Okay kiddo, have you ever heard of the word "biotic"? It's a fancy science word that has to do with living things like plants and animals. So, a semi-biotic system is a special kind of system where living things (plants and animals) are working together with non-living things (like rocks or soil) to create a balanced environment.
Let's imagine a pond as an example of a semi-biotic system. The water in the pond is non-living, but it's what the living things like fish, turtles, and plants need to survive. The plants in the pond use the water to make energy through a process called photosynthesis. The fish and turtles eat the plants and other small organisms, which helps keep the pond clean and balanced.
So, in a semi-biotic system, everything is working together to create a healthy environment for all the living things. It's kind of like a big team of plants, animals, and non-living things working together to keep each other happy and healthy. Pretty cool, huh?