Example of journal entry (Level 4+) Journal Entry #1: Introduction to Interactions within Ecosystems (This lesson introduced ecology and the interactions within an ecosystem.) Ecosystems are complex networks of abiotic and biotic factors. Humans are a biotic factor and also have one of the most significant impacts on ecosystems. For example, as seen in the video “Strange Days on Planet Earth”, due to human activity and transportation alien species are introduced on a daily basis in almost every ecosystem. This fast paced invasion can lead to an ecological change that will negatively affect everything from the native population to communities, and eventually the entire ecosystem. Since small effects can have huge consequences, it is important to recognize the impact of these changes as they may lead to the next major mass extinction and threaten biodiversity on Earth.