Trees are plants, and plants grow where they can. They make their own food using the energy in sunlight, carbon from the air, and water from the soil. This process is called photosynthesis. In order to grow and thrive, trees need to be able to carry on the process. Plants are also sedentary organisms; they don’t move around in their environments. Wherever they are growing is where they have to grow, or die trying. Plants get the things they need to grow (water, soil, sunlight, air) from their own immediate surroundings.