Answer:
Autotrophs, producers and Plants
Explanation:
Trees occupy a special position in the food web of most of all organisms. They can belong to several specie of plants and can vary in physical traits like height, fruit kind, fruiting non fruiting aspect etc. But three things that can describe trees are:
1: Autotrophs: This is because trees can prepare their own food through the process of photosynthesis and several other organisms depend upon them for food.
2: Producers: Being able to synthesize their own food, trees are known as producers because they not only prepare their own food but also food for many other organisms like humans.
3: Plants: Because trees are just a sub category or kind of plants, the terms plants can be used to describe several characteristics of trees.
Hope it helps!