Warm-Up #34 Complete analyzing data #1-4 on page 79 of your text Complete #1-6 Section Assessment on page 80 of your text.

Cycles of Matter The Biosphere

Objectives Describe how matter cycles among the living and nonliving parts of an ecosystem. Explain why nutrients are important in living systems. Describe how the availability of nutrients affects the productivity of ecosystems.

Recycling in the Biosphere Law of Conservation of Energy and Law of Conservation of Matter—both energy and matter are conserved. Energy --(light→chemical→heat) --needs a constant input since much is lost to heat throughout the biological processes. Matter—not a one way path—cycles throughout the ecosystem—same amount is always present in the biosphere—just in different forms.

Biogeochemical Cycles Connect biological, geological and chemical aspects of the biosphere. Water Carbon Nitrogen Phosphorus

Biogeochemical Cycles In studying cycling of water, carbon, nitrogen, and phosphorus, ecologists focus on four factors: 1. Each chemical’s biological importance 2. Forms in which each chemical is available or used by organisms 3. Major reservoirs for each chemical 4. Key processes driving movement of each chemical through its cycle

One H2O molecule may take as long as 4000 years to complete 1 cycle. The Water Cycle Evaporation Transpiration Condensation Precipitation One H2O molecule may take as long as 4000 years to complete 1 cycle.

The Water Cycle Biological Importance: All living things require water to survive. Forms available: Water Vapor, Liquid Water and Ice Major Reservoirs: Oceans, Lakes, Rivers, Atmosphere Key Processes Driving Movement: Evaporation (Transpiration) Condensation (clouds) Precipitation (rain, snow, etc) Runoff

Nutrient Cycles All the chemical substances that an organism needs to sustain life. Every living organism needs nutrients to build tissues and carry out essential life functions. Like water, nutrients are passed between organisms and the environment through biogeochemical cycles.

The Carbon Cycle ONLY photosynthesis removes Carbon from the atmosphere. Other processes key to this cycle: Respiration Decomposition

The Carbon Cycle Biological Importance—Carbon forms the framework for the organic molecules essential to all organisms. Forms Available—Carbon Dioxide, Calcium Carbonate, Coal, Oil, Gas Major Reservoirs—CO2 in atmosphere, CaCO3 in the ocean Key Processes—photosynthesis, respiration, burning of fossil fuels, weathering, erosion, decay, volcanism

The Nitrogen Cycle The atmosphere is about 80% nitrogen. Mainly bacteria make this nitrogen available to the rest of the living world by chemically treating it and making it available to plants.

The Nitrogen Cycle Biological Importance: Forms Available: Nitrogen is a component of amino acids, proteins, and nucleic acids and is a crucial and often limiting plant nutrient Forms Available: Ammonia, Nitrates, Atmospheric Nitrogen Major Reservoirs: Atmosphere, Soil Key Processes: Nitrification, Denitrification, Ammonification, Nitrogen Fixation, Decomposition, Lightning Storms

Study Guide page 106

The Phosphorus Cycle Very localized cycle with no atmospheric component. Like the nitrogen and carbon cycles phosphorus is take into the food chain through plants.

The Phosphorus Cycle Biological Importance: Organisms require phosphorus as a major component in nucleic acids, phospholipids, ATP, and as a mineral constituent of bones and teeth Forms available: Inorganic phosphate Major Reservoirs: Rock and soil minerals, ocean sediments Key Processes: Erosion, Runoff, Mineral absorption by plant roots

Nutrient Limitation Primary Productivity—the rate at which organic matter is created by producers. Limiting Nutrient—a single nutrient whose availability will limit the primary productivity of an ecosystem. Land ecosystems are much more nutrient rich than the oceans. In oceans, phosphorus is generally the limiting nutrient.

Algal Bloom When an aquatic ecosystem receives a large input of a limiting nutrient—such as large amounts of phosphorus from fertilizer runoff—the result is often an immediate increase in the amount of algae and other producers. This increase of algae is known as algal bloom. Large blooms can sometimes disrupt the equilibrium of an ecosystem.

Summary How does matter cycle among the living and nonliving parts of an ecosystem? How is this different than the flow of energy? Why are nutrients important in living systems? Water? Carbon? Nitrogen? Phosophorus? How does the availability of nutrients affect the productivity of ecosystems?

Study Guide page 107

Homework Homework Packets STUDY FOR TEST Complete Study Guide page 108 Warm-Ups #33-35—6 points Study Guide—4 points Food Web Activity—5 points Extra Credit—Online practice test, phschool.com, webcode cba-2030 STUDY FOR TEST Complete Study Guide page 108