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Leaf Me Alone! The Movement of Nutrients Between Trees and the Soil

This article is from Issue Tropical - Vol. 3 No. 1.

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In this study, the scientists studied trees growing on Puerto Rico, an island in the Caribbean. The scientists wanted to know if different trees contribute different amounts of nutrients to the soil. By learning if some kinds of trees contribute more nutrients to the soil, the scientists could determine if those kinds of trees should be planted in areas where the soil needs more nutrients. 

Welcome to the Tropical edition

Note to Educators

Education Standards Correlations


Meet the scientists that contributed to this article:

"Science Topics" covered in this article:
  • Life Science

"Environmental Topics" covered in this article:
  • Forest and Grassland Use (Educators)
  • The Value of Forests and Grasslands (Educators)
  • Vegetation Management (Educators)

Regions covered in this article:
  • Southern

"Thinking About Science Themes" covered in this article:
Scientists use many ways to determine the quality of a thing. Most often, scientists use numbers to determine the amount of a particular quality a thing has. Sometimes, using numbers is not the best way to determine something's quality. For example, how could you determine how much better (a quality) your dinner tastes after you add salt to it? You would taste it and make a judgment. This judgment would be based on a comparison with how it tasted before you added salt. This is a way of determining quality without using numbers. You could quantify this quality of good taste by asking everyone in your neighborhood to taste your dinner before and after adding salt. Then, you could count the number of people who said it tasted better. Quality can be judged with or without numbers. Usually, scientists use numbers because numbers are less subject to individual choice or opinion, as when they measure height or weight. In this study, the scientists wanted to know the quality of leaves that fell from trees. Quality was determined by the amount of nutrients found in the fallen leaves. Do you think the scientists used numbers to determine quality in this case? Why or why not?
Specific "Thinking About Science" Themes:
  • Scientific Topics
  • The Scientific Process

"Thinking About Environmental Themes" covered in this article:
Food chains describe the flow of energy from one organism to another. A flow of energy occurs when one organism digests another. When this happens, some of the energy is lost to the environment. The food chain starts with green plants. Green plants are the only type of organism that can convert sunlight into food by photosynthesis . In forests, some of the green plants are consumed by animals such as insects and deer, but most of them are consumed by decomposers as dead plant material. Decomposers include bacteria, fungi (fun ji), and small animals such as earthworms. Decomposers move nutrients from the dead plant material to the soil. Once in the soil, plants can use the nutrients for new growth. The scientists in this study wanted to know whether some kinds of fallen leaves have more nutrients than other kinds of leaves. If so, those leaves would provide more nutrients to the soil, making more nutrients available to the plants.
Specific "Thinking About the Environment" Themes:
  • Food chain

NSE Standards covered in this article:
  • Abilities necessary to do scientific inquiry (A)
  • Earth in the solar system (D)
  • Populations and ecosystems (C)
  • Regulation and behavior (C)
  • Science as a human endeavor (G)
  • Structure and function in living systems (C)
  • Transfer of energy (B)

Science Benchmarks covered in this article:
  • Habits of Mind: Critical-Response Skills
  • The Living Environment: Diversity of Life
  • The Living Environment: Flow of Matter and Energy
  • The Living Environment: Interdependence of Life
  • The Nature of Science: Scientific Inquiry
  • The Nature of Science: The Scientific Enterprise
  • The Physical Setting: Energy Transformations
  • The Physical Setting: Processes that Shape the Earth
  • The Physical Setting: The Earth