The food preservative sorbic acid can be extracted from Eurasian mountain ash berries (commercially available) and used to show antifungal properties in microbiological investigations. Techniques for extraction, purification, ultraviolet analysis, and experiments displaying antifungal activity are described. A systematic search for similar…

Describes an activity (suitable for high school or college) in which the effects of competition in the structuring of ecological communities are examined. The exercise also offers an introduction into species diversity; more advanced classes may be encouraged to seek reasons for differences in insect diversity on different trees. (Author/JN)

A field-based exercise which illustrates one aspect of how leaves in multilayered trees take advantage of light microenvironments is presented. Procedures, tree selection and data analysis are discussed. (CW)

Two exercises on the dispersal of tree seeds by the wind are presented. Procedures, equipment, and analysis for the still air and wind dispersal activities are described. Nineteen references are listed. (CW)

Provides information on state trees for each of the 50 states and the District of Columbia. Includes for each state: (1) year in which state tree was chosen; (2) common and scientific names of the tree; (3) arbor day observance; (4) address of state forester; and (5) drawings of the tree, leaf, and fruit or cone. (JN)

Tree-ring analysis in geomorphology can be incorporated into a number of undergraduate methods in order to reconstruct the history of a variety of geomorphic processes. Discusses dendrochronology, general principles of dendrogeomorphology, field sampling methods, laboratory techniques, and examples of applications. (TW)

Suggesting advantages of using forests to teach succession, briefly outlines procedures for gathering evidence of succession including numbers, ages, and sizes of trees. Five plot studies conducted by students at the University of Victoria are also described. (DC)

Presents two techniques involving simple and inexpensive demonstrations: (1) explains how pressure inside cells gives them mechanical strength, and (2) shows how water can be pulled up stems. Both can be adapted to suit a variety of levels of instruction. (PR)

Reviews common wild, cultivated, and household plants which may be harmful to humans by causing allergic reactions, dermatitis, physical injury, or internal poisoning. Includes brief descriptions of plants, their potential harm, and some illustrations. (DC)