3.4 Cycles of Matter
How does matter move through the biosphere?- How does water cycle through the biosphere?
- What is the importance of the main nutrient cycles?
- How does nutrient availability relate to the primary productivity of an ecosystem?
biogeochemical cycle • nutrient • nitrogen fixation • denitrification • limiting nutrient
Outline Make an outline using the green and blue headings in this lesson. Fill in details as you read to help you organize the information.
THINK ABOUT IT Living organisms are composed mostly of four elements: oxygen, carbon, hydrogen, and nitrogen. These four elements (and a few others, such as sulfur and phosphorus) are the basis of life's most important compounds: water, carbohydrates, lipids, nucleic acids, and proteins. In short, a handful of elements combine to form the building blocks of all known organisms. And yet, organisms cannot manufacture these elements and do not “use them up.” So, where do essential elements come from? How does their availability affect ecosystems?
Recycling in the Biosphere
How does matter move through the biosphere?
Matter moves through the biosphere differently than the way in which energy moves. Solar and chemical energy are captured by primary producers and then pass in a one-way fashion from one trophic level to the next—dissipating in the environment as heat along the way. But while energy in the form of sunlight is constantly entering the biosphere, Earth doesn't receive a significant, steady supply of new matter from space. Unlike the one-way flow of energy, matter is recycled within and between ecosystems. Elements pass from one organism to another and among parts of the biosphere through closed loops called biogeochemical cycles, which are powered by the flow of energy as shown in Figure 3–13. As that word suggests, cycles of matter involve biological processes, geological processes, and chemical processes. Human activity can also play an important role. As matter moves through these cycles, it is transformed. It is never created or destroyed—just changed.
VISUAL ANALOGY
THE MATTER MILL
Figure 3–13 Nutrients are recycled through biogeochemical cycles. These cycles are powered by the one-way flow of energy through the biosphere.
Use Analogies How is the water flowing over the water wheel similar to the flow of energy in the biosphere?
Table of Contents
- Formulas and Equations
- Applying Formulas and Equations
- Mean, Median, and Mode
- Estimation
- Using Measurements in Calculations
- Effects of Measurement Errors
- Accuracy
- Precision
- Comparing Accuracy and Precision
- Significant Figures
- Calculating With Significant Figures
- Scientific Notation
- Calculating With Scientific Notation
- Dimensional Analysis
- Applying Dimensional Analysis