This forum response adds a conceptualization of harmony to Dopico and Vazquez' investigation of pedagogy that combines citizen science, environmental and cross-cultural research, and service-learning. Placing many appropriate and significant aspects of culturally situated science education in an authentically relational context beyond the…

Examines aspects of competitive exclusion, which develops when two species jointly utilize a vital resource that is in short supply. When this occurs, one of the species will eventually eliminate the other from the habitat where their distributions overlap, unless one or both species evolve differences that reduce competition. (JR)

Describes construction of a model ecosystem using a 10-gallon aquarium with a sand, water and air interface. Pesticides are placed on sorghum plants grown on the terrestrial portion. After 30 days, movement of the pesticide is traced using radioisotope techniques, from terrestrial to aquatic organisms. Details for calculating concentration factors…

Presents a set of simulation models for use in teaching population dynamics. These models are designed specifically for use with a programmable pocket calculator, and can be used to demonstrate growth of populations with discrete or overlapping generations and also to explore effects of density-dependent and -independent mortality. (Author/CS)

Directions for the construction of a model bog habitat are provided including examples of plants and animals which may be suitable. Activities that use this model are suggested. Background information on the ecology and chemistry of the bog is included. (CW)