Answer: For the first question, altering land/habitats, modifying ecosystems - change the biogeochemical cycle. A list would be; Agriculture, Deforestation, Overpopulation, Plastic Production, Production of black carbon.
Secondly, the differences between deforestation & degradation is that deforestation is when forests is converted yo non-forest uses- for example, turning forest land into agriculture or roads. Degradation happens when forests lose their capacity abilities to provide goods for the nature & us humans.
Explanation: 1. These affect the ecosystem because in order for humans to survive, they use natural resources from ecosystems that harms them.