Ecosystems are made up of interacting, interdependent parts, which are always interacting with and changing each other. Healthy ecosystems are long-lasting. In a long-lasting ecosystem the number of plants and animals may increase and decrease over time, but there are always enough individuals to reproduce and establish the next generation. In this Biograph Virtual Lab your challenge is to build a model of a long-lasting, healthy pond ecosystem using Toolblox programming blocks.