), brings them into the water cycle and moves them all over the Earth through the atmosphere, ground and surface water, connecting ecosystems that are separated by great distances.

And microscopically – in cells and organisms Unicellular organisms that live in water absorb needed dissolved substances

Blood, a water-based solution, transports molecules of nutrients and wastes organisms

Nutrients dissolved in water get transported through plants

All living chemical reactions are basically in water Did you know you are a walking bag of about 400 simultaneous chemical reactions?

Water is a great moderator of Earth’s climates and the internal T of organisms

Water’s high specific heat capacity

As a liquid evaporates, the surface of the liquid that remains behind cools - Evaporative cooling. Evaporative cooling moderates temperature in lakes and ponds and prevents terrestrial organisms from overheating. Evaporation of water from the leaves of plants or the skin of animals removes excess heat.

Human Impacts Acid precipitation: dead water systems, no maple syrup!

Human Impacts Climate change: increase in global temperatures increases evapotranspiration and drought

Human Impacts Increase in human population increases demand for water. Some say the next world war will be over water.

Human Impacts Algal blooms (eutrophication) and creeping dead zones owing to agricultural and human wastes, fertilizers

Creeping Dead Zones

Health Hazards Polluted drinking water: bacteria and viruses from sewage and agricultural waste (cholera, food poisoning, hepatitis) – every 10 seconds a child dies from polluted drinking water. pesticides, industrial chemicals, heavy metals radioactive materials

Death from Unsafe Water

WATER AND CYCLING OF MATTER The hydrologic cycle plays a central role in nutrient cycles (biogeochemical cycles). This flow chart demonstrates only some of the interactions between these cycles.

CARBON/OXYGEN CYCLE

Carbon Sinks (storage)

Largest carbon sink: the ocean dissolved CO 2 in the water methane hydrates (CH 3 H 2 O) trapped in ocean floor

Human Impacts Deforestation and burning of fossil fuels contributes to climate change and global warming

Nitrogen Cycle Nitrogen is a structural component of DNA and protein. It is crucial for leaf growth and making chlorophyll the pigment that is necessary for photosynthesis.

NITROGEN CYCLE The atmosphere is 78% N 2 (g). However, most organisms cannot use N 2 (g) but they can use ammonium (NH 4 + ) and nitrate (NO 3 - )

NITROGEN CYCLE The atmosphere is 78% N 2 (g). However, most organisms cannot use N 2 (g) but they can use ammonium (NH 4 + ) and nitrate (NO 3 - ). Nitrogen fixing bacteria (found in nodules in legumes – clover, peas, alfalfa) and in the soil change N 2  NH 4 + by nitrogen fixation. Decomposers also supply ammonium when they decompose dead organisms by ammonification.

NITROGEN CYCLE The atmosphere is 78% N 2 (g). However, most organisms cannot use N 2 (g) but they can use ammonium (NH 4 + ) and nitrate (NO 3 - ). Nitrogen fixing bacteria (found in nodules in legumes – clover, peas, alfalfa) and in the soil change N 2  NH 4 + by nitrogen fixation. Decomposers also supply ammonium when they decompose dead organisms by ammonification.

NITROGEN CYCLE Nitrogen fixing bacteria (found in nodules in legumes – clover, peas, alfalfa) and in the soil change N 2  NH 4 + by nitrogen fixation.

NITROGEN CYCLE Decomposers also supply ammonium when they decompose dead organisms by ammonification.

NITROGEN CYCLE Nitrifying bacteria in the soil convert the ammonium to nitrite and nitrate. Plants can use either ammonium or nitrates for growth and building chlorophyll.

NITROGEN CYCLE Denitrifying bacteria complete the cycle and return N 2 (g) to the atmosphere. A similar cycle occurs in the water.

NITROGEN CYCLE NITROGEN FIXATION – N 2 gas to NH 4 + (ammonium) Nitrogen-fixing bacteria that live in the roots of clover and alfalfa (legumes) and in soil convert the nitrogen gas (from the atmosphere) to ammonium (NH 4 + ) AMMONIFICATION – organic wastes (from dead plants & animals) are converted by decomposers to ammonium NH 4 +

NITROGEN CYCLE NITRIFICATION– bacteria (aerobic) in the soil convert ammonium to nitrites (NO 2 ) and then nitrates (NO 3 ) ASSIMILATION – plants uptake NO 3 (nitrates) which is dissolved in the water, to be used for photosynthesis Add oxygens

NITROGEN CYCLE DENITRIFICATION – bacteria convert nitrates back to N 2 which returns to the atmosphere to complete the cycle N 2

Human Impact Agriculture removes nitrogen from the soil. We add it back by annual crop rotation (crop- legume-crop-legume) or fertilizers.

Human Impact Excess nitrogen in fertilizers and animal waste  algal blooms and creeping dead zones Lake Ontario

The Nitrogen Cycle _int_nitrogen/ _int_nitrogen/

THE SULFUR CYCLE Sulfur is needed for proteins and vitamins in living organisms. Bacteria are essential to this cycle, just like the nitrogen cycle. Plants need sulfur as sulfate (SO 4 2- )

Volcanos, low tide smells from decomposition, deep sea vents

Human Impact Humans release large amounts of sulfur into the air: industries, burning fossil fuels, sour gas  acid precipitation (sulfurous acid) Kills water systems, damages plants and leaches nutrients from the soil

THE PHOSPHORUS CYCLE Phosphorus is essential for life (DNA, ATP, bones, teeth) but is only in limited quantities on Earth. Keeps producers in check, but limits crop production.

THE PHOSPHORUS CYCLE Phosphorus is found in living organisms, land, and water, but it does not cycle through the atmosphere. It comes originally from rocks, is released by weathering and becomes phophate (PO 4 3- ) which living organisms can use.

Human Impact Detergents and fertilizers add phosphates to our water  algal blooms

Learning Check Can you fill in the blanks on the BLM cycles? Can you ace your Ch2/3 practice test? Can you do your checklist?